Preemptive Channel Allocations for Cellular Networks with Multiple Sectors

Abstract—This paper presents preemptive channel allocations (PCA) for multiple-sector cellular networks, where directional antennas are used to divide the coverage of a cell into a number of same-sized sectors. When traffic in a sector unexpectedly increases, call blocking probability will increase accordingly. To remedy channel insufficient problem in a single sector, two aspects of channel preemptions are utilized. First, to reduce the blocking probability of new calls, the proposed PCA allows a new call to preempt an ongoing call when the ongoing call is located in the overlapping regions of two adjacent sectors or two neighboring cells. Second, the reserved channels not only can be used by the handoff calls, but also by the preempted calls. For the purpose of performance evaluation, we build an analytical model with four-tuple Markov chains. Numerical results show that the proposed PCA scheme improve the system performance in terms of the blocking and preemption probabilities. Keywords-Preemptive channel allocations; multiple sectors; cellular networks; blocking probability; Markov chains; I