IMPACT OF THE LOCATION AREA STRUCTURE ON THE PERFORMANCE OF SIGNALINGCHANNELS IN WIRELESS CELLULAR NETWORKS

The authors consider connection-oriented wireless cellular networks su ch as IS-54, IS-95, GSM, and wireless ATM networks. These are connecti on-oriented digital networks which employ separate radio channels for the transmission of signaling information. A forward signaling channel is a common signaling channel assigned to carry the multiplexed strea m of paging and channel-allocation packets from a base station to mobi le stations. For wireless ATM networks, paging and virtual-circuit (VC ) allocation packets are multiplexed across the forward signaling chan nels as part of the VC setup phase. A reverse signaling channel, which employs a contention-oriented medium access algorithm, is used by mob ile stations to send channel-request and location-update packets. A lo cation area is a region which includes a specified set of adjacent cel ls; it is used to track the location of mobile stations. Mobile units must reregister as they cross the boundary of a location area. The cha nnel setup and paging response times are critical performance factors in the design of the signaling subsystem. A location area structure mu st be suitably selected to ensure that acceptable levels of such perfo rmance functions are achieved. A network which employs small location- areas will experience a high rate of location updates, while larger lo cation areas lead to higher traffic intensities of paging messages. In this article, combining the operation of forward and reverse signalin g channels, the authors overview a method for calculating the performa nce behavior of signaling messages. Subsequently the impact of the loc ation area structure on the performance of the signaling system is inv estigated.