Achievable QoS in an Interference/Resource-Limited Shared Wireless Channel

Abstract

In this work, the region of achievable QoS-which is central to the development of a call admission control mechanismis precisely described for a system of heterogeneous VBR sources with real-time service constraints. The QoS for each application is defined in terms of a packet dropping probability. Packets may be dropped due to delay violations and channel induced errors. The shared transmission resources are defined to be the slots (packet transmission times) of a TDMA frame. The region of achievable QoS is precisely described for a interference/resource-limited network by considering the underlying TDMA-MAC structure and the physical channel. A simple DLC protocol that combats the effects of the wireless channel while satisfying the real-time requirements is proposed and its impact on the region of achievable QoS is evaluated. The results presented here clearly illustrate the negative impact of a poor channel and the positive impact of the employed DLC protocol on the achievable QoS.