nexedge system guide ver2.50

System Guide

Version: 2.50

Last Updated: Language: Document No.:

May 10, 2011

NXDN™ ™

English SG -11-0001

Cover 2 SYSTEM GUIDE Ver.2.50

Revision History

Version Edition

1.00

2.00

2.50

First edition Amendments due to V2.00 release (System expansion by multicast, IP conventional, etc) Amendments due to V2.50 release (Addition Product Models, NEXEDGE Applications Enhancement, etc)

SYSTEM GUIDE Ver.2.50 Cover 3

Document Revision This document shall from time to time be changed without notice. This document is created and published for the products

having the following design specifications.

Firmware Version

Field Programming Unit Version

Software Copyrights All copyrights and other intellectual property rights for this technical document as well as the software described in this technical

document and help texts and manuals attached to the software are owned by Kenwood Corporation.

A right to use the software described in this technical document is granted to a licensee by Kenwood Corporation; however, the

title to and ownership of the software shall be owned by Kenwood Corporation. Refer to the help texts attached to this software

for details.

Kenwood Corporation does not warrant quality and performance of the software described in this technical document to

conform to the applicability of any use and Kenwood Corporation shall be free from liability for any defects, damage or loss or

from any warranty for anything other than what is expressly described in this technical document.

Any distribution, resale, lease, waiver, assignment to this technical documents and help texts attached to the software shall

strictly be prohibited.

Item Version How to Verify

KPG-109D 2.30 Can be viewed in the About KPG-109D dialog box of KPG-109D.

KPG-110SM 2.50 Can be viewed in the About KPG-110SM dialog box of KPG-110SM.




KPG-150AP 1.00 Can be viewed in the About KPG-150AP dialog box of KPG-150AP

KTI-4 1.01.00 Can be viewed in the "KTI-4 Information" of Web browser.

KAS-10 2.00 Can be viewed in the About dialog box of KAS-10.

KAS-11 1.00 Can be viewed in the About KAS-11 dialog box of KAS-11.

Item Version How to Verify

NXR-700(H)/ NXR-800(H)/ NXR-900 2.50.00 Can be viewed in the Tools > Repeater Information dialog box of KPG-109D or viewed in the Program >Firmware Update dialog box of KPG-110SM.

NX-200/ NX-300, NX-210/ NX-410, NX-200S/ NX-300S, NX-700(H)/ NX-800(H)/ NX-900 2.50.00 Can be viewed in the Tools > Transceiver Information dialog box of KPG-111D.

NXR-710/ NXR-810 1.40.00 Can be viewed in the Tools > Repeater Information dialog box of KPG-129D.

NX-220/ NX-320 1.00.00 Can be viewed in the Tools > Transceiver Information dialog box of KPG-141D.

Cover 4 SYSTEM GUIDE Ver.2.50

Firmware Copyrights The title to and ownership of copyrights for firmware embedded in Kenwood product memories are reserved for Kenwood

Corporation.

Any modifying, reverse engineering, copying, reproducing or disclosing on an Internet website of the firmware is strictly

prohibited without prior written consent of Kenwood Corporation.

Furthermore, any reselling, assigning or transferring of the firmware is also strictly prohibited without embedding the firmware in

Kenwood product memories.

Document Copyrights Copyright 2010 by Kenwood Corporation. All rights reserved.

No part of this manual may be reproduced, translated, distributed, or transmitted in any form or by any means, electronic,

mechanical, photocopying, recording, or otherwise, for any purpose without the prior written permission of Kenwood.

Disclaimer This document is intended to provide basic and general information about the product specifications of the products listed above

and the system configuration. The intended purpose of all technical descriptions herein shall be to improve your understanding

of the product specifications and system configuration. The descriptions provided in this document are carefully examined and

are believed to be entirely reliable. Kenwood shall be entirely free from any responsibility and liability for inapplicability, damage

or loss arising from inaccuracies in this document and reserves the right to change the product specifications herein in order to

improve readability, function or product design. Applicability of the descriptions in this document may vary depending upon the

product specifications and configurations of relevant equipment.

Furthermore, you are not licensed nor entitled to use and divert to your application any descriptions in this document.

Contact Kenwood Corporation for further details.

The AMBE+2TM voice coding Technology embodied in this product is protected by intellectual property rights including patent

rights, copyrights and trade secrets of Digital Voice Systems, Inc. This voice coding Technology is licensed solely for use within

this Communications Equipment. The user of this Technology is explicitly prohibited from attempting to extract, remove,

decompile, reverse engineer, or disassemble the Object Code, or in any other way convert the Object Code into a

human-readable form. U.S. Patent Nos. #5,870,405, #5,826,222, #5,754,974, #5,701,390, #5,715,365, #5,649,050, #5,630,011,

#5,581,656, #5,517,511, #5,491,772, #5,247,579 and #5,195,166.

SYSTEM GUIDE Ver.2.50 1

Contents

Document Contents

1 NEXEDGE Digital System ................................................................................................................................................1 1.1 Introduction...................................................................................................................................................................1 1.2 Audience ......................................................................................................................................................................1 1.3 NEXEDGE and NXDN................................................................................................................................................1 1.4 Product Portfolio...........................................................................................................................................................2

2 Technology Comparison .................................................................................................................................................3 2.1 Digital Technologies.....................................................................................................................................................3 2.2 FDMA and TDMA........................................................................................................................................................3

2.2.1 TDMA (Time Division Multiple Access) .............................................................................................................3 2.2.2 FDMA (Frequency Division Multiple Access)....................................................................................................4

2.3 Spectrum Efficiency.....................................................................................................................................................4 2.4 Operating Modes.........................................................................................................................................................5

2.4.1 Direct Mode Operation........................................................................................................................................5 2.4.2 Repeater Mode Operation..................................................................................................................................6 2.4.3 Repeater Mode Operation (IP Conventional)....................................................................................................6 2.4.4 Trunked Mode Operation (Single Site)..............................................................................................................7 2.4.5 Trunked Mode Operation (Multi Site).................................................................................................................7

2.5 Trunking - What is it?...................................................................................................................................................8 2.6 Analog to Digital Migration ..........................................................................................................................................9

2.6.1 Mixed Mode.........................................................................................................................................................9 2.6.2 Shared Mode and AUX Mode..........................................................................................................................10

3 NEXEDGE Products........................................................................................................................................................12 3.1 General.......................................................................................................................................................................12 3.2 Portable Radios .........................................................................................................................................................12 3.3 Mobile Radios ............................................................................................................................................................13 3.4 Repeaters...................................................................................................................................................................14 3.5 Optional Units.............................................................................................................................................................15 3.6 Software Packages ...................................................................................................................................................16

3.6.1 KPG-109D – Repeater Programming Software .............................................................................................16 3.6.2 KPG-111D – Portable and Mobile Radios Programming Software ..............................................................17 3.6.3 KPG-141D – Portable Radios Programming Software..................................................................................17 3.6.4 KPG-129D - Repeater Programming Software..............................................................................................18 3.6.5 KPG-110SM System Manager Software........................................................................................................18

3.7 Application Software..................................................................................................................................................18 4 System Design Considerations ....................................................................................................................................19

4.1 OCXO for 6.25 kHz operating mode........................................................................................................................19 4.2 Frame-Sync cable requirements and configuration................................................................................................20 4.3 12.5 kHz versus 6.25 kHz?.......................................................................................................................................21 4.4 Trunked System – How Many Voice Users per Traffic Channel?..........................................................................21 4.5 Expected down times upon the system programming ...........................................................................................21

4.5.1 Channel Delete..................................................................................................................................................22 4.5.2 Firmware Update...............................................................................................................................................23 4.5.3 Change Site/ System Information ....................................................................................................................23 4.5.4 FPU data Update ..............................................................................................................................................23 4.5.5 Fleet/ ID Information Update.............................................................................................................................23 4.5.6 Repeater Swap for repair..................................................................................................................................23 4.5.7 Channel Add......................................................................................................................................................24 4.5.8 Site Add..............................................................................................................................................................25 4.5.9 Automatic Control Channel Rollover................................................................................................................25

2 SYSTEM GUIDE Ver.2.50

Contents 4.6 Power-on Standby.....................................................................................................................................................26 4.7 System Key File.........................................................................................................................................................26 4.8 Dialup Modem Connection .......................................................................................................................................27 4.9 Single Site design considerations.............................................................................................................................28 4.10 Multi-site .....................................................................................................................................................................28

4.10.1 Multicast Routing...............................................................................................................................................29 4.11 GPS/AVL data capacity.............................................................................................................................................30 4.12 IP Switches – Hub, Switch, Router?.........................................................................................................................31 4.13 IP Links.......................................................................................................................................................................32 4.14 IP Bandwidth Requirement.......................................................................................................................................33

4.14.1 Unicast Network Requirements .......................................................................................................................33 4.14.2 Multicast Network Requirements .....................................................................................................................34

4.15 Antenna Networks.....................................................................................................................................................37 4.16 RF Combining............................................................................................................................................................40

4.16.1 Bandpass Duplexer...........................................................................................................................................40 4.16.2 Receive Splitter Amplifier..................................................................................................................................40 4.16.3 Transmit Ferrite Isolator ....................................................................................................................................40 4.16.4 Cavity Combiner................................................................................................................................................41 4.16.5 Transmit Hybrid Combiner................................................................................................................................41

4.17 Advantages and disadvantages between combining systems: .............................................................................42 4.18 Pictures of typical RF components Duplexer, combiners, RX multi-coupler .........................................................43 4.19 3rd Party Equipment..................................................................................................................................................44

4.19.1 RF Combiner/ RX Splitter and Duplexers........................................................................................................44 4.19.2 IP Switches/ Routers.........................................................................................................................................44 4.19.3 RF Amplifiers .....................................................................................................................................................45 4.19.4 Power Supplies .................................................................................................................................................45

5 Trunking Roaming Considerations..............................................................................................................................46 5.1 Intersite Group Call....................................................................................................................................................46 5.2 Expanded Multi-Site Capability.................................................................................................................................46

5.2.1 New Intersite Group Call (Unicast)...................................................................................................................46 5.2.2 New Intersite Group Call (Multicast) ................................................................................................................47 5.2.3 New Intersite Group Call (Unicast)...................................................................................................................48 5.2.4 New Intersite Group Call (Multicast) ................................................................................................................49

5.3 Intersite Call settings..................................................................................................................................................49 5.4 Dynamic Allocation ....................................................................................................................................................50 5.5 Group Registration ....................................................................................................................................................52

5.5.1 GID Registration Expiry ....................................................................................................................................52 5.6 System Search Policy ...............................................................................................................................................54 5.7 Background Hunt.......................................................................................................................................................55 5.8 Background Hunt Level Margin................................................................................................................................55 5.9 Adjacency Information...............................................................................................................................................56 5.10 Roaming Related Settings........................................................................................................................................57 5.11 How a Subscriber Unit Roams.................................................................................................................................58 5.12 Setup Recommendation...........................................................................................................................................58 5.13 Case Study.................................................................................................................................................................59

5.13.1 Background Hunt (Tip 1)...................................................................................................................................61 5.13.2 Background Hunt (Tip 2)...................................................................................................................................61

6 IP Conventional Network Roaming Considerations .................................................................................................62 6.1 Intersite Call in the Conventional Repeater System................................................................................................62 6.2 Intersite Call................................................................................................................................................................62 6.3 Site Roaming (Voting) ...............................................................................................................................................63 6.4 Beacon Signal............................................................................................................................................................63

SYSTEM GUIDE Ver.2.50 3

Contents 7 System Scale & Upgrade Case Study .........................................................................................................................64

7.1 USB Key and Activation File .....................................................................................................................................64 7.1.1 System Size.......................................................................................................................................................64 7.1.2 Home Site ID Planning .....................................................................................................................................65 7.1.3 Single-site Installation........................................................................................................................................66 7.1.4 Channel adding to a Single-site system ..........................................................................................................67 7.1.5 Removing a Repeater for Repair .....................................................................................................................67 7.1.6 Multi-site System Installation ............................................................................................................................68 7.1.7 Channel Adding to a Multi-site System............................................................................................................68 7.1.8 Site adding to a Multi-site system.....................................................................................................................69 7.1.9 Non-linked site added to a Multi-site-system...................................................................................................70

8 System Monitor Function...............................................................................................................................................71 8.1 System Monitoring Capability in NEXEDGE...........................................................................................................71 8.2 System Overview.......................................................................................................................................................71

8.2.1 System Overview - Network.............................................................................................................................72 8.2.2 System Overview - Hardware ..........................................................................................................................72

8.3 Channel State ............................................................................................................................................................73 8.4 Channel Load ............................................................................................................................................................73 8.5 Communication Log ..................................................................................................................................................74

8.5.1 Communication Log - Extract...........................................................................................................................75 8.6 Statistics - Airtime Accumulation ...............................................................................................................................76 8.7 System Log - System, Hardware .............................................................................................................................76 8.8 Diagnostic Log ...........................................................................................................................................................77

9 Vocoder and Digital Technology ..................................................................................................................................78 9.1 Vocoder ......................................................................................................................................................................78 9.2 Cyclic Tone Response...............................................................................................................................................79 9.3 Contributions of Digital Technology ..........................................................................................................................79 9.4 Audio Issues Case Study..........................................................................................................................................80

9.4.1 Background Noise Suppression ......................................................................................................................80 9.4.2 High Sensitivity Microphone .............................................................................................................................80 9.4.3 Intelligibility and Signal Level ............................................................................................................................81 9.4.4 Antenna and Signal Level.................................................................................................................................82 9.4.5 Uplink and Downlink Signals............................................................................................................................82 9.4.6 Appropriate root cause analysis.......................................................................................................................83 9.4.7 System Design Reference................................................................................................................................83 9.4.8 To Improve Audio Intelligibility ..........................................................................................................................83

9.5 NEXEDGE Audio Features.......................................................................................................................................85 9.5.1 Constant RX audio level ...................................................................................................................................85 9.5.2 Constant TX audio level....................................................................................................................................85 9.5.3 Tune RX audio response to match the received audio environment ............................................................85 9.5.4 Tune TX audio response to match the transmit environment........................................................................85 9.5.5 External microphones adjustment....................................................................................................................85 9.5.6 RX Audio Low Cut.............................................................................................................................................85 9.5.7 Noise Suppressor..............................................................................................................................................85 9.5.8 Vocoder Update Information ............................................................................................................................86

10 NEXEDGE Radio System Applications...................................................................................................................87 10.1 RF Link .......................................................................................................................................................................87 10.2 Simple dispatching solution-Kenwood KAS-10 AVL & Dispatch Software.................................................88

10.2.1 Main features and functions..............................................................................................................................88 10.3 Wireless Image System............................................................................................................................................89

10.3.1 Components......................................................................................................................................................89 10.3.2 Main features and functions..............................................................................................................................90

4 SYSTEM GUIDE Ver.2.50

Contents 10.3.3 Transfer Time of Image Data ...........................................................................................................................90

10.4 Over the Air Programming ........................................................................................................................................91 10.4.1 Main features and functions..............................................................................................................................91

10.5 The Telephone Interconnect Adapter.......................................................................................................................92 10.5.1 Main features and functions..............................................................................................................................92

10.6 Alarm enunciator – NX-700/ NX-800/ NX-900 and Zetron M1570 SentriData.....................................................93 11 FAQ - Frequently Asked Questions .........................................................................................................................95 Appendix A - IP - Some Background Info.................................................................................................................................98

A.1 Network and Ethernet Technologies...........................................................................................................................98 A.2 Ethernet Technology ...................................................................................................................................................98 A.3 IP Addresses and Subnets .........................................................................................................................................99

Appendix B - NXR-700/ NXR-800/NXR-900 error messages, status LED and OCXO LED information.........................101 Appendix C - Glossary of Terms.............................................................................................................................................104

SYSTEM GUIDE Ver. 2.50 CONTENTS 1

NEXEDGE Digital System

1 NEXEDGE Digital System

1.1 Introduction

NEXEDGE is Kenwood’s new cutting edge digital conventional and trunked radio system, designed to meet high demands in

today’s competitive commercial and professional radio system environment.

Digital efficiency, compatibility to legacy systems to facilitate a simple and cost effective and smooth migration from the analog

transceiver world to the digital transceiver world are just a few advantages Kenwood NEXEDGE can deliver.

Kenwood’s experience in radio design, audio quality and high quality control has made NEXEDGE possibly the best digital

conventional and trunked system solution available today.

1.2 Audience

This document is intended for use by Kenwood partners who have already been introduced to the new digital Kenwood

NEXEDGE radio system, its components and its various operating modes.

Although basic trunking operation is explained, further knowledge of trunked radio systems and their application is assumed.

1.3 NEXEDGE and NXDN

NEXEDGE

Is a trademark name of Kenwood Corporation and a generic term used when referring to Kenwood‘s new Digital

Communication System.

Kenwood‘s Digital Communication System NEXEDGE consist of:

NX-200/ NX-300, NX-200S/ NX-300S, NX-220/ NX-320, NX-210/ NX-410 VHF/ UHF/ 800MHz Portable Radio

NX-700/ NX-800/ NX-900, NX-700H/ NX-800H VHF/ UHF/ 800MHz Mobile Radio

NXR-700/ NXR-800/ NXR-900, NXR-700H/ NXR-800H, NXR-710/ NXR-810 VHF/ UHF/ 800MHz Repeater/ Base Station

Note: Depending on areas, handled or sold models are different.

Contact and confirm your regional Kenwood sales representatives for handled models and more details in your area.

NXDN

Is a trademark name of Kenwood Corporation and ICOM Inc.

NXDN refers to the Digital Air Interface protocol used by both Kenwood and ICOM.

Figure 1-1 NEXEDGE and NXDN

NXDNTM

(Air interface, FDMA, NEXEDGE 6.25/12.5kHz,IDAS 6.25kHz) Supporting Basic Features ( voice call, etc.)

Conventional Original application

Kenwood (NEXEDGETM)

ICOM (IDASTM)

Conventional Original application

Trunking Original application

(Type -C)

Trunking Original application

(Type - D)

2 CONTENTS SYSTEM GUIDE Ver. 2.50

NEXEDGE Digital System 1.4 Product Portfolio

Figure 1-2 Kenwood Product Portfolio

Figure 1-3 NEXEDGE Product Categories

Figure 1-2 shows the Kenwood NEXEGDE products portfolio and product line up, Figure 1-3 shows the product positioning and

categorisation.

NX-210 / NX-410

Digital System Radio

Features

Analog System Radio

Analog Conventional Radio

Simple Analog Conventional Radio

NX-200 / NX-300

NX-220 / NX-320

Pric

e

LTR

MPT

P25

Conventional Analogue

NXEDGE Conventional

NEXEDGE Trunking

Features

Mar

ket

Tier


Technology Comparison

2 Technology Comparison

2.1 Digital Technologies

Table 2-1 Digital Two-way Radio Technologies

2.2 FDMA and TDMA

Kenwood’s new generation digital system is based on the FDMA standard. There are three common transmission schemes on

the market, such as FDMA (Frequency Division Multiple Access), TDMA (Time Division Multiple Access), and CDMA (Code

Division Multiple Access). CDMA will not be explained further in this document.

FDMA divides the given spectrum into channels by the frequency domain. Each call is allocated one channel for the entire

duration of the call.

TDMA divides the spectrum into channels by the time domain as well. A channel in the frequency domain is divided among

multiple users. Each call is allocated a slot in the channel for a small amount of time.

To be able to program Kenwood NEXEDGE hardware a system programming training course should be attended.

2.2.1 TDMA (Time Division Multiple Access)

Cons

Limited Communication distance due to the delay in the slot (TETRA: up to 35 km approximately)

Repeater required (Multi-slot is not available in Direct Mode)

Not real physical 6.25 kHz technology (6.25 kHz equivalent)

Figure 2-1 Image of Two-slot TDMA

NEXEDGE Digital in US Digitals in Europe

Common Air Interface

NXDNTM P25 Phase 1 dPMR DMR DMR TETRA

Category PMR

Conventional/ Trunking

PMR Conventional/

Trunking

License Free: dPMR446

PMR Mode 1&2: Conventional PMR Mode 3:

Trunking

Tier II PMR

Conventional

Tier III PMR

Trunking

PMR Trunking

Modulation Type 4-level FSK π/ 4-QPSK

Channel Bandwidth 6.25 kHz/ 12.5 kHz 12.5 kHz 6.25 kHz 12.5 kHz 25 kHz

Channel Access FDMA TDMA

Channel / Carrier 1 2 2/ 4

Gross Bit Rate 4800/ 9600 bps 9600 bps 4800 bps 9600 bps 36 kbit (4 ch)

Market World wide USA EU World Wide EU/ China/ Asia/ Africa



2.2.2 FDMA (Frequency Division Multiple Access)

Pros

Enables 2-party communication in direct mode

Pure very narrow technology resolving frequency resource issue

Figure 2-2 Image of FDMA (6.25 kHz x 2)

2.3 Spectrum Efficiency

In TDMA, the continuous transmission is divided into slots, which can be occupied by data or voice.

In FDMA the channels occupy a frequency spectrum in either 25 kHz, 20 kHz, 12.5 kHz or 6.25 kHz.

There is not much difference in the overall performance of current modulation techniques because of modern vocoders, but

FMDA systems are generally superior for larger installations and for direct communication requirements between transceivers,

since FDMA system do not need any timeslot synchronization.

FDMA is also simpler than TDMA when it comes to servicing and maintenance. Basically with the 2-slot TDMA method, in direct

mode operations only one of the slots can be used for communications, so 6.25 kHz frequency efficiency is not achieved

(Requires complex control).

With TDMA the guard time required between slots to prevent data collision reduces the coverage area and the effective data

rate per slot; FDMA is not subject to such limitations.

Kenwood NEXEDGE can work in either 12.5 kHz or 6.25 kHz digital trunking mode or 25/ 20/ 12.5 kHz FM analog mode.

Below overview drawing that shows the relation between the standard 12.5 kHz channel emission and the new 6.25 kHz

channel emissions masks.

6.25 kHz channels in 1 x 12.5 kHz channel.

Note: Frequency coordination involves discussion on the regional frequency regulatory.

Note: Depending on areas, used channel spacing of FM analog mode are different.

Figure 2-3 Spectrum Efficiency



2.4 Operating Modes

Kenwood NEXEDGE has been designed to integrate seamlessly into current radio system applications. NEXEDGE systems

support the following NXDN digital and legacy analog mode:

1. Direct Mode

2. Repeater Mode

3. Repeater Mode (IP Conventional)

4. Trunked Mode (Single Site)

5. Trunked Mode (Multi Site)

NEXEDGE equipment can support legacy analog modes for easy migration from analog to digital.

2.4.1 Direct Mode Operation

Direct Mode is the most simple and elementary operating style in wireless telecommunication. It is also called P-to-P (that

stands for Peer to Peer) as the communication is made between terminals by on a simplex frequency. Communication

coverage is determined by transceiver’s transmission output power. One or multiple terminals can be configured as a Base

Station at fixed location with high performance antenna system in order to obtain the wide coverage. A single frequency, called a

Channel is used essentially among the terminals in the field.

Figure 2-4 Direct mode operation



2.4.2 Repeater Mode Operation

In order to expand the coverage, a repeater is often installed on a high site. NEXEDGE repeaters can be used as a base

terminal by connecting a microphone on the panel. The transmission towards repeater is called Uplink or Inbound while the

other direction is called Downlink or Outbound and different frequencies are to be applied. Together with Direct Mode operation,

Repeater Mode operation is also called Conventional operation as to compare with Trunking Mode operation that will be

discussed later.

Figure 2-5 Repeater mode operation

2.4.3 Repeater Mode Operation (IP Conventional)

NEXEDGE repeaters have IP link capability that enables up to 48 sites wide area repeater system. Kenwood calls it IP

Conventional System and provides roaming (also known as Voting) features that allow subscriber units to always operate on the

best site.

Figure 2-6 Repeater mode operation (IP Conventional)



2.4.4 Trunked Mode Operation (Single Site)

NEXEDGE trunking mode provides larger capacity, enhanced call capabilities, improved security and faster communications

with simpler user operation than conventional systems. The system automatically assigns channels for faster efficient use of

spectrum, allowing users to concentrate on the job at hand. The 3,000 of each Unit ID and Group ID per site capacity provides

ample unit and fleet organization capabilities. Group and Individual calls enjoy complete privacy as other users in the system

cannot monitor the calls. The Priority Monitor feature will monitor for up to 4 high priority talk groups and switch users to those

calls in progress so important calls aren’t missed. During peak usage hours, system Call Queuing stacks call requests and

processes calls when a channel becomes available. System operators can assign important individuals higher queue priority

and even pre-empt lower priority users for more important dispatch and emergency calls. Well known features, such as Late

Entry, Broadcast Call, Remote Group Add, ESN validation, remote Stun/ Kill/ Revive are all included and supported as

standard.

Figure 2-7 Trunked mode operation (Single Site)

2.4.5 Trunked Mode Operation (Multi Site)

The network option leverages the power of IP to link up to, currently, 48 digital trunking sites together for wide area roaming and

calling capabilities. Scalable networks can be created over existing IT assets, private microwave, spread spectrum links or

carrier services using standard 10/100 Base-T Ethernet switches and routers. IPSec VPN tunnelling provides an encrypted

secure communications link within any IP network. Subscriber units use advanced control channel hunting algorithms, RF signal

strength and digital signal quality to automatically determine the best sites to register on while moving throughout the network.

The 60,000 Group IDs and Unit IDs network capacity provides ample scope for large organizations and multi-user system

sharing.

Figure 2-8 Trunked mode operation (Multi Site)



2.5 Trunking - What is it?

Trunking means that a radio system infrastructure controls and handles call request and data transmissions of transceivers in its

radio coverage over a number of transceiver channels.

The trunking infrastructure consists of at least 2 or more RF channels and logic controllers. A bundle of frequencies is used to

allocate calls, thus making more efficient use of the frequencies.

Frequencies are combined into a trunk of resources, rather than separate, single channels. Hence the phrase: Trunked radio

system. Most trunked radio systems follow the same concept, whereby a Control Channel (CC) receives and organizes call

requests and data transmissions and a Traffic Channel (TC) handles the actual voice communication path.

See below for a typical channel allocation sequence in a trunked radio system.

Figure 2-9 Typical trunked system channel allocation sequence

The CC transmits and receives continuously and allocates voice call requests to available TC’s respectively if resources are

available.

The CC controls the TC’s and allocates the call requests according to the call parameters, such as Priority, Queue and others to

an individual TC. A traffic channel in the Kenwood NEXEDGE digital trunked radio system can be assigned to a talk group or an

individual call in two different ways.

■ Transmission Trunking

Assign the traffic channel for the duration of that transmission. Once the transmission is over, the call is terminated.

A new traffic channel is assigned for the next transmission. A conversation with multiple transmissions will require a new traffic

channel for each transmission.

■ Message Trunking

Assign the traffic channel to a talk group for the entire conversation. The conversation is deemed to be finished when the delay

between transmissions exceeds a preset time. The trunking controller may terminate a conversation if the traffic channel is

required for a higher priority use.

If Kenwood NEXEDGE is compared with other current or new digital radio systems, care should be taken as some of them do

not offer real channel trunking, including a control channel, instead they are based on simple channel scanning function.



2.6 Analog to Digital Migration

For the system owners or integrators, migration from existing analog system is one of the biggest concern from investment

planning perspective. NEXEDGE with migration friendly NXDN digital protocol that adopts 4-level FSK and FDMA offers various

migration scenarios as shown below.

1. Mixed Mode (for conventional operation)

2. Shared Mode (for trunked operation)

3. AUX Mode (for trunked operation)

2.6.1 Mixed Mode

Mixed Mode allows field users to operate in both analog and digital by switching each modes seamlessly and automatically.

All the NEXEDGE terminal and repeater products support this Mixed Mode in whatever combination of FM wide, FM narrow,

NXDN narrow and NXDN very narrow.

Figure 2-10 Mixed mode

■ Mixed Mode - Terminal

Figure 2-11 Mixed mode (Terminal)

Transceiver to receive both analog FM and digital NXDN signals

Talkback in the same mode of receiving signal in a timer period

Configurable default transmission mode (Analog or Digital)


Technology Comparison ■ Mixed Mode - Repeater

Figure 2-12 Mixed mode (Repeater)

Repeater to receive both analog FM and digital NXDN signals

Talkback in the same mode of receiving signal in a timer period

In base station mode with attached microphone (PTT), TX mode is configurable (Analog or Digital)

2.6.2 Shared Mode and AUX Mode

NEXEDGE repeaters can be used as duplex repeater in Analog Mode or communication channel in Digital Mode while the

repeater serves as a traffic channel. The repeater transmits in Analog Mode if the PTT switch is activated by an external device

while the repeater is not used as a communication channel in Digital Trunking Mode.

■Shared Mode Operation

In the configuration below, a repeater for Traffic Channel 2 can be used as an analog conventional repeater while no talk

channel is assigned on the repeater by NXEDGE system controller. When this repeater is on busy with analog transceiver users,

NEXEDGE system controller skips this channel for traffic channel allocation.

Figure 2-13 Shared mode operation


Technology Comparison ■ AUX Mode Operation

Below is an example configuration shared with MPT analog trunked system. In this drawing TCH2 and 3 are commonly

used as analog traffic channel with MPT system. Channel busy status is mutually informed each other via Cross Busy

Input/Output. Similar configuration should be applicable for any analog system. Contact with your Kenwood technical staff for

more details.

Figure 2-14 AUX mode operation


NEXEDGE Products

3 NEXEDGE Products

3.1 General

The Kenwood NEXEDGE offering consists of three main hardware component categories and optional equipment category:

1) NX-200/ NX-300, NX-200S/ NX-300S, NX-220/ NX-320, NX-210/ NX-410, VHF/ UHF / 800MHz Portable Radio

2) NX-700/ NX-800/ NX-900, NX-700H/ NX-800H VHF/ UHF / 800MHz Mobile Radio

3) NXR-700/ NXR-800/ NXR-900, NXR-700H/ NXR-800H, NXR-710/ NXR-810 VHF/ UHF / 800MHz Repeater/ Base Station

4) KTI-3/ KTI-4/ KVT-11 Optional Unit

Note：Due to frequency considerations and applicable –Regulatory Body regulations some Kenwood models may not be available in some

geographical locations. Contact your local Kenwood sales representative for the model available in your area.

3.2 Portable Radios

The Kenwood NEXEDGE NX-200/ NX-300 VHF/UHF portable radios feature a small and durable body. These NEXEDGE

radios support FM conventional, LTR, 5-Tone (Europe) and NXDN digital system operating modes as well as variety of

signaling, encryption and emergency functions. The NEXEDGE series of radios offer a variety of LCD and Key pad

configurations ranging from a LCD with 6 programmable function keys and a full DTMF pad to a simplified highly durable case

with no front buttons or LCD display.

The NX-220/320 VHF/UHF radios are capable of analog FM, NXDN digital and Mixed mode operation with up to 5W TX output

power.

The NX-210/ NX-410 series provides a larger keypad for easier key operability and is also available for VHF/ 800MHz users.

The NX-210 is available for 5W model and the NX-410 is available for 3W model only.

Contact your regional Kenwood sales representatives for more detailed information and radio specifications.

Figure 3-1 NX-200/300 Models


NEXEDGE Products


3.3 Mobile Radios

The NX-700(H)/ NX-800(H)/ NX-900 operate in the VHF/ UHF/ 800MHz bands respectively, The NX-700(H)/ NX-800(H)/

NX-900 radios are available for vehicle mount or base station use in the NEXEDGE system. These NEXEDGE radios support

FM conventional, LTR, 5-Tone (Europe) and NXDN digital system operating modes as well as variety of signaling, encryption

and emergency functions. In addition to the standard 30 W model (K version), high power models that have 50W (VHF), 45W

(UHF) TX output power are also available. The NX-900 is available –as a 15W model only.

The NX-700(H)/ NX-800(H)/ NX-900 are capable of analog FM, digital NXDN and Mixed mode operation. Trunking capabilities

are a standard feature of the NX-700(H)/ NX-800(H)/ NX-900 radios and will require no added cost to transition from

Conventional to Trunking operation.


Figure 3-4 NX-700/ NX-800/ NX-900



NEXEDGE Products

3.4 Repeaters

The NXR-700(H)/ NXR-800(H)/ NXR-900 are Kenwood NEXEDGE repeater units with an embedded trunking controller and

are packaged in a 1U 19” rack mount chassis. The NXR-700(H)/ NXR-800(H)/ NXR-900 repeaters are capable of analog FM,

digital NXDN and Mixed mode operation with 5W or 25W TX output. The NXR-900 as 800MHz model is available exciter output

level (0.36W) only. The NXR-700/ NXR-800/ NXR-900 repeaters continue to employ all the necessary I/O’s for traditional

analog trunking controllers. This allows sharing the digital repeater resources with an existing analog system for a flexible

migration path from analog to digital subscriber units.

Connecting multiple NXR-700/ NXR-800/ NXR-900 via an ordinary IP switch, a trunking site can be setup. A multi-site system

can be easily constructed by connecting a number of these trunking sites via an IP network. Contact your regional Kenwood

sales representatives for more detailed information and radio specifications.

Figure 3-5 NXR-700(H)/ NXR-800(H)/ NXR-900

The NXR-710/ NXR-810 NEXEDGE repeaters offer a lower cost networkable solution when equipped with the optional network

interface unit KTI-3. The KTI-3 enables a network connection with multiple other repeaters to provide a wide area

communication solution. The NXR 710/810 IP Conventional Network protocol is compatible with NXR-700/ NXR-800/ NXR-900.

The NXR-710/ NXR-810 NEXEDGE repeaters transmit a maximum of 50/ 40W (VHF/ UHF) without the need for an external

power amplifier. The NXR-710/ NXR-810 NEXEDGE repeaters guarantee a 100% duty cycle at 25W for both the VHF and

UHF models and a 50% duty cycle at full power (50W VHF / 40 W UHF). The 2U size chassis provides clear and powerful

audio with a large size audio speaker for base operations as well as auxiliary back panel slots for external devices such as

power supply or RF filters.


Figure 3-6 NXR-710/ NXR-810


NEXEDGE Products

3.5 Optional Units

IP Network Connector for NXR-710/ NXR-810 Series Conventional IP Network feature is available for NXR-710/810 repeaters with the Network Interface Unit KTI-3.

Figure 3-7 KTI-3

Telephone Interface Adapter for NXR-700/ NXR-800/ NXR-900 Series The KTI-4 Telephone Interconnect Adapter adds telephone system connectivity to the NXR-700/ NXR-800/ NXR-900

based trunking system with analog telephone patch, such as the Zetron M30, M735 or others. It is ideal for customers who

intend to enhance the flexibility of networks by connecting trunking system to a telephone line.

Figure 3-8 KTI-4

Image Encoder for NX-700/ NX-800/ NX-900 Mobile Radio Series The KVT-11 Image Encoder captures still images from the camera, compresses each original image and sends it via

NEXEDGE Digital Radio link to the base station. In order to view the image the KAS-11 Image Viewer software is required.

Figure 3-9 KVT-11


NEXEDGE Products

3.6 Software Packages

The Kenwood NEXEDGE software suite comprises 5 different software packages as shown below.

KPG-109D: NXR-700(H)/ NXR-800(H)/ NXR-900 repeater programming software

KPG-111D: NX-200/ NX-300, NX-200S/ NX-300S, NX-210/ NX-410, NX-700(H)/ NX-800(H)/ NX-900 transceiver

programming software

KPG-141D: NX-220/ NX-320 transceiver programming software

KPG-129D: NXR-710/ NXR-810 repeater programming software

KPG-110SM: System Manager software

Not all software packages are required for all possible configurations. See next slide below for a list of combinations available. Table 3-1 Software packages

1. Digital Conventional, without NXR repeater

KPG-111D - portable and mobile radios programming software

KPG-141D - NX-220/ NX-320 portable radios programming software

2. Digital Conventional (including IP Linked Conventional), with NXR repeater - required software packages



KPG-109D - NXR-700(H)/ NXR-800(H)/ NXR-900 repeater programming software

KPG-129D - NXR-710/ NXR-810 repeater programming software

3. Digital Trunking, single or multi site

KPG-109D - NXR-700(H)/ NXR-800(H)/ NXR-900 repeater programming software



KPG-110SM - System Manager software, activation file and hardware key (USB dongle)

3.6.1 KPG-109D – Repeater Programming Software

The KPG-109D software is used to program the following items in a Kenwood NEXEDGE NXR-700(H)/ NXR-800(H)/ NXR-900

repeater.

Frequencies

Mode or operation per channel/ frequency

IP Network configuration for IP Conventional system

Figure 3-10 Repeater NXR-700

Operating Style Conventional IP Conventional Trunking

NXR-700(H)/ NXR-800(H)/ NXR-900

Repeater KPG-109D KPG-109D KPG-109D

NX-200/ NX-300, NX-200S/ NX-300S, NX-210/ NX-410

Portable KPG-111D KPG-111D KPG-111D

NX-700(H)/ NX-800(H)/ NX-900

Mobile KPG-111D KPG-111D KPG-111D

NX-220/ NX-320 Portable KPG-141D KPG-141D KPG-141D

KPG-110SM

NXR-710/ NXR-810 Repeater KPG-129D KPG-129D

(KTI-3 required) N/ A


NEXEDGE Products

3.6.2 KPG-111D – Portable and Mobile Radios Programming Software

The KPG-111D software is used to program the following features in a Kenwood NEXEDGE NX-200/ NX-300, NX-200S/

NX-300S, NX-210/ NX-410, NX-700(H)/ NX-800(H)/ NX-900 terminal radios.

Terminal settings

UID’s, GID’s, display, buttons, etc

Trunking Zones

Hunt table

Frequency table

Figure 3-11 Terminal and Mobile Radios NX-200/ NX-700

Note: For Trunking operation, a system key file has to be created by the KPG-110SM software manager. The KPG-111D software needs to

import the system key file to be able to program trunking and multi site features.

3.6.3 KPG-141D – Portable Radios Programming Software

The KPG-141D software is used to program the following features in a Kenwood NEXEDGE NX-220/ NX-320 portable radios.

Terminal settings

UID’s, GID’s, display, buttons, etc

Trunking Zones

Hunt table

Frequency table

Figure 3-12 Terminal Radios NX-220

Note: For Trunking operation, a system key file has to be created by the KPG-110SM software manager. The KPG-141D software needs to

import the system key file to be able to program trunking and multi site features.


NEXEDGE Products

3.6.4 KPG-129D - Repeater Programming Software

The KPG-129D programming software is used to configure the following items in a Kenwood NEXEDGE NXR-710 or NXR-810

repeater.

Frequencies

Mode or operation per channel/ frequency

IP Network configuration for IP Conventional system

Figure 3-13 Repeater NXR-710

3.6.5 KPG-110SM System Manager Software

The KPG-110SM System Manager software is used to program the following features and to perform the following functions in

a Kenwood NEXEDGE trunked radio system.

Creation of System Key file

The System Key file is then imported into KPG-111D

Systems settings

IP Address assignment

Single site, multi site

Site Information

Channels (Control/ Traffic)

ID Service Class settings

Fleet Information

GID’s and UID’s

Live system monitoring and system health checking

Call logging, System operation logging features

3.7 Application Software

The Kenwood NEXEDGE application software suite comprises 3 main software packages as shown below.

AVL & Dispatch Software/ KAS-10

The KAS-10 V2 software features a direct IP connection to a NEXEDGE trunked radio system.

Image Viewer Software/ KAS-11

This software allows, in conjunction with a KVT-11 Image Encoder, to build a wireless image transmission system

OTAP Manager/ KPG-150AP

This software is used to remotely reprogram radios in the field, meaning that all radio parameters can be reprogrammed

wirelessly over the air.


System Design Considerations

4 System Design Considerations

4.1 OCXO for 6.25 kHz operating mode

If any of the three following conditions occurs when creating a NXR-700(H)/ NXR-800(H)/ NXR-900 system, please use the

KXK-3M or KXK-3M2.

When there is legal demand for frequency stability in your area.

When you want to operate the system with a stable frequency over a long duration.

When using 6.25 kHz Trunking. (The Control Channel and Traffic Channel frequencies must be in sync.)

OCXO unit is not required to be installed in all channels of the site. The OCXO reference frequency can be shared with other

channels via the 10MHz signal interface on the rear panel. Refer the Figure 4-1 and connect each channel properly.

Note: NXR-900 can output a10MHz signal by converting the internal 19.2MHz TCXO signal. Other channels can be connected and kept

synchronised without the need for a KXK-3. But it is still recommend that a KXK-3 should be installed into the system to keep stable

performance and frequency stability.

Refer to ESD (Electrostatic Discharge) guidelines during handling and installation of the KXK-3 option!

The Figure 4-1 below shows the typical KXK-3 installation.

Figure 4-1 KXK-3 installation

Table 4-1 Reference Frequency Oscillator

Repeater Model Frequency Accuracy

NXR-700/800 1.0ppm @19.2 MHz Internal TCXO

NXR-900 0.5ppm @19.2 MHz

OCXO (KXK-3 M) Option board 0.5ppm @10 MHz

OCXO (KXK-3 M2) Option board 1.0ppm @10 MHz



4.2 Frame-Sync cable requirements and configuration

Figure 4-2 shows FRAME SYNC cabling requirements for a 4-channel Kenwood NEXEDGE digital trunked radio system

which has KXK-3.

Frame-Sync cables are mandatory and have to be installed when 2 or more repeaters are installed in a trunked radio system.

Refer to the cabling configuration below for more information.

Figure 4-2 Frame Sync cables and Frequency Sync cables

Care should be taken if the KXK-3 is installed and more than 10 repeaters need to be linked using the REF-OUT and REFIN

terminals.

For more information and an application note how this can be achieved, contact your local Kenwood technical support team.

Table 4-2 Frame Sync cable specification

Note: Frame Sync cable is an accessory of NXR-700(H)/ NXR-800(H)/ NXR-900.

Item Specification

Cable Length 20 cm (7.9 inches) or less

Cable Capacitance 2 pF or lower

Delay 20 μs or less

Number of Connected Repeaters A maximum of 30 repeaters



4.3 12.5 kHz versus 6.25 kHz?

Some considerations to choose 12.5 kHz (narrow) over 6.25 kHz (very narrow) for an application.

12.5 kHz (narrow) is the preferred mode when the customer requires data applications to work over the radio network, since

the 12.5 kHz mode offers a higher data bandwidth than 6.25 kHz. The over-the-air data rate in 12.5 kHz is 9600 bps, with a

net data rate available for transparent data transmission to be about 3700 bps.

6.25 kHz provides better sensitivity by about 3 dB, which means an increase in coverage.

6.25 kHz over-the-air data rate is 4800 bps, with the net data rate for transparent data transmission is about 1850 bps. The

6.25 kHz bandwidth offers better range and better interference resilience compared to 12.5 kHz.

However, if 6.25 kHz (very narrow) is required on trunking operation, the optional KXK-3 is required, one unit per site, to

guarantee long term frequency stability, synchronize the Control Channel and Traffic Channel frequencies.

The decision whether to use narrow or very narrow bandwidth operation has to be taken system wide. It is not

possible to mix 12.5 kHz and 6.25 kHz modes in one system.

The Kenwood NEXEDGE radio system and the subscriber transceivers can be re-programmed and reconfigured at any time

to suit customer requirements.

4.4 Trunked System – How Many Voice Users per Traffic Channel?

One major consideration for the correct design of a trunked radio system is the number of possible users per Traffic Channel.

How many users can work in a trunked radio system per channel without a problem?

The rule of thumb:

80-90 users per Traffic Channel!

Meaning that with a reasonable probability of getting a free channel, a 4-channel system (1 Control Channel and 3 Traffic

Channels) can handle about 240 to 270 users.

Reality and experience have shown that a 4-channel system can handle up to about 350 users. But this depends highly on

the relation between individual calls and group calls being used in the system.

The more groups calls and the shorter the average group call speech time, the bigger the radio population can be.

4.5 Expected down times upon the system programming

Temporary system downtime will occur due to site configuration change or addition/deletion of the system or user parameters.

Triggers of system downtimes are shown below.

Site Apply

Multi Apply

Write data to the System

Firmware Update

Control Channel Error

Restart (Soft Reset)

Upon execution of these operations, the system will reboot the repeaters sequentially. Moreover, Power Cycle or Firmware

Update requires embedded TCXO/ OCXO frequency matching time, if the KXK-3 option is installed. All times listed in the next

table are approximate and maximum times experienced.



Table 4-3 Nominal reboot time

Note: LAN Bandwidth: 100 Mbps

4.5.1 Channel Delete

Channel delete does not affect any other sites’ operation. The site of which a channel delete operation takes place will be

detached from the system and other sites continue trunking operation without that site.

Delete of Least Number Channel Least Number Channel in a site outputs Sync Frame from the RJ-11 port on the back panel. Deleting this channel causes

the loss of the Sync Frame signal and the site displays “E6” error message. The site will recover and reboot within

approximately 1min 10sec.

Delete - Control Channel No downtime occurs except when the removed repeater is a Control Channel with least channel number. When a site

detects an error such as CH Power Down for 10 consecutive seconds, the control channel role will automatically be taken

over by another channel which becomes a control channel or dual function channels.

Delete - Traffic Channel No downtime occurs except when the removed repeater is the least channel number.

Figure 4-3 Channel delete

Trigger PC I/F Condition Reboot Time

IP Address Write COM 30 seconds

without Time Adjustment 20 seconds Site Apply COM

Time Adjustment Another 20 seconds

Multi Apply LAN 1 min 10 seconds

LAN 35 seconds Write Data to the System

COM 40 seconds

without Time Adjustment 40 seconds Channel Reconfiguration → Site Apply

COM Time Adjustment Another 15 seconds

System Information → Write COM 1 min 10 seconds

COM NXR-810/ NXR-710 2 min 20 seconds

LAN 5 min 55 seconds Firmware Update

COM NXR-700/ NXR-800

11 min 40 seconds

by KPG-129D 15 seconds FPU data Update COM

by KPG-109D 25 seconds

- When removed CCH is the least number channel 1 min 10 seconds Control Channel Switch-over

- When removed CCH is not the least number channel 15 seconds

Conventional Reset COM 35 seconds

Power Cycle - 1 min 10 seconds

Restart LAN Soft Reset 35 seconds



4.5.2 Firmware Update

The target site goes into PC Mode and the trunking operation holds. The other sites continue to work normally.

Target site Downtime = 400 seconds (Approx. depending on the file size)

4.5.3 Change Site/ System Information

Change of System Information and Site Information, in other words edit of the Frequency Number, Adjacent CCH, Add CCH

and Delete CCH require to execute “Write Data to the System”. This will cause about 40 sec of downtime at each site

sequentially.

All sites “Write Data to the System” 40 seconds = Total 40 seconds (Approx.)

4.5.4 FPU data Update

Downtime depends on the channel type. Sites that are not being upgraded continue trunking operation.

Control Channel When applying the FPU data update to the control channel, the control channel role will automatically be switched over to

the next candidate channel and trunking operation continues.

Traffic Channel No Downtime occurs

Lowest Number Channel During FPU data update the Frame Synchronization output halts. Therefore other channels will lose Frame

Synchronization signal and stops trunking operation until the FPU data write completion.

4.5.5 Fleet/ ID Information Update

Add or Change of Fleet, GID and UID information can be done by “Write ID Data to the System” which does NOT require

system reboot upon execution.

While the system is updating the ID information by “Write ID Data to the System” the system continues trunking operation.

4.5.6 Repeater Swap for repair

Repeater swap for repair can be done without system down by “Channel Reconfiguration” menu. Via serial cable with this

reconfiguration feature, the failed repeater unit can be swapped not affecting any other repeaters or sites under operation.

Figure 4-4 Channel Reconfiguration Window



4.5.7 Channel Add

Channel add-on requires the following steps. Consider that system down time occurs by Conventional Reset until the end of

the configuration sequence. Expected downtime depends on number of channels. Refer 4.5 Expected down times upon the

system programming for typical down time of considerable events.

Channel Frequency Setup to the new repeater

Conventional Reset on the site

Network Configuration for the new repeater

Single Site Apply to the site

Site Information Setup

Write Data to the System

Multi Site Apply to the entire system

Figure 4-5 Channel add



4.5.8 Site Add

Site add-on requires the following steps. Note System down time occurs when performing Write Data to the System and Multi

Site Apply in the series of configuration. Refer 4.5 Expected down times upon the system programming for typical downtime

of considerable events.

Channel Frequency Setup

Network Configuration

Single Site Apply

Site Information Setup

Fleet Information Setup

Write Data to the System

Multi Site Apply

Figure 4-6 Site add

4.5.9 Automatic Control Channel Rollover

Control channel task is taken over automatically at preset interval configured in the Site Information. This activity is done in the

background.



4.6 Power-on Standby

“Power-on Standby” feature is pre-programmed as default in order to prevent unintended transmission during the system

integration which may cause fatal damage to the PA and/or connected peripheral equipments.

“Power-on Standby” must be disabled otherwise the NXR repeaters will not start transmission automatically after reboot or

loss of power.

Figure 4-7 Power-on Standby checkbox

4.7 System Key File

A System Key File (skf file) is required to configure subscriber units used in your system. The system key file can be created

with your System Manager (KPG-110SM) and the subscriber units configured with this proper System Key File only can be

authenticated by the system.

Figure 4-8 System Key File handling flow



4.8 Dialup Modem Connection

Several notes should be taken into consideration when using a Dialup Modem.

Execute “Multi Apply” for sharing the additional site information

Modem baud rate MUST be set to 9600 bps (DTE Speed)

Set communication port (KPG-110SM) to “COM” and “Modem”

Enter all sites’ telephone numbers into the phone book

Straight RS-232C (Null modem) cables must be used

Enable the “RTS/CTS Flow Control”

Modem baud rate MUST be set to 9600 bps

Repeater serial port is set its baud rate to 9600 bps

Figure 4-9 Dialup connection system topology



4.9 Single Site design considerations

When designing a single site trunked radio system, initially only very little information is required, such as:

How many radio users?

・ See section 4.4 Trunked System – How Many Voice Users per Traffic Channel?

・ Future upgrade plans?

What is the main traffic pattern?

・ Group calls?

・ Individual calls?

・ Average speech and call time, if possible

Data applications to work over the radio system, such as Kenwood KAS-10 AVL & Dispatch software?

・ How much data to be sent over the radio system?

Where is the system going to be installed?

・ In a building? What type of building?

・ Sky scraper/high rise/factory etc.?

・ Outside – with wide area coverage?

・ Underground?

What antenna system is required - antenna design considerations

4.10 Multi-site

Multi-site systems are single site systems, linked together. This means that for the initial planning of each site, the same

information as mentioned above is required.

In addition to this, information on multi-site behavior and link requirements is required, such as:

How many transceiver users are expected in each site?

How many transceivers are likely to roam between the sites and how often?

Are there any data applications expected to run over the multi-site system?

How many of the calls will be multi-site calls?

Will there be more individual multi-site calls or group multi-site calls?

What will the intersite link structure look like?

How much intersite link resilience is required?

Are the IP links secure? Do they need to be?

If so, what type of intersite links are we going to use?

Do we use own IP infrastructure (IP microwave links for example) or use a commercially available Internet Service

Provider (ISP) solution?

Has the customer got its own IP infrastructure or do we have to build one?

If the customer owns the IP infrastructure, talk to their IT department regarding fixed IP addresses and respective routers

and switches.

Potential security concerns regarding connecting Kenwood NEXEDGE to a customer owned IT infrastructure can be

overcome by using VPN capable routers.

Based on the knowledge gained from the above questions a design of the intersite links and IT infrastructure should be

possible. For IP intersite link traffic volume calculation, refer to sections 4.13 IP Links and 4.14 IP Bandwidth Requirement.



4.10.1 Multicast Routing

In the unicast scheme, a packet is delivered only to a specific single host. In the multicast scheme, a packet is delivered to a

group of hosts that have expressed interest in receiving the packet. With multicast, a host can send only one copy of a packet

into the network (i.e. Multicast router), and the network will make copies of the packet and deliver one copy to each interested

host.

■ Unicast Scheme

Figure 4-10 Unicast scheme

Host repeater creates number of copy packets for target sites

Heavy traffic as sites increases

■ Multicast Scheme

Figure 4-11 Multicast scheme

Host repeater only send single packet to the core router

Core router copies packets for the targets

Traffic volume dramatically reduced



4.11 GPS/AVL data capacity

Kenwood NEXEDGE supports GPS, AVL and standard data transmission. Refer to the short explanation of the data

capabilities with reference to sending GPS position data.

Under ideal condition at one base station:

Auto Report - 1 GPS call takes one to two seconds: 30 reports per minute

Polling - 1 GPS call takes three seconds: 20 reports per minute

Voice and surrounding noise conditions may affect the number GPS reports.



4.12 IP Switches – Hub, Switch, Router?

Hub, Switch, Router – what is the difference?

Hubs, switches, and routers are all devices which let you connect one or more computers to other computers, networked

devices, or to other networks. Each has two or more connectors called ports into which you plug in the cables to make the

connection. Varying degrees of switching, routing happens inside the devices, and therein lays the difference.

A hub is typically the least expensive, least intelligent, and least complicated of the three. Its job is very simple: anything that

comes in one port is sent out to the others. Every computer connected to the hub “sees” everything that every other computer

on the hub sees. The hub itself is not aware of the data being transmitted.

A switch does essentially what a hub does but more efficiently. By paying attention to the traffic that comes across it, it can

“learn” where particular addresses are. For example, if it sees traffic from machine A coming in on port 2, it now knows that

machine A is connected to that port and that traffic to machine A needs to only be sent to that port and not to any of the others.

The net result of using a switch over a hub is that most of the network traffic only goes where it needs to go rather than to

every port. On busy networks this can make the network significantly faster.

A simple way to think of a router is as a computer that can be programmed to understand, possibly manipulate, and route the

data it’s being asked to handle. For example, broadband routers include the ability to “hide” computers behind a type of

firewall which involves slightly modifying the packets of network traffic as they traverse the device. All routers include some

kind of user interface for configuring how the router will treat traffic. The really large routers include the equivalent of a

full-blown programming language to describe how they should operate as well as the ability to communicate with other

routers to describe or determine the best way to get network traffic from point A to point B.

For the purpose of the Kenwood NEXEDGE single site and multi-site connection, we will only look at switches and routers.

See below for two typical IP site configuration examples including a simple IP switch:

Figure 4-12 Typical NEXEDGE single site IP configuration

The second configuration below, shows a typical two site NEXEDGE configuration and IP setup with two IP routers and a

VPN based WLAN connection in between.

Figure 4-13 Typical NEXEDGE multi-site IP configuration



4.13 IP Links

When connecting a multi-site Kenwood NEXEDGE system via an IP link, the following circumstances should be taken into

account.

There are many different variations of wireless or wired IP links available. Some of which are more suited to a mission critical

radio system application than others.

Below a non-exhaustive list of possible IP networks.

Customers internal, own IP network

Commercial ISP (Internet Service Provider)

IP sections within a bigger IP network – so called Virtual Networks

Transceiver IP links

Microwave IP links

Public IP Networks Public IP Networks are available for a reasonable commercial value in most areas. Internet Service Providers (ISP’s) offer

various services that can range from 128 kbps to 10 Mbps or more.

While these offers present a good commercial value, they do have a potential drawback.

The system integrator/ installer and end user have no direct influence on the quality of service offered through these ISP’s. If

a technical fault has occurred with the ISP’s hardware or software or other components, the system integrator and end user

are required to wait until the ISP or responsible party has rectified that fault.

Potential loss of income and certainly loss of intersite service, and operational problems, could be the result. A service level

agreement (SLA) should be part of the contract with a public ISP, whenever possible.

Private IP Networks Although mostly more expensive than a solution based on Public IP Networks, they offer a better and more controllable

quality of service to the users Kenwood NEXEDGE multi-site digital trunked radio system.

There are a number of options. Which one is best depends entirely on the budget and available resources and the

customer’s requirements.

Some of the examples:

● Use of customers existing IP network

・ Consider network capacity required and security implications.

・ Use IP switch with VPN facility to secure transceiver networks IP access.

・ Consider Virtual IP Network within the customer IP network.

● Build new IP interlink network.

・ Wireless network.

・ Consider network capacity requirements.

・ Consider security requirements.

・ Consider network redundancy requirements.

・ Consider obstacles existing and not yet existing!

・ Wire or GBN (Ground Based Network) based network.

・ Consider network capacity requirements.

・ Consider security requirements.

・ Consider network redundancy requirements.



4.14 IP Bandwidth Requirement

NEXEDGE IP bandwidth calculation should be done not only for voice communication (VoIP) but also call session initiation

process (SIP) which occurs every time making an intersite call. In this section, calculation formulas are introduced by network

types. For multicast network, required bandwidth varies by network topology. Network bandwidth calculation must be

discussed in the system design phase considering network type, system size and future system expansion.

As unicast scheme is used for multicast call initiate session, unicast SIP bandwidth calculation can be commonly used for

multicast call initiate session.

In case of a VPN connection, the amount of data varies by Encryption and Authentication method. Therefore, the VPN

connection is not in the scope of this section.

4.14.1 Unicast Network Requirements

Bandwidth Calculation (6.25 kHz Very Narrow) Voice Packet Upstream

BW = 21.75 *x * y

Voice Packet Downstream

BW = 21.75 *x

SIP Packet Upstream

BW = (17.32 + 29.86 * y) *x

SIP Packet Downstream

BW = (34.24 + 18.86 * y) *x

Required network bandwidth can be calculated with formulas above where…

x stands for “Number of traffic channels”

y stands for “Number of Intersite Call available sites” -1

Bandwidth Calculation (12.5 kHz Narrow) Voice Packet Upstream

BW = 41.5 *x * y


BW = 41.5 *x

SIP Packet Upstream

BW = (17.32 + 29.86 * y) *x


BW = (34.24 + 18.86 * y) *x






4.14.2 Multicast Network Requirements

In this document, following 3 types of topologies are introduced for NEXEDGE multicast system.

1. Mesh Network

In this network topology, a multicast router sends copies of IP packets to all the target routers. Bandwidth calculation can be

done by the formula in the next slide below.

Figure 4-14 Mesh network

Mesh Network Bandwidth Calculation (6.25 kHz Very Narrow) Voice Packet Upstream

BW = 21.75 *x * y


BW = 21.75 *x

SIP Packet Upstream

BW = (17.32 + 29.86 * y) *x


BW = (34.24 + 18.86 * y) *x




Mesh Network Bandwidth Calculation (12.5 kHz Narrow) Voice Packet Upstream

BW = 41.5 *x * y


BW = 41.5 *x

SIP Packet Upstream

BW = (17.32 + 29.86 * y) *x


BW = (34.24 + 18.86 * y) *x






2. Star Network with Core Router

In this network topology, a multicast router only send a packet to the core router – also known as a rendezvous point – then

the core router makes copies for all the target routers. Hence the bandwidth calculation at the router WAN port only needs to

be done for a path to the core router. The formula is shown below.

Figure 4-15 Star network with core router

Star Network Bandwidth Calculation (6.25 kHz Very Narrow) Voice Packet Upstream

BW = 21.75 *x


BW = 21.75 *x

SIP Packet Upstream

BW = (17.32 + 29.86 * y) *x


BW = (34.24 + 18.86 * y) *x




Star Network Bandwidth Calculation (12.5 kHz Narrow) Voice Packet Upstream

BW = 41.5 *x


BW = 41.5 *x

SIP Packet Upstream

BW = (17.32 + 29.86 * y) *x




BW = (34.24 + 18.86 * y) *x




3. Cascade Connection Network

Cascade connection is sometimes used in the microwave system where metal line is unavailable. In this topology, line load

is accumulated at each router node so bandwidth calculation varies node by node considering number of channels at each

site.

As various connection and site plan can be assumed, a single bandwidth calculation formula cannot cover for all the

cascade connection. For cascade connection, contact with your regional Kenwood technical support for required bandwidth

calculation.

Figure 4-16 Cascade connection network



4.15 Antenna Networks

The transmit and receive antenna networks are equally as important as the rest of the radio system, as they determine the

radio coverage to a large extent.

There is a large variation of different antennas and antenna systems available. Gain and/or directional antennas allow for a

more precise RF coverage of a specific area compared to 0dB, unity gain antenna or omni directional antennas.

The antenna network can be used to balance the radio systems RF characteristics. It does not make sense to have the

system radiate with 150W ERP (effective radiated power) and the portable transceivers radiate with only 5W, as the radio

system may still be “heard” by the portable transceiver, but the portable transceiver may not be able to reach the radio system

anymore.

Balancing the RF coverage footprint means that the radio system transmission coverage range is equal or a little better

compared to the coverage range of the return RF signal expected from the subscriber unit (mobile or portable transceiver).

To double the coverage of a radio system you need to quadruple its RF output power!

Meaning, that you need to increase the RF output power from, say 25W, to 100W to double the radio systems coverage area.

In conclusion, you need more expensive base stations, more expensive RF combining systems, cooling has to be adjusted to

dissipate the extra heat generated, maybe a bigger uninterruptible power supply (UPS) system needs be installed and, last

but not least, the system will use more electricity.

Do it with better antenna design instead!

There are two basic antenna variations available.

Omni directional antennas

Directional antennas

・ YAGI antennas (10° to 60° typical, horizontal opening, depending on gain)

・ Sectional antennas (for example 90° or 120° horizontal opening)

Depending on the desired coverage area a directional (YAGI), omni directional or sectional antenna with or without down tilt

can be used.

Examples 1) Railway or Motorway applications

These types of applications generally require a long straight coverage area, rather than a circular coverage area.

See below Figure 4-17 Side view – Typical road or railway multi-site antenna radiation pattern for an example how a

railway or road antenna system could look like.

Figure 4-17 Side view - Typical road or railway multi-site antenna radiation pattern



2) Compound, factory or area coverage with one site or two sites

Figure 4-18 Top view - Area coverage example with one side

Figure 4-19 Top view - Area coverage with two sites and sectional antennas

For limiting the coverage range in an application in which only a comparatively small geographical area should be

covered, a down tilt antenna system may be considered.

See below for a concept of a down tilt antenna application. Down tilt antenna systems can be realised with directional

Yagi or omni directional ground plane antennas. The picture below shows a down tilt antenna system with a directional

Yagi antenna adjusted downwards.



Figure 4-20 Side view - Concept of a down tilt antenna installation

3) RF over Fibre Optic (RFFO)

An alternative solution to installing multiple sites in a complex RF coverage requirement is a system called RF over fibre optic.

An RFFO system converts RF signals into light signals and transmits the light via a fibre optic cable to a remote amplifier.

The amplifier converts the light signals back into RF signals and retransmits the RF signals.

These systems can work both ways, transmit and receive.

Figure 4-21 RF over fibre optic concept drawing

With RFFO the RF signal from the base stations is collected via a RF combiner and directional couplers. From the directional

couplers the RF signal is then fed into a RF to fibre conversion unit.

The advantage here is that a single Kenwood NEXEDGE site can be used to supply a complex RF coverage supply pattern,

such as an airport, a large building or similar structures.

Since the RF is repeated and retransmitted at the repeater sites without any, or just very minimal, runtime delay through the

Fibre Optic system and the retransmitted RF is phase-synchronized with the main transmitter site, the complete system

looks like a single site system to the roaming subscriber units.

Disadvantage is the higher price of the main fibre optic distribution unit and the linear repeater amplifiers at each repeater

station, plus the installation of the required fibre optic cable.



4.16 RF Combining

In order to connect multiple base stations to a single antenna system, an RF combining system is required.

Base station combiners general consists of a Bandpass Duplexer, a Receive Splitter Amplifier and either a Hybrid Combiner

or a Cavity Combiner or a combination of both.

Base station combining forms an essential part of a cost effective antenna system. It controls the interference to your own

mobiles and those of other users. It enables expansion of multi-channel systems without having to erect additional antennas

therefore reducing site rental costs and maximizing existing space on premium site locations. It protects the transmitter in

case of an antenna failure and allows all co-sited transmitters and receivers to function at the same time.

Here is a brief description of the combiner sub systems:

4.16.1 Bandpass Duplexer

This is a combination of two Bandpass filters one tuned to cover the bandwidth of the transmit frequencies and the second to

cover the band width of the receive frequencies. The purpose of using Bandpass filter technology is to stop the transmission

out of band noise getting into the receive path and de-sensing the receiver and to give sufficient isolation between transmit

and receive frequency bands for full duplex operation

Figure 4-22 Bandpass filters

The two filters are harnessed with critical phasing harnesses to optimize the matching between the transmit and receive paths.

Typically duplexers give > 70 dB isolation between the two frequency bands. The required isolation depends on radio's output

power.

4.16.2 Receive Splitter Amplifier

The Receive Splitter Amplifier (RSA) is a device that is designed to split the receive signals of a specific band from the

antenna to the site receivers. A pre-selector bandpass filter effectively attenuates any out of band signals whilst allowing the

receive frequency band to pass with minimal pre-amplifier loss. This pre-selector filter is followed by a low noise amplifier to

overcome the Bandpass filter, cable and receive splitter loss (typically overall gain of an RSA is set between 0 and 3 dB). The

noise parameter of the amplifier has to be carefully chosen to minimize in impact of the increase in the noise floor of the

receive signal. Typical noise figure of the is <2.5 dB with an IP3 of >+30 dBm.

Figure 4-23 Receive Splitter Amplifier

4.16.3 Transmit Ferrite Isolator

The ferrite isolators are used obtain isolation between adjacent transmitter channels (typically >45 dB). The device protects

the individual transmitter from damage in the event of a large amount of reflected power being reflected back from the

antenna and also reduces the risk of intermodulation products being generated in the power amplifier stages of the adjacent

transmitters.



Figure 4-24 Ferrite isolator

4.16.4 Cavity Combiner

The cavity resonator is a high Q (10,000) filter with low insertion loss. The cavities are harnessed together in a chain with

critical matching harnesses for maximum rejection between the adjacent transmit channels. Due to the filter response the

minimum transmit channel spacing are as follows

Transmit and Transmit Channel spacing, typical

VHF Low Band 50 to 88 MHz = 100 kHz

VHF High Band 110 to 225 MHz = 150 kHz

UHF 380 to 520 MHz = 200 kHz

When additional channels are phase harnessed into the cavity chain a minimum insertion loss is added to the system

(typically 0.3 dB). The increase number of channels added to the cavity chain means that greater care over the selection of

the transmit Bandpass filter in duplexer is required. This due to the increase in the peak power levels associated with

multi-channel combining.

Figure 4-25 Cavity combiner

4.16.5 Transmit Hybrid Combiner

The purpose of the transmit hybrid combiner is to combine two transmitter inputs equally to two ports. Frequently one output

port is terminated into a terminated load thus giving effectively one antenna port. Minimum channel spacing for the hybrid

combiner is 6.25 kHz, however any other channel spacing is supported such as 12.5/ 20/ 25/ 30/ 50/ 125/ 150 kHz etc.. Note

that a hybrid combiner has a high insertion loss of 3.2 dB per hybrid coupler. As the hybrid combiner works in a pyramid

structure as additional combiner ports are added the insertion loss will increase by 3.2 dB typically. Check with your chosen

RF combiner manufacturer if their equipment supports minimum of 6.25 kHz channel spacing.



Figure 4-26 Transmit hybrid combiner

4.17 Advantages and disadvantages between combining systems:

Table 4-4 Comparison of combiners’ characteristics

Hybrid Combiners Cavity Combiners

Advantages Advantages

No channel limitations Low insertion loss (4 channels typically 4.0 dB)

No field retuning within the band Expandable with minimum insertion loss increase (typically 0.3 dB per channel)

Low cost Improved isolation with cascaded cavities

Small size Good intermodulation performance

High insertion loss Physically size (large 7 U per 2 channels)

Each expansion not less than 3 dB additional insertion loss. For large systems additional antennas may be required to keep the insertion loss within reasonable limits.

Channel spacing limitations. Requires in-field retuning to change frequencies

Higher cost than the hybrid combiner



4.18 Pictures of typical RF components Duplexer, combiners, RX

multi-coupler

Figure 4-27 4 Cavity duplex filter

Figure 4-28 2 Channel hybrid combiner with isolators

Figure 4-29 Miniature 4 Channel RX multi-coupler

Figure 4-30 19" Rack-mount 8 channel RX multi-coupler



4.19 3rd Party Equipment

4.19.1 RF Combiner/ RX Splitter and Duplexers

Kenwood does not currently offer system integration services and thus does not resell third party equipment, such as the

equipment listed below or described in this document.

RF Combiners, splitters and duplexers are available from a number of suppliers.

4.19.2 IP Switches/ Routers

Kenwood have tested a number of IP switches, mainly manufactured by Cisco/ Linksys. Check RoHS, CE status, legal

requirements and regulations for your respective country.

Kenwood have no affiliation with Cisco Systems or Linksys and similar products with equal specifications are available from

other manufacturers.

There are different requirements for IP switches for single site and for multi-site applications!

Single Site

・ IP switch does not need to have a WAN port.

・ IP switch does not need to support VPN (Virtual Private Network).

Multi-site

・ IP Switch/ router requires port for connection to WAN IP network.

・ Consider a router with a secondary WAN port for redundancy reasons.

・ IP switch/ router requires VPN capability for enhanced security.

See below a selection of IP switches suitable for Single Site and Multi-site applications.

Note: ONE port on the switch/ router is required per NXR-700/ NXR-800/ NXR-900 repeater connected to the switch/ router in each site!

Table 4-5 Typical Single Site IP Switches

Table 4-6 Typical Multi-site IP switches/ routers with VPN support

See Linksys Routers web page. How to setup a VPN tunnel on two Linksys Routers for example setups.

http://www.cisco.com/en/US/products/ps9923/products_qanda_item09186a0080a3653d.shtml

Model Number Manufacturer Number of Ports

SD205 Linksys 5

SD208 Linksys 8

SD216 Linksys 16

SR224 Linksys 24

Model Number Manufacturer Number of Ports

RV042 Linksys 4

RV082 Linksys 8

RV016 Linksys 16



4.19.3 RF Amplifiers

The NXR-700 and NXR-800 E version repeaters generate 25W output power, continuous duty. The K version, for non EU

use, repeaters come with a 5W exciter and the NXR-900 come with a 0.36W exciter, rather than a build in 25W power

amplifiers.

This may make it necessary to employ an additional power amplifier to increase the overall power output of the NXR-700,

NXR-800 and NXR-900 repeaters and the system as a total.

Standard FM power amplifiers can be used.

If power amplifiers are to be used in a system, the following considerations should be taken into account:

Power output required per channel?

Can the RF combiner cope with the RF input power?

Cooling of the RF power amplifiers?

・ Passive, convection cooling, or active, fan assisted, cooling

Where to install the RF power amplifiers in the rack?

Heat output – BTU.

Environmental, operating temperature range, at the proposed installation site?

Ease of maintenance.

Can my power supply system cope?

Do I need a UPS system and what are the standby and supply time criteria?

4.19.4 Power Supplies

Each NXR-700, NXR-800 or NXR-900 repeater requires a 13.8 V DC power source that can deliver approximately 10 A.

When building a trunked radio system with more than 2 channels, the distribution from the power supplies (PSUs) becomes

more important.

There are a number of methods one can use:

One PSU to feed all NXR-700, NXR-800 and NXR-900 repeaters and ancillary equipment.

・ Disadvantage – if the one PSU fails the whole system will stop working

One PSU to feed a selection of NXR-700, NXR-800 and NXR-900 repeaters.

・ The rule of thumb is that one PSU should feed 2 NXR-700, NXR-800 or NXR-900 repeaters

Generally one would expect to see an Uninterruptible Power Supply (UPS) cover the possibility of a mains failure. Design and

dimensioning of a UPS system will not be discussed in this document.


Trunking Roaming Considerations

5 Trunking Roaming Considerations

5.1 Intersite Group Call

Intersite call is a function that allows calls beyond the sites. Depending on the backhaul network used and system network

category number of intersite call capable sites varies.

Table 5-1 Intersite Call table

Network Type Network Category Maximum System Capacity Number of Intersite Group Call Capable Sites

Local 30 16 Unicast

Regional 48 16 Local 30 30

Multicast Regional 48 48

5.2 Expanded Multi-Site Capability

5.2.1 New Intersite Group Call (Unicast)

Up to 16 sites (including own site) can be covered by an Inter-site group call.

Network Category: Local

Figure 5-1 New intersite group call (Unicast)



5.2.2 New Intersite Group Call (Multicast)

All the 30 sites are Intersite Group Call available with Multicast Network.

Network Category: Local

Figure 5-2 New intersite group call (Multicast)



5.2.3 New Intersite Group Call (Unicast)

Up to 16 sites (including own site) can be covered by an Inter-site group call.

Network Category: Regional

Figure 5-3 New Intersite Group Call (Unicast)



5.2.4 New Intersite Group Call (Multicast)

All the 48 sites are Intersite Group Call available with Multicast Network.

Network Category: Regional

Figure 5-4 New Intersite Group Call (Multicast)

5.3 Intersite Call settings

For a public service provider, also known as a SMR (Specialized Mobile Radio) operator, NEXEDGE trunked system offers two

types of Intersite Call configurations below. These can be configured by Intersite Call table in the GID Class of Service.

Dynamic Allocation

For a user group for which the system operator wants to restrict the operating sites, Dynamic Allocation confines the group

within specific sites.

Group Registration

For a user group who needs to travel all the sites in the multi-site system, Group Registration allows effective channel

resource assignment up to 6 sites.



5.4 Dynamic Allocation

In the Intersite Call Table, a system operator can define operational service site by checking the “Valid” checkbox for each GID.

This configuration can be done in the GID Class of Service. In the meantime, by enabling the Dynamic Allocation NEXEDGE

multi-site system allocate a traffic channel resource only for the site where Group Call subscriber unit exists.

Figure 5-5 Dynamic Allocation setting in the Call Table



Figure 5-6 Site assignment by the Dynamic Allocation

As explained above, Dynamic Allocation will be suitable for SMR type radio rental business.



5.5 Group Registration

By enabling the Group Registration, each subscriber unit registers its presence to the system with its awaiting GID. This is an

essential setting for Dynamic Allocation in order to assign a traffic channel only for the site where a subscriber unit is registered.

(This must be enabled for most of the multi-site system essentially.)

Figure 5-7 Group Registration

Group Registration is a function to register a GID used for a subscriber unit to the system.

In the case that a Group Call is initiated in a multi-site system (i.e. Intersite Call), subscriber units belonging to a group are called,

using channel resources (frequencies) across multiple sites. In this case, to use channel resources efficiently, it is necessary to

appropriately recognize the location of subscriber units that are waiting for a Group Call and also inhibit transmissions on

channels where no subscriber unit that have to receive the Group Call exists.

If a Group ID is not used within approximately 12 hours after the Group ID registration is refreshed, the system will delete the

registered Group ID. The Group ID registration information is refreshed upon occurrence of either of following events:

Call-out and response by a Group Call

Group Registration

5.5.1 GID Registration Expiry

A group registration record is expired after 12 hours of no activity. For the trigger station (fixed location terminal) such as base

station of a taxi company or fire station those which need to be turned on always but no radio activities may be expected over 12

hours. If the fixed terminal is called after 12 hours of no activity, he cannot be paged due to cleared GID record.

Recommendations;

Not to use “Dynamic Allocation” for the site where the trigger station always registered (Static operation). In order to keep

the trigger station always on the same site, “Site Lock” is also recommended.

Power cycle exercise is highly encouraged especially for the vehicle radio user that may not power off over the night or

over the weekend. “Ignition Sense” use should reduce the risk of this issue.

This setting can be done for each GID CoS.



Figure 5-8 Static Site setting



5.6 System Search Policy

For the Out-of-Range Level setting, NEXEDGE subscriber units can be configured from 3 levels called “System Search Policy.

They are named Roaming Preferential, Normal and Site Preferential prepared for various system setting preferences. System

Search Policy is a parameter that can be configured by KPG-111D, terminal radio FPU.

Note that System Search Policy does NOT determine Roaming Likeliness.

Figure 5-9 Out-of-Range level by System Search Policy

Figure 5-10 System Search Policy setting in the Hunt Option

Table 5-2 Approximate Out-of-Range Level by System Search Policy

System Search Policy Roaming Condition (Approximate RSSI Level)

Roaming Preferential -100 dBm to -105 dBm

Normal -115 dBm to -120 dBm

Site Preferential Below that of Normal



5.7 Background Hunt

Background Hunt is a function that allows the subscriber unit to periodically search for neighboring control channels to acquire a

control channel with higher signal strength while the subscriber unit is in the standby state on a control channel.

The subscriber unit waits to receive the Adjacent Control Channels information, which is broadcasted on the control channel

(Broadcast Message). Intended channels (frequencies) for the Background Hunt are only provided via this Broadcast Message.

Figure 5-11 Overall image of the Background Hunt

5.8 Background Hunt Level Margin

While System Search Policy determines Out-of-Range Level, this Background Hunt Level Margin is the one that determines the

Roaming Likeliness.

When Background Hunt is enabled, subscriber unit seeks another control channel available that provides better signal condition

at pre-specified interval while the subscriber unit is on a control channel. If a candidate control channel provides

better signal strength of more than Background Hunt Level Margin specified level, then the subscriber unit will roam to the

candidate control channel.

Background Hunt Level Margin can be configured within 0 to 42 dB in the step of 6 dB with subscriber unit FPU, KPG-111D.

Figure 5-12 Roaming likeliness by Background Hunt Level Margin



Figure 5-13 Background Hunt Level Margin setting in the Hunt Option

5.9 Adjacency Information

Adjacency Information is a Broadcast Message that provides subscriber units with adjacent sites’ control channel information for

optimal roaming. Each site must be configured to broadcast appropriate control channels information so that subscriber units in

the site coverage area do not search for control channels unnecessarily but search possible channels only.

Adjacency Information can be configured via System Configuration with System Manager KPG-110SM.

Figure 5-14 Overall image of the Adjacency Information configuration



5.10 Roaming Related Settings

Roaming related settings are summarized below.

1. Search Interval

2. Level Margin

• Switch over threshold level from Current Control Channel receiving level

• Large number for unlikely to roam

3. Adjacent Site Information

• Background hunt channel informed via broadcast channel

Figure 5-15 Roaming related settings by KPG-111D and KPG-110SM



5.11 How a Subscriber Unit Roams

Subscriber unit roams as illustrated below

Figure 5-16 Roaming sequence in the NEXEDGE trunking mode

1. When current signal level falls

2. And is below -88 dBm

3. And the Candidate Channel level exceeds the Level Margin

4. Then the Subscriber Unit roams to the candidate channel

5.12 Setup Recommendation

The following chart discusses an actual roaming level example when a candidate control channel signal level is -73 dBm and

varies current control channel level. From this, you can see that only “Level Margin” determines roaming likeliness and “System

Search Policy” determines Out-of-Range level.

As explained earlier, only when a candidate channel exists, “Level Margin” is applied and the subscriber unit roams so System

Search Policy has nothing to do with roaming.

Subscriber unit starts Hunt Sequence when current channel level falls to the System Search Policy level. This is not “Roaming”

but “Channel Search” due to loss of a control channel.

Roaming setting below -105 dBm is not suitable because receiver audio quality will be degraded in such low signal condition.

Note:

Roaming level varies depending on the candidate signal level.

Out - of - Range Level at “Site Preferential” varies by Narrow and Very Narrow.



Figure 5-17 Actual Roaming Level Measurement Value (Example)

5.13 Case Study

In the multi-site system below, there are two user groups that have Preferential Site configuration of Site1 and Site2 respectively.

For traffic load dispersion, each subscriber unit should stay on its Preferential site as much as possible.

Figure 5-18 Case Example - A subscriber unit travelling to a smaller site

Now a subscriber unit, which Preferential Site is Site 2, is travelling towards Site 1. The signal level from Site 1 is stronger than

that of Site 2, but the subscriber unit should NOT roam to Site 1 and stay on Site 2 from traffic load (Channel resource)

dispersion perspective. In this case, the Background Hunt “Level Margin” is not valid to keep the subscriber unit on his

Preferential Site.



Setting Tip 1:

Set Preferential Site where the subscriber unit should roam in, most of the time. This is the most important parameter for Traffic

Load Management.

Figure 5-19 Preferential Hunt Control Channel table in the KPG-111D Zone Edit

Setting Tip 2:

“Level Margin” is not effective when a subscriber unit roams to a Neighbouring Site from his Preferential Site. Even the signal

from the Neighbouring Site is stronger than the “Level Margin”, as long as the subscriber unit can receive the Preferential Site

signals, subscriber unit stays on the Preferential Site until the subscriber unit loses the Preferential Site signal.

“Level Margin” is used when the subscriber unit roams from a Non-Preferential Site to other Non-Preferential Sites as a

parameter for the roaming likeliness.

Figure 5-20 Level Margin setting in the KPG-111D Hunt Options



5.13.1 Background Hunt (Tip 1)

Adjacency Information

When thinking about Adjacent site, you should think about radio signal coverage not just physical adjacency.

Let say Site 4, has neighboring site of Site 3, with its very tall antenna tower that provides super wide coverage, field radios

probably be able to roam in Site 4 wherever and which ever Site coverage they are in. When a subscriber unit is very close to

Site 1 antenna, but captures Site 4 signal somehow, for the subscriber unit to roam to Site 1 by Background Hunt, Site 4 must

broadcast that its adjacent sites are not only Site 3, but also Site 1. If Site 4 only broadcasts adjacency information of Site 3, the

subscriber unit in Site 1 coverage which is currently roaming on Site 4 cannot roam to Site 1.

Figure 5-21 Background Hunt (Tip-1)

5.13.2 Background Hunt (Tip 2)

Figure 5-22 Background Hunt (Tip-2)

In Message Trunking Operation

1. Background Hunt search occurs when the subscriber unit is on a CCH at every search interval

2. If call occurrence is very frequent and the subscriber unit cannot stay on the CCH

3. In this case, the subscriber unit cannot roam to another site

Adequate Search Interval must be set considering actual call load.


IP Conventional Network Roaming Considerations

6 IP Conventional Network Roaming Considerations

6.1 Intersite Call in the Conventional Repeater System

NEXEDGE enhancement released in Feb 2010 enables network capability for a Conventional Repeater system. This provides

end users to link 2 or more sites via IP backbone across large areas, throughout large building or across large campus such as

an amusement park or college.

Figure 6-1 Intersite Call in the conventional repeater system

6.2 Intersite Call

Enhanced NEXEDGE provides two types of backhaul network capability corresponding various size of systems. Network type

can be configured in the IP Casting shown below.

For Multicast network, up to 48 sites are Intersite Call capable. For Unicast, up to 16 sites are Intersite Call capable.

Figure 6-2 IP Casting setting by the KPG-109D


IP Conventional Network Roaming Considerations

6.3 Site Roaming (Voting)

This will provide portable and mobile radios to automatically select the best site and allow for smooth transition from site to site.

The subscriber units listen for a Beacon Signal (also known as a Heart Beat Signal) transmitted from the repeater, when

searching for a candidate site in the Conventional IP System.

Figure 6-3 Site Roaming (Voting)

Terminologies:

In NEXEDGE system, terminologies “Site Roaming” and “Beacon Signal” are used for digital mode IP conventional. They are

also known as “Voting” and “Heart Beat Signal” in analog systems.

6.4 Beacon Signal

Repeaters transmit Beacon Signals periodically when they are not in use. Subscriber units compare signal strength of the

received Beacon Signals from each site for judging the best signal site. Best signal site is then selected as a TX revert channel.

Figure 6-4 Beacon Signal


System Scale & Upgrade Case Study

7 System Scale & Upgrade Case Study

7.1 USB Key and Activation File

A NEXEDGE trunked system requires a USB key to gain access to the system for configuration. Each USB key is given a

unique system code to identify a specific system. When a customer purchases a system, Kenwood provides a USB key

together with an Activation File that includes all the system parameters given for the system based on the purchasing record.

The System Manager software KPG-110SM, cannot be started without proper USB key in order to prevent unauthorized

accesses. Upon a customer request for the system upgrade, Kenwood will provide a new Activation File that includes updated

system parameters. With the Activation File, the customer can reconfigure his system using his USB key to gain access the

system.

Distribution flow is shown below.

Figure 7-1 USB Key and Activation File distribution flow

7.1.1 System Size

Network Category

NXDN common air interface stipulates system size, in other words maximum number of sites in the system as “Network

Category”. Local network category can handle up to 30 sites and is suitable for small to medium size systems in general.

For the system that has over 30 sites, “Regional” Network Category System Code must be used.

With a system code in the “Regional” category, NEXEDGE provides up to 48 sites system capability.


System Scale & Upgrade Case Study Intersite Call Table

Intersite Call Table in the GID Class of Service setting defines sites where Intersite Group Call service is available for the

GID. Call capable sites depends on the network type (Unicast or Multicast) and USB key network category (Regional or

Local).

7.1.2 Home Site ID Planning

Home Site ID Planning

In NEXEDGE trunked system, ID information of fleets (i.e. subscribers) is registered in the repeater units where the ID

defines as Home Site. Due to the memory size limitation and from site down risk management perspective, it is

recommended to disperse the ID storage for large-scale systems.

With expanded maximum number of sites, Home Site (Fleet Information Storage) should be planned carefully.

Figure 7-2 NEXEDGE trunked system example

ID Information Storage

ID information of a fleet is stored in the non-volatile memory of the repeaters which are configured as the Home Site.

A site where a fleet most likely roams in should be configured as the Home Site.

Note: maximum number of fleets does NOT depend on the number of channels of the site.

Figure 7-3 Fleet setting by the KPG-110SM

Network Type Network Category Maximum System Capacity Number of Intersite Group Call Capable Sites

Local 30 16 Unicast

Regional 48 16

Local 30 30 Multicast

Regional 48 48

Table 7-1 Intersite Call table


System Scale & Upgrade Case Study System Scale

With the system size expansion in the new launch firmware, KPG-110SM requires to define maximum number of home

sites, fleet range and ID range for initial system design and new smx file creation. Table below shows default numbers that

are changed by the System Scale configured in the Plan Initialize window.

Figure 7-4 System Scale setting by the KPG-110SM

*1 Large is only available with Regional Category System Code

7.1.3 Single-site Installation

A single-site installation with 5 channels:

A USB key together with an Activation file needed

Kenwood to provide a USB Key

Customer to configure a Single-site (Site #1) with KPG-110SM

Figure 7-5 Single site installation

Table 7-2 Default Numbers of IDs System Scale Home Site Range Fleet/ Site GID/ Site UID/ Site

Standard 1 to 16 300 3000 3000

Intermediate 1 to 30 150 1500 1500

Large*1 1 to 48 100 1000 1000



7.1.4 Channel adding to a Single-site system

Adding a repeater (channel) to existing 5ch Single-site:

Customer to request channel adding from 5 to 6

New Activation File with updated info will be provided by Kenwood

No USB Key update needed

Customer to additionally configure the added repeater, applying IP address then Site Info > Site Edit > to add the 6th

channel

Figure 7-6 Channel adding to a single-site system

7.1.5 Removing a Repeater for Repair

Removing of a channel from operating 5ch Single-site for repair:

This is a case that a repeater malfunctions and needs to be fixed but the system has to keep its operation.

Failed repeater can simply be removed from the system

No USB key or Activation File needed

No System Manager configuration change needed

In case the failed repeater is unable to be fixed and need a replacement unit that has a different ESN, an updated

Activation File with the newly replaced repeater’s ESN is required.

Figure 7-7 Removing a repeater for repair

Note: Spare Repeater: Spare repeaters may be needed for large systems. The activation file system cross-checks ESNs for every single

repeaters. Spare repeaters need to be pre-registered in the Activation File in advance. Spare repeaters cannot be commonly registered in

among different systems.



7.1.6 Multi-site System Installation

Installing a two sites multi-site from scratch:

This is a case that a multi-site consists of two sites is installed from scratch. Each site requires site monitoring with site equipped

PC

A USB key and an activation file needed

A USB key is for setting both sites

Figure 7-8 Multi-site system installation

7.1.7 Channel Adding to a Multi-site System

Adding 2 more channels to an in-service multi-site system:

This is a case that the user wants to add 2 channels to one of the site in the multi-site system that is currently under operation.

Customer to request channel adding from 8 to 10

New Activation File with updated info to be provided by Kenwood

No USB Key update needed

Customer to additionally configure the added repeater, applying the IP address then Site Info > Site Edit > to add the

channels



Figure 7-9 Channel adding to a multi-site system

7.1.8 Site adding to a Multi-site system

Adding a site to an in-service multi-site system:

This is an expansion case in the multi-site system. Another 5-channel site is added in this scenario.

Customer to request Kenwood dealer to upgrade a site to existing system

USB key need not to be returned to Kenwood

Kenwood to provide new Activation File to upgrade the system

User to configure the Site C information with KPG-110SM

Existing subscriber units roaming into site C need FPU data reconfiguration

Figure 7-10 Site adding to a multi-site system



7.1.9 Non-linked site added to a Multi-site-system

Non-linked site in the Multi-site System:

This case can happen in the process of adding site or when a site loses the network connection for failure.

Site C can operate as a stand alone Single-site

Note: Site C can operate as a single-site (non-network-linked). It is recommended to verify single site operation before linking with other sites so

that any Site C related problems will not affect other users in operation.

Figure 7-11 Non-linked site added to a multi-site system


System Monitor Function

8 System Monitor Function

8.1 System Monitoring Capability in NEXEDGE

NEXEDGE Trunking system provides various System Monitoring functions for system operators to see system health condition.

System Overview

Channel State

Channel Load

Communication Log

Statistics - Airtime Accumulation

System Log

Diagnostic Log

8.2 System Overview

System Overview is a function to see real time channel status of repeaters that are available in each site. Repeater’s IP address

and its operating status are shown in the list. By pressing “Hardware” or “Network”, further information will be indicated as

following.

Figure 8-1 System Overview



8.2.1 System Overview - Network

Network related information can be displayed in this window. LAN connecting status is indicated on the right top by 3 color

indicator.

Figure 8-2 System Overview - Network

Table 8-1 Status Indicator

8.2.2 System Overview - Hardware

Hardware related information can be displayed in this window. Parameters are shown in 8 bit (256 levels) value except for

temperatures. These figures are raw data for internal circuitries and nominal values depend on repeater individual variability or

configurations. Therefore, Kenwood is not able to guaranty nominal range, hence use this function to detect failure in

comparison to normal condition under customer’s responsibility.

Figure 8-3 System Overview – Hardware

Not Connected

Standby

In Data Transmission



8.3 Channel State

Live call status can be monitored in the Channel State window. Caller ID, Called ID, Call Type (Broadcast/ Conference/

Individual/ Interconnect) and Call Status (Control/ Traffic/ Composite/ Idle/ Failure) are displayed with call duration by channel in

a site.

Figure 8-4 Channel State

8.4 Channel Load

The Channel Load graph shows usage rate of a channel for the last 10 minutes. The usage rate is calculated based on data for

the last 24 hours and will be updated every 10 minutes. Since the system always retains data for the last 24 hours, a dispatcher

can monitor the usage status for the 24-hour period prior to the time when the dispatcher started monitoring. This data is not

stored in the repeater memory.

Vertical Axis:

Vertical axis indicates the usage rate. The upper limit is automatically changed based on the maximum usage rate.

Horizontal Axis:

Horizontal axis indicates the time. The current time appears in the rightmost position.

Figure 8-5 Channel Load



8.5 Communication Log

Communication Log is a communication record of all the call events occurred in a site. Following information is recorded in the

log file.

・ Record Type:

Voice Call/ Short Data Call/ Long Data Call

・ Call Type:

Individual/ Broadcast/ Conference

・ Emergency:

Emergency/ Normal

・ Caller ID, Receiver ID

・ Call Duration, Date

・ Cause of the termination

・ Call Direction:

Intra (Closed in a site)/ src (Outgoing)/ dst (Incoming call with site #)

・ Channel Number

Figure 8-6 Communication Log



8.5.1 Communication Log - Extract

Communication Log is stored in a repeater memory (or CF card if installed) in each site. Log data can be saved as a CSV file by

“Extract” function, not only just viewing on the monitor display. Moreover, extracted data file can be used for statistic call record

analysis that is mentioned in the next section Statistics.

Figure 8-7 Communication Log - Extract

Note: Please contact your Kenwood dealer about Compact Flash Card available with NEXDGE system operation.



8.6 Statistics - Airtime Accumulation

By Airtime Accumulation, the Communication Log file extracted in the previous section is statistically analyzed and displayed.

Time-oriented Communication can be converted into ID based call time accumulation data by this feature.

Converted Airtime Accumulation data can be saved as a CSV file.

Figure 8-8 Statistics - Airtime Accumulation

8.7 System Log - System, Hardware

System Log is a Trunking system operation recording feature for system failure analysis. System operation activities such as

error termination, system update and so on are recorded in a log file. There are Network Log and Hardware Log recoded

individually. With these logs forwarded to Kenwood technical personnel, failure analysis support will be available.

Figure 8-9 System Log - System, Hardware



8.8 Diagnostic Log

Diagnostic Log can record further detailed system activity, than the System Log explained in the earlier section. In case of

unforeseen system trouble that System Log cannot detect the cause, by sending this Diagnostic Log to Kenwood technical

personnel trouble shooting support will be available. Note Diagnostic Log is not designed for field engineers to analyze the

failure, but for Kenwood design centre therefore it is unreadable by the application software.

Figure 8-10 Diagnostic Log


Vocoder and Digital Technology

9 Vocoder and Digital Technology

9.1 Vocoder

Voice Coding means to convert voice audio signal into digital signal and then eliminate the unnecessary information for

transferring and recording or convert it into an efficient format. They can be categorized into two types below.

(1) Waveform coding

This coding method minimizes the distortion between the source audio signal and the coded audio signal. The higher the bit

rate, the better the audio quality. When the bit rate is not sufficient, audio quality drops exponentially. It is a low compression

but has better audio loopback delay and low cost performance on the other hand. As examples, there are MBE (Multi-Band

Excitation), LSP (Line Spectrum Pair), PARCCR (PARtial auto-CORrelation), WI (Waveform Interpolation), MELP (Mixed

Excitation Linear Prediction) coding methods.

(2) Vocoder (Analysis-by-Synthesis Coding)

The vocoder extracts audio signal parameters as synthetic wave models by analyzing the digitalized voice audio signal at

coding stage and based on the parameters, it synthesizes the voice audio signal at the decoding stage. As the vocoder only

transfers the extracted analyzed parameters and not aims to precisely reproduce the source signal, it can drastically reduce

the bit rate as a result. However, on the other hand, the audio quality depends on the synthetic wave modeling and even with

the higher bit rate it cannot help improve the audio quality in general. As vocoder examples, there are MBE(Multi-Band

Excitation), LSP(Line Spectrum Pair), PARCCR (PARtial auto-CORrelation), WI (Waveform Interpolation), MELP (Mixed

Excitation Linear Prediction).

In addition, hybrid coding can be introduced. This coding method also models the source audio’s signal elements and by

A-b-S process (Analysis-by-Synthesis), it transfers both audio element parameters and the rest of information which cannot

be modeled in parameters by minimizing the distortion from the source waveform. For instance, CELP (Code Excited Linear

Prediction coding), VSELP (Vector Sum Excited Linear Prediction), PSI-CELP (Pitch Synchronous Innovation Code Excited

Linear Prediction) are categorized as hybrid vocoders. Since the hybrid coding also models the source audio signal, it can be

considered one of the Vocoder coding. Thus the AMBE+2TM can be placed in the Vocoder category.

Figure 9-1 Typical signal processing image of Waveform Coder and Vocoder



As mentioned above, a vocoder is a voice audio data compressor which leverages human acoustic characteristic. As it extracts

to send characteristic voice formants from the source audio, it can drastically reduce the data quantity as compared to the

waveform coding types. However, due to artificial voice generators being used in the decoder stage, the output audio could

sound like robot speech (computer operated auto answering machine for example). Although the vocoder technologies have

improved the audio quality in these years, it is still noticeably different to that of analog.

However, Digital processing merits against Analog need to be mentioned here again. The biggest benefit of digital processing is

the “Narrow Band Transmission”. It can robustly convey the message with minimal data quantity. Thus, NXDN’s AMBE+2TM

vocoder attains 6.25 kHz band width communication which is only half band width of conventional analog 12.5 kHz technologies.

Moreover, Vocoder equipped error correction processing contributes to better voice clarity and keeps high quality

communication under the extreme noise environment or fading propagation where the radio works with in its sensitivity limit.

In a sense, vocoder technologies for wireless telecommunication prioritize securely conveying key elements of the source audio

sacrificing the fidelity in the interfered condition where errors occur.

9.2 Cyclic Tone Response

As no cyclic tone exists in human voice, the vocoder eliminates those tone elements processing as noise.

Therefore;

・ Buzzer, Siren, alarm or whistle may not sound as-is at the receiver

・ Telephone modems or data modems that use audible tone signal cannot be connected to Digital Radio

・ Single tone (Sine-wave) sweeping method cannot be used for audio response measurement

9.3 Contributions of Digital Technology

What End-Users can Experience with Digital Radio:

Consistent performance throughout coverage area with no gradual fade at fringes?

・ Sound Clarity

・ Background Noise Reduction

What End-Users can NOT Experience with Digital Radio:

Hi-fi Audio like “CD Quality” → Focusing on “Clarity”

Solving historic RF problems (interference issues) → Digital cannot resolve RF issues



9.4 Audio Issues Case Study

9.4.1 Background Noise Suppression

One of the AMBE+2TM vocoder’s strong points is noise suppression that emphasizes the speaker’s voice eliminating

background noise. In this process the vocoder gives the noise signal some digital processing to reduce sensory noise level.

When the user speaks off from the mic, his/ her voice could possibly be affected by the noise suppression as the vocoder may

not clearly identify target voice. His/ her voice may sound tinny or unusual at the receiver unit.

Figure 9-2 Conceptual image of high-noise environment audio interference

In extremely noisy environments your voice may be interfered by background noise. In this case, think of accessories such as

Headset type microphone or Speaker Microphone with Noise Canceller to improve audio intelligibility.

9.4.2 High Sensitivity Microphone

In the small dispatch center room with monitoring receiver to confirm that dispatch call is properly transmitted, a desktop

microphone that has high microphone sensitivity can easily pickup own voice from the receiver with greater delay (as compared

with analog).

Figure 9-3 Conceptual image of high-sensitivity microphone issue

In this case, nearby dispatchers’ voice, PC Keyboard typing noise or monitoring audio from a receiver could degrade

communication intelligibility. For better intelligibility, appropriate audio accessories such as headset microphone, directional

microphone or telephone receiver type microphone should be considered.



9.4.3 Intelligibility and Signal Level

While ordinal Analog in the coverage fringe area (weak signal) gets disturbed by receiver noise (White Noise) gradually as

distance increases, Digital receivers do not have such gradual noise. However, a Digital receiver in such low signal fringe area

can no longer provide intelligible audio as the received digital data should be error corrected due to propagation loss therefore

original audio quality is degraded. This is true for all digital radio systems.

At the system coverage design, make sure that sufficient RF signal level is presented for entire system coverage.

Figure 9-4 Difference between Digital and Analog in the coverage fringe

Figure 9-5 Error correction working hard in the weak signal field



9.4.4 Antenna and Signal Level

Some antennas have strong directional and polarization characteristic. For instance, when the antenna is installed on the top of

a tall building or tower, RF level right underneath the antenna could be very poor (especially in the closed indoor environment).

Make sure that sufficient RF signal is presented when you experience audio intelligibility issue.

Figure 9-6 Antenna directional characteristics to be considered

9.4.5 Uplink and Downlink Signals

RF signal level must be confirmed for both, uplink and downlink for a repeater system. You cannot judge the entire receiving

condition by just checking the downlink RSSI only. Cellular phones have advanced roaming protocol and sufficient numbers of

base stations so hardly experience audio degradation caused by weak RF signal.

Figure 9-7 Different signal level on uplink and downlink



9.4.6 Appropriate root cause analysis

When experiencing sound degradation with sufficient RF signal…

→ Background Noise at Transmitter can be suspected

When experiencing occasional sound degradation…

→Vocoder starts its bit error correction. Signal may get weak or interfered.

When experiencing sound degradation with receiving interruption…

→ Receiver could be in the coverage fringe area where analog cannot be used.

RF field strength can vary significantly depending on the position of the person and the way the radio is held. In case of

insufficient field strength or operation in the RF fringe coverage area, communication can drop out suddenly in digital mode,

compared to analogue mode where the signal degradation happens more gradually.

If the user experiences problems with communication in certain areas of the expected coverage area, consider the installation of

additional sites, or fill-in sites.

9.4.7 System Design Reference

Unlike analog, it is not possible to identify that you are in the coverage fringe area by receiver noise. For system coverage

optimization RF Signal Level validation is a must.

Figure 9-8 Extended coverage by NXDN Digital system

For critical communication system, “Clear Voice Coverage” should be used for the Radio Site design.

9.4.8 To Improve Audio Intelligibility

Several practices are recommended to improve audio intelligibility with digital transceiver.

(a) Propose appropriate accessory use for the system under high-noise environment. Some headset type or throat-mic

accessories with its microphone near to the mouth are well designed for noisy environment. When selected appropriately

considering end-user’s operation style, it can dramatically improve intelligibility.

(b) Place the microphone element 0.5 to 2 inches, about 2cm to 5cm, (depending on the application) from your mouth. Adjust

the elements so that your voice can directly input. It is very important for audio intelligibility.



Figure 9-9 Recommended talk positions

(c) Advice end-users to speak with consciously clear, loud and controlled voice. This kind of simple practice can greatly improve

the audio intelligibility.

(d) Remove the noise source as far as possible.

Figure 9-10 Environment noise

(e) Constant frequency elements such as warning tones or alarms may harm audio intelligibility in digital two-way radios.

Placing a microphone away from the alarm source or covering it with free hand can improve audio intelligibility dramatically.

Figure 9-11 Constant frequency



9.5 NEXEDGE Audio Features

NEXEDGE incorporates a variety of configurable audio features, which help to customise the audio response for increased

customer satisfaction.

9.5.1 Constant RX audio level

Incoming radio transmissions from different radio users may have different volume levels depending on the radio user’s voice

level. This might be uncomfortable to listen to in case of the receiver listening through a headset or ear phone. RX AGC feature

reduces the difference of TX audio level. The voice level can be selected from High or Low and that is adjusted automatically

according to the setting of RX AGC.

9.5.2 Constant TX audio level

Transmitted audio level changes with the distance of the speaker to the microphone. The TX AGC feature corrects this

differential, adjusting the gain of the voice dynamically and makes the TX voice level almost the constant.

9.5.3 Tune RX audio response to match the received audio environment

The RX Audio Equalizer mode is selected from the three available modes, which are High Boost / Flat / Low Boost.

In case of usage in a noisy environment, High Boost for the RX Audio Equalizer might clear the receiving audio sufficiently. On

the other hand, in case of usage in quieter environments, High Boost audio might not be suitable, select Low Boost.

9.5.4 Tune TX audio response to match the transmit environment

The TX Audio Equalizer effects noise reduction and helps clearing the voice, too.

It is possible to adjust the transmission voice from the three modes, which are High Boost/ Flat/ Low Boost.

9.5.5 External microphones adjustment

Different external microphones have various TX audio responses due to their chassis and element parts. Selecting the proper

microphone type corrects TX audio difference and reduces RX audio sound difference.

9.5.6 RX Audio Low Cut

While analog FM mode has to eliminate audio elements below 300 Hz for modulation limiting, NEXEDGE digital mode originally

contains these audio frequencies that provides end-users powerful and clear sound as a result. However, in some cases such

with an in-ear headset or operation in a noisy environment, low frequency range could be too much emphasized. NEXEDGE

uses an Audio Low Cut Filter to alleviate this issue.

9.5.7 Noise Suppressor

Noise Suppressor is a FPU configurable function that reduces background noise on transmit audio in NXDN digital mode.

In case of high-noise environment, with Noise Suppressor enabled, background noise can actually be suppressed at

transmitting radio and receiving radio can experience clear voice with reduced noise. However, due to high level noise voice

elements may be suppressed together with noise and received audio may be warbled or degraded in intelligibility.

In this case, by disabling the Noise Suppressor, received audio naturalness can be improved with analog resembled audio

feeling. (Note that background noise is audible in this case due to no background reduction)

Note:

Noise Suppressor reduces noise at transmitting radio. Therefore, Noise Suppressor (Enable/ Disable) does not do anything for received

audio noise.

Noise Suppressor effect may not be experienced in the quiet environment.

Noise Suppressor is only valid for NXDN digital mode. No difference is made for Analog mode by switching it (Enable/ Disable).



9.5.8 Vocoder Update Information

It supports the latest AMBE+2TM Vocoder version (Version 1.6.0).

Therefore, the performance for high frequency background noise (electronic equipment alarm, etc.) is improved.

Additionally, the NXR-710/NXR-810 is supported from the first version.


NEXEDGE Radio System Applications

10 NEXEDGE Radio System Applications

The NEXEDGE Radio System has a number of applications available such as RF Link and Image AVL & Dispatch Software

shown below.

This section will review other applications, which are currently available and could be used to enhance the Kenwood NEXEDGE

system offering and add additional value.

RF Link

AVL & Dispatch Software

Wireless Image System

Over -the- Air Programming

Telephone Interconnect Adapter

Alarm Enunciator

10.1 RF Link

Kenwood's Digital Conventional repeater can be used to construct an IP linked Conventional Network System without the

physical IP-network.

When the RF Link mode is set configured in the repeater, the signal received by RF is transmitted only to the network and the

signal received from the network is transmitted by RF.

Note:

・ NXR-700(H)/ NXR-800(H)/ NXR-900, NXR-710/ NXR-810 supports the RF Link mode.

・ NXR-700(H)/ NXR-800(H)/ NXR-900, NXR-710/ NXR-810 can use coexistence on the IP-network.

・ NXR-710/ NXR-810 needs KTI-3 to be connected to the IP-network.

Figure 10-1 RF Link



10.2 Simple dispatching solution-Kenwood KAS-10 AVL &

Dispatch Software

Kenwood’s KAS-10 AVL & Dispatch software allows for easy and simple integration with the Kenwood NEXEDGE transceivers.

The new version 2 has been improved and is now able to connect via IP Network to a NEXEDGE trunked radio system.

10.2.1 Main features and functions

999 Mobile ID Capacity

FleetSync or NEXEDGE Messaging & AVL

Analog Conventional, LTR and 5-Tone Operation

NEXEDGE Conventional/ Trunked/ Trunked IP Network Operation

MDI (Multiple Document Interface) window

Imported JPEG, BMP, GIF, EMF or WMF Image Maps

Digital Voice Systems, Inc USB-3000™ AMBE+2™ Vocoder for IP Network Operation (purchase separately)

Enhance Long Data Message

All mobile icon clear from Map

Microsoft Windows XP/ Vista/ 7 (32/64 bit) operating system

Microsoft MapPoint 2006 / 2009 / 2010 Software (purchase separately) or Imported Maps

Note: Contact and confirm your regional Kenwood sales representatives about adaptation of MapPoint version.

Figure 10-2 KAS-10 System Overview image

Note: USB-3000™ requires 64 bit USB drivers while used with Windows-64 bit operating systems. Refer to DVSI homepage for more detailed

and latest information.



10.3 Wireless Image System

This system can be used to transfer an image captured by a camera in a monitor station to a base station via a NEXEDGE

digital communications system (Conventional & Trunking).

In this system, the NX-700, NX-800 and NX-900 are employed for transmitting and receiving data, such as an image and

various messages.

10.3.1 Components

This innovative system consists of a monitor station and a base station, linked via NEXEDGE digital transceivers with

Transparent Data Transmission feature. Still images are transmitted from the monitor station to the base station computer,

which serves as the control center. Several monitor stations can be monitored simultaneously.

Monitor station consists of a surveillance camera, KVT-11 Image Encoder and NX-700/ 800/ 900.

Base station consists of a computer running the KAS-11 Image Viewer software and NX-700/ 800/ 900.

Figure 10-3 Wireless Image System

Note: The following JVC surveillance cameras are recommended for use with this system.

Figure 10-4 JVC Surveillance Cameras




An image can be transferred by selecting 1 monitor station from multiple monitor stations (cameras) by operation of a base

station and can be displayed on a PC with KAS-11 Image Viewer installed at a base station.

An image can automatically be transferred from multiple monitor stations (cameras) at a certain time interval and can be

displayed on a PC with KAS-11 Image Viewer installed at a base station.

The image size can be selected from 160×120 (pixels), 320×240 (pixels) and 640×480 (pixels).

Quality (image quality) and Display Format (Display method) of an image to be transferred from a monitor station (camera)

can be configured.

If images have been stored in KVT-11 Image Encoder, an image that is transferred previously can be transferred again by

increasing the image quality of the image.

The KVT-11 applies MPEG-4 AVC / H.264 video compression to the images from the camera. This ensures twice the

compression possible using JPEG and with less video noise.

A transferred image can be stored in either BMP or JPEG file format in a PC of a base station.

10.3.3 Transfer Time of Image Data

Table 10-1 Transfer Time of Image Data

Image transfer time (sec.) Image Quality Narrow (12.5kHz) Very narrow (6.25kHz)

Premium 46 95

Super Fine 32 59

Very Fine 20 35

Fine 12 20

Standard 9 13

Note: Transfer time will vary depending on the selected image quality and NEXEDGE system configuration. Transfer times are approximate.



10.4 Over the Air Programming

The OTAP Manager software (KPG-150AP) provides Over-the-Air Programming capabilities. Over-the-Air Programming allows

wireless Programming for NEXEDGE digital subscriber unit data. Normally radios have to be programmed modification data by

FPU (Field Programming Unit) through a programming cable. The use of the OTAP Manager does not require the user to

collect radios to modify or update radio setting anymore. This function can give our customers more easy radio management

and cost efficiency.


FPU Data Management

・ Multi-system Capable

・ Can manage all NEXEDGE subscribers data

・ User-friendly simplified icons

・ Easy Programming

Efficient Data Control

・ Efficient Data Transfer

・ Single Data File for Large Fleets

Over-the-Air Management

・ Un-manned Sessions

・ Fail Safe OTAP Process

・ OTAP Session Logging

Figure 10-5 Over the Air Programming

Note: The OTAP Manager can manage 1 system and 10 Units as default. Order more licenses from Kenwood to manage more radios. The

OTAP Manager can handle up to 16 systems and up to 100,000 units.



10.5 The Telephone Interconnect Adapter

The Interconnect Adapter (KTI-4) connected to a NEXEDGE Trunked System converts analog telephone voice into digital and

enables communication between a telephone and a radio. It connects to PABX/PSTN through the analog telephone patch

equipment like Zetron Model 30 (for export market only) or Model 735.

Figure 10-6 KTI-4 Telephone Interconnect Adapter


Up to 6 KTI-4 Lines per Trunked Site

Up to 100 KTI-4 Lines per Trunked Network

KTI-4 can connect through IP, best location for PABX/PSTN can be used

Speed Dial:

・ Limit Calls to Specific Phone Numbers / PABX Extensions

・ 255 Numbers Max. (32 digits per number)

Call Restrictions Settings:

・ Permit / Inhibit Toll, Long Distance and International Dialing

・ Permit / Inhibit Pay Per Call Services

Barring specify numbers

Digit range limitation (Minimum / Maximum)

Browser based programming for KTI-4

Firmware of KTI-4 update through IP network

Figure 10-7 Telephone Interconnect

Note: Must use Zetron Model 30 Revision 1.03 or later for KTI-4 use.



10.6 Alarm enunciator – NX-700/ NX-800/ NX-900 and Zetron M1570

SentriData

The SentriData is designed to connect to monitoring equipment that outputs an ASCII text stream, usually through the

equipment’s logging printer port. When the SentriData detects a preselected string, it alerts a prioritized list of contacts.

An alert may be a telephone call using pre-recorded messages, a private transceiver call, or a page.

The SentriData also has 8 digital I/O points that are individually configured as inputs or outputs, plus an analog input and a relay

output. Users can remotely control the SentriData outputs and poll the status of the alarms and I/O points.

The SentriData has three functional options:

Real-Time Clock and Printer Port support alerting based on day and time, receiving data from a device’s parallel printer

port, and sending data from the SentriData to a printer. The data going to the printer port is buffered in both software and

hardware. The parallel port is also unidirectional.

Radio Paging provides 2-tone, POCSAG, and 5 or 6-tone paging for analog systems.

Voice Memory supports voice (audio) messaging and is available for 60 minutes.

Figure 10-8 NEXEDGE/M1570 Connection overview

1) Portable radio sends status message to mobile radio, or external input triggers action.

2) Mobile radio decodes status message and sends out RS232 data string via its data port.

For example: “12345”

Note: Set "COM port" for [Data] and "Status Message Serial Output" for [Enable] by KPG-111D.

3) M1570 decodes the data string “12345” and converts it into an alarm action. These actions could be one or any of the

following:

• Play Voice message via M1570 radio/audio port to via analog radio or to PA system.

• Dial telephone and play voice message.

• Dial POCSAG paging system and send POCSAG message.


NEXEDGE Radio System Applications Potential applications:

Alarm and status monitoring.

The M1570’s radio port can be connected to a PA (Public Address) system, thus by sending a status message via the

radio system, an announcement can be triggered. Such announcements could be evacuation messages, general

announcement messages etc.

Machinery Monitoring

Machines or devices providing external digital outputs.

Radio System monitoring

Digital outputs from the radio system repeaters, air conditioning system or power supply can be connected to the M1570,

which in turn can raise an alarm in case of any equipment failure. The digital outputs can be activated from the incoming

phone line via DTMF.


FAQ – Frequently Asked Questions

11 FAQ - Frequently Asked Questions

///Question 1 .. How will a digital radio react when it is used in a crowded environment, where lots of radio signals are present that might interfere with the digital communications?

////Answer 1 … Kenwood NEXEDGE digital radio system based on the NXDN protocol in FDMA is very robust and resilient.

If the NXDN's enhanced error correction can recover a received signal, then the user will not be aware of the

radio receiving an interfered signal. Increasing the interference signal level will cause the receiver to lose the

natural voice characteristics. If the interference signal is beyond the NXDN's enhanced error correction

recovery capability, the radio will stop emitting the audio signal.

//Question 2 . Can Kenwood NEXEDGE radios when used in “peer to peer” mode be mixed with IDAS

transceivers manufactured by ICOM?

///Answer 2 … Yes, basic interoperability has been confirmed.

///Question 3 How will we do on- site measurements when operating 6.25 kHz digital communications, do we

need specific test-equipment?

////Answer 3… No specific test equipment is required, since tests can be conducted in standard 12.5 kHz channel spacing.

However, the frequency stability of KXK-3 OCXO Unit is +/-0.15 ppm, having the 2-year aging characteristic

of +/-0.25 ppm. To keep the characteristic of 0.5 ppm in UHF, maintenance is needed every two years. Also,

a high-accuracy reference oscillator and frequency counter which can measure from 10 to 1 Hz are needed

for adjustment of OCXO.

///Question 4 . Is the repeater NXR-700/ NXR-800 E-type (for European market) 25W continuous duty?

////Answer 4 … Yes, the Kenwood NEXEDGE NXR-700 and NXR-800 E-type repeaters are continuous duty rated for 25W.

///Question 5 . Can we connect multiple repeaters using the IP-network? Idea is to create some kind of simulcast

system.

////Answer 5 Yes, Kenwood NEXEDGE system repeaters can be connected via IP. However, it will not be able to work as

a simulcast system as this requires additional synchronisation between the repeater sites. As long as

non-overlapping frequencies are used, the system will work fine. Additional IP switching equipment may be

required.

///Question 6 Do we need to align the front-end of the NXR-700 or NXR-800 receiver to the desired frequency?

////Answer 6… Yes, the NXR-700 or NXR-800 requires alignment of the front-end filter. VHF switching bandwidth is 3 MHz,

UHF switching bandwidth is 5 MHz. This ensures best RF performance.

///Question 7 Does NXR-700 or NXR-800 repeater generate alarms in case of VCO unlock, power down, etc …

////Answer 7… Yes, the NXR-700 or NXR-800 auxiliary outputs can be programmed as alarm outputs. See below for the

currently supported alarm conditions:

• Receive Unlock

PF (Receive Unlock) output port will be activated if the reception PLL circuitry becomes unlocked.

• Transmit Unlock

PF (Transmit Unlock) output port will be activated if the transmission PLL circuit is unlocked. The Busy LED

will flash while the transmission PLL circuit is unlocked.


FAQ – Frequently Asked Questions ///Question 8. .. Do the NXR-700 and NXR-800 communicate these types of alarms over the IP connection?

////Answer 8… No, this feature is currently not supported. The KPG-110SM software can be used to monitor NXR

hardware.

///Question 9 ... Is there a dispatcher application that can be connected to the NXR-700 and NXR-800 IP interface?

////Answer 9… Yes, this is supported. The KAS-10 Version 2 is able to connect via IP Network to a NEXEDGE trunked

radio system.

///Question 10 Can Kenwood assist in pre-calculation of Intermodulation risks in case of multiple frequency sites?

////Answer 10 This is a service most suppliers of RF combining equipment offer. Currently Kenwood has no plans of

offering such a service.

///Question 11 When using the trunked radio system, do we have the possibility to perform remote monitoring

functions on the performance and statistics of the running system? Some kind of ‘dial in facility’

would be appreciated.

////Answer 11 Yes, the Kenwood NEXEDGE KPG-110SM software offers these features.

///Question 12 When sharing NXDN voice channels with MPT1327 voice channels, can we keep on using CTCSS

tones in the MPT1327 channels?

////Answer 12 KPG-109D can be used to configure the sharing channel as either “shared” or” AUX”. Both operating modes

apply CTCSS signaling for built-in decoder and encoder, if required.

///Question 13 In a multi-site trunked system, where do we keep the user data-base?

////Answer 13 Currently, the database is kept in Home site. The Home site is selected during Fleet programming in the

KPG-110SM programming software. Future plans may involve a database server instead of the current

system. In addition, site configuration data file called “smx” is the system configuration itself and is stored on

the PC where the KPG-110SM is installed.

///Question 14 Do we have to use a high stability clock for the 6.25kHz operation?

////Answer 14 FCC Part 90 specifies that 6.25kHz channel step operated UHF base station’s frequency stability must be

within +/-0.5ppm. If your country mandates the same for 6.25kHz operation, please use the optional KXK- 3

OCXO. However, as long as your system works on 12.5kHz channel step KXK-3 is not required even in

6.25kHz very narrow mode.

Regardless of your county mandates and VHF/ UHF, the optional KXK-3 must be used if the system works

on 6.25kHz trunking operation.

///Question 15 Is it possible to make a back-up file of the entire system (containing all hardware and user data)?

////Answer 15 KPG-110SM data file contains the system configuration. KPG-109D data file contains the frequency

configuration. The customer must save both files for complete system back-up.

///Question 16 In case of adding new users ID to the trunked system, does the system need to do a reboot? And

how long will it take before the new ID’s can work on the system?

////Answer 16 See section 4.5. Expected Downtime Accompanied with System Programming.


FAQ – Frequently Asked Questions ///Question 17 Can we have multiple USB-keys, to be used in combination with KPG110SM, for the same system?

For example with 24/7 maintenance contracts that involve more engineers that need to have access

to the system at all times.

////Answer 17 Yes, if a customer needs a second USB-key, then contact your local Kenwood office for further information.

///Question 18 When interconnecting trunking sites, we have to respect a maximum latency of the network? What

is the maximum latency possible?

////Answer 18 The maximum latency and Jitter is listed below.

Packet Delay: Less than 500 ms

Packet Jitter: Less than 100 ms

///Question 19 Does the Kenwood NEXEDGE system use UDP or TCP packages to transport the voice data over

the IP-network?

////Answer 19 The Kenwood NEXEDGE system is using TCP and UDP protocol for the IP connection.


Appendix A - IP - Some Background Info

Appendix A - IP - Some Background Info

A.1 Network and Ethernet Technologies

Generally speaking, communication networks can be divided into two basic types: circuit-switched (or connection-oriented)

and packet-switched (or connectionless). The telephone system is an example of a circuit-switched network.

When you make a phone call, a dedicated connection (or circuit) is established between you and the person you called.

The circuit capacity and the quality of service are guaranteed throughout the entire call. The main advantage of

circuit-switching is guaranteed capacity; once a connection is established, the capacity of a circuit is guaranteed. One of the

disadvantages of circuit switching is the cost structure; cost is fixed based on connection, independent of usage.

On the other hand, packet-switched networks are connectionless. In a packet-switched network, data to be transferred

across the network is divided into small pieces called packets. A packet carries special information in the header that

enables the network hardware to know how to send it to the specified destination. Because network resources are only

required when there is data to send, the same network resource can be shared by many communications concurrently.

This leads to more efficient bandwidth usage and therefore lower cost per communication.

Because network resources are shared, the network could become overloaded, causing longer delay and packet drops.

This is the main disadvantage of packet-switching; network capacity is not guaranteed.

The Internet is an example of a packet-switched network. It was originally designed to transport data only. However, due to

recent advances in network technology, real-time audio and video streaming over the Internet has become very common.

Packet-switched networks can be loosely divided into two broad types based on geographical distance:

Local area network (LAN) and wide area network (WAN). A LAN covers a small geographical area such as a home, a single

building, a group of buildings, or a small campus. Most LANs connect personal computers (PCs) and servers.

Because the distance is short, a LAN can operate at a very high speed with a short delay.

A WAN covers a relatively broad geographical area such as a city, a state, or even a country. WANs are used to connect

LANs together over long distances. Compared to LANs, WANs operate at slower speeds and have much longer delays.

A.2 Ethernet Technology

Ethernet is the most popular technology for interconnecting LAN devices. Standardized as IEEE 802.3, it defines a number

of wiring and signaling standards at the physical layer, the means of network access at the data link layer, and a common

addressing format. Ethernet devices can operate over different types of medium such as twisted-pair cable, coaxial cable,

and fibre optics.

The three commonly used data rates for operation over twisted-pairs cables are:

・ 10 Mbps (Mega-bit per seccond): defined in 10BASE-T standard

・ 100 Mbps: defined in 100BASE-TX standard under Fast Ethernet

・ 1000 Mbps: defined in 1000BASE-T standard under Gigabit Ethernet

Each Ethernet device (or transceiver) is assigned a unique 48-bit address known as its Ethernet address or Media Access

Control (MAC) address. The address is usually written in hexadecimal form, for example, 00A0C9357F1D. Ethernet

addresses are managed by the IEEE. Companies that manufacture Ethernet devices must purchase blocks of Ethernet

addresses and assign them in sequence to their Ethernet devices. An Ethernet address is permanently bound to the

hardware device and should not be changed by software. In addition to the unique addresses assigned to Ethernet devices,

there are many addresses reserved for multicast and one address reserved for broadcast.

Ethernet technology was originally designed to use a shared medium (coaxial cable) with a bus topology where all Ethernet

devices in the network are attached to the common medium. A scheme called “carrier sense multiple access” with collision

detection (CSMA/CD)” was used to avoid two devices transmitting at the same time. However, this limits communication,

because it can only occur in one direction at any given time (half-duplex). As Ethernet technology progressed, Ethernet hubs

were introduced to connect multiple Ethernet devices together to form a single segment.

An Ethernet hub is a fairly unsophisticated broadcast device with multiple ports. When it receives a signal (or packet) from

one port, it simply broadcasts the signal out on every other port. It does not inspect the traffic passing through it. With

Ethernet hubs, all Ethernet devices have to operate in half-duplex because signal collision could still occur (when two

devices transmit at the same time into an Ethernet hub). To eliminate the problem of signal collision and allow for full-duplex

operations, Ethernet switches were created.


Appendix A - IP - Some Background Info An Ethernet switch is an intelligent network device with multiple ports. Each port in a switch has its own isolated collision

domain. Therefore, an Ethernet device connected to a switch port can operate in full-duplex because the link to the switch

port is a point-to-point link without other devices sharing the same link. An Ethernet switch inspects all the packets entering

its ports and decides how to forward them. Each Ethernet packet carries a source Ethernet address and a destination

Ethernet address. By observing the source Ethernet addresses in the packets entering its ports, a switch can learn the

Ethernet address of the device connected to each of its ports. When a switch receives an Ethernet packet, it compares the

destination Ethernet address in the packet to the learned device Ethernet address of each of its ports. If a match is found, the

switch will forward the packet only to the port with the matched Ethernet address.

If no match is found, the switch will forward the packet to every port except the port of entry. With intelligent packet

forwarding and full-duplex communication, a switch offers much better performance than a hub.

Therefore, switches have replaced hubs as the primary network equipment for interconnecting Ethernet devices. Due to the

widespread use of switches, the modern Ethernet looks very different from the early Ethernet. Ethernet technology has

transformed from half-duplex “shared Ethernet” to full-duplex “switched Ethernet”.

Even though Ethernet devices can operate at different speeds and different duplex modes, two Ethernet devices (including

switch ports) connected to the same link must be configured to operate at the same speed and same duplex mode. Auto-

negotiation is a procedure by which two connected Ethernet devices advertise their capabilities and choose the best speed

and duplex mode that both can support. With auto-negotiation, Ethernet devices can configure themselves to use common

transmission parameters. However, not all Ethernet devices support auto-negotiation. Sometimes, for performance reasons,

auto-negotiation is disabled on purpose by the manufacturer or user. When an Ethernet device capable of auto-negotiation

is connected to a device that does not support auto-negotiation or whose auto-negotiation capability is disabled, the device

capable of auto-negotiation can detect the speed of the non-auto-negotiating device and match it, but the duplex mode is

always half duplex. As long as both connected devices operate with the same speed and same duplex mode, the link will

work fine.

However, when one device operates in full-duplex, while the other device operates in half-duplex, the link throughput will

drop to a much slower rate than the link speed. This situation is called “duplex mismatch”, which must be avoided.

Therefore, when connecting an Ethernet device into a switch, the user should be aware of the auto-negotiation capabilities

of the Ethernet device and the switch. If the Ethernet device does not support auto-negotiation or its auto-negotiation

capability is disabled, the user should use a “managed switch”, which allows the user to configure its port parameters such

as speed and duplex mode to match the parameters used by the connected Ethernet devices.

A.3 IP Addresses and Subnets

An IP address (or Internet address) is a 32-bit number used to identify a host in an IP network. It is usually expressed as four

numbers separated by periods such as A.B.C.D where A, B, C, and D are decimal numbers between 0 and 255. For

example, 192.168.0.10 is an IP address. Within an isolated private network, the user can arbitrarily assign IP addresses to

the hosts in the network as long as each address is unique.

However, when a private network is connected to the Internet (a public network), the user must use registered IP addresses

for all external communications in order to avoid address duplication.

An IP address has two parts: a network portion (or prefix) that identifies a particular network, and a local portion that identifies

a particular host within the network. The division between the network portion and the local portion is arbitrary (depending on

network size and assignment). All the hosts within a network must be assigned the IP addresses with the same network

portion. A network can be further divided into several sub networks (or subnets) for reasons such as simplifying

administration, separating physical networks, or controlling network traffic. For example, a network with 150 hosts can be

divided into three subnets, and each subnet, connected by a separate Ethernet network, has 50 hosts.

One obvious reason for dividing the network is that an Ethernet network with 50 hosts will be much less congested than the

one with 150 hosts. With subnets, the local portion of an IP address can be viewed as having two parts: a subnet portion that

identifies a particular subnet within a network, and a host portion that identifies a particular host within the subnet. Again, the

division between the subnet portion and the host portion is arbitrary (depending on subnet size and assignment). All the

hosts within a subnet must be assigned the IP addresses with the same network portion and the same subnet portion.


Appendix A - IP - Some Background Info For example, a network with 16-bit prefix address 128.10.0.0 can have two subnets such as 128.10.1.0 and 128.10.2.0,

where the subnet portion is 8 bits wide. Within the subnet 128.10.1.0, a host can have an IP address such as 128.10.1.1 or

128.10.1.2. A subnet is identified by its subnet address (the combination of network portion and subnet portion) and subnet

mask. A subnet mask is a 32-bit binary number used to mask an IP address (by performing a bitwise AND operation) to

generate a subnet address.

Usually, a subnet mask is expressed in the form of an IP address. For example, a subnet mask 255.255.255.0 and host IP

address 128.10.1.1 specify the subnet address 128.10.1.0 (with 24 effective bits).Subnets are interconnected by gateways

(routers). To send an IP packet from one host to another host within the same subnet, the packet is delivered directly (by the

physical network such as an Ethernet) to the destination host without going through the subnet gateway. However, to send

an IP packet from one host in one subnet to another host in a different subnet or network, the packet must first be delivered

to the subnet gateway. The gateway then forwards the packet to the destination host or another gateway that continues to

route the packet toward the destination host. How does a host know an IP packet should be sent to its subnet gateway

instead of to another host within the same subnet? The answer is simple with the help of a subnet mask.

When an IP packet is ready to be transmitted, the host performs a bitwise AND operation using its subnet mask and the

destination IP address of the packet. If the result matches its subnet address (the bitwise AND of its subnet mask and its IP

address), the destination host is within the same subnet and the packet should be sent directly to the destination host.

If the result does not match its subnet address, the destination host resides outside of its subnet and the packet should be

sent to its subnet gateway. Subnets are invisible outside their networks; they are only known within their networks IP

addresses can be divided into the following three types based on addressing scope:

Unicast

This is the most common type. A unicast IP address is assigned to an individual host (including gateways and routers).

When the destination IP address of an IP packet is a unicast address, the packet is only delivered to the host that owns

the destination IP address.

Multicast

A multicast IP address is associated with a group of interested hosts. The IP addresses from 224.0.0.0 to

239.255.255.255 are designated as multicast addresses. When a host sends an IP packet to a multicast address, it

only sends out one copy into the network. The network will make copies and send one copy to each interested host.

To express its interest in a particular multicast address, a host must join that multicast address (by sending an IGMP

Join message to the network).Multicast makes it easy for a host to send the same packets to many interested hosts.

Broadcast

A broadcast IP address allows a host to send IP packets to all hosts in a network or subnet. There are two types of

broadcast: directed broadcast and limited broadcast. In a directed broadcast to all hosts in a network, the broadcast

address is an IP address with the local portion equal to all 1’s. Similarly, in a directed broadcast to all hosts in a subnet,

the broadcast address is an IP address with the host portion equal to all 1’s. The special IP address 255.255.255.255 is

used in the limited broadcast to all hosts in a subnet (or a network without subnet). When a host does not know its IP

address and subnet address at startup, it uses limited broadcast to request and learn its network parameters.

There are some IP addresses reserved for special purposes. The IP address 127.0.0.1 is designated as a loopback

address (activity on this address loops back to itself). When a host sends an IP packet to 127.0.0.1, the packet will be

looped back by the IP stack without being sent out. This loopback address is mainly used for testing only.

The IP addresses in the following three ranges are designated as private addresses.

They can only be used in private networks and are not routable.

10.0.0.0 to 10.255.255.255

172.16.0.0 to 172.31.255.255

192.168.0.0 to 192.168.255.255

The IP address of a host can be statically configured or dynamically assigned at start up (by a DHCP server). Using the

statically configured IP addresses is a simpler way to set up a small network.

Reference

Zetron, Inc. “P25 Understanding VoIP: Network Characteristics, Protocols, and Test Tools”, White Paper, 005-1389B,

February 2008.


Appendix B - NXR-700/ NXR-800/ NXR-900 error messages, status LED and OCXO LED information

Appendix B - NXR-700/ NXR-800/ NXR-900 error messages, status

LED and OCXO LED information Status LED information

Table B-1 Status LED information

17-segment LED Information

Table B-2 17-segment LED information

OCXO status LED Table B-3 OCXO status LED information

Repeater Status LED Display Remarks

Non-priority Channel (ADD) (Conventional) 16. The “.” lights at the right of the right digit. Non-priority Channel (DEL) (Conventional) 16 -

Priority Channel (Conventional) .1 The “.” lights at the right of the left digit. Scan Mode (Conventional) SC - Un-programmed E1 This display appears if no channel data is configured.

Blanked channel data E2 This display appears if a channel for which no data is configured is selected.

PLL Unlock E3 Transmitter PLL Unlock: TX LED blinks. Receiver PLL Unlock: BUSY LED blinks.

Blanked transmit frequency data E4 This display appears if the repeater attempts to transmit on a channel for which no transmit frequency is configured.

IP address configuration E5 IP address configuration error(s) is detected in the system.

Frame Timing Error E6 Appears if no frame clock is entered while the repeater is in Trunking Mode.

Over Temperature Protection E7 Appears upon activation of temperature protection (overheat protection at PA module). If the protection is activated, transmission is disabled and this state cannot be reset until the repeater is turned OFF.

LED Status Remarks

OFF No OCXO installed, internal reference used

GREEN Correct OCXO operation

ORANGE External frequency reference signal received

RED Error with internal or external reference signal

Status LED - left to right Function

1 Flashes when the system starts up. If the system starts up properly, the LED turns Off. The LED 1 lights if the repeater is used as a master unit of the SYNC signal in Trunking Mode.

2 Flashes while the repeater is handling a Long Data Call. 3 Flashes while the repeater is handling a Voice Call.

4 If the repeater is serving as a control channel, the LED 4 indicates that a trunking control signal is being transmitted. While a trunking control signal is properly transmitted, the LED 4 flashes at rapid intervals.

5 Flashes while the repeater is receiving a Long Data Call. 6 Flashes while the repeater is receiving a Voice Call.

7

If the repeater is serving as a control channel, the LED 7 indicates that a trunking control signal is being received. If a subscriber unit transmits by using random access and if the repeater receives the control signal, the LED 7 momentary lights. If there are many access attempts from multiple subscriber units, the LED 7 may flash at rapid intervals. While the repeater is serving as a control channel or Conventional Channel, the LED 7 lights as described below.

The LED 7 momentarily lights upon reception of data, such as Status, along with the Voice Call. While a Voice Call is made in a Digital Narrow System, audio frames and data frames are alternately

received; hence, the LED 7 flashes at the intervals of each transmission.

The LED 7 momentary lights upon completion of a Voice Call or Long Data Call.

8 If an error is detected in the received data, the LED 8 lights. The LED 8 may light in response to noise. Also, the LED 8 may momentarily light upon completion of a call, but this is not an error.



Communication Log - Cause (Normal Messages)

Table B-4 Communication Log - Cause (Normal Messages)

Communication Log - Cause (Error Messages) Table B-5 Communication Log - Cause (Error Messages)

Code Cause Description

N001 Registration accepted A registration request successfully accepted.

N002 Receive successed A short message or status message successfully completed with acknowledgement.

N003 Send successed A short message or status message successfully completed without acknowledgement.

N004 Call Disconnect Communication terminated by a request from the caller unit

N005 Call Disconnect Communication terminated by a request from the receiver unit

N006 Disconnected by Trunking Controller Communication terminated by the system controller

N007 Call Limit Time-out Communication terminated due to call timer timeout

N008 Traffic Channel Failure Communication terminated due to Traffic Channel failure(s)

N009 Other Failure Communication terminated due to other cause

N010 Location successed with Group failed Location Registration successed but Group Registration failed

N011 Location successed with Group refused Location Registration successed but Group Registration refused


E001 Registration failed Location Registration/Deregistration failure Affiliation failure No response from transceiver or authentication time-out

E002 Registration refused

Location Registration/Deregistration refused Affiliation refused Caller Unit service not allowed Receiver Group service not allowed Caller Unit not available Receiver Unit not available

E003 Temporary failure Temporary network failure detected Multi-site network disconnected

E004 Equipment congestion Traffic congestion detected in network equipment Channel busy/Insufficient call resource End of Multi-site communication (with no reason)

E005 No other resource available No resource available Other resource error

E006 Service Unavailable Requested service not available Service not supported

E007 Step error Error in the received message Essential information not provided Information item not defined/invalid Other process step error class

E008 Service not permitted Requested service is restricted Caller Unit service not permitted Receiver Unit service not permitted Receiver Group service not permitted

E009 Unregistered Location not registered No Caller Unit information No Receiver Unit information No Receiver Group information

E010 No response No response from the receiver unit Authentication time-out

E011 Incoming call rejection Incoming call rejected by receiver unit




E012 Busy state Requested ID in use Caller Unit busy Receiver Unit busy Receiver Group busy

E013 Queuing interruption Queued call terminated by time-out HUNT-RESP (que_cancel)

E014 System undefined ID used System undefined ID used Caller Unit not available Receiver Unit not available Receiver Group not available

E015 Channel unavailable Traffic channel not available (channel restriction, Failsoft, etc)

E016 Network failure Network problem occurred Routing failure

E017 Temporary failure Temporary system failure detected

E018 Equipment congestion All traffic channels not available (Channel busy)

E019 Resource Unavailable Resource not available Other cause of resource error

E020 Memory Full Receiver unit abort due to over buffer STAT_RESP/SDCALL_RESP Cause (NACK (Memory Full))

E021 Abort Other cause of receiver unit abort STAT_RESP/SDCALL_RESP Cause (NACK (Abort))

E022 Other Error Other cause of error Other undefined condition (force release, etc.)


Appendix C – Glossary of Terms

Appendix C - Glossary of Terms

10/100BASE-T

This combines the 10BASE-T and 100BASE-TX Ethernet standards into a single term. 100BASE-TX is a general term

referring to a group of fast Ethernet standards used for transmission over twisted-pair cables, etc. 10BASE-T is another

Ethernet standard. Both 10BASE-T and 100BASE-TX are used to link equipment in a star-configured LAN via a hub.

10BASE-T can be used to transmit data at up to 10Mbps over a maximum distance of 100 meters, while 100BASE-TX is

capable of data transmission at 100Mbps over the same distance. 100BASE-TX equipment is usually compatible with

10BASE-T, so it is possible for them to coexist on a single network.

2-tone (Two-tone)

This refers to two-tone squelch. This function employs a sequential transmission of 2 audible tones for user selection,

enabling the receiver to hear an alert tone. It can also be used for group calling.

4-level FSK modulation

Frequency Shift Keying (FSK) is a modulation method by which the instantaneous frequency of a carrier is discretely

changed according to a digital code. For example, with 2-level FSK, bit 0 changes the carrier frequency to -Δf, while bit 1

changes the carrier frequency to +Δf. With 4-level FSK, codes 00, 01, 10 and 11 indicate frequency shifts of +Δf, +3Δf, -Δf

and -3Δf. Using 4 values instead of 2, 4-level FSK allows for double the data rate; alternatively, it is possible to send the

same amount of data using half the bandwidth. Since FSK modulation has a constant envelope, the effects of amplitude

shift are reduced and a non-linear Class C amplifier can be used.

AGC

Abbreviation for Automatic Gain Control

Air Interface

Protocol specifying connection and transmission methods between transceiver units in a digital mobile radio system.

AMBE+2TM

Vocoder developed by Digital Voice Systems, Inc. The new vocoder technology has been shown to outperform DVSI’s

previously industry-leading AMBE+ Vocoder, that outperformed G.729 and G.726 vocoders while operating at only 4.0 kbps,

and DVSI’s baseline AMBE vocoder technology. It is designed to be particularly robust and perform exceptionally well even

under bit errors and acoustic background noise conditions. Source dvsinc.com.

AUX

Abbreviation for Auxiliary port. A terminal for connecting a peripheral device.

AVL

Automatic Vehicle Location. A system or service using a transceiver terminal and a vehicle-mounted GPS device that

enables owners to prevent vehicle theft or locate stolen vehicles. It can also provide trip information for bus and other

transport service passengers, and increase operational efficiency for trucking companies.

BMP

The image data is decomposed to points. And BMP (bitmap) is the method to record and reproduce the position and the

attribute of the data.

BTU

The British thermal unit (BTU) is a unit of energy. It is approximately the amount of energy needed to heat one pound of

water one degree temperature. (1 BUT=1.054853 kJ=0.000293 kW/h)

Conventional Mode

A communications method whereby the user selects the appropriate channel for a call, since a control device to assign a

traffic channel is not available. In Direct Mode Operation mobile transceivers communicate with each other directly, while in

Repeater Operation they communicate via a repeater.


Appendix C – Glossary of Terms CCH, CC

Control Channel

CRC

A Cyclic Redundancy Check/ Checksum (CRC) is a check code for data verification and the algorithm is based on cyclic

codes. The Vocoder always checks CRC code and accepts data frame.

CTCSS

Continuous Tone-Coded Squelch System. A circuit that adds continuous tones to the transmitted signal to enable the other

party to screen out unwanted signals and receive only the desired station. This is common for business radio systems as it

allows multiple transceivers to use the same radio frequency. Equivalent to Kenwood’s QT (Quiet tone) system.

DB25

25-pin type D-subminiature or D-sub connector.

DCS

Digital Coded Squelch. While CTCSS modulates a carrier with a continuous tone signal, DCS uses a continuous NRZ data

stream. Equivalent to Kenwood’s DQT (Digital Quiet Talk) system.

Default Gateway

A router that serves as an access point (for a network or subnet) to outside networks.

DQT

Digital Quiet Talk. DQT has 512 codes (from 000 to 777 in octal notation) but 86 code sets are actually used. Since DQT

uses FSK modulation with binary data, it is more complex than QT and is incompatible with QT.

DTMF

Dual-Tone Multi-Frequency. Tones are emulated by pressing the 0 to 9, A, B, C, D, * and # keys. This is different from

CTCSS, since it operates in the audio range and cannot be transmitted simultaneously with voice audio.

Duplex

A communications method for simultaneous transmission and reception using two separate frequencies.

EIA

Electronic Industries Alliance.

ESN

Electronic Serial Number, a unique number assigned to individual transceiver units for identification purposes.

Ethernet

A family of frame-based computer networking technologies for LANs, standardized as IEEE 802.3. Originally proposed by

Xerox and DEC (now part of Hewlett-Packard).

Equalizer

Equipment that processes and adjusts the frequency response of an audio signal.

FDMA

Frequency Division Multiple Access. A channel access method in which a radio system shares spectrum by assigning

different frequencies to multiple users.

FEC (Forward Error Correction)

Forward error correction (FEC) can correct an error data frame without re-transmission. The transmitting transceiver adds

redundant data to its digital data, Also, the receiving transceivers can detect and correct errors without asking the sender for

additional data or resend.


Appendix C – Glossary of Terms Firewall

A security device that inspects and filters (denies or permits) network traffic passing through it based one set of rules.

Firewalls are used to prevent unauthorized outside users from accessing private networks, and control what outside

resources their inside users have access to.

FleetSync

FleetSync is the generic name for Kenwood’s proprietary message communications system that utilizes MSK (Minimum

Shift Keying) signaling.

FleetSync allows the user to identify individual transceivers as well as send and receive text messages. FleetSync also

supports serial communications, allowing the user to connect a computer or other external device to the transceiver.

FleetSync provides diverse messaging functions not possible with conventional voice communications, and it supports a

wide variety of operating environments.

FM

Frequency Modulation, a technique for modulating an analog signal. The information is transmitted by modulating the

frequency. FM offers better sound quality with less noise than AM, although FM requires more bandwidth and is therefore

not very efficient.

FPU

Field Programming Unit, programming software for loading various settings into transceiver unit.

Fringe Area

Boundary of the coverage area of a transmitter in which signals are weakened and distorted.

Gateway

The word “gateway” has different meanings depending on where it is used. It can be used for a network gateway, which is a

router that connects an inside network or subnet to outside networks such as a WAN or the Internet. It can also be used for a

device such as a PSTN or transceiver gateway that converts one protocol to another or one signal format to another. GPS

Global Positioning System. Developed by the United States military, GPS technology uses signals from about 30 satellites to

provide accurate information about one’s position on the Earth. The latitude, longitude and altitude of the receiver can be

determined with an accuracy ranging from twenty meters or more to just a few centimeters.

Hub

A device with multiple ports for connecting multiple Ethernet devices together to form a single network segment. Hubs work

at the physical layer (layer 1) of the OSI model. When a hub receives a signal (an Ethernet packet) from one port, it simply

broadcasts the signal out on every other port. It does not inspect the traffic passing through it. All Ethernet devices connected

by hubs must operate in half-duplex mode due to potential signal collision. Today, hubs have mostly been replaced by

switches and therefore have become obsolete.

I/O

Input-Output.

IMBE

Improved Multi-Band Excitation, an audio compression technology developed by Digital Voice Systems, Inc. (DVSI).

IP (1)

Internet Protocol. The protocol used for data transmission across the Internet. IP forms the foundation of the Internet, and

hence plays a major role in Internet activity.


Appendix C – Glossary of Terms IP (2)

International Protection. IEC standard IEC60529 (Degrees of protection provided by enclosures) specifies the level of

protection from intrusion by body parts, foreign materials or liquids into electrical equipment enclosures. ‘IP’ is followed by a

number indicating the level of protection. The first digit describes the degree of protection from foreign materials, and the

second from liquids. For example, in the case of IP 54, ‘5’ indicates that the device is dust resistant, though there should be

no harmful effects if a small amount of dust enters the enclosure, while ‘4’ indicates that there will be no harmful effects if a

small amount of water is splashed on the equipment from any direction. In the case of IP 55, the second ‘5’ indicates that

water sprayed directly from a nozzle onto the device enclosure from any direction will have no harmful effects.

IPSec

Internet Protocol Security. IP packet encoding standards for encrypted communications across the internet.

JPEG

Format form of image data.

LAN (Local Area Network)

A network that covers a small geographical area such as a home, a single building, a group of buildings, or a small campus.

Most LANs connect personal computers (PCs) and servers. Because the distanceis short, LANs can operate at very high

speeds with short delay. A LAN can contain multiple subnets.Today the dominant LAN technology is Ethernet.

LTR

Logic Trunked Radio. A trunked radio system developed in the late 1970s by the E. F. Johnson Company.

Managed Switch

A network switch that allows the user to configure and control each individual port. The configuration options normally

include at least the port on or off setting, link speed, duplex mode, virtual LAN, and Spanning Tree Protocol. When

connecting an Ethernet device that does not support auto-negotiation or its auto-negotiation capability is disabled, the user

should use a managed switch and configure the connected port to match the link speed and duplex mode used by the

connected Ethernet device for the best performance. In contrast to a managed switch, an unmanaged switch has no

configuration interface or options.

MapPoint

A specific software program created by Microsoft that allows users to view, edit and integrate maps.

Mission-Critical

A key business mainframe system that operates 24/7, or other systems that cannot be turned off without impacting normal

business operations are referred to as “mission-critical.”

Multi-site

A system that has multiple sites connected via a network.

OCXO

Oven-Controlled Crystal Oscillator. A highly stable oven-type crystal oscillator in which internal temperature fluctuations are

kept to a minimum to ensure precise transmit performance.

PABX

Abbreviation of private automatic branch exchange

PF

Programmable Function Key. Such keys are assigned functions with an FPU.

POCSAG

POCSAG is a data transmission standard for mainly pager. The data is transmitted with +/- 4.5 kHz FSK modulation. 0 is

high frequency, 1 is low frequency. Data speed can select from 512 bps, 1200 bps, 2400 bps.

PSTN

Abbreviation of Public Switched Telephone Network


Appendix C – Glossary of Terms Push-to-Talk

Abbreviated as PTT. A simplex or half-duplex communications service, where it is only possible to talk while the transmit

button is pushed down.

QT

Quiet Talk. Kenwood’s CTCSS system using EIA tones. This enables the user to call groups or individuals on a single

frequency.

RAN

Radio Access Number. With NXDN this digital signaling ensures smooth communication among groups using the same

channel in conventional mode. It has similar functionality with QT/DQT for analog.

RF

Radio Frequency. Refers to the frequency of the radio waves or electrical signals used as a carrier for wireless

communications.

Router

A device with multiple interfaces for interconnecting multiple networks (or subnets). Routers work at the network layer (layer

3) of the OSI model. They route IP packets from one network to another network based on IP addresses.

RSSI

Received Signal Strength Indicator. A circuit incorporated into a receiver that indicates the strength of a received signal.

TCH, TC

Traffic Channel

TDMA

Time Division Multiple Access. A channel access method whereby a radio system assigns users different time slots on the

same frequency. One frequency can thus be shared by multiple stations.

Trunking

A “trunk” is a communications channel between two points, and “trunking” refers to automatically sharing trunks. A radio

system with this capability is a “trunked system,” a concept analogous to the way phone lines are switched by an exchange.

Traffic channels in a repeater site are thus automatically distributed. Since the controller in a trunked system identifies

available repeaters and assigns them to users, a trunked system improves the operation rate of repeaters and offers more

spectral efficiency than a conventional system.

Scan

To sequentially receive on specific channels stored in memory, in order to search for a valid transmission.

Simplex

Communication in one direction at one time. Therefore, simplex communication on the same frequency must alternate

between transmission and reception.

Site

A term to describe an aggregate of repeaters in a system in one location.

SU

Subscriber unit


Appendix C – Glossary of Terms Subnet (Subnetwork)

A single IP network can be divided into several subnets for reasons such as simplifying administration, separating physical

networks (to reduce broadcast traffic), or controlling network traffic. A typical subnet is a physical network served by one

router (the subnet gateway or default gateway). When sending an IP packet from one host in one subnet to another host in a

different subnet or network, the packet first has to be delivered to the subnet gateway, then the gateway forwards the packet

to the destination host or another gateway which continues to route the packet toward the destination host.

Subnets are only visible within their networks. They are invisible outside their networks.

Switch

A device with multiple ports for connecting multiple Ethernet devices together. Each port in a switch has its own isolated

collision domain. Therefore, an Ethernet device connected to a switch port can operate in full-duplex mode. Generally

speaking, switches work at the data link layer (layer 2) of the OSI model.

They inspect the source and destination Ethernet addresses of the packets that enter each port, and only forward the

packets to the connected devices that the packets were destined for. With intelligent packet forwarding and allowing

full-duplex communication, a switch offers much better performance than a hub Note the definitions of managed and

unmanaged switches in this glossary.

UHF

Ultra High Frequency. The UHF band is defined as 300 MHz to 3 GHz. UHF waves are not reflected by the ionosphere and

propagation loss is larger than it is for VHF. UHF waves are mainly used for line-of-sight or short-distance communications.

Since the wavelength is short, a small antenna is sufficient for mobile transceivers.

USB

Universal Serial Bus. A standard routing system for connecting computers and peripheral equipment.

USB-3000™

Vocoder Unit manufactured by Digital Voice Systems, Inc.

VHF

Very High Frequency. The VHF band is defined as 30 MHz to 300 MHz. VHF waves are not reflected by the ionosphere

most of the time, and propagation loss is comparatively large. VHF is used mainly for line-of-sight communications.

Vocoder

A type of audio compression technology. Vocoder systems analyze the human voice and can generate an “artificial” voice.

This dramatically reduces the amount of information needed to store speech, from a complete audio recording to a series of

numbers.

VPN

A virtual private network (VPN) is one of encrypted network connection method. VPN can protect transmission data and

construct private network virtually in public IP network.

YAGI Antenna

A Yagi-Uda Antenna, commonly known simply as a Yagi antenna or Yagi, is a directional antenna system consisting of an

array of a dipole and additional closely coupled parasitic elements.

WAN (Wide Area Network)

A network that covers a relatively broad geographical area such as a city, a state, or even a country. WANs are used to

connect LANs together over long distances. Compared to LANs, WANs operate at slower speeds and have much longer

delay. They often use transmission facilities provided by telephone companies. Popular WAN technologies include DSL,

SONET, ATM, Frame Relay, and ISD.

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