FR-MAC: a frame relay MAC for capacity and throughput enhancements in multi-rate wireless LANs

There has been much research effort to exploit the multi-rate capability of WLANs to improve performance. While these approaches focused on exploiting good channel conditions for direct transmission between stations, there are no considerations of performance degradation by low rate transmissions due to poor channel conditions. Thus, we propose a frame relay based MAC protocol, termed FR-MAC, to tackle this issue and to improve network performance. The key idea of FR-MAC is that the time required to transmit a frame using an intermediate station as a relay can be much smaller than the direct transmission at a lower rate, if the intermediate station between the source and the receiver can relay the frame at higher rates. Simulation results show that the proposed protocol improves network performance and the amount of improvement significantly increases as the number of relayed stations and the payload size are increased.