A cooperative MAC protocol with neighbor nodes information for ad hoc networks

Distributed coordination function (DCF) is a compulsory medium access control (MAC) scheme in IEEE 802.11 protocol. In order to avoid the performance degradation due to hidden nodes, DCF adopts RTS/CTS mechanism to decrease collisions. However, the cost of RTS/CTS sharply increases with the number of wireless nodes. This paper has proposed a cooperative MAC protocol (C-MAC) for time-slotted Ad Hoc networks, which resolves collisions by introducing neighbor nodes information. A scheduling algorithm based on the neighbor node list is used to determine which node can transmit data at a particular time slot. In this paper, we analyze the throughput of IEEE 802.11 DCF and C-MAC in mathematics. An inference is obtained: when the network topology is fixed, the throughput of C-MAC is higher than the one of DCE The simulation results proves this inference. C-MAC significantly improves DCF in terms of increasing throughput by 20%~40%. Moreover, C-MAC can obviously improve the fairness of wireless nodes.