Coordinated dynamic physical carrier sensing based on local optimization in wireless ad hoc networks

Carrier sensing schemes have been recognized as a key knob for improving network performance. The distributed coordination function (DCF) and its modifications focus on the feature of the ongoing transmission links to enhance link throughput, however, a lack of coordinated adjustment of the surrounding nodes may reduce the aggregate throughput of entire network. In this paper, we are concerned with the delayed transmissions from exposed terminals, and interference and collisions from hidden terminals. We classify the neighboring areas for a given transmission link into three areas: a hidden area, an exposed area and an overlapped area, and then propose a coordinated dynamic physical carrier sense (CDPCS) scheme in which the carrier sensing threshold (CST) values of the neighbors are adjusted at the same time to achieve local optimization by utilizing the exchanged information and states of neighboring nodes. Simulation results show that the proposed schemes can work effectively.