An adaptive energy-efficient MAC protocol “Guardian” for wireless sensor networks

Wireless sensor networks are collections of sensors that are equipped with a radio and form a wireless network together. The main advantages of wireless sensor networks are fast and easy deployment, and low maintenance cost. Energy is a scarce resource in such networks, which has a great impact on the design of hardware and software. The hardware is cheap and limited. Software is specialized; network protocols must be designed for sensor communication patterns and focus on low energy consumption. The easiest way to reduce energy consumption is to turn off the radio when it is not needed as the major part of energy is being consumed in radio transmission and reception. In order to overcome the power inefficiency and to increase the adaptivity of network, a new MAC(Medium Access Control) protocol “Guardian” has been design. The specialized guardian node ensures energy efficiency of its child node .Initially all the nodes are in sleep mode, they wake up after a defined quanta of time to check at the guardian node, weather any request is to be served. Implementation of the Guardian protocol on OMNeT++ has shown that, in an idle situation, the radio can be turned off for as much as 92.3% of the time, reducing the total energy used with more than 90%. Guardian protocol could be implemented in all sorts of scenarios due to it´s high adaptivity. It could be implemented even in a situation with high message rates without increase the latency.