Handover following in a mobile radio system by monitoring signalling messages

摘要

A method is provided of following a communication transaction during which a commuincating mobile station (12) is handed-over from one radio cell to another in a mobile radio system. The transaction is followed across the handover by monitoring signaling messages on the signaling paths in the mobile radio system to detect the occurrence of common parameters related to communication transactions subject to handover. By correlating these parameters it is possible to associate fragments of the same transaction that give rise to signaling messages on different signaling paths. Thus in the case of a GSM mobile radio system with monitoring of the A interfaces, the parts of a communication transaction split by a handover from one BSC (17A) to another (17Z), can be associated by correlating the RR3 Handover Command signaling units appearing on the signaling links (68,69) to the old and new BSCs (17A,17Z). This correlation can conveniently be done at a central station (42) to which the signalling path monitors (40A,40Z) send report messages when they detect handovers occurring. A similar correlation can also be done when monitoring the Abis interfaces. <IMAGE>