Mapping between SCCP and BSSMAP

Circuit Identity Code is a traffic chanel id on A-interface and valid between MSC and BSC only. By knowing CIC MSC or BSC may correlate each signalling message from other peer on A-interface with appropriate call. There is switching matrix in BSC similar one in MSC but smaller. It is BSC related task to switch subslot on A-bis interface to subslot on A-ter interface (timeslot on A-interface) only during call time. There is no permanent static mapping a radiointerface TCH to A-interface TCH.

Dear, Sachin,
Yes, it is optional parameter, but if MSC requests TCH from BSC for speech call then terrestrial circiut (CIC) also must be allocated in Assignment Request. This CIC is correlated in BSC with Local Reference and TCH after TCH assignment. Using this information BSC switches the CIC with A-bis subslot assosiated with allocated TCH.

Dear, Sachin,
There is no meaning to have a static mapping because number of TCH on radiointerface > number of TS on A-interface. There is low probability that all TCH on all BTS will occupied simultaneously. And BSC must to support concentration function similar one Access Network (e.g. V.5.2) does in PSTN.

i want to kno how can i give diffrent device chanel in e1 such like fox or RTU

Hi,
Please let me know what will be the behavior of BSC if it receives 2 assignment request with different CIC on the same SCCP connection.