Mobility management for wireless mobile networks.

摘要

Mobility is an important characteristic of wireless mobile networks. The location of a called mobile user must be determined within a certain time limit before any service can be delivered. Thus, mobility management is a key component for the wireless networks to effectively deliver wireless internet services. In the current wireless systems, the mobility management is accomplished by a two-tier hierarchical architecture consisting of Home Location Register (HLR) and Visitor Location Register (VLR). With the increase of the user population and service types, the current mobility management scheme faces serious challenges. Many research works have been carried out to improve the mobility management procedures for the future generation wireless communication networks. In our research, we propose a few new mobility management schemes based on either pointer forwarding or user mobility patterns. In the pointer forwarding based schemes, the user mobility management operation is improved by two kinds of pointer setup procedures and an additional level of management entity---Mobility Agent (MA). The MAs can be distributed among the network based on the current traffic load and user mobility so that the new schemes are more adaptive and robust while minimizing the total signaling traffic. Motivated by the observation that many mobile users follow some daily routines which can be used to predict the users' locations, we propose a user mobility pattern based scheme called MPBS. In this scheme, the users' locations can be determined with less signaling exchange according to the user profiles. We show that this scheme can significantly reduce signaling traffic. Our third research thrust is the mobility management for Mobile IP networks. Currently, the mobility over the Internet is addressed by the Mobile IP protocol. In our research, we present a dynamic hierarchical Mobile IP mobility management strategy (DHMIP). In the DHMIP scheme, an FA hierarchy is set up dynamically among the network and is specific for every mobile user. We also develop a rigorous analytical model to evaluate the performance. The results show that the DHMIP scheme solves the heavy location update traffic problem in Mobile IP protocol effectively.