부산대학교 도서관

Wireless sensor and actuator networks (WSANs) are expected to be come fundamental technologies supporting machine-to-machine (M2M) communication and the internet of things (IoT). However, wireless sensors face inherent limitations because they must provide high demand response (DR) despite severely limited battery power. In an effort to achieve both power-saving characteristics in addition to high DR, we are working on research and development of radio-on-demand sensor and actuator networks (ROD-SANs), in which each node is equipped with a wake-up receiver that allows all nodes to stay in sleep mode most of the time, and transmit only after a wake-up signal is received. Since the wake-up signal can also include channel information, the sender nodes can direct the receiver nodes to switch communication channels when needed. However, as the number of nodes using the same channel increases, packet collisions occur more frequently, thereby degrading response performance. On the other hand, frequent channel switching inevitably increases channel switching delays. To simultaneously reduce both packet collisions and channel switching delays, we have extended the average-channel-utilization-based channel switching (ACS) scheme, discussed in our previous work on single-hop communication in a way that allows it to provide efficient performance in multi-hop communication. In this paper, based on simulations, we show how our scheme can improve the delivery ratio performance by approximately 20%.