Date Added: Oct 2012
In this paper, the authors consider a joint macro-relay network with densely deployed Relay Stations (RSs) and dynamically varied traffic load measured by the number of users. An energy efficient strategy is proposed by intelligently adjusting the RS working modes (active or sleeping) according to the traffic variation. Explicit expressions related to the network energy efficiency are derived based on stochastic geometry theory. Simulation results demonstrate that the derived analytic results are reasonable and the proposed strategy can significantly improve the network energy efficiency. The coexistence of relays and conventional macrocells namely joint macro-relay network is proposed as a promising network deployment to provide coverage extension and throughput enhancement, while significantly lowering the network energy consumption.