关键词：传感器；带宽；睡眠技术；监听
摘 要：Sensors have limited resources such as energy, computational power and bandwidth, and thus they require protocols and techniques that are resource aware and energy efficient. As energy waste through idle listening, retransmissions and overhearing are some of the primary causes of reduced lifetime in wireless sensor networks, sensor sleeping is critically important. Sleeping techniques prolong the network lifetime by placing components of the sensor node into a sleep mode while aiming to minimize the impact on application performance. Sensor sleeping can be applied to different layers of the protocol stack, and a cross-layer sleep manager can orchestrate sleeping in multiple layers simultaneously. In this chapter, the importance of sensor sleeping, the various sleeping techniques proposed and the applications using these approaches are discussed.