中文摘要：

针对单Radio多信道MAC协议需要全网时间同步、占用大量正交信道、多信道隐终端较多以及单跳多信道广播数据大量丢失等问题，提出了一种基于竞争的多信道MAC协议—HM-MAC。该协议无需全网时间同步，通过动态预约技术降低了正交信道占用量，利用握手机制减少了多信道隐终端数目，同时，HM-MAC采用基于概率的广播发送者协调机制，减少了广播数据丢失，提高了广播效率。在理论上分析了所用信道数目、多信道隐终端数目以及广播效率等性能参数。实验结果表明：HM-MAC可以有效地解决多信道隐终端数目较多的问题，显著地提高了广播效率和网络吞吐量。

英文摘要：

Aiming at single radio multi-channel MAC protocol＇s problems, such as the requirement of time synchronization and lots of orthogonal channels, large number of multi-channel hidden terminals, loss of single-hop multi-channel broadcast data, etc, the authors propose a competition based multi- channel MAC protocol, called HM-MAC, to tackle those problems for wireless sensor network. In HM-MAC, all the nodes work without time synchronization, use few orthogonal channels and take advantage of handshake mechanism to reduce the number of multi-channel hidden terminals. Meanwhile, a probability based sender adjustment broadcast scheme is presented, which reduces the loss of data and improves broadcasting efficiency. By theoretical analysis of the unicast mode, the number of used channel as well as the number of multi-channel hidden terminals are obtained. And, via theoretical analysis of the broadcast mode, the broadcasting efficiency of HM-MAC broadcast scheme is also obtained. More importantly, broadcast efficiencies of current multi-channel broadcast scheme are analyzed theoretically. In addition, a detailed comparison between HM-MAC broadcast scheme and other multi-channel broadcast schemes is presented. Finally, the theoretical analysis is verified via simulation experiments. The results of simulation experiment show that HM-MAC reduces the number of multi-channel hidden terminals effectively, and improves broadcasting efficiency as well as network throughput significantly.