Delay Performance Analysis of a Two-Stage Cross-Layer Scheduler for Wireless LANs

The transport of real-time data flows over wireless channels can be optimized by cross-layer schedulers which serve the different users dependent on their traffic load and channel state. This paper investigates the delay performance of a two-stage cross-layer scheduler which has been designed to meet the above requirements. The well-known Weighted Fair Queuing Scheduler can tramsmit packets within a guaranteed delay that can be analytically determined, however the delay cannot be adjusted directly. The latter is possible with the scheduler discussed in this paper, where a transmission is performed in a stochastic way which means a certain percentage of the packet is lost, which is however often tolerable for applications such as video or VoIP. An analytical approach of the delay performance of the scheduler is given and validated by simulation results.