Leveraging Dynamic Spare Capacity in Wireless Systems to Conserve Mobile Terminals' Energy

In this paper we study several ways in which mobile terminals can backoff on their uplink transmit power in order to extend battery lifetimes. This is particularly effective when a wireless system is underloaded as the degradation in user's perceived quality of service can be negligible. The challenge, however, is developing a mechanism that achieves a good tradeoff among transmit power, idling/circuit power, and the performance customers will see. We consider systems with flow-level dynamics supporting either real-time or best effort (e.g., file transfers) sessions. The energy-optimal transmission strategy for real-time sessions is determined by solving a convex optimization. An iterative approach exhibiting superlinear convergence achieves substantial amount energy savings, e.g., more than 50% when the session blocking probability is 0.1% or less. The case of file transfers is more subtle because power backoff changes the system dynamics. We study energy-efficient transmission s...

• Type: Journal
• Year: 2010
• Where: TON
• Authors: Hongseok Kim, Gustavo de Veciana
• Keywords: Energy Savings, File Transfer, TON 2010, Transmit Power