Network Configuration for Two-Tier Macro-Femto Systems With Hybrid Access

In this paper, we study uplink network configuration in a two-tier macro-femto heterogeneous system with hybrid access control. We consider a system where one macro base station and a cluster of adjacent femto base stations together serve a number of mobile users. In this system, base stations and users make decisions in various network configuration processes with different optimization objectives. Such decision making processes are usually correlated and an efficient mechanism is needed to coordinate the decision makers. In this work, we propose a five-stage network configuration mechanism where access control, resource allocation and power management are performed sequentially at the base stations and users, respectively. We show that this mechanism provides incentive for the FBSs to operate at the hybrid access mode. We model the configuration mechanism as a multi-stage decision making process and formulate a multi-level optimization problem. We analyze the problem in a bottom-up manner, and propose efficient algorithms to solve the optimization problem in each level sequentially. Simulation results show that the proposed network configuration mechanism achieves a higher system utility than configuration mechanisms with topology-based hybrid access or closed access.