Mumbai University > Information Technology > Sem 7 > Wireless Technology

Marks: 10M

Year: Dec 2015, May 2016

ME is made up of two entities

1. Mobile Equipment (ME) – portable device
2. Subscriber identity module (SIM)
3. Protected by password or pin
4. Smart card contains IMSI (international mobile subscriber identity)

BTS: encodes, encrypts, multiplexes, modulates and feed RF signals to antenna

• Communicates with mobile station and BSC
• Consists of transceiver (TRX) units

BSC: base station controller

• Manages radio resources for BTS
• Handles call setup
• Handover for each MS

MSC: mobile switching center

• Heart of network
  • Billing
  • Mobility management
  • Communication between GSM and other networks

HLR: home location register

• Stores info about each subscriber that belongs to IMSC in permanent and temperory fashion
• Contains IMSI

VLR: visitor location register

• Temporary database which updates whenever new MS enters its area
• Contains mobile roaming in its area

AUC: protects network from fraud

ELR: equipment identity register stores IMEI nos. and prevents calls from stolen devices.

OMC: operations and maintenance center for fault report, performance supervision etc.