Call Admission Control in OFDM Wireless Multimedia Networks

Call admission control is an effective mechanism to guarantee robust services in wireless networks. In this paper, we present several call admission control algorithms and queueing models for the subcarrier allocation in the OFDM-based wireless multimedia networks. Call connection requests are differentiated into narrow-band call and wide-band call. For either class of calls, the traffic process is characterized as batch arrival since each call may request multiple subcarriers to satisfy its quality-of- service (QoS) requirement. The batch size is a random variable following a probability mass function (pmf) with realistically maximum value. In addition, the service time for various classes are different. The formulae for the significant performance metrics call blocking probability and bandwidth utilization are developed. Numerical investigations are presented to demonstrate the interaction between key parameters and performance metrics. The performance tradeoff among different call admission control algorithms are discussed. Moreover, the analytical model has been validated by the simulation. The methodology as well as result provides an efficient tool for planning the future generation OFDM-based broadband wireless access system.