Analytic Modeling of Handoffs in Wireless Cellular Networks

In this paper, we report our recent work on closed form solutions to the blocking and dropping probability in wireless cellular networks with handoff. First, we develop a performance model of a cell in a wireless network where the effect of handoff arrival and the use of guard channels are included. Fast recursive formulas for the loss probabilities of new calls and handoff calls are given. Algorithms to determine the optimal number of guard channels and the optimal number of channels are developed. To determine the handoff arrival rate into a cell, a fixed-point iteration scheme is proposed, and the uniqueness of the fixed-point is shown. Then, we allow for failure and repair of channels and hence provide a performability analysis for cellular systems. We present a hierarchical model combining both perofrmance and availability and its closed form solution. Performability measures of interest are explicitly given.