IEEE 802.11 MAC protocol enhanced by busy tones

Two novel MAC schemes are proposed to solve the hidden terminal problem and the exposed problem in ad hoc networks with large interference range. With the aid of dual busy tones, one scheme is a simple enhancement to IEEE 802.11, and the other is to exactly signify the interference range by adjusting the transmission power of busy tones. Both of the two schemes are able to prevent the collisions of data/ACK packets. The numerical results show that the two proposed schemes are able to enhance the saturation throughput of IEEE 802.11 significantly. The proposed VPDBT MAC can balance the trade off between spatial reuse and collision avoidance.