Reduced-Packet-Delay Generalized Buffer-Aided Relaying Protocol: Simultaneous Activation of Multiple Source-to-Relay Links

TLDR: The proposed schemes are designed to allow multiple relay nodes to receive a source packet through source-to-relay broadcast channels, resulting in multiple copies of the source packet, which are stored in relay node buffers.

Abstract: Motivated by the recent buffer-aided relaying protocol that selects the best available link at each time slot, we herein introduce an additional degree of freedom to the protocol by simultaneously exploiting multiple links between the source node and the multiple buffer-aided relay nodes, which is enabled owing to the broadcast nature of wireless channels. More specifically, the proposed schemes are designed to allow multiple relay nodes to receive a source packet through source-to-relay broadcast channels, resulting in multiple copies of the source packet, which are stored in relay node buffers. As the explicit benefits of its increased design degree of freedom, the proposed protocols attain a significantly lower end-to-end packet delay than the conventional buffer-aided relaying protocols, which is achieved without imposing any substantial penalty on the achievable outage probability. Furthermore, the proposed protocol is capable of reducing the overhead required for monitoring the available links and buffer statuses of the relay nodes. Based on the Markov chain model, we derive the theoretical bounds of the outage probabilities of the proposed protocols.