Wireless packet scheduling with signal-to-noise ratio monitoring

A key challenge in packet scheduling over a wireless channel is to achieve effective throughput against bursty errors. Although there have been several proposals on packet scheduling for a wireless channel, they are only based on bi-modal channel states: good or bad. In this paper we propose a new packet scheduling scheme for wireless links based on receiver's Signal to Noise Ratio (SNR). The scheme is referred to as SNR-based Packet Scheduling (SPS). In SPS, outgoing packet flows are scheduled such that the flows with higher SNR values have larger weights in scheduling. SPS can achieve effectiveness by adopting a flexible mapping between weight and SNR. We present measured results of the relationship between throughput and SNR as well as the design and implementation of SPS. In our experiments, SPS has shown its effectiveness in enhancing total throughput for hosts with good and bad wireless connectivity over a wireless LAN.