Energy aware cross layer uplink scheduling for multihomed environments

With the continuous evolution of wireless technologies, there is today a plethora of access networks ranging from wireless hotspots to high speed cellular networks. Within this rich environment and with multimodal terminals that are able to connect to different wireless technologies at once, users are expecting to benefit from higher throughput and enhanced QoS. However, the coexistence of several wireless systems rises different technical challenges including interface selection, packet scheduling, multi-path routing and mobility management. At the network level, recent protocols such as MTCP and mSCTP allow session continuity and offer the possibility of seamlessly adapting IP routing during a transmission session. These protocols are mainly based on the use of a set of IP addresses that can be associated to the same terminal and user session. But at the access level, efficient packet scheduling mechanisms on multiple interfaces are still required. New rules and approaches are needed to select the most suitable technology that better fits QoS requirements considering the dynamic mobile user environment. In addition, optimizing energy consumption should also be considered in order to lengthen mobile terminals' battery lifetime. In this paper we propose an energy efficient cross layer scheduling mechanism for multi-homed wireless terminals. The proposed algorithm goes through the use of energy models for both 802.11n and LTE technologies to dynamically select the more suited technology according to users' context. Performance evaluations of the proposed algorithm are presented and discussed. They show that a significant energy saving can be achieved while respecting applications QoS requirement.