Call admission control and resource allocation of wireless networks

Abstract

In the next–generation wireless communication, Orthogonal Frequency Division Multiplexing (OFDM) is a potential key technology. A CAC scheme is proposed for subcarrier allocation in OFDM–based wireless multi–service network. Call connection requests are divided into two classes: (i) narrowband calls and (ii) wideband calls. Traffic is characterised as batch arrival process for both classes of the calls, so that each call may request multiple subcarriers to satisfy its Quality of Service (QoS) requirement. There is a provision of buffer for narrowband calls, whereas the sub–rating scheme is used for wideband calls. The successive over–relaxation method is employed to solve the set of steady–state equations governing the traffic model. Various performance measures such as blocking probability of wide and narrowband calls, overall blocking probability of the calls and bandwidth utilisation are established. The sensitivity analysis has also been carried out to depict the effects of various system parameters on the performance measures.