Distributed spectrum-efficient routing algorithms in wireless networks

This paper applies spectral efficiency as a performance measure for routing schemes and considers how to obtain a good route in a wireless network as the network signal-to-noise ratio (SNR) varies. The motivation for this study is to combine different wireless routing perspectives from networking and information theory. The problem of finding the optimum route with the maximum spectral efficiency is difficult to solve in a distributed fashion. Motivated by an information-theoretical analysis, this paper proposes two suboptimal alternatives, namely, the approximately ideal path routing (AIPR) scheme and the distributed spectrum-efficient routing (DSER) scheme. AIPR finds a path to approximate an optimum regular path that might not exist in the network and requires location information. DSER is more amenable to distributed implementations based on Bellman-Ford or Dijkstra's algorithms. The spectral efficiency of AIPR and DSER for random networks approaches that of nearest-neighbor routing in the low SNR regime and that of direct communication in the high SNR regime. Around the regime of 0 dB SNR, the spectral efficiency of DSER is up to twice that of nearest-neighbor routing or direct communication.