Measurement-based admission control in UMTS

In this paper, we develop an efficient Call Admission Control (CAC) algorithm for UMTS systems. We first introduce the expressions that we developed for Signal-to-interference (SIR) for both uplink and downlink, to obtain a novel CAC algorithm that takes into account, in addition to SIR constraints, the effects of mobility, coverage as well as the wired capacity behind the base station, for the uplink, and the maximal transmission power of the base station, for the downlink. As of its implementation, we investigate the measurement-based approach as a means to predict future, both handoff and new, call arrivals and thus manage different priority levels depending on a tunable coefficient. Compared to classical CAC algorithms, our CAC mechanism achieves better performance in terms of outage probability and QoS management.