TDMA-Based Cooperative MAC Protocol for Multi-Hop Relaying Networks.

In this letter, we propose and analyze a time division multiple access (TDMA)-based cooperative medium access control (MAC) protocol for wireless multi-hop relaying networks. The fundamental drawback of a reservation-based MAC protocol is channel waste, i.e., the existence of idle slots. The proposed MAC, called cooperative relaying TDMA (CR-TDMA), allows a packet that is pre-assigned to a busy relay node to be reassigned to a neighbor node with an empty queue, i.e., a helper node. With the assistance of helper nodes, the relay node can process multiple packets during only one frame. Furthermore, CR-TDMA does not require additional overhead, such as mini-slots or additional packet header information for negotiations of cooperative communication. The numerical and simulation results show that CR-TDMA can significantly improve performance if helper nodes are available and can also guarantee equivalent or better performance than a conventional TDMA even in the worst cases.