Mac Layer Protocol For Ad Hoc Network

Ad hoc networks are deployed rapidly without reliance on existing network infrastructure and are self-configurable. Due to its characteristics of without any fixed infrastructure and without being limited by fixed topology. Ad hoc networks are applied in civilian emergency and military environment. Besides, it can supply rapid configurable ability as wireless access network.The Medium Access Control (MAC) protocol used in wireless Ad hoc networks is IEEE 802.11 DCF (Distributed Coordination Function). But IEEE 802.11 DCF exists many problems in multi-hop networks. For example due to the Binary Exponential Backoff algorithm used in IEEE 802.11. it leads to fairness problem. That is to say, some stations grab the shared channel and other stations suffer from starvation. In order to solve the fairness problem, [4] proposes MILD (Multiple Increase Linear Decrease) algorithm. But MILD and EIED algorithm are both proposed in WLAN model.This paper compares BEB .. MILD and EIED algorithm in wireless, multi-hop Ad hoc networks. Simulation tool is NS2~[6]. Besides, simulation results show that using MILD and EIED can improve the fairness of network. There is a tradeoff between the total throughput and fairness. Besides, this paper studies MAC protocols using directional antennas and MAC protocols for reliable broadcast support in Ad hoc networks. Then this paper summarizes the proposed protocols and displays my proposals on existed problems.