On the Feasibility of Sharing Spectrum Licenses in mmWave Cellular Systems

TL;DR

This paper demonstrates the theoretical feasibility of uncoordinated spectrum license sharing in mmWave cellular systems, showing it can improve per-user rates and reduce costs, especially with narrow beams and low user density.

Contribution

It provides a theoretical analysis of spectrum license sharing in mmWave systems, including SINR and rate distribution, and compares shared versus exclusive licensing strategies.

Findings

Sharing increases per-user rate with narrow beams

Sharing is beneficial at low user densities

Shared licenses can match exclusive licenses with less bandwidth

Abstract

The highly directional and adaptive antennas used in mmWave communication open up the possibility of uncoordinated sharing of spectrum licenses between commercial cellular operators. There are several advantages to sharing including a reduction in license costs and an increase in spectrum utilization. In this paper, we establish the theoretical feasibility of spectrum license sharing among mmWave cellular operators. We consider a heterogeneous multi-operator system containing multiple independent cellular networks, each owned by an operator. We then compute the SINR and rate distribution for downlink mobile users of each network. Using the analysis, we compare systems with fully shared licenses and exclusive licenses for different access rules and explore the trade-offs between system performance and spectrum cost. We show that sharing spectrum licenses increases the per-user rate when antennas have narrow beams and is also favored when there is a low density of users. We also consider a multi-operator system where BSs of all the networks are co-located to show that the simultaneous sharing of spectrum and infrastructure is also feasible. We show that all networks can share licenses with less bandwidth and still achieve the same per-user median rate as if they each had an exclusive license to spectrum with more bandwidth.