On the Benefits of Network-Level Cooperation in Millimeter-Wave Communications

TL;DR

This paper evaluates the advantages of network cooperation in millimeter-wave wireless networks, analyzing how relay-assisted transmission schemes impact delay and throughput under various configurations.

Contribution

It provides a comprehensive analysis of relay-assisted millimeter-wave networks, comparing directional and broadcast schemes, and identifies conditions where cooperation improves performance.

Findings

Relay-assisted networks can enhance throughput and reduce delay.

Broadcasting can outperform directional transmission in certain scenarios.

Beam alignment duration and node positioning significantly influence network performance.

Abstract

Relaying techniques for millimeter-wave wireless networks represent a powerful solution for improving the transmission performance. In this work, we quantify the benefits in terms of delay and throughput for a random-access multi-user millimeter-wave wireless network, assisted by a full-duplex network cooperative relay. The relay is equipped with a queue for which we analyze the performance characteristics (e.g., arrival rate, service rate, average size, and stability condition). Moreover, we study two possible transmission schemes: fully directional and broadcast. In the former, the source nodes transmit a packet either to the relay or to the destination by using narrow beams, whereas, in the latter, the nodes transmit to both the destination and the relay in the same timeslot by using a wider beam, but with lower beamforming gain. In our analysis, we also take into account the beam alignment phase that occurs every time a transmitter node changes the destination node. We show how the beam alignment duration, as well as position and number of transmitting nodes, significantly affect the network performance. Moreover, we illustrate the optimal transmission scheme (i.e., broadcast or fully directional) for several system parameters and show that a fully directional transmission is not always beneficial, but, in some scenarios, broadcasting and relaying can improve the performance in terms of throughput and delay.