XY-expansion: Joint search and clock synchronization for wireless sensor and actor networks

Due to the movement of actors and duty cycle of sensor nodes, the problem of emergent data forwarding from sensor nodes to mobile actors is very challenging. Meanwhile, clock synchronization is essential for the event-related data forwarding process. Inspired by the research results in multi-agent systems, we consider the search packet as an agent moving in the network to search mobile actors. Then a new strategy called XY-expansion is proposed to control the search process. The clock synchronization problem is considered among the involved nodes in the search process, which is of importance to the data forwarding following the search process without incurring too much extra overhead.