Using Buffers in Trust-Aware Relay Selection Networks With Spatially Random Relays

It is well recognized that using buffers in relay networks significantly improves the transmission reliability, which is often at the price of higher packet delay. Existing buffer-aided relay networks are all based on the physical links among cooperative nodes. This may, however, lead to performance degradation in practice, because those cooperative nodes may not trust each other for cooperation even though their physical connections are strong. In this paper, we propose a novel buffer-aided relay selection scheme to align data transmission with both strong and trusted links. By maintaining the buffer lengths as close as possible to the newly introduced target buffer lengths, the proposed scheme is able to balance the outage performance and packet delay. Both the outage probability and average packet delay are analyzed for spatially random relays. Particularly, we show that the outage performance may have error floors because of the trusts. The analysis shows that using buffers in trust-aware relay networks is able to either increase the diversity order or lower the error floor of the outage probability.