QoS evaluation of energy-efficient ML-MAC protocol for wireless sensor networks

Power management is an important issue in wireless sensor networks (WSNs) because wireless sensor nodes are usually battery powered, and an efficient use of the available battery power becomes an important concern specially for those applications where the system is expected to operate for long durations. This necessity for energy efficient operation of a WSN has prompted the development of new protocols in all layers of the communication stack. If the radio transceiver is the most power consuming component of a typical sensor node, large gains can be achieved at the link layer where the medium access control (MAC) protocol controls the usage of the radio transceiver unit.This paper presents an energy-efficient multi-layer MAC (ML-MAC) protocol simulated in QualNet 5.2. This protocol is designed to achieve low duty cycle, prolonged network lifetime and low number of collisions. Sensor nodes in ML-MAC have a very short listening/active time that would reduce the energy consumption during communication. In addition, number of collisions is minimized which saves the energy required to re-transmit corrupted data packets.