Effective Connection Admission Control Research Articles

Wide-Band TD-CDMA MAC With Minimum-Power Allocation and Rate- and BER-Scheduling for Wireless Multimedia Networks

A wide-band time-division-code-division multiple-access (TD-CDMA) medium access control (MAC) protocol is introduced in this paper. A new minimum-power allocation algorithm is developed to minimize the interference experienced by a code channel such that heterogeneous bit-error rate (BER) requirements of multimedia traffic are satisfied. Further, from analysis of the maximum capacity of a time slot, it is concluded that both rate and BER scheduling are necessary to reach a maximum capacity. Based on the new minimum-power allocation algorithm as well as on rate and BER scheduling concepts, a new scheduling scheme is proposed to serve packets with heterogeneous BER and quality of service (QoS) requirements in different time slots. To further enhance the performance of the MAC protocol, an effective connection admission control (CAC) algorithm is developed based on the new minimum-power allocation algorithm. Simulation results show that the new wide-band TD-CDMA MAC protocol satisfies the QoS requirements of multimedia traffic and achieves high overall system throughput.

Distributed admission control for power-controlled cellular wireless systems

It is well known that power control can help to improve spectrum utilization in cellular wireless systems. However, many existing distributed power control algorithms do not work well without an effective connection admission control (CAC) mechanism, because they could diverge and result in dropping existing calls when an infeasible call is admitted. In this work, based on a system parameter defined as the discriminant, we propose two distributed CAC algorithms for a power-controlled system. Under these CAC schemes, an infeasible call is rejected early, and incurs only a small disturbance to existing calls, while a feasible call is admitted and the system converges to the Pareto optimal power assignment. Simulation results demonstrate the performance of our algorithms.