This thesis studies the main characteristics of Wireless Sensor Networks (WSN), especially 'the issue of energy efficiency' in the wireless MAC layer, and proposes three new MAC protocols. These are named as TEEM (Traffic aware, Energy Efficient MAC), MAC-CROSS and LE-MAC (Latency and Energy aware MAC) protocols, respectively.
The first scheme (TEEM) makes the active duration adaptive by utilizing the two novel approaches of 'adaptive listen period' and 'RTS piggybacking' and hence achieves a significant decrease in power consumption. The second scheme (MAC-CROSS) can solve the 'compulsory wake-up' problem by using a cross-layer concept between MAC and routing layers. Finally, the last scheme (LE-MAC) supports the balance of the energy consumption and data latency in wireless sensor networks.
By being studies on NS2 simulation environments and being implemented on real sensor network test-beds with Motes sensors, the proposed three schemes are proved to be improved in terms of energy efficiency.