On the Optimal SINR in Random Access Networks with Spatial Reuse

In this paper we consider a simple model for a homogeneous random access system with spatial reuse. Our aim is to obtain insight into how physical layer parameters should be determined in order to maximize the total throughput-distance per unit area. In an infinitely dense network, we find that the optimal SINR threshold is asymptotically zero. Furthermore, we find that the optimal distance between transmitter and receiver is asymptotically non-zero. For finitely dense networks, we find that the optimal SINR threshold for packet detection is considerably smaller than that used in many current systems, and that the optimal distance between transmitters and intended receivers is larger than would be expected from prevailing conventional wisdom. These result suggest that the throughput performance of current systems may be improved by operating at lower values of SINR.