A Cross-Layer Power Controlled MAC Protocol in Wireless Sensor Networks

Wireless communication channel and limited communication resource lead MAC protocol to be one of pivotal issue in wireless sensor networks. Focus on energy efficiency and avoidance of packets collision, a power controlled MAC that is named cross-layer power alternative MAC (CLPA-MAC) is proposed. In CLPA-MAC, nodes send packets with tow different transmission power levels instead of one fixed value. A power alternative scenario is discussed to help nodes choose appropriate power level to send packets. For saving energy, avoiding collision and reducing time delay, routing table based transmission mechanism is proposed. This cross-layer mechanism leads nodes to discern the available data and utilize the channel reasonably. Relatively, the frame of RTS/CTS/DATAACK is designed to adapt the power alternative scenario and cross-layer mechanism. With the simulations, the proposed protocol is evaluated in comparison with S-MAC and PCSMAC from transmission power of nodes to time delay. The performance of CLPA-MAC is verified to be efficient and competent.