This letter proposes a novel Multihop Dual Modular Clock Algorithm (M-DMCA) for efficient node discovery in cognitive radio-based emergency response networks. M-DMCA supports dual-channel selection per timeslot and incorporates a three-way handshake mechanism to significantly reduce rendezvous time. Performance evaluation under a worst-case scenario with 20 nodes, asymmetric channel sets of size 20, channel similarity index (m) as 2, and high primary radio activity shows that M-DMCA achieves a 24% reduction in rendezvous time compared to the multihop Extended Modular Clock Algorithm (EMCA), outperforming existing rendezvous protocols.

翻译：本文提出了一种新颖的多跳双模块时钟算法（M-DMCA），用于在基于认知无线电的应急响应网络中实现高效的节点发现。M-DMCA支持每个时隙的双信道选择，并采用三向握手机制以显著减少会合时间。在最坏场景下的性能评估表明（包含20个节点、大小为20的非对称信道集、信道相似性指数（m）为2以及高主用户活动），与多跳扩展模块时钟算法（EMCA）相比，M-DMCA将会合时间减少了24%，其性能优于现有的会合协议。