A wakeup scheme for sensor networks: achieving balance between energy saving and end-to-end delay

Energy saving is a critical task for sensor networks with limited energy supply. Wakeup schemes that turn off sensors' radio when communication is not necessary have great potential in energy saving. However, existing wakeup schemes encounter critical tradeoffs between energy saving and wakeup latency, and little attention has been paid to reducing the packet end-to-end delay while preserving the energy saving capability. We argue that a long delay can be detrimental for large sensor networks. We propose a wakeup scheme that helps to achieve the balance between energy saving and end-to-end delay. The conditions under which the proposed scheme can show improvement are identified.

1. Introduction

The rapid development in microelectronics and wireless communication technologies makes the deployment of large scale sensor networks possible. The communication among sensors is typically driven by events. In many applications (e.g., intrusion detection, disaster alarming, etc.), events occur rather infrequently. For such scenarios, sensors spend a considerable fraction of lifetime to monitor the environment, during which little communication is needed and sensors are said to be in the “monitoring state”. Once events are detected, sensors may need to leave the “monitoring state” and actively communicate with each other.