Performance and Cost Evaluation of Fixed Relay Nodes in Future Wide Area Cellular Networks

Future cellular networks are expected to provide significantly higher capacity than today´s systems. This might require a denser access point deployment, with a potential increase in network deployment cost as a consequence. A promising way to reduce cost is a multi-hop deployment where wireless relay nodes (RN) are introduced to enhance capacity and coverage. In this paper, a deployment procedure for a static radio environment is considered, adding RNs incrementally as a complement to initially deployed macro base stations (BS). Different strategies of deploying BSs and RNs, providing equal service levels, are analyzed from a cost perspective. We develop a methodology that can determine and compare the most cost efficient deployment mixes of BSs and RNs. Further, we compare a deployment of macro BSs and relays with a deployment of macro BSs and micro BSs. Results show that relays are more cost efficient if the micro BS cost is between 10 and 15 % higher compared to the cost of an RN.