Semi-distributed radio resource management for elastic traffic in a hybrid network

Owing to the proliferation of different Radio Access Technologies (RAT) in the same operating area, a mobile user is capable of connecting concomitantly to diverse wireless networks in order to meet more easily its target performance. In this paper, we consider the downlink of a multi-class hybrid network with two RATs: WiMAX and 3G LTE. We put forward a semi-distributed Radio Resource Management (RRM) scheme for elastic traffic where both the system and mobile users intervene in the resource management policy. The proposed scheduling scheme is original in the sense that users with elastic traffic have a counterintuitive behavior: they will try to occupy the least amount possible of bandwidth to accommodate QoS stringent streaming traffic. A non-cooperative game is used to load balance the traffic of elastic users between the two available RATs aiming at minimizing their bandwidth consumption. We characterize the Nash Equilibriums (NE) of the RRM game and study the efficiency of a best response algorithm to achieve those equilibriums. Moreover, we propose a fully decentralized algorithm based on replicator dynamics to attain NEs. The system role is to apply an admission control algorithm that limits the number of ongoing connections so that elastic traffic is sustained with a guaranteed minimal rate.