Unidirectional-Valve Based Scheduling for Energy-Efficient Packet Transmission

Abstract

For transmitting a packet over a wireless link, the energy can be saved by decreasing the transmission rate, but the rate is restricted by the arrival time and deadline. This paper proposes unidirectional-valve (UDV) based scheduling for energy-efficient transmission, where the considered packets have individual arrivals and deadlines. The problem can be relaxed into two scenarios: (1) the packets arrive at individual arrivals but have a common deadline; (2) the packets all arrive at the beginning but have individual deadlines. For the two relaxed scenarios, the most energy-efficient scheduling policies are achieved by the forward and backward UDV algorithms, respectively. For the general scenario with individual arrivals and deadlines, the whole transmission time is divided into a series of segments by employing the rate-switching instants of the two relaxed scenarios, and next the forward and backward UDV algorithms are performed recursively on each segment, until it cannot be divided into more segments. The proposed UDV scheduling not only achieves the optimal energy efficiency, but also has low computational complexities, thus it makes a significant sense for packet transmission.