On the optimal number of hops in infrastructure-based fixed relay networks

Abstract

In this paper we analyze the optimal number and locations of fixed radio relay stations forming links in infrastructure-based wireless networks. Under the assumptions of using orthogonal channels for the hops and all links having the same average path loss exponent, we show using the spectral efficiency as a metric that the optimal relay locations are at equal intervals along the straight line between source and destination whenever multihop is to be utilized. We show that a single-hop fixed radio link can be efficiently (from a spectral efficiency perspective) replaced with the link only if the single-hop SNR has a relatively low value. We introduce a multi-hop criterion to quantify the single-hop SNR value below which a more efficient replacement exists. We also determine the optimal number of hops for the links having relays disposed in straight line at equal intervals