A distributed power and rate control scheme for mobile ad hoc networks

The IEEE 802.11 Distributed Coordination Function (DCF) is the medium access protocol widely used for wireless local networks (LAN). Unfortunately, IEEE 802.11 DCF described in the standard faces some challenges when adopted for multi hop networks, which arise from the presence of the so-called hidden stations. This can cause degradation of the network throughput performance and energy consumption. Solving the hidden terminal problem will increase the possibility of the so-called exposed terminal and vice versa. In this paper, we present a novel scheme, called PRAS-CP ( transmission power and rate adaptive scheme with collision prevention), which enhances network performance through balancing the tradeoff between the hidden terminals and the exposed terminals. To accomplish this, PRAS-CP integrates the Physical/MAC attributes ( the carrier sensing range and the interference range) and carrier sensing mechanisms (PCS, VCS) to assign the appropriate data rate and transmission power values to successfully exchange the RTS/CTS DATA/ACK packets. Simulation results under different scenarios are used to demonstrate the significant throughput, energy gains, and fairness that can be obtained by PRAS-CP.