Theoretical Analysis of Hybrid Buffer-Aided Cooperative Protocol Based on Max–Max and Max–Link Relay Selections

Motivated by the recent max-link protocol and the max-max protocol, both of which were developed for a simple dual-hop buffer-aided cooperative network, we present a novel hybrid buffer-aided cooperative protocol that attains the benefits of high reliability and reduced packet delay. More specifically, we incorporate a two-stage relay selection strategy, which is capable of attaining a low outage probability comparable to the max-link protocol. In addition, the proposed protocol maintains a beneficial end-to-end packet delay, which is lower than that of the max-link protocol in the realistic scenario supporting finite source-packet transmissions. Furthermore, by introducing a periodic Markov chain model, we derive the theoretical outage probability of our hybrid buffer-aided scheme under the realistic assumption of finite-buffer relays. Our analytical and simulation results demonstrate that the proposed protocol benefits from the aforementioned high-diversity reliable performance and the reduced end-to-end packet delay.