Transmission Order Deducing MAC (TOD-MAC) protocol for CSMA/CA wireless networks

The increase in physical (PHY) layer transmission rates in IEEE WLAN does not necessarily give the corresponding increase of MAC layer throughput because of MAC overhead such as PHY headers and contention time. To improve MAC layer efficiency, we propose the Transmission Order Deducing MAC (TOD-MAC) protocol, which controls packet length in such a way that the transmission duration is adjusted to implicitly provide necessary information for a node to determine its transmission order among all the nodes in a network. Each node transmits frames of different duration, and thus the other nodes can determine the time when they can transmit, which has the same effect as announcing the transmission order, without using a control message. Each node transmits a frame in a round robin manner, which minimizes the idle time between two consecutive transmissions without collisions, and significantly improves the MAC efficiency in very high speed CSMA/CA wireless networks. Extensive simulation results indicate that TOD-MAC achieves high throughput performance, short/long-term air-time fairness in multi-rate networks and excellent transient behavior in dynamic environments.