Abstract: The topology of WSN in coal mine is band-type, which seriously constrained the energy balance among sensor nodes. Uneven clustering strategy can effectively balance energy consumption among nodes in the global sense,making it suitable for coal mine application. We presented an energy-balanced routing protocol on the basis of adaptive clustering mechanism which can construct unequal clusters according to the metrics such as distance to the sink node, energy level and node density. In competing cluster head, tentative cluster heads decided whether to become a cluster head according to the relative energy level compared with neighbor tentative nodes, avoiding the nodes having low energy level being cluster heads. During the data transmission stage,inter-cluster multi hop routing algorithm was designed,taking the linear topology of cluster heads in to account The algorithm not only considered the minimum energy consumption of the path but also concerned energy balance among forwarding nodes to protect those low-energy nodes. Simulation results show that the routing protocol dramatically balances the energy consumption among nodes and achieves an obvious improvement on the network lifetime.

Key words: Coal mine, Wireless sensor network, Band-type network, Energy balancing, Uneven clustering, Multi-hop routing