Multi-level Dynamic Guard Channels for Priority Access in Cellular Systems

A multi-level dynamic guard channels (MLDGC) scheme to efficiently provide priority access for handoff calls over new calls in cellular systems is proposed. The switch between levels is controlled by the number of dropped calls. Each additional level has an increasing number of guard channels as triggered by the number of dropped calls. An analytical formulation of the steady state probabilities, new call blocking probability, handoff call blocking probability and system utilization is presented. The handoff call arrival rate is iteratively obtained. Numerical results show that the performance of MLDGC is almost the same as a fixed guard channels (FGC) scheme under light load. However, the advantage of the MLDGC scheme is demonstrated under heavy load where the handoff call blocking probability is much better than that of a FGC scheme, giving more priority and protection to handoff calls over new calls.