An efficient polling MAC for wireless LANs

Polling schemes are an important class of medium access control (MAC) proto cols for wireless local area networks (WLANs). A major drawback of these sc hemes is their inefficiency when only a small number of mobile stations hav e packets to transmit. This inefficiency is due to the polling of mobile st ations with no packets to transmit, which delays the transmissions of mobil e stations with packets. In this paper, we suggest a new polling MAC which exploits the capture phenomena and enables simultaneous polling and transmi ssions of information packets. Mathematical analysis and simulation results show that the new MAC overcomes the above inefficiency considerably, and t hus it is more efficient in the sense that it enables higher throughput and a lower access delay. For example, we show scenarios in which the average access delay is reduced by about 30% and the throughput increases by 66%-75 %.