| dc.description.abstract | Wireless sensor networks (WSNs) have been used in variety of applications such as in military and defense, process control industry and health monitoring applications. In WSNs, sensors are in small size with limited battery capacity and idle listening is a crucial problem which consumes more energy. Duty cycling (DC) is a technique which is used in many medium access control (MAC) protocols to reduce idle listening. In this thesis, we propose an asynchronous DC protocol, namely energy balancing asynchronous cooperative transmission medium access control (EB-ACT-MAC), which balances the remaining energy of sensor nodes to extend network lifetime. Furthermore, we evaluate EB-ACT-MAC using MATLAB and compare with previously proposed asynchronous cooperative transmission MAC (ACT-MAC) and a popular asynchronous predictive wakeup MAC (PW-MAC) protocol. Numerical results demonstrate that EB-ACT-MAC protocol shows better performance over the existing protocols in terms of network longevity and the energy efficiency. Moreover, we present ns2 simulation results for PW-MAC and another popular MAC protocol called receiver initiated MAC (RI-MAC) protocol. Results show that PW-MAC has lower overall duty cycle and shorter latency when compared with RI-MAC. Besides, we propose and describe another new MAC protocol which we refer it to as asynchronous in-turn transmission MAC (AIT-MAC) protocol. Key words: Wireless sensor network, MAC protocol, duty cycling, energy balancing, cooperative transmission. | nb_NO |
