多预约信息转发的协作信道预约多址接入协议

针对Ad Hoc网络中实时业务在背景业务繁重时信道接入效率低的问题,提出一种邻节点协作转发信道预约信息(CRI)的多址接入协议(M-CCRM).节点在发送数据分组前,选取多条CRI作为其数据开销,在控制该开销不超过预先设定门限的基础上,将这些CRI随分组一起发送；收到数据分组的邻节点提取其携带的CRI,记录下那些自己位于其预约范围内的CRI,避免在这些CRI的预约时段内接入信道.M-CCRM协议扩大了CRI的覆盖范围,解决了由于信道衰落和(或)分组冲突导致的CRI丢失问题,提高了实时业务的信道接入效率.仿真结果表明,当开销门限为0.02时,M-CCRM协议的实时业务发送失败概率比基本信道预约协议和基本协作预约协议分别降低了31％和20％.

A Multiple Access Control Protocol with Multiple Reservation Information Relay and Cooperative Channel Reservation

A new multiple access control(MAC) protocol called M-CCRM is proposed to solve the problem of poor channel access efficiency for real-time traffic in Ad Hoc networks with heavy background traffic loads.The proposed protocol bases on the idea of distributing channel reservation information(CRI) through cooperative relays of neighboring nodes.Before a node transmits a packet,multiple CRIs are carefully selected and piggy-backed with the packet so as to limit the corresponding overheads caused by carrying CRIs to be lower than a predefined threshold.By overhearing the packet,neighboring nodes record some of the CRIs as long as they are within the channel reservation distance of the CRIs,and then avoid to access the channel while the traffic indicated by the CRIs are carrying on.The proposed MAC protocol enlarges the coverage area of the announced CRIs,and avoids the possible missing of CRIs caused by channel fading and(or) packet collisions.Therefore,the channel access efficiency for real-time traffic is significantly increased.Simulations and comparisons with the basic channel reservation protocol and the basic cooperative channel reservation protocol show that when the overheads caused by carrying CRIs are limited to be lower than 2%,the transmission failure rates of real-time traffic of the proposed protocol are reduced by 31% and 20%,respectively.