中文摘要：

为解决水下无线传感器网络中由于水声信号传播的时-空不确定性引起的空间公平性问题,并有效实现多信道通信,提出了一种基于单收发器的水下多信道MAC协议,即SFM-MAC。该协议利用水下定位信息进行时空信息转换,避免全网同步;通过RTS/CA/CL/CTS握手机制避免多信道隐蔽终端问题,并实现公平接入。采用马尔科夫链构建了控制信道的预约模型,理论分析并计算了考虑预约碰撞条件下的多信道MAC协议的理论吞吐量。仿真实验表明：SFM-MAC的网络公平性指数较传统RTS/CTS类协议提高15%;在2个业务场景下,网络有效吞吐量较单信道水下MAC协议SFAMA和多信道水下MAC协议UMMAC分别提高60%~70%及12%~15%,证明SFM-MAC可以有效提高网络公平性与网络吞吐量。

英文摘要：

This paper proposes a multi-channel medium access control（ MAC） protocol named SFM-MAC to tackle the spatial fairness problem that results from the spatial-temporal uncertainty in underwater sensor networks（ UWSNs） and to realize multi-channel communication. SFM-MAC enables hosts to utilize multiple channels via only one transducer. The proposed protocol,combining with the location information,fairly accesses channels and avoids the multi-channel hidden terminal problem by a RTS / CA / CL / CTS handshaking scheme. The Markov chain was used to build the reservation model of the control channel,and the theoretical throughput of the multi-channel MAC protocol under the reservation collision condition was analyzed and computed. The simulation results show that comparing with the traditional RTS / CTS protocol,SFM-MAC achieves a better fairness index that increases by15%. Additionally,the results showed that SFM-MAC outperforms slotted FAMA and UMMAC in terms of network throughput by 60% ~ 70% and 12% ~ 15% in two representative network scenarios,respectively,proving that SFMMAC can effectively improve network fairness and throughput.