written 5.9 years ago by | • modified 5.9 years ago |
As shown in the figure, the signaling at the radio interface (Um) consist LAPDm at layer 2. LAPD is the modified version of LAPD (link access protocol channel)
Layer 3 is diviided into 3 sublayers that deal with radio resource management C mobility management (MM), and connectio management (CM), respectively.
- The radio resouce management is concern with managing logical chas including the assignment of pagine channels, signal quality measurer reporting and handoff.
- The mobility managemetn provides function necessary to sup user/terminal mobility such as terminal registration, location upadates authentication and IMSI detach/attach.
- The connection management is concern with call and connection com establishing and clearing calls/connections, managemetn of supplemt services and support of the SMS.
- The Abis interface between the BTS and the BSC tends to be a properitary inter in most GSM implementations.
- The radio resource layer (RR') in the BTS is responsible for cha establishment and release, handoff and paging.
The BTS managemetn (BTSM) layer looks after the management c aspects of the radio channels, including radio link layer, control chan and transceiver management.
The BSC to MSC interface (A interface ) and the interface between and MSC VLR/HLR or another MSC deploy ITU-T signalling system 7 (SS7) using
- MTP (message transfer part)
- SCCP (signalling connection control part)
- TCAP (transcation capability application part)
MAP (mobile application protocol)
Connection between the MSC and other PSTN/ISDN exchanges utilize the Telephone user part (TUP) or the ISDN user per (ISUP) specific to the country or region.