Adaptive Buffer-aided Wireless Relay Communications with Mixed Status Update and Throughput Traffic

In this paper, we consider a buffer-aided wireless relay communication network, where both status update and throughput traffic are randomly generated at source node according to mixed task-related data generation model, and then transmitted to destination node with the assistance of one buffer-aided relay node. The problem of maximizing the throughput performance of the throughput traffic subject to age of information (AoI) constraint for status update is formulated. By solving the problem under the Lyapunov optimization frame-work, adaptive buffer-aided wireless relaying scheme is obtained, in which link transmission selection, transmission scheduling of mixed status update and throughput traffic, as well as transmit power and transmission rate by source node and relay node, will be jointly adjusted in order to maximize the long-term averaged throughput performance according to the underlying channel state information (CSI), the buffer state information (BSI), the energy-consumption status information (ESI) of all nodes, as well as the AoI status information (ASI) of the status update traffic. Our analysis unveils that, the AoI service requirement by status update traffic has a significant impact on the achievable throughput performance of the throughput traffic. Now the achievable end-to-end throughput performance will be dependent on the arrival rate, the AoI constraint by the status update traffic. Meanwhile, unlike the adaptive buffer-aided relaying scheme with pure throughput traffic, now there exists an optimal Lyapunov control parameter $V$ in terms of the realized throughput performance.