Mobile networks

Revision as of 14:34, 10 October 2012

A mobile network is composed by the following parts:

• Mobile Station (MS)
• The base stations subsystems (BSS)
• The network and switcing subsystem (NSS)
• The operations and support subsystem (OSS)

Mobile Station (MS):

• the mobile equipment (Ex: phone)
• the SIM (Subscriber identity Module) card that uniquely identified the card by the IMSI (International Mobile Subscriber Identity).

The base station subsystem (BSS):

• base station (BTS) - it defines a cell in the network
• base station controller (BSC) - controls a group of BTSs. Does handoffs, frequency hoppings, exchange functions and power control over each managed BTS

The network and switching subsystem(NSS)

• Home location register(HLR) - holds all subscribers in a network. Keeps subscriber specific information like MSISDN, IMSI, current location of the MS, roaming restrictions, additional features.
• AUC
• EIR
• Mobile switching center (MSC) - handles call routing, call setup, and basic switching functions. Does inter BSC handoffs and coordinates inter MSC handoffs
• GMSC
• Visitor location register (VLR) - is associated a local area(LA). Keeps information similar to the one in the HLR for the users in it's current local area