Novel heuristics for call admission control in cellular systems

This paper proposes three new heuristic call admission control algorithms for a cellular system that carries a single class of homogeneous traffic and uses fixed channel assignment; the weighted sum scheme, the probability index scheme, and the hybrid control scheme. The weighted sum scheme uses the weighted sum of the number of calls underway in various cells when making the admission decision. The probability index scheme computes a probability index, which reflects the forced-termination probability of a new call arrival, and admits those calls with low probability indices. The hybrid control scheme combines the weighted sum scheme and the probability index scheme. These novel algorithms are compared with three known algorithms: the reservation scheme, the linear weighting scheme, and the distributed admission control scheme. Each of the algorithms attempts to optimize two quality of service (QoS) metrics: the new call blocking probability, which is the probability that a new call is denied access to the system, and the forced-termination probability, which is the probability that a call is terminated prematurely (i.e., prior to call completion). Based on our simulation results, the hybrid control scheme yields the best performance and the weighted sum scheme is second. The reservation scheme does relatively well considering its simplicity.