中文摘要：

针对无线传感器网络中控制信道饱和问题以及三重隐终端问题，提出了一种异步多信道MAC协议—RIM（receiver-initiated MAC）。RIM利用接收端开始的传输机制有效地解决了控制信道饱和问题＇同时采用了基于概率的随机信道选择机制避免了三重隐终端问题。而且，RIM支持一种简单且可靠的异步广播机制。通过基于马尔可夫链的理论分析，得到了RIM中节点的最优占空比。为验证RIM的实际性能，进行了模拟和真实实验。实验结果表明，与其他多信道MAC协议相比，随着信道数及网络负载的增加，RIM增加了网络吞吐量，降低了传输所消耗的能量，同时也提高了广播的可靠性，达到了能量有效的目的。

英文摘要：

To tackle control channel saturation and triple hidden terminal problems, this paper proposes RIM, a receiver-initiated multi-channel MAC protocol with duty cycling for WSNs. By adopting a receiver-initiated transmission scheme and probability-based random channel selection, RIM effectively alleviates, if not completely eliminates, control channel saturation and triple hidden terminal problems. In addition, RIM exploits a simple but reliable asynchronous broadcast scheme to solve the problem of broadcast data loss with reliable broadcast-intensive applications. More importantly, RIM is fully distributed with no requirements of time synchronization or multi-radio. Therefore, RIM is very easily implemented in resource-constrained sensor nodes. Via the theoretical analysis, the optimal duty cycle are obtained, respectively. The simulation and real testbed experimental results show that RIM achieves significant improvement in energy efficiency with increasing benefit when the number of channels and traffic loads increase, while maintaining higher throughput. Moreover, RIM exhibits a prominent ability to enhance its broadcast reliability.