Date Added: May 2012
Heterogeneous networks improve the spectrum efficiency and coverage of wireless communication networks by deploying low-power nodes on top of the conventional network nodes. In this paper, the authors consider a heterogeneous cellular network with multiple low-power Relay Nodes (RN) deployed in each cell using in-band wireless backhaul between the RN and the Base Stations (BS). The RNs work cooperatively with the BSs on the downlink communication towards the User Equipments (UE). Due to the disparity between the transmit powers of the BSs and the RNs, mobile association schemes developed for the conventional homogeneous networks may lead to a highly unbalanced traffic loading with most of the traffic being concentrated on the BSs.