In wireless sensor networks during critical event monitoring only a small number of packets have to be transmitted. The alarm packet should be broadcast to the entire network as earlier, if any critical event is detected. Therefore, broadcasting delay is an significant problem for the request of the unsafe event monitoring. To extend the network lifetime some of the sleep scheduling methods are forever employed in WSNs it results in a important broadcasting delay. A novel sleep scheduling technique to be planned it is based on the level-by-level offset schedule to attain a low distribution delay in wireless sensor networks (WSNs). There are two phases to set the alarm broadcasting primary one is, if a node detects a critical event, it make an alarm message and quickly transmits it to a center node the length of a pre-determined path with a node-by-node offset way. Then the center node broadcasts the alarm message to the other nodes along another prearranged path without collision. An on demand distance vector routing protocol is recognized in one of the traffic direction for alarm transmission. The proposed system is used in military and forest fire application.

Wireless Sensor Network (WSN), critical event monitoring, sleep scheduling, broadcasting delay

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