提高信道监听质量是降低能量消耗和提高通信效率的有效方法。提出了一种低占空比、低碰撞的PB—MAC(predict-baseMAC)协议。通过发送节点精确预测接收节点的唤醒时间,降低占空比;采用基于预测的重建连接机制和数据重传机制,有效地避免碰撞和实现高效重传。OMNet++仿真实验结果表明:在50节点随机网络中,PB-MAC的平均占空比、发送消息耗能和平均碰撞次数分别比RI-MAC少68.60%、24.75%、68.05%,比X.MAC少64.39%、64.05%、70.54%。同时,在网格网络中PB—MAC的性能也优于RI-MAC和X-MAC。
Improving the quality of channel listening is an effective way to reduce energy consumption and improve communication efficiency. PB-MAC(predict-base MAC), a novel low duty cycle and low collision asynchronous MAC protocol was presented. PB-MAC lowers sensor duty cycle by enabling senders to predict receiver wakeup times. An ef- ficient prediction-based reconnection and retransmission mechanism was introduced to achieve low collisions and high efficiency retransmission. Comparison of PB-MAC on OMNet++ with RI-MAC and X-MAC was evaluated. Evaluated on scenarios with 50 random disposed nodes, the average duty cycle, consumed energy and average collisions for PB-MAC is 68.60%, 24.75% and 68.05% less than those of RI-MAC and 64.39%, 64.05% and 70.54% less than those of X-MAC respectively. In grid network, PB-MAC also outperforms RI-MAC and X-MAC protocols.