Listen Before Receive for Coexistence in Unlicensed mmWave Bands

TL;DR

This paper introduces Listen-Before-Receive (LBR), a novel spectrum sharing technique for unlicensed mmWave bands that enhances coexistence fairness by involving receivers in channel access decisions, addressing limitations of traditional LBT.

Contribution

It proposes the LBR method for shared spectrum access in mmWave bands, integrating receiver input to improve coexistence fairness among RATs like 5G NR and WiGig.

Findings

LBR can improve coexistence fairness in unlicensed mmWave bands.

Potential implementations of LBR with LBT and self-contained slots are discussed.

LBR addresses limitations of transmitter-only sensing in directional transmissions.

Abstract

Listen-Before-Talk (LBT) has been adopted as the spectrum sharing technique that guarantees a fair LTE/Wi-Fi coexistence in the unlicensed spectrum at the 5 GHz band. Differently, at mmWave bands, where beamforming is a must to overcome propagation limits, LBT scope becomes limited because the interference layout changes due to the directionality of transmissions. In this regard, this paper proposes a Listen-Before-Receive (LBR) technique for shared spectrum access and analyzes its potentials to promote a fair coexistence of multiple Radio Access Technologies (RATs) in unlicensed mmWave bands, as, e.g., 5G New Radio (NR) access technology and Wireless Gigabit (WiGig) devices using IEEE 802.11ad/ay standard. Since the less likely but still harmful interference situations with directional transmissions can no longer be detected easily at the transmitter, we believe that the receiver has useful information to be used. The main idea of LBR is that we provide to the receiver a say when it comes to allowing/preventing the access to the channel. In this line, we propose potential implementations of LBR, in conjunction with LBT and the self-contained slot, for NR-based access to unlicensed mmWave bands.