06.introduction To Cdma

Introduction to CDMA

Objectives  Introduce

CDMA Networks

– What is CDMA? – What are the benefits? – What is CDMA2000? – Future of CDMA – How does a CDMA call work?

What is CDMA?  Code

Division Multiple Access

– Unique identification of users through

digital codes – Simultaneous use of radio spectrum by multiple users  Digital

Spread Spectrum Technology  Uses wideband radio channel  Built-in interference minimization

Spread Spectrum Techniques  Use

of wide band to transmit relatively narrow band data  Types of spread spectrum techniques: – Frequency Hopping Spread Spectrum

(FHSS) – Direct Sequence Spread Spectrum (DSSS)

CDMA Concept $%&@#

CDMA can bring big business

This is John Doe

• Cocktail party in same room (same wide band channel) • Use different languages (different digital codes)

CDMA Advantages 

Advantages from a user perspective – Inherent privacy – Higher capacity – Increased battery life – Reliable handoffs (Soft handoff) – Quality (Multipath diversity)



Advantages from an operator perspective – Simpler deployment (Same frequency everywhere) – Capacity (Variable rate coding, power control) – Cost reduction (backhaul efficiency) – Fully compatible evolution path

Soft Handoff  “Make-before-break”

approach  Graceful, non-muted handoff  Allows mobile to transmit with less power requirements

Cell A

Cell B

Power Control  Increases

battery life  Dynamic control of power transmitted to and from mobile  Reduces interference to other users  Increases system capacity

CDMA2000

CDMA2000 Network Architecture CS-CN MSC/VLR

HLR

IS-41

AC

RAN

PS-CN

BSC

PDSN/ FA

AAA Server

HA

IP Network

MS BTS

Internet

cdma2000 (1x) Capabilities Technology

Data Rates

Spectrum

Services

IS-95 A/B

115.2 kbps

1.25 MHz

Voice and circuit switched data services

1xRTT

614.4 kbps

1.25 MHz

Voice, circuit data, and packet data

1X-EV-DO

2.45 Mbps

1.25 MHz

Packet data services

1.25 MHz

Voice, Circuit, Packet and multimedia services

1X-EV-DV

3.09 Mbps

CDMA2000 Major Players Equipmen t Vendors

Service Providers

Ericsson Lucent Technologies Motorola Nortel Networks

North America

Sprint PCS Verizon Bell Mobility

Japan Korea

KDDI SK Telecom

India

Tata, Reliance, BSNL

Organizations

CDMA Development Group (CDG) 3G Global Partnership Project 2 (3GPP2)

Handsets LG Motorola Nokia Kyocera Samsung

CDMA2000 Radio Access Network 1x and 1x-EV A-Interface

BSC R-P Interface

Circuit Switche d CN

PSTN / ISDN

Packet Switche d CN

Internet

1x 1.25 M Hz Car rier (sa 1.2288 me as Mcps s IS-95) preadin g rate (same IS-95) as

• Backward compatible with IS-95 • IS-95 and 1x users supported on the same carrier • Higher capacity (expected gain > 50%) • True support for high-speed packet data • Supplemental channel provides support for asymmetric data rates and bandwidth on demand

1xEV-DO  Data

evolution option for CDMA2000

networks  Provides

data rates up to 2 Mbps using 1x

carrier  Does

not provide voice services, optimized

for data services only  Requires

IS-95

dedicated carrier 1xEV1x

DO 1xEVDO

For Voice + Data High-Speed Data

1xEV-DV  Data

and voice evolution option for

CDMA2000 networks  Provides

data rates up to 3 Mbps using 1x

carrier  Supports

voice and data simultaneously

 Backward

compatible to 1x – can share

same carrier IS-95

1x

1xEVDV

Voice and High Speed Data

End-to-End Flows

Circuit-Switched Call Setup Service Request Exchange

Service Request Exchange Authentication

Radio Channel

Terrestrial Link Setup

Terrestrial Link

MSC

Service Connect and Synchronization

BSC/ BTS

MS

Radio Link Setup

Packet-Switched Call Setup Service Request Exchange

Service Request Exchange

MSC

RAN Authentication Radio Link Setup

R-P Session Link

IP Netwo rk

Mobility related connection/setup (if required)

HA

Point-to-Point Connection Setup

HLR/AC

PDSN

Radio Channel

BSC/ BTS

MS

Service Connect and Synchronization

R-P Session Setup

IS41

Summary       

CDMA stands for Code Division Multiple Access CDMA uses the same frequency in adjacent cells User channels are differentiated using unique digital codes (similar to different languages) Soft handoff is making a new link before dropping the old one Soft handoff increases reliability of handovers Major CDMA providers in India are Tata Tele, Reliance, BSNL 2 evolution options for 1x CDMA: 1xEV-DO (Data Only) and 1xEV-DV (Data and Voice)