PRESENTATION ON

CBSC

CONTENTS :

Introduction of AN

Introduction of SDU

Introduction of VPU

Introduction of MM

Introduction of XC

Capacity of RAN Element

Basic Call Flow

CDMA Network ArchitectureCDMA Network Architecture

MM

SDU

Voice pathData path

AAA

PDSN

To Packet Data

NetworkTo PSTN

XC

HAMSC

OMC-RVPU

Packet Backhaul

ANAN

1X Packet BTS 1X Packet BTS 1X Packet BTS

MS / AT MS / AT MS / AT

MS - Mobile StationAT - Access TerminalBTS - Base Transceiver stationAN - Access NodeSDU - Selection & Distribution

UnitVPU - Vocoder Processing UnitXC - TranscoderMM - Mobility Manager OMCR - Operation & maintenance

Centre for RadioMSC - Mobile Switching centerPSTN - Public Switched Telephone NetworkPDSN - Packet Data Serving NodeAAA - Authentication, Authorization and Accounting ServerHA - Home Agent Routers

BSC (Base Station Controller)Base Station Controller manages the radio resources for one or more BTS.

BSC is connection between Mobile station and MSC

BSC interfaces with PCF (Packet Control Function) for packet data call.

BSC Gathers calls from many BTSs and passes them to MSC.

• BSC reserves radio frequencies, manages handoff of mobile unit from one cell to another within BSS, and controls paging

AN(Access Node)

The AN hardware architecture consists of two custom frames, the Aggregation Point frame and the IP Switch frame.

AN = MGX + MLS

AN (Access Node):The Access Node (AN), a set of IP switches and routers, interconnects all of the cellular infrastructure devices and transports IP–based traffic to and from the CDMA 2000 (1X) cellular network.

The Aggregation Point and IP Switch frames, in addition to housing the Cisco equipment, provide power distribution functions.

MGX :-

The Aggregation Point frame houses one or two Aggregation Points (MGX 8800/8850 )

CARDS IN MGX :-

1. FRSM OR MPSM2. PXM3. RPM4. SRM

WORKING OF MGX CARDS FRSM ( Frame Relay Service Module )

One FRSM card has 8 E1 It has (N+1) per shelf redundancyConversion of Packet frames to ATM ( Asynchronous Transfer Mode ) cells

MPSM (Multiservice Protocol Service Modules)

It has 16 E1

PXM (Switched Mode Processor )

It is the brains of the MGXIt controls all the cardsIt provides Internal ATM switchingIt handles RPM redundancyIt also has 1:1 hot standby Redundancy

SRM (Service Resource Module)

It provides redundancy control for the FRSM cards.It has 2N Redundancy

RPM (Router Processor Module )

It determines the path to route traffic to & fro the next NE

PP ( Patch Panel )

MGX connected with MLS through this panel .

MLS connected with SDU through this panel .

VPU , MM , ROUTER all are connected with MLS through this panel .

MLS ( Multi Layer Switch )

It performs all switching operation in BSC

IT has two layer

layer 2

layer 3

The IP Switch interconnects the other cellular infrastructure devices and supports various types of Ethernet LAN interfaces.

SDU (Selector & Distributor Unit) Description  

The SDU (Selection/Distribution Unit) provides the following main functions:

Soft handoff reverse link selection and forward link distribution

Soft handoff detection

Global power control

Speech vocoding negotiation

Packet data interworking and buffering

ATM interworking for Inter-Vendor Soft Handoff (IVSHO) Gateway.

Signaling Traffic Flow : SDU to BTS

Cards in SDU An SDU consists of a single shelf of equipment. Physical

devices include the following: SPROC (System Processor) ISB (Interface Service Board) CCA BPP (Bearer Payload Processor) MLS_SDU_LINKs Relays Power supplies Fans.

All are visible on the management interface.

SDUs are not interconnected and are managed individually by the system. Software and data must be loaded into each by the OMCR, statistics are collected separately, and commands are sent to each.

An SDU can be configured for:

SDF/PCF functionality only

IVSHO functionality only

Both.

The MM views multiple SDUs as a pool of SDF and PCF resources to be allocated. The MM makes requests through a Resource Allocator (RA) function residing on an SPROC and the RA selects the particular resource instance for the call. The MM and SDU negotiate the available resource via the Resource Management protocol. Multiple MMs can connect with multiple SDUs.

SPROC :The SPROC performs the following functions:

S Acts as the SDU system processor.

S Performs the “Resource Allocation/Management” function.

ISB :The ISB is the hub/star switch and the primary network interface.

VPU ( Vocoder Processor Unit ) Description  

The VPU (Vocoder Processing Unit) provides transcoding, in other words, transforming digitally vocoded signals to/from Pulse Code Modulation. The VPU performs transcoding between PCM and digital vocoding as well as echo cancellation.

A VPU consists of a single shelf of equipment. Physical devices include the SPROC, ISB, CCA, BPP, DOC3, MLS_VPU_LINKs, control relays, power supplies, and fans and all will be made visible on the management interface.

VPUs are not interconnected and are managed individually by the system - software and data must be loaded into each by the OMC-R, statistics are collected separately, commands are sent to each, etc.

The VPU provides blocking and unblocking of TERCKTS through the interface with the MSC through the MM. The MM makes requests through a Resource Allocator (RA) function residing on an SPROC and the RA selects the particular resource instance for the call. The MM and VPU negotiates the available resource via the Resource Management protocol. Multiple MMs can connect with multiple VPUs.

VPU Architecture :

MM ( Mobility Manager )

It’s a main part of CBSC .

It controls functioning of all devices .

It carries only signalling and not traffic .

MM I --- Card Based System.

MM II -- Server Based System.

Signaling Traffic Flow : MM to BTS

XC ( Transcoder )

It forms Token ring between XC & MM , It must be UP

UNO (Universal Network Operator)

Event / Alarm Management

Performance Management

Configuration Management

Access Node Functioning:

SDU CAPACITY –

Total Number of BPP card in 1 SDU = 13

1 BPP card having = 12 DSP chip

1 DSP Chip can support = 32 calls at a time

Calls supported by 1 SDU = 13*12*32

= 4992 calls(5000 calls apprx.)

VPU Capacity –

Total Number of BPP card in 1 VPU = 15

1 BPP card having = 18 DSP chip

1 DSP Chip can support = 10 calls at a time

Calls supported by 1 VPU = 15*18*10

= 2700 calls at a time

MM Capacity –

MM-I = 5000 Erlang MM-II = 7000 Erlang

MLS Capacity = 40,000 Erlang

Conclusion - 1 MLS can supports = 8 MM-I or 5 MM-II ( max.) For 1 MM-I = 2 VPU+ 1 SDU

Traffic link between MSC-VPU = 27 + 63 =90 E1

1 E1 support = 30 calls

total calls supported by 1 VPU = 90*30 = 2700 calls

VOICE TRAFFIC FLOW:

DATA CALL TRAFFIC FLOW:

Operations and Maintenance Center

The operator uses the OMC–R to generate the configuration files for the IP Switch, in terms of adding links to the network, and other functions.An Operations and Maintenance Center – IP (OMC–IP) will handle

operations and maintenance control for the Access Node components and interface with the existing network management

architecture, i.e. the OMC–R and UNO platforms. Cisco software products are planned to run on a Sun hardware platform with a Solaris operating system. Other BSC elements, such as the SDU, MM, XC, and BTS are supported and managed by the OMC–R.

THANK YOU