Green Networking in Cellular HetNets: A Unified Radio Resource Management Framework with Base Station ON/OFF Switching

摘要

In this paper, the problem of energy efficiency in cellular heterogeneousnetworks (HetNets) is investigated using radio resource and power managementcombined with the base station (BS) ON/OFF switching. The objective is tominimize the total power consumption of the network while satisfying thequality of service (QoS) requirements of each connected user. We consider thecase of co-existing macrocell BS, small cell BSs, and private femtocell accesspoints (FAPs). Three different network scenarios are investigated, depending onthe status of the FAPs, i.e., HetNets without FAPs, HetNets with closed FAPs,and HetNets with semi-closed FAPs. A unified framework is proposed tosimultaneously allocate spectrum resources to users in an energy efficientmanner and switch off redundant small cell BSs. The high complexity dualdecomposition technique is employed to achieve optimal solutions for theproblem. A low complexity iterative algorithm is also proposed and itsperformances are compared to those of the optimal technique. The particularlyinteresting case of semi-closed FAPs, in which the FAPs accept to serveexternal users, achieves the highest energy efficiency due to increased degreesof freedom. In this paper, a cooperation scheme between FAPs and mobileoperator is also investigated. The incentives for FAPs, e.g., renewable energysharing and roaming prices, enabling cooperation are discussed to be consideredas a useful guideline for inter-operator agreements.