QoS scheduling for energy-efficient wireless communication

In this paper we present a QoS scheduler that assigns the bandwidth over the wireless channel such that the amount of energy spend by the mobile is minimized, while maintaining the Quality of Service of the connections. Energy efficiency is an important issue for mobile computers since they must rely on their batteries. We have designed and implemented an energy-efficient architecture and MAC protocol for wireless multimedia traffic. The scheduling is based on two mechanisms, 1) a short term transmission frame scheduling that concatenates uplink and downlink traffic of one mobile, and 2) a long-term scheduling, that tries to collect traffic as much as possible within the QoS requirements of the connections. The result is that the transceiver can be in a low-power operating mode for an extended period of time and that the number of operating mode transitions is reduced.