Wait and Watch Technique: Removing Time synchronization overhead in Wireless Sensor Network

Wireless sensor networks are a nascent type of ad-hoc networks that had drawn the interest of the research community in last few years. They require working together for distributed tasks. Accurate and reliable time is one of the needs for some of its applications. The use of traditional time synchronization protocols for wired network is restricted by severe energy constraint in sensor network. The realization of time synchronized network poses many challenges, which are the subject of active research in the fileld. In this paper we argue that clock synchronization provides a lot of overhead, and can be eliminated in some of the cases. We advocate that sensor should be allowed to run unsynchronized. The time when any event of interest occurs, the sensor node records that event in its memory with timestamp from its cluster head's clock, instead of its local clock.