Impact of physical layer parameters on the MAC throughput of IEEE 802.11 wireless LANs

In this work, we investigate the impact of physical layer parameters packet error rate (PER) reduction, range extensions and data rate enhancement - on the MAC throughput of 802.11 networks, We present a new analytical model for the MAC throughput that takes into account variable data rate transmissions, packet losses due to collisions, and packet losses due to channel fading. Our new model shows decent agreement with simulation results. The analytical and simulation results indicate if one attempts to increase the MAC throughput by reducing re-transmissions via PER reduction, the physical layer processing time (captured in the SIFS) should not be increased substantially. Otherwise, throughput losses is observed. On the other hand, allowing for the data rate enhancement via range extensions (by keeping the PER constant and moderate increase in the SIFS) may increase the MAC throughput measurably. For one particular scenario, we show a 25% increase in the MAC throughput for a nominal increase in the range of less than 25%.