Cellular Systems Flashcards
List wireless connectivity characteristics
Transmission Errors
Low bandwidth
Long or variable latency
Asymmetry in bandwidth and error characteristics
Cellular System?
Space divided into cells
Base Station is responsible to communicate with hosts in the cell
Mobile Stations can change cells while communiciating
Main Elements of a mobile system
Physical User equipment Radio Access Network RAN Core Network Logical Air interface
GSM Network Architecture
Base Station Subsystem (BTS - BSC)
Network Switching Subsystem
MSC - data traffic nw - GMSC
VLR HLR AuC
Model of Cellular System
Core Network CN - Radio Access Network - RAN - Radio Interface - User Equipment
What is a mobile station?
Communicates the information with the user and modifies to the transmission protocols of the air interface to communicate with the BSS
What elements does a mobile station have?
Mobile Terminal
An interface with the user
Subscriber Identity Module
Smart card issued by the SP.
What is BSS?
Base Station Sub-System
Between the air interface and the fixed wired infrastructure
transcoding
What does BSS consist off?
Base Transceiver Station
Base Station Controller
what is BTS?
Counterpart of the mS for physical communication
what is BSC?
A group of bts is controlled by bsc
Network Switching Sub-System (NSS)
Is responsible for network operation
What is MSC?
Mobile Switching Centre
Hardware part of the wireless switch that can communicate with PSTN swithes as well with other MSCs
What is HLR?
A database that handles the management of all the subscriber account of particular operator
What is VLR?
Temporary database identifyin the subscribers visiting the coverage area
