MAC-PHY enhancement for 802.11b WLAN systems via cross-layering

The paper analyses the performance of a novel MAC-PHY scheme for wireless local area networks (WLAN) that makes use of distributed queues and cross-layer concepts to improve radio channel utilisation. Analytical values for the maximum throughput performance are derived as a function of different scenario parameters. The obtained results show that the proposed scheme outperforms throughput bounds achieved when using a legacy 802.11 MAC protocol. The usage of distributed queues and cross-layer information eliminates back-off periods and collisions in data packet transmissions, makes performance to be independent of the number of stations transmitting in the system and provides stability for high load conditions. Furthermore, the cross-layer concept allows the MAC layer to improve its decisions by means of physical layer information knowledge.