1. 1

2. AGENDA
 Introduction.
 What is Spread Spectrum.
 Architecture of CDMA.
 Application of CDMA.
 Limitations of CDMA.
2

3. INTRODUCTION
 CDMA is a digital wireless technology.
 It uses Spread Spectrum technique.
 It was pioneered and commercially developed by QUALCOMM .
 Interim Standard-95 , standards for first generation CDMA cellphone
technology.
 The first CDMA system was launched in September 1995 by Hutchison
Telephone Co. Ltd. in Hong Kong and SK Telecom in Korea.
3

4. Spread Spectrum Technique
Carrier + Carrier +
Data Data
PN code PN code
Generator Generator
TRANSMITTER RECEIVER
4

5. ARCHITECTURE OF CDMA
MS M SC PSTN
Um E Ai
Abis A B
BT S BSC M S C/SSP VLR
BSS
Q C D
M N N
MC MC HLR AUC
MSS
5

6. APPLICATION OF CDMA
6

7. ARCHITECTURE OF CDMA
7

8. LIMITATIONS OF CDMA
 As the number of users increases its performance decreases.
 ‘FAR-NEAR’ problem.
 It is limited in terms of Coverage and Roaming.
 It does not have a SIM card that makes M-Commerce difficult.
8

9. THANK YOU
9