Energy consumption in monitoring and communication protocols for wireless sensor networks became one of the most important performance objective.We assume a commonly accepted sensor network model in which sensors can interchange idle and active modes both for monitoring and communicating. We introduce a reliability requirement for distributed target-monitoring protocols and prove that previously considered protocols [1],[2] are reliable.

In this paper we propose a new Deterministic Energy- Efficient Protocol for Sensor networks (DEEPS) aimed at prolonging the lifetime. We prove that DEEPS is reliable and compare DEEPS with several known target-monitoring protocols in NS2 environment using LEACH[4] protocol for data delivery to the base. We implemented the full-fledged simulation of the monitoring protocols on NS2 combined with LEACH[4] as a communication protocol, and performed extensive experimental study of several protocols showing almost 2 times increase in the lifetime for DEEPS over known protocols.