多跳无线网络中可并行发送的多信道 MAC 协议

摘要

A novel slotted multichannel medium access control (MAC)protocol is proposed to resolve hidden terminal and exposed terminal problems,and improve the probability of concurrent packet transmissions for multihop wireless networks.In the proto-col,channel reservation,data packet transmission and confirmation can be simultaneously carried out by dividing entire channel into control channel (CCH),data channel (DCH)and acknowledgment channel (ACH),which greatly decreases the transmis-sion collision probability of control packets and data packets in multihop network environment.In addition,dual reservation mechanisms of reservation slot and contention minislot are proposed to effectively decrease the collision probability of channel res-ervation and greatly improve channel access efficiency.According to transmission interference pre-backoff,sensing backoff and packet collision backoff mechanisms,network model and performance analysis are presented.Numerical simulations show that compared to the IEEE 802.11 distribution coordination function (DCF)protocol,the proposed protocol has obviously multiple ac-cess performance improvement under the same total data rates.%为了解决多跳无线网络中的隐藏终端和暴露终端问题，提高并行分组发送机会，提出了一种时隙多信道媒质接入控制（medium access control，MAC）协议，通过划分控制信道（control channel，CCH）、数据信道和确认信道使得信道的预约与数据分组的传输、确认能够并行进行，避免了多跳网络环境下控制分组与数据分组发送之间发生碰撞的问题。在 CCH 上的预约时隙和竞争微时隙的双重竞争退避机制降低了信道预约的碰撞概率，使得节点可以快速有效地接入信道。根据节点的发送冲突预先判断退避、侦听退避和碰撞重发3种情况，建立了网络分析模型，并进行了性能分析。研究结果表明，与 IEEE 802．11 DCF协议相比，该协议在相同总数据速率情况下具有较大的多址性能改善。