introduction to cellular networks

NDI Communications - Engineering & Training

Introduction to Cellular NetworksIntroduction to Cellular Networks

Part 1 Part 1 –– Traditional NetworksTraditional Networks

© NDI Communications ©

Lesson Content

Introduction

The network evolution

Early (2.0-2.5G) cellular networks

Broadband (3.0-3.75) Cellular Networks

Commercial and economical issues

Wireless and Cellular Networks - History

In 1905, Guglielmo Marconi invented the first

Radio application for Naval requirements

In 1912, with the drowning of the Titanic, Radio

communications became essential

In 1930, the First mobile transmitter was

developed. First – Simplex communications.


In 1935, FM – Frequency Modulation

developed. Later used in WW2 by the US

In 1942, a Patent for Frequency Hoping was

registered by actress Hedy Lamarr and

composer George Antheil. Later developed to

CDMA. They called it “Secret Communication

System ”

During the years 1946-1968, wireless

communications developed for government

services – Police, Fire departments etc…


1979 in Tokyo, Japan. Later in the early 80’s

in the US and Europe – the first real mobile

hone, including handoff.

In the early-mid 80’s, various technologies

came, like WLL, LMDS, and Wireless LAN.

In the mid-late 90’s, development of 2.0G+

cellular networks, along with the emerging of

wireless data networks.

Since the early 2000’s, fast cellular and

wireless services, along with advanced, IP-

Based services

What do we have today ?

Cellular technologies

Started 1.0G, analog communications

Today (2009), 3.5G moving to 4.0G (LTE and LTE-Advanced)

technology

Wireless technologies:

Wireless LAN (WiFi), for urban areas, mostly private networks,

moving to mobility

Fixed WiMAX for high bandwidth, SP networks

Where is it in the Network?

First Mile Access

DSLAM

CMTV

Wireless

Cellular

FO Technologies

Service Networks

Internet

Voice

VideoVideo

AOL

Earthlink

Yahoo

PSTN

Skype

Vonage

Direct TV

Content Aggregator

Core/Switching

Network

Some Wireless Principles – Radio

Communications

In wireless / mobile communications, the principle is to get the

maximum capacity from the air, or what called – the air interface.

For this purpose, we use the following techniques:

Frequency bands – that we are allowed to use (Government Licenses)

Modulation – that carry the information over the radio waves

Multiplexing – that shared the air interface between different users.

What is it All About?

How much bps can we get from every Hz ???(The Shannon’s Theorem)

C = W * log2 (1 + S/N)

Channel Capacity[Bits/sec] Signal

Bandwidth [Hz]

Signal to Noise

Ratio[Number]

Claude E.Shannon

How it works – The beginning

Traditional mobile service was structured in a fashion similar to

television broadcasting

One very powerful

transmitter located at

the highest spot in an

area would broadcast

in a radius of up to

50Km.

And Then ….

With one antenna – limited cover and number of users

Therefore – split into many low power transmitters

The Solution - Cells

Frequency reuse

Different color –

different frequency

In the example N (Reuse factor) =7

Practical Frequency reuse – Cell Splitting

We start with Macro-Cells

Rural areas

Then Micro-Cells

More crowded rural areas

Then Pico-Cells

Urban area

C

D

E

G

F

A

Macro cells

B

C

D

E

G

F

AMicro cells

BC

DE

G

F

B

A

Pico cells

Moving Between Cells

Mobile phones moves between cells

The handset should not be disconnected

BaseStation

F2

BaseStation

F1

The Solution - The Handover Process

RSSI RSSI RSSI

FRQ A FRQ CFRQ B

Handover

Happens Here

RSSI - Received Signal Strength Indicator

Handover

Happens Here

Access Methods

The Major Air-Interface Methods are:

Frequency Division Multiple Access (FDMA)

Time Division Multiple Access (TDMA)

Code Division Multiple Access (CDMA)

Frequ

ency

Time

Cod

e

FDMA

Frequency

Time

Cod

e

TDMA

Fre

quen

cy

Time

Cod

e

CDMA

The Cellular Network Structure

Cell phones

The UserThe UserThe UserThe User

The RadioNetwork

The AccessThe AccessThe AccessThe AccessNetworkNetworkNetworkNetwork

Circuit Switching

Packet Switching

The CoreNetwork

The SwitchingThe SwitchingThe SwitchingThe SwitchingNetworkNetworkNetworkNetwork

Mobile Internet

Intelligent NetworkAdvanced Services

Intelligent

Network

The ServicesThe ServicesThe ServicesThe Services

FO Cables

FO Cables

MW

AirInterface


Lesson Content

Introduction






Early Technologies – 1G to Early 3G

Evolution

NMT GSM

TACScdmaOne(ANSI-95)

1990 1995 2000 2005

GRPS (2,5G) and

EDGE (2.75G)

[Upto 384Kbps]

cdmaOne

(ANSI-95-B)

[64-115]

AMPS

D-AMPS(TDMA)

ANSI-136

IS-136

(ANSI-136-A/B)

[Upto 64Kbps]

1G 2G 2.5G

3GPP

WCDMA R.99

[2Mbps]

Cdma2000

(1.25/3.75MHz)[307-2048Kbps]

Early 3.0G

TDMA-EDGE(IS-136HS)

[Upto 384Kbps]

Wireless and Mobile 3G Technologies

Evolution

2005 2006 2007 2008 2009 2010

IEEE 802.16-2004/

ETSI HiperMAN

OFDM

3GPP

HSDPAR5

3GPP

HSUPA

R6

3GPP MIMO/

HSPA+ R7

SAE/LTE R8

3GPP2

1xEVDV

RevA

3GPP2

1xEVDORevB

IEEE 802.16e-2005/

ETSI HiperMANSISO/OFDMA

IEEE 802.16e-2005/ETSI HiperMAN

MIMO/Beamforming/OFDMA

3G to 4G

WiMAX

3GPPWCDMA

R.99

3GPP2

1xEVDO

Rev0

Cellular Standards (1.0-3.0G) - Summary

CDMA2000 1xEV-DO (IS-856) 3GPP2

UMTS (UTRAN), WCDMA-FDD, WCDMA-TDD, UTRA-

TDD LCR (TD-SCDMA)

3GPP3G (IMT-2000)

WiDENOther

CDMA2000 1xRTT (IS-2000) Cdma/3GPP2

HSCSD, GPRS, EDGE/EGPRS GSM/3GPP2G transitional

(2.5G, 2.75G)

CDPD, iDEN, PDC, PHSOther

CdmaOne (IS-95)Cdma/3GPP2

GSM, CSDGSM/3GPP2G

NMT, Hicap, Mobitex, DataTACOther

AMPS, TACS, ETACSAMPS family 1G

TechnologiesFamily

Cellular Standards (3.0G+) - Summary

IEEE 802.16m (WiMAX)Other

LTE AdvancedCdma/3GPP2

LTE AdvancedGSM/3GPP4G (IMT-

Advanced)

Mobile WiMAX (IEEE 802.16e-2005) � Flash-OFDM,

IEEE 802.20

Other

EV-DO Rev. A, EV-DO Rev. BCdma/3GPP2

HSDPA, HSUPA, HSPA+, LTE (E-UTRAN) GSM/3GPP3G transitional

(3.5G, 3.75G,

3.9G)

TechnologiesFamily

Wireless and Mobile Communications –

Cellular Networks

2010200320011985 1992-2000

1.0G

Analog Systems

Speech Only

Voice

No Data

2.0G

TDMA/GSM/CDMA

Speech

SMS

WAP

Voice

30-40Kbps

Data

2.5G

GPRS/1XRTT

Speech and packet based Data Services

Voice100-200Kbps

Data

3.0G-3.5G

UMTS/CDMA 2000

HSDPA/HSUPA

1xEVDO/DV

Video Streaming, Video conference, High speed Packet Data

Voice

1-5Mbps Data

4.0G

LTE Advanced

100’s Mbps data transfer

Voice

5-100Mbps

Data

Voice Over IP


Lesson Content

Introduction






The 2.0G Networks

The critical problem in 1.0G was capacity. The main requirement was

to increase it

These requirements brought several new technologies:

The general characteristics of Time Division Multiple Access (TDMA)

Global System for Mobile Communications (GSM)

CDMA - Code Division Multiple Access

Promise to significantly increase the efficiency of cellular telephone

systems to allow a greater number of simultaneous conversations.

The GSM Network

GSM, or Global System for Mobile Communications, is a second

generation technology.

The focus in GSM was to support roaming throughout Europe.

An ETSI standard. In use all around the world.

GSM is not only an air interface standard, but includes the entire

network.

Of the numerous individual standards that define an entire GSM

network, only a small portion deal directly with the air interface. That

air interface was standardized to be TDMA.

The GSM Network

BSCBTS

BTS

Mobile

Station

Access Network:

Base Station Subsystem

HLR VLR EIR AuC

MSCPSTN

Core Network:

GSM CS network

SS7

GSM Interfaces Parallel North American Technology – cdma1

GSM Air Interface

FDMA:124 channels of 200KHzTotal 25MHz Uplink

25MHz DownlinkTDMA:8*TS for channel

GPRS and EDGE for Early Data Applications

The two key benefits of GPRS were:

Better use of radio and network resources

Completely transparent IP support

GPRS optimises the use of network and radio resources. It uses radio

resources only when there is data to be sent or received.

GPRS have added two major components, that are still used in cellular data

networks:

GGSN (Gateway GPRS Support Node) {DHCP and FW} – for filtering and firewall, Charge

collections and PDN access

SGSN (Serving GPRS Support Node) {Switch} – for Authentication, Authorisation,

Encryption, Compression, Mobility management, Charge collection, BSS interface

EDGE was a Pre-3.0G network, that improved data-rate by better modulation

techniques

The Cellular Network Structure – 2.0G-2.5G

BSC

PCU

Packet

Network

Packet

Network

SGSN

IP netIP net

GGSN

Data NetworkData Network

TRAU MSC

PSTNPSTN

Circuit Switching

Packet Switching

VLR

BTS

Mobile

Device

BTS

HLR


Lesson Content

Introduction






3.0G - Introduction

Started as IMT–2000 (International Mobile Telecommunications-2000):

Used worldwide

Used for all mobile applications

Support both packet-switched (PS) and circuit-switched (CS) data

transmission

Offer high data rates up to 2 Mbps (depending on mobility/velocity)

Offer high spectrum efficiency

The IMT-2000 Vision

IMT-SC* Single Carrier (UWC-136): EDGE

GSM evolution (TDMA); 200 KHz channels; sometimes called “2.75G”

IMT-MC* Multi Carrier CDMA: CDMA2000

Evolution of IS-95 CDMA, i.e. cdmaOne

Now – 3GPP2

IMT-DS* Direct Spread CDMA: W-CDMA

Evolution of GSM - UMTS

Now - 3GPP

IMT-TC** Time Code CDMA

Originally from 3GPP; UTRAN TDD

Came from China; TD-SCDMA

IMT-FT** FDMA/TDMA (DECT legacy)

A Few Words About 3G+ Standards

3GPP(W-CDMA)

ETSI

ARIB

ATIS

CCSA

TTA

TTC

3GPP2(CDMA2000)

TIA

ITU-TIMT2000

3.0G – UMTS / W-CDMA

UMTS - Universal Mobile Telecommunications System

Spread Spectrum CDMA radio technology

All sites transmits in the same frequencies

They differ by codes

High capacity for voice and data applications

Standardized by 3GPP

Basic 3.0G UMTS Cellular Network

Architecture

RNC

3G

handset Node B

UMTS Access Network

PacketSwitchedNetwork

SGSN

HSPA - HSDPA / HSUPA / HSPA+

High Speed Packet Access (HSPA) is a generic term adopted by the UMTS

Forum to refer to improvements in the UMTS Radio Interface

HSPA refers to both the improvements made in the UMTS downlink, often

referred to as High Speed Downlink Packet Access (HSDPA) and the

improvements made in the uplink, often referred to as High Speed Uplink

Packet Access (HSUPA)

HSPA Releases:

Release 5 - HSDPA (High Speed Downlink Packet Access)

Downlink – 14.4Mbps, Uplink – 384Kbps

Release 6 - HSUPA (High Speed Uplink Packet Access)

Downlink – 14.4Mbps, Uplink - 5.76Mbps

Release 7 - HSPA+

Downlink – 56.0Mbps, Uplink - 22.0Mbps

HSDPA - High Speed Downlink Packet Access

Technology changes:

A new common High Speed Downlink Shared Channel (HS-DSCH) which

can be simultaneously shared by multiple users

The usage of multiple codes with Spreading Factor 16 (SF-16) for the

downlink transfer of data

The use of a shorter Transmission Time Interval (TTI) of 2ms, which

enables higher speed transmission in the physical layer,

The use of fast scheduling

The use of Adaptive Modulation and Coding (AMC),

The use of fast retransmission based on fast Hybrid Automatic Response

reQuest (HARQ) techniques.

Bandwidth:

Downlink – 14.4Mbps, Uplink – 384Kbps

HSDPA Categories

HSUPA - High Speed Uplink Packet Access

Similarly to HSDPA in the downlink, HSUPA defines a new radio

interface for the uplink communication. The overall goal is to improve

the coverage and throughput as well as to reduce the delay of the

uplink dedicated transport channels.

Technology changes:

A new dedicated uplink channel,

Introduction of H-ARQ,

Fast Node B scheduling.

Bandwidth:

Downlink – 14.4Mbps, Uplink – 5.76Mbps

HSPA+ (Evolved HSPA)

HSPA+ provides HSPA data rates up to 56 Mbit/s on the

downlink and 22 Mbit/s on the uplink through the use of:

2*2 MIMO - Multiple-Input Multiple Output - multiple-antenna

technique

Higher order modulation (64QAM)

Bandwidth:

Data rates of up to 56Mbit/s (D) and 22Mbit/s (U) represent

theoretical peak sector speeds.

The actual speed for a user is lower.

Future revisions of HSPA+ support up to 168 Mbit/s using multiple

carriers.

HSPA+ and MIMO technology

MIMO on CDMA based systems acts like virtual sectors to give extra

capacity closer to the mast.

HSPA+ All-IP Network Architecture

HSPA+ also introduces an optional all-IP architecture for the

network where base stations are directly connected to IP based

backhaul and then to the ISP's edge routers.

The technology also delivers significant battery life

improvements and dramatically quicker wake-from-idle time -

delivering a true always-on connection.

HSPA+ should not be confused with LTE, which uses a new air

interface.

Radio Capacity Evolution

Delay Improvements in HSPA Technologies

HSPA, HSPA+ and LTE



Part 2 Part 2 –– LTE LTE –– Long Term EvolutionLong Term Evolution


Lesson Content

Introduction and Objectives

LTE Network Architecture

LTE Radio Interface

Innovations ad applications

Services and Implementation


3GPP Evolution

3GPP Evaluation

Release 99 (2000) - UMTS/WCDMA

Release 5 (2002) – HSDPA, multiple codes in Downlink channel

Release 6 (2005) - HSUPA, MBMS (Innovations ad applications)

Release 7 (2007) – HSPA+/E-HSPA - DL MIMO, IMS (IP Multimedia Subsystem),

optimized real-time services (VoIP, gaming, push-to-talk), early All-IP Network

implementation

Release 8 (2009) - LTE (Long Term Evolution), new air-interface and network

architecture (SAE)

Release 9 (2010) - minor changes to release 8

Release 10 (2011+) – LTE Advanced

Long Term Evolution (LTE)

3GPP work on the Evolution of the 3G Mobile System started in November 2004

Currently, standardization in progress in the form of Rel-8

First deployments – late 2009 (Telia-Sonera)

LTE – Long Term Evolution - Objectives

Higher performance

100 Mbit/s peak downlink, 50 Mbit/s peak uplink

Reduced latency (to 10 ms) for better user experience

Scalable bandwidth up to 20 MHz

Backwards compatible

Works with GSM/EDGE/UMTS systems

Utilizes existing 2G and 3G spectrum and new spectrum

Supports hand-over and roaming to existing mobile networks

Reduced CAPEX/OPEX via simple architecture

Reuse of existing sites and multi-vendor sourcing

Wide application

TDD (unpaired) and FDD (paired) spectrum modes

Mobility up to 350kph

Large range of terminals (phones and PCs to cameras)Co-existence with legacy standards – GSM

and W-CDMA-based UMTS and cdmaOne or CDMA2000) networks

Full support for IP services - Mobile TV, Radio and television broadcasts and more

All-IP network - radio interface is purely optimized for IP transmissions not having to

support ISDN traffic – packet based network only

LTE Performance Requirements

Data Rate:

Instantaneous downlink peak data rate of 100Mbit/s in a 20MHz downlink

spectrum (i.e. 5 bit/s/Hz)

Instantaneous uplink peak data rate of 50Mbit/s in a 20MHz uplink

spectrum (i.e. 2.5 bit/s/Hz)

Cell range

5 km - optimal size

30km sizes with reasonable performance

Up to 100 km cell sizes supported with acceptable performance

Cell capacity

Up to 200 active users per cell (5 MHz) (i.e., 200 active data clients)

Technical Details of LTE

Multiple access scheme

Downlink: FDMA (also called DMT)

Uplink: Single Carrier FDMA (SC-FDMA)

Adaptive modulation and coding

DL modulations: QPSK, 16QAM, and 64QAM

UL modulations: QPSK and 16QAM

Rel-6 Turbo code: Coding rate of 1/3, two 8-state constituent encoders, and a

contention- free internal interleaver.

Bandwidth scalability for efficient operation in differently sized allocated

spectrum bands

Possible support for operating as single frequency network (SFN) to support

MBMS


Lesson Content



LTE Radio Interface




System Architecture Evolution (SAE)

System Architecture Evolution (SAE) is the core network architecture of

3GPP's future LTE wireless communication standard.

SAE is the evolution of the GPRS Core Network, with some differences.

The main principles and objectives of the LTE-SAE architecture include:

A common anchor point and gateway (GW) node for all access technologies

IP-based protocols on all interfaces

All IP network - Simplified (and much cheaper!) network architecture

All services are via Packet Switched domain

Support mobility between heterogeneous RATs, including legacy systems as GPRS,

but also non-3GPP systems (say WiMAX)

SAE - System Architecture Evolution

IASA - Inter-Access System Anchor


Lesson Content



LTE Radio Interface




Duplexing Methods for Radio Links

Mobile Station

Base Station

Forward link

Reverse link

)FDDDivision Duplex (Frequency

Forward link frequency and reverse link frequency are different

In each link, signals are continuously transmitted in parallel

Mobile Station

Base Station

Forward link (F1)

Reverse link (F2)

Example of FDD systems

Transmitter

Receiver

BPF: Band Pass Filter

BPF

BPF

Transmitter

Receiver

BPF

BPF

F1

F2 F1

F2

Mobile Station Base Station

)TDDDivision Duplex (Time

Forward link frequency and reverse link frequency is the same

In each link, signals take turns using the channel

Mobile Station

Base Station

Forward link (F1)

Reverse link (F1)

Example of TDD Systems

Transmitter

Receiver

BPF: Band Pass Filter

BPF

Transmitter

Receiver

BPF

F1 F1

Mobile Station Base Station

Synchronous Switches

Downlink Scheme - OFDM

LTE uses OFDM for the

downlink – that is, from

the base station to the

terminal.

OFDM meets the LTE

requirement for

spectrum flexibility and

enables cost-efficient

solutions for very wide

carriers with high peak

rates.

OFDM uses a large

number of narrow sub-

carriers for multi-carrier

transmission.

FDM

OFDM

User 1User 1User 1User 1 User 2User 2User 2User 2

OFDMA

Single user on every channel

Multiple users on every channel

Uplink Scheme - SC-FDMA

The LTE uplink transmission scheme for FDD and TDD mode is based on SC-

FDMA (Single Carrier Frequency Division - Multiple Access).

This is to compensate for a drawback with normal OFDM, which has a very

high Peak to Average Power Ratio (PAPR). High PAPR requires expensive and

inefficient power amplifiers with high requirements on linearity, which

increases the cost of the terminal and also drains the battery faster.

SC-FDMA solves this problem by grouping together the resource blocks in

such a way that reduces the need for linearity, and so power consumption, in

the power amplifier. A low PAPR also improves coverage and the cell-edge

performance.

Still, SC-FDMA signal processing has some similarities with OFDM signal

processing, so parameterization of downlink and uplink can be harmonized.

Multiple Antenna Techniques

MIMO employs multiple transmit and receive antennas to substantially enhance the air

interface.

It uses space-time coding of the same data stream mapped onto multiple transmit

antennas, which is an improvement over traditional reception diversity schemes where

only a single transmit antenna is deployed to extend the coverage of the cell.

MIMO processing also exploits spatial multiplexing, allowing different data streams to be

transmitted simultaneously from the different transmit antennas, to increase the end-user

data rate and cell capacity.

In addition, when knowledge of the radio channel is available at the transmitter (e.g. via

feedback information from the receiver), MIMO can also implement beam-forming to further

increase available data rates and spectrum efficiency

SISO, MISO, SIMO, MIMO …

SISO - Single Input, Single Output

SIMO - Single Input, Multiple Output

MISO - Multiple Input, Single Output

MIMO - Multiple Input, Multiple Output

MIMO Example

Beamforming

Beamforming is a technique

whereby the receiver (typically at a

base-station) adjusts its

transmission or more typically

reception parameters, so as to

concentrate on particular parts of

the cell and not in others.

The purpose of beamforming is to

Maximize the receptivity from the

user and two,

Minimize receptivity from a noise

source. The diagram below shows

how this works

Paired frequency bands defined by 3GPP

for LTE

Unpaired frequency bands defined by 3GPP

for LTE

TD-LTE and FD-LTE (TD-CDMA and FD-CDMA)

The two modulation schemes available in LTE have a high degree of commonality.

The differences exist to accommodate the fact that TD-LTE uses the same pipe to transmit

and receive.

The discontinuous nature of uplink and downlink, however, means operators have the

flexibility to adapt the UL/DL traffic ratio.

This feature allows operators to support different traffic types and symmetry, a common

feature with rich content and video delivery.

LTE Bandwidth


Lesson Content



LTE Radio Interface




SON – Self Organized Network

The term Self-Organizing Network (SON) is generally taken to mean a

cellular network in which the tasks of configuring, operating, and

optimizing are largely automated.

SON focuses mostly on the radio-access, which is the most

consuming resource in the cellular network

One objective of SON is to eliminate as much pre-planning of network

configuration as possible. SON does allow for pre-planned network

configurations, but strongly encourages as much of the network

configuration be automatically generated / discovered as possible

LTE MBMS (E-MBNS) Concept

Digital radio and video transmission per network:

For all users on the

network

For all users in a

geographic area

For a group of users

One way or two-way

user-controlled service

MBMS - Multimedia Broadcast Multicast Services

Femtocells and Picocells

CustomerOperatorSite rental

Locally DeterminedCentrally PlannedFrequency/Radio

parameters

CustomerOperatorTransmission to

Operator’s Network

CustomerOperatorInstallation

FemtocellPicocellAspect

LTE-Advanced

Heterogeneous networks with macro, picocells, relays,

femtocells

Multi carrier aggregation of 40 MHz to 100 MHz

User Deployed Femtocells and Repeaters

Operator Deployed Picocells and relays

LTE-Advanced

Increased data rates and lower latencies for all users in the cell

Data rates scale with bandwidth - Up to 1 Gbps peak data rate

Aggregating 40 MHz to 100 MHz channels provide peak data rates of

300 Mbps to 750 Mbps1(2x2 MIMO) and over 1 Gbps(4x4 MIMO)

LTE - Advanced

LTE Advanced introduces 8x8 DL MIMO, 4x4 UL MIMO and UL

Beamforming


Lesson Content



LTE Radio Interface




Services

The Future Connections

LTE Operating Bands (TS36.101 rel. 9)

The Future – SP Commitments

Standardization Process (SEP-2010)



Part 3 Part 3 –– Competitive Technologies and Competitive Technologies and Advanced NetworksAdvanced Networks


Lesson Content

WiFi and 802.11n

WiMAX


What is Wireless LAN (WiFi)?

General:

A wireless LAN or WLAN is a wireless local area network

Based on the IEEE 802.11 standards

Performance

Typical range is on the order of 10’s of meters

10’s to 100’s of Mbps, depends on standard

Reasonable reliability, low cost devices

Free frequency band – no licenses required !!!

Wireless and Mobile Communications – WiFi

802.11 published in 1997. Works in

The 2.4GHz Band. BW – up to 2 Mbps

Uses DSSS/FHSS Modulation

802.11a Published in 1999. Works in

The 5MHz Band. BW – up to 54Mbps

Uses OFDM modulation

802.11b Published in 1999. Works in

the 2.4GHz Band. BW up to 11.0 Mbps

Uses DSSS modulation

802.11g Published in 2003. Works in

The 2.4GHz Band. BW up to 54Mbps

Uses OFDM modulation

802.11n Published in 2007 (Draft).

Works in The 2.4/5.0GHz Bands. BW up to

248Mbps. Uses OFDM and MIMO

f3f2f1

The 802.11 ArchitectureFixed Terminals

AP

APAP

Unlicensed Frequency Bands

Ultra-low frequency (ULF) -- 0-3 Hz

Extremely low frequency (ELF) -- 3 Hz - 3 kHz

Very low frequency (VLF) -- 3kHz - 30 kHz

Low frequency (LF) -- 30 kHz - 300 kHz

Medium frequency (MF) -- 300 kHz - 3 MHz

High frequency (HF) -- 3MHz - 30 MHz

Very high frequency (VHF) -- 30 MHz - 300 MHz

Ultra-high frequency (UHF)-- 300MHz - 3 GHz

Super high frequency (SHF) -- 3GHz - 30 GHz

Extremely high frequency (EHF) -- 30GHz - 300 GHz

ExtremelyLow

VeryLow

Low Medium HighVeryHigh

InfraredVisibleLight

Ultra-violet

X Ray

Audio

AM Broadcast

Shortwave Radio FM Broadcast

Television Infrared Wireless LAN

Cellular (840 MHz)NPCS (1.9 GHz)

UltraHigh

SuperHigh

UltraLow

5.15-5.25GHz5.25-5.35GHz5.725-5.825

2.4 – 2.483GHz

802.11b/g Channels

2.400GHz 2.441GHz 2.483GHz

111 6

2 7

3 8

4 9

5 10

1 2 3 4 5 6 7 8 9 10 11

5MHz

22MHz

11 Non-overlapping channels

22MHz channel bandwidth, 5MHz channel spacing

The ISM Frequency Bands

The ISM (Industrial, Scientific and Medical) frequency bands

(900 MHz & 2.4 GHz) are un-licensed in most of the world

The ISM rules varies depending on the country:

In the US, the FCC allocates both the 900 MHz and 2.4 GHz band

with 1W maximum power

In Europe, the ETSI allocates only the 2.4 GHz band with 100

mW maximum power


Lesson Content

WiFi and 802.11n

WiMAX


What is WiMAX

WiMAX - Worldwide Interoperability for Microwave Access

Fixed (and nomadic) access: 802.16-2004/802.16d (8/2004)

Mobile access: 802.16e (5/2005)

Typically 2-8 Km’s, Maximum cell size ~45 Km’s

Maximum speed 100 Mbps (64QAM/20MHz)

Wireless and Mobile Communications –

WiMAX

Mid-late 90’s

Early technologies – LMDS, MMDS

No standardization

2001-2003 Early standards,

802.16 - 10-66GHz LOS,

802.16a – 2-11GHz NLOS

2004 – 802.16-2004 (802.16d)

Revision and consolidation of all of

the above

2005 – 802.16e (802.16-2005)

OFDMA, Mobility, Improved security,

Improved MIMO, Competing 4.0G

WiMAX Topologies

Fixed P2PBackhaul

(802.16-2004)Fixed P2MP

Backhaul (LOS)(802.16-2004)

802.16-2004

Fixed/NomadicAccess Provider/Enterprise

Network (NLOS)(802.16-2004/802.16d)

Nomadic Broadband complementary to 3.0G-4.0G

(802.16e)

802.16d (802.16-2004)

IEEE standard for the fixed wireless broadband

802.16d supports both services:

Time division duplex (TDD)

Frequency division duplex (FDD)

Used for fixed access:

Outdoor – when the antenna is located outside the building

Indoor – when the antennas are located inside the building

802.16-2004 (previously 802.16d)

Wi-Fi

Directional antennas

When installed, it’s aligned with base station

It’s fixed – it never moves location

Always higher throughput than omni-directional antenna

Applications

Rural / Macro-cell deployments

Wi-Fi hot spot backhaul

High bandwidth residential connectivity

Challenging environments

Fixed WiMAX, Outdoor

Subscriber Station

802.16-2004 (previously 802.16d)

Omni-directional antenna

Do not require alignment with base

station

Portable but fixed when in use

Lower throughput than directional

Applications

Consumer CaTV/DSL-like

broadband

Customer self installation

predecessor for portable/mobile

Fixed WiMAX, Indoor

Subscriber Station

WiMAX Mobility - 802.16e

Omni-directional antenna

Not aligned with base station

Location can vary

Portable to support both fixed and mobile use

Can be moving while in use

Lower throughput than directional antenna

Lower throughput than Omni-directional (Indoor Fixed)

Applications

Competitor to the 4.0G cellular networks



Part 4 Part 4 –– Advanced NetworksAdvanced Networks


Lesson Content

The "All-IP" core network structure

Mobile IP

SIP and IMS


AIPN – All IP Network – Network Architecture

Service Environment:

Servers and Services

IP Backbone:

MPLS, Ethernet. Routing environment

Access Networks:

Cellular, WIFi, Copper, Optical, …

LTE

Pre-LTE Land-Line

WiFi/WiMAX


Lesson Content


Mobile IP

SIP and IMS


The Problem with Mobility

Internet

Host B

Gateway A171.68.0.0

Gateway C140.31.0.0

Mobile Node171.68.69.10

“Connect to171.68.69.10”

Gateway A replies to Host B with an ICMP host

unreachable

The mobile node (laptop), can work on in two ways:

Fix IP, in which the new local network will not recognize him

Dynamic IP, in which it will take up to several minutes to the network to know him

(ideally)

Where is 171.68.69.10???

141.31.0.0/16


Lesson Content


Mobile IP

SIP and IMS


SIP and IMS

SIP – Session Initiation Protocol

Signaling protocol for IP-Based networks

Signaling for all application types – Voice, Video, gaming, Net-

Meeting, Social-Networks ….

IMS – IP Multimedia Subsystem

Signaling, media and billing protocols, for multimedia over cellular

networks

Summary

Thanks for your time

Yoram Orzach

NDI Communications

[email protected]

introduction to cellular networks

Technology

g cellular networks

wireless communications

g upto

cellular networks history

cellular technologies

cellular networks commercial

wireless mobile communications

g technologies evolution