MAC Protocol Design Based on Satellites Presence for Low-Energy Wireless Sensor Networks

A satellite is a way that allows a system administrator to receive data collected by sensors in different geographical areas. To realize this task, a medium access control (MAC) protocol in sensor networks must minimize power consumption in order to extend the lifetime of sensor nodes. To remedy this problem, we first assumed an architecture based on a Low Earth Orbit satellite and a network of heterogeneous sensors (Ordinary Nodes ‘ONs’ and Cluster Heads ‘CHs’). We proposed a MAC protocol, called Satellite Sensor MAC (SS-MAC), which avoids the different causes of energy dissipations. The basic idea behind our protocol is to minimize the number of communications. This number is based on the data quantities collected by each ON (or each CH) in order to extend the lifetime of ONs, which means extend the network lifetime. Our protocol uses four periods: a period for the grouping nodes to form clusters, a Transmission/Reception period between ONs and their CHs, a period when the satellite allocates slots to CHs and a period when CHs send their data to the satellite. Finally, the energy consumption in each period was evaluated through its protocol analysis, numerical results and Markov chain models. All these results have shown the energy-efficient of the SS-MAC protocol.