On dynamic policies to switch off relay nodes

Regenerative (or non-regenerative) wireless relays have recently emerged as a key technology for future and emerging mobile wireless networks, since they allow quick network roll out and improved capacity and coverage of existing networks. Nonetheless, the usefulness of extra capacity (and/or coverage) afforded by relay nodes is largely wasted insofar as the network load is small. This is because the base station (BS) can leverage the spare radio resources to serve the users. Hence, in time periods of low utilization wireless relays can be potentially switched off so that the overall energy consumption of the network is reduced. In this paper dynamic decision rules are derived to switch off relay stations with a view to increase the energy efficiency of mobile relay-aided cellular networks. Numerical investigations reveal that the proposed schemes provide significant benefits in terms of energy consumption compared to the standard “always-on” policy for relay nodes.