Traffic prediction based access control in wireless CDMA networks supporting integrated services

In this paper an access control protocol is proposed and analyzed for an integrated video/voice/data DS-CDMA (direct-sequence code division multiple access) system. The protocol involves predicting the residual capacity available to non real-time data services in the reverse link (mobile to cell-site). Each real-time voice or video call is assumed to handle bursty traffic by utilizing one or more DS-CDMA channels, in parallel, as provisioned in IS-95-B and cdma2000 standards. The arrival of new calls well as the variations in the aggregate bit-rate of the existing real-time calls, and hence the number of occupied channels with respect to time, are modeled as a two-dimensional imbedded DTMC (discrete time Markov chain) process. The state of the Markov process is predicted to compute the residual capacity or the number of data packets that could be scheduled in the next time slot. Simulation results obtained, using synthetic data, are presented to demonstrate the viability of the approach. The main contribution of the paper is that it presents a simple yet effective application of the two-dimensional imbedded Markov chain model in the access control of integrated services in the reverse link of a CDMA cell.