An energy-efficient wireless routing protocol for distributed structural health monitoring

Congestion-induced packet loss leads to throughput degradation in wireless sensor networks and often requires energetically expensive retransmissions. Though collisions can be avoided (CSMA/CA), the required carrier-sensing also increases the sensor node energy consumption. In this paper, an energy-efficient routing protocol for a distributed monitoring application is proposed. Although the development of the new protocol was motivated by a specific use-case, it is applicable to all static-topology wireless sensor networks where multiple sensor nodes need to simultaneously distribute information to all other nodes in the network. First, we model the globally known network topology as two directed graphs representing reachability and interference. Based on this model, we define an integer linear program to find a collision-free communication schedule with the minimum number of transmissions and receptions required for distributing the data (multi-commodity information flooding). As these ILPs are hard to solve for larger networks, we also propose a heuristic for scheduling. Compared to other advanced flooding protocols, the proposed schedule can reduce wireless activity by up to 90 %, with the heuristic solver achieving a solution quality just 4 % worse than the optimal ILP solution.