Efficient scheduling schemes for real-time traffic in wireless networks

In this paper, we study the problem of scheduling real-time traffic in wireless TDMA channels. Specifically, we propose scheduling schemes that dramatically improve the delay performance of individual flows, while at the same time provide fairness and quality of service (QoS) guarantees. Previous works in this area have overlooked one or more of these aspects, so our study is both novel and valuable. Our first scheduling scheme assigns equal delay to all flows. However, it turns out that insisting on equal delays can adversely affect network utilization. We propose a second, related scheduling scheme which improves the network utilization by exploiting the time-varying nature of wireless channel conditions, while at the same time minimizing delay violations. We observe that the impact of these two schemes on delay and network utilization depend strongly on the channel characteristics. Interestingly, our proposed equal-delay scheme appears to perform well over a wide range of channel characteristics, with the added advantages of its simplicity for implementation and admitting an analyzable admission control