On the Performance Analysis of Call Admission Control with SIR Guard Margin in WCDMA Systems with Multi Class, Non-Uniform Traffic Distribution

摘要

This study presents the performance of call admission control and resource reservation schemes in WCDMA cellular systems with multi-class traffic and non-uniform traffic distribution among cells. In order to minimize the handoff dropping probability, the mobility of the user is predicted based on the mobility history of users. The mobility prediction scheme used in this research is based on computational learning theory, which has shown that prediction is synonymous with data compression. In order to utilize resource more efficiently, we predict not only the cell to which the mobile will handoff but also the time of occurrence of handoff. Based on the mobility prediction, resource is reserved in terms of Signal to Interference Ratio Guard margin (SIRGM) to guarantee a defined target handoff dropping probability. It is considered that the traffic distribution is non uniform among cells and some amount of resource is reserved for the traffic originated in the neighboring cells. Three types of traffic i.e., voice, audio, video each requiring different data rates are considered. The admission threshold is adaptively controlled to achieve a better balance between guaranteeing handoff dropping probability and maximizing resource utilization. Simulation results show that the mobility based resource reservation scheme outperforms the static-reservation scheme.