The Delay-Security Trade-off in Two-hop Buffer-Aided Relay Wireless Network

Two-hop relay wireless networks serve as a class of attractive network model for the performance study of general multi-hop wireless networks, understanding their fundamental security and delay performance have been critical issues for them to support various applications with different quality of service requirements. This paper studies the end-to-end delay of a two-hop buffer-aided relay wireless network with multiple relays and an eavesdropper intercepting both the source-relay link and relay-destination link. To derive the end-to-end delay, we first apply Markov chain to calculate the average queue length. With the help of secure transmission probability, the average queue length and Little's Law, we then obtain the end-to-end delay of the concerned network. Finally, simulation and numerical results are provided to verify our theoretical analysis and also to illustrate the delay-security trade-off.