Interference Aware (IA) MAC. An Enhancement to IEEE 802.11b DCF

The IEEE802.11 has been devised explicitly for low mobility and single access point scenarios, so its effectiveness is impaired in conditions with not negligible interference in ad hoc and/or in infrastructure modes. Well known problems typical of these scenarios are the so called hidden and exposed terminals. In this paper we propose and test a novel MAC layer for wireless LANs, able to improve the performance of IEEE802.11 DCF (distributed coordination function) in environments with high interference levels. The key point is to insert information about received power and interference levels into MAC control packets. By computing an estimation of the interference increasing due to an eventual transmission (forbidden with IEEE802.11 because blocked by the virtual carrier sensing), the number of parallel transmissions can grow significantly.