Handoff Management for Integrated Wireless Mobile Networks

Abstract

One of the key challenges in integrated wireless and mobile networks is to efficiently support multi-class services as each type of services has distinct characteristics and quality of service (QoS) requirements. Problems in handoff algorithm or its parameters may lead into call drops with a direct effect on user satisfaction. This is particularly critical for 3G systems, where high data rate users will be prime candidates for being dropped. Unnecessary handoff leads to degraded call quality and waste of capacity in signaling. Since the cell-size is constantly decreasing, therefore it is important to devise a handoff algorithm which identify users with different mobility and data rate characteristics and maximize the utilization of network infrastructure. A Multiple Queuing System for handoff in integrated real-time and non-real time service with priority reservation and preemptive priority handoff scheme is being analyzed which categorizes the service calls into four different types, namely, real time and non-real time service originating calls, and real-time and non-real-time handoff request calls and divide the channels among these four types of services according to their priorities. The system is modeled using a multidimensional Markov chain and a numerical analysis is presented to estimate blocking probabilities of originating calls, forced termination probability, and average transmission delay. Our results show that the predictions of the analytical model are in very good agreement with simulation results. Scheme significantly reduces the forced termination probability of real-time service calls. The probability of packet loss of non real-time transmission is shown to be negligibly small, as a non-real-time service handoff request in waiting can be transferred from the queue of the current base station to another one.