Research On Location Management In GSM-R System

How to trace mobile stations effectively and how to establish the communication with them rapidly, i.e. location management, has become one of the challenging topics in mobile communication. It is quite significant that rational, effective and optimized location management strategies are designed and feasible schemes are given as well.Nowadays, GSM-R system plays a more and more important role in the development of the railway, and it has become the direction of the railway communication. Location management is quite important in GSM-R system because of the shortage in frequency resource, the complicated user catalog and the strict requirements for security and real-time.In this dissertation, the essential theory of location management is introduced at first. Then, the location management scheme in the current 2G mobile communication system is introduced and its open questions are discussed. Subsequently, the location management schemes to be used in the 3G system are studied deeply. In the following chapters, location update and paging are discussed respectively.Based on the particular features of railway communication, a "Group Location Management" strategy for GSM-R system is proposed in order to reduce the location management cost, and two feasible schemes are given according to the current network architecture. One of them, which is named as "Group Location Management Scheme based on GID and VVLR" in this paper, is researched in detail. Compared with the current location management scheme through simulation, Group Location Management Scheme based on GID and VVLR has a lower signaling cost due to the obvious reduction in the number of location updates. As either the number of users in a train or the number of location areas through which a user travels increases, the superiority of this scheme increases. At last, a comparison between the two Group Location Management schemes is made; suggestions about how to apply Group Location Management in GSM-R system are given for engineering reference.