Abstract: Environmental monitoring is major application of Wireless sensor networks. WSNs consist of sensor nodes. Each sensor node accoutered with low cost sensor, small battery and a microcontroller. Environmental monitoring need battery powered sensor nodes active for long period, which tends to drain battery easily. Repeatedly charging or changing of batteries is not practical solution. In order to widen network lifetime, reduction in energy consumption of sensor nodes is a major challenge. So, energy efficiency of WSNs need to be improved. The different WSN energy efficient techniques used in environment monitoring are review here.
Keywords: Environmental monitoring system, Energy efficiency, Wireless sensor network, GPS, Zigbee.