Joint Control to Improve Spatial Reuse for Mobile Ad Hoc Networks

Spatial reuse in a wireless network can allow multiple communications to proceed concurrently. Usually it seems that the more concurrent transmissions are allowed, the more the aggregate throughput can be sought. Unfortunately, to increase the level of spatial reuse, medium access control (MAC) protocols should either reduce the transmit power or increase the carrier sense (CS) threshold dynamically, which will make the SINR at the receiver decrease. With the decrease of SINR, the data rate sustained by each transmitter will also decrease, which counteracts the gain of simultaneously transmissions and leads to the degradation of network performance. The conflict among SINR and spatial reuse of the data rate suggests that there should be a tradeoff between them. In this paper, on the basis of theoretical analysis, we propose a dynamic joint control (JC) mechanism to adjust transmit power, sense threshold and data rate, based on the former transmit status, to increase the level of spatial reuse and improve performance in terms of aggregate throughput and energy efficiency.