Effective capacities of dual-hop networks with relay selection

This work studies the effective capacities of dualhop networks with relay selection. The source uses buffer to store the arrival packets. For non-buffer relays, they forward the packets received from the source to the destination in the next time slot in the same transmission frame. For buffer-aided relays, they can store the received packets and forward them in future transmission frame(s). Two different buffer-aided relays can be selected for packet reception and packet forwarding in a frame to exploit the relay selection diversity in both relay and access links. As a result, higher throughput can be achieved as compared to the case of non-buffer relays at the expense of increased buffering delay. To provision delay QoS guarantees, the source and buffer-aided relays operate under statistical delay guarantees in terms of maximum delay violation probabilities. The effective capacities (i.e., maximum constant arrival rates to the source) are characterized as function of the signal-to-noise ratios (SNRs) of the source and relays, delay parameters, and fading distributions.