PL-MAC Protocol for Wireless Sensor Networks of the Underground Tunnel

The structural health monitoring (SHM) is indispensable to safety operation of subway system. SHM largely depends on wireless sensor networks (WSNs) to perform a variety of tasks such as vibration monitoring, crack detection, and water leakage detection. According to specific task requirements, multiple types of sensor nodes are singled out to form WSNs applied for subway system. When these sensor nodes are deployed in the subway monitoring fields, it is hard for traditional Medium access control (MAC) protocol to establish communications links for data transfer. Considering the complex underground environments, Priority level-based MAC (PL-MAC) is developed for sensor nodes to fairly and efficiently share communication resources among themselves.