Describe radio aspect and security aspects of IS-95 system.

27views

written 5.8 years ago by

teamques10 ★ 68k

• modified 5.8 years ago

Radio aspects of IS 95system

Moduation	Quadrature phase shift keying or variations
Channel/Chip rate	1.2288 Mcps
Nominal data rate (Rate Set 1)	9.6 kbps
Filtered bandwidth	1.23 Mhs > 1.25 Mhz with guard band
Coding	Convolutional coding Constraint lenth = 9 Viterbi decoding
Interleaving	With 20 ms span

Security aspect of IS 95

CAVE (cellular authentication and voice encyrption) algorithm is used .
Uses a 64 bit A-key along with ESN and Random number to generate 128 bit shared secret data (SSD) • SSD is divided into two 64 bit blocks – (A for authentication, B for encryption)
Challenge/Response technique for Authentication .
Random number is used to create key for encryption of voice and data

enter image description here

CSS- Cellular Subscriber Station

BS-Base station

MSC- Mobile switching center

HLR-Home location registers

EIR-Equipment identity register

VLR- Visiting location registers

AC- Authentication center

Mobile Switching Centre- (MSC): The MSC co-ordinates the activities of all the base stations and connects the entire cellular system to the PSTN. A typical MSC handles 100,000 cellular subscribers and 5,000 simultaneous conversations at a time, and accommodates all billing and system maintenance functions as well. Communication between the BS and mobiles is defined by a standard Common Air Interface (CAI) that specifies four different channels.

Base Station-BS- The base station is installed for every cell. It communicates with all the mobile stations existing in its cell. The BS Communicates with the mobile switching center (MSC).

ADD COMMENT EDIT