Virtual-Link Relay Selection Scheme for Buffer-Aided IoT Based Cooperative Relay Networks

This paper investigates the performance of a buffer-aided cooperative relay network. In the proposed design, each location in a buffer is assumed to act independently called the virtual relay having a buffer of size 1. The relay selection is based on the instantaneous strength of the wireless link and status of the virtual relay buffer. The proposed scheme is analyzed for symmetric and asymmetric channel conditions and also for symmetric and asymmetric buffer sizes at the relay. Markov chain is used to model the evolution of buffer status and to derive the closed-form expressions for outage probability, diversity gain, delay, and throughput. The proposed design achieves the diversity gain of (L
₁
+ L
₂
+ · · · + L
_K
), where L
_i
is the buffer size of the i-th relay and K is the total number of relays.