Pricing-based distributed mobile association for heterogeneous networks with cooperative relays

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, we 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. In this paper, we propose a new mobile association framework for the heterogeneous wireless networks with intra-cell node cooperations. The proposed framework aims to maximize the network capacity and balance the traffic load among the network nodes. Furthermore, we introduce a pricing mechanism to enable the distributed implementation of the proposed scheme. Numerical results show that a prominent improvement in network capacity can be achieved by the proposed pricing-based mobile association scheme.