A simple analytical framework for location management in personal communication systems

Efficient mobility management for portable stations (PS's)-handoff, channel assignment and locating-will play an important role in future personal communication systems (PCS's). Among these tasks, location management plays a critical role for wide-area roaming. The key elements of locating are location registration/updating and paging. Due to the smaller cell size in PCS, the high boundary crossing rate of PS will result in more frequent location area (LA) updating. This, in turn, will result in more interrogations with location registers, which will generate a higher volume of access and signaling traffic (SS7 traffic). One solution to this problem is to increase the size of LA, which, unfortunately, also increases paging traffic. Efficient paging algorithms may generate relatively less paging traffic such that larger LA's may become plausible. Depending on the call-arrival rate to the cell, boundary crossing rate, optimum size of LA, and paging technique used, the overall cost could vary substantially. The paging techniques considered in this paper are simultaneous paging and sequential paging. The two schemes are studied in detail in order to understand the problems associated with location management in the PCS environment. In the authors' opinion, this paper provides, for the first time, a simple yet powerful analytical framework which can be used to analyze "intelligent" paging schemes as well as simultaneous and sequential paging.