Synergy between adaptive channel coding and media access control for wireless ATM

Abstract

We propose mechanisms to exploit the synergy between the media access control (MAC) layer and the physical layer for wireless ATM applications. For simplicity, the system considered consists of a single server and a single wireless ATM terminal. A number of virtual circuit connections (VC), with varying quality of service (QoS) requirements, are supported. We focus on two components of the wireless ATM system, namely the channel encoder and the ATM scheduler in the MAC layer. The channel encoder is responsible for protecting the ATM cells over the hostile radio channel while the ATM scheduler is responsible for allocating limited resources to the ATM cells for each virtual connection so as to meet the specified QoS requirements. We consider two configurations, namely System-I with isolated adaptive channel encoder and ATM scheduler, and System-II with bi-directional information exchange. It is found that significant performance improvement on the cell loss rate (CLR) and the mean cell delay (MCD) could be achieved for systems exploiting the synergy.