Call processing functions in the integrated satellite and GSM system

Integrating satellite-PCN and GSM system can reduce the system cost and enhance the mobile accessibility. However, the specific properties of the satellite systems require modifications to the GSM system to adapt itself to different integration scenarios. This paper addresses various difficulties and issues on performing the call processing function in the satellite segment of two integration scenarios: the single MSC integration scenario and the split MSC integration scenario. With each integration scenario, modifications to the GSM signalling protocols, call processing procedure and related function distribution have been made accordingly to accommodate the specific features of the satellite systems. Comparisons between these two scenarios are given. Under the criteria of minimum modification to the existing system and minimum network signalling load, the optimal integration scenario can be identified.