Reducing transmission redundancy of trail-based search strategy in wireless sensor and actor networks

In wireless sensor and actor networks, when an event is detected, the sensor node needs to transmit an event report to inform the actors. Due to the actor´s mobility, its location is always unavailable to sensor nodes. Therefore, the search strategies are always used to transmit data without the actor´s location information. In this paper, we study the trail-based search (TS) strategy which uses the trail information left by mobile actors to improve the search efficiency. Based on the numerical analysis, we prove that there exists nontrivial transmission redundancy in TS strategy. To improve the efficiency of the search strategy, we propose a trail-based search with redundancy reduction scheme (TS-R). The basic idea of TS-R is utilizing the actor´s trail information to locally determine the relay nodes. The theoretical and numerical analysis proves that TS-R can reduce the transmission redundancy without the loss of reliability.