On improving the performance of IEEE 802.11 with multihop concepts

It is well known that IEEE 802.11 provides a physical layer multirate capability. In this paper, we propose a novel MAC layer relay-enabled point coordination function (PCF) protocol, called rPCF, to exploit this capability. With multiple data rates in response to different channel conditions, if the direct link has low data rate, data packets may be delivered faster through a relay node. To enable MAC layer relay, the access point needs to collect information about the channel conditions, and notify mobile nodes which data rate to use and whether to use a relay node. We design protocols to achieve this goal and refine these protocols to minimize the control overhead. Simulation results show that rPCF can significantly improve the system performance in terms of system throughput and transmission delay with a very small control overhead.