Exploring Relay Cooperation for Secure and Reliable Transmission in Two-Hop Wireless Networks

TL;DR

This paper analyzes secure and reliable relay cooperation in finite two-hop wireless networks without eavesdropper channel information, providing exact results on eavesdropper tolerance and proposing new protocols for different path-loss scenarios.

Contribution

It offers the first exact analysis of eavesdropper tolerance in finite networks and introduces new relay selection protocols for practical scenarios.

Findings

Maximum eavesdropper tolerance determined for different protocols

Optimal relay selection improves secrecy performance

New protocol balances load and secrecy in distance-dependent path-loss

Abstract

This work considers the problem of secure and reliable information transmission via relay cooperation in two-hop relay wireless networks without the information of both eavesdropper channels and locations. While previous work on this problem mainly studied infinite networks and their asymptotic behavior and scaling law results, this papers focuses on a more practical network with finite number of system nodes and explores the corresponding exact result on the number of eavesdroppers one network can tolerant to ensure desired secrecy and reliability. We first study the scenario where path-loss is equal between all pairs of nodes and consider two transmission protocols there, one adopts an optimal but complex relay selection process with less load balance capacity while the other adopts a random but simple relay selection process with good load balance capacity. Theoretical analysis is then provided to determine the maximum number of eavesdroppers one network can tolerate to ensure a desired performance in terms of the secrecy outage probability and transmission outage probability. We further extend our study to the more general scenario where path-loss between each pair of nodes also depends the distance between them, for which a new transmission protocol with both preferable relay selection and good load balance as well as the corresponding theoretical analysis are presented.