QoS provisioning for wireless ATM by variable-rate coding

This paper presents a solution to the problem of providing quality-of-service (QoS) guarantees in an ATM network with wireless links. The suggested resolution to this problem is through selectable-rate channel coding. In particular, rate-compatible punctured convolutional (RCPC) codes are employed due to their several attractive features that make them favorable for ATM-based applications. In this adaptive scheme, the RCPC code rate is intelligently varied in response to the channel's nonstationary behavior according to the channel state information (CSI). This yields an equivalent stationary channel with a fixed and predetermined bit-error rate (BER) in which QoS can be guaranteed. In order to demonstrate the performance of RCPC codes in providing and maintaining the QoS, a lognormal fading channel model is assumed. An architecture is proposed for the wireless link. This system assumes that accurate CSI is available at the transmitter as well as at the receiver. Bandwidth utilization of the proposed system under various channel conditions is then evaluated, plotted, and discussed.