MOBILITY MANAGEMENT SCHEMES AND THEIR CHARACTERISTICS FOR ADVANCED PERSONAL COMMUNICATION SERVICES IN DISTRIBUTED ENVIRONMENTS

A mobility management scheme that reduces signaling traffic load and c onnection setup time is a pivotal issue in designing future personal c ommunication service (PCS) networks to satisfy. Quality of Services re quirements and use network resources efficiently. Particularly, requir ed is scalable mobility management, to meet the explosive growth in nu mber of users for the current second-generation wireless communication systems, and to materialize PCS concepts such as terminal, personal, and service mobility. Many mobility management schemes have been propo sed for the reduction of signaling traffic. However, these schemes hav e not been sufficiently compared using a unified performance measure t hat is free of assumptions as to mobility model or database architectu re. In this paper, we categorize the various mobility management schem es for advanced PCSs in distributed environments into four types and c larify the appropriate domain for each type. To do this, we settled on the number of signals at connection setup and location registration a s a unified performance measure, since this value closely relates to c onnection setup time and network efficiency. We found two kinds of sch emes with replicating and caching functions of user information that a re extremely effective for reducing signaling load and hence connectio n setup time. These schemes are appropriate when the probability that a user is in his/her home area is relatively small or the connection s etup rate is relatively high compared to the location registration rat e. These are the most likely situations in the advanced PCS For global environments.