Abstract

There has been a great interest lately in the utilization of the ATM technology for networks. Especially in recent years, wireless ATM has emerged. The wireless links are characterized by higher, time-varying error rates and burstier error patterns in comparison with the fiber-based links from which ATM was designed. The mean time error checking and correction get more and more important and necessary. In this work, a new multilayer error control technique is presented and analyzed for ATM networks. While standard Go-Back-N ARQ technique is applied end to end, a new lost-cell concealment technique cooperates below as a forward error correction mechanism that also operates end to end. As the cell travels the inter-network enroute to the destination ATM user node interface (UNI), the CRC is checked and the cell is dropped or passed to the next ATM hop accordingly. The error detection and correction techniques above are applicable to connection oriented traffic, however in this work we deal with the connectionless case. The choice of one of these alternatives has its implication on the CRC regeneration at each ATM Network Node Interface (NNI). In this work we present the hierarchy of the error control technique above, and analyze the end to end user performance in terms of net throughput and reliability. In the process we investigate the interactive effects of the channel and ATM signaling parameters on the system performance, with particular emphasis on the design of the error control scheme.