Gains of Restricted Secondary Licensing in Millimeter Wave Cellular Systems

摘要

Sharing the spectrum among multiple operators seems promising in millimeterwave (mmWave) systems. One explanation is the highly directional transmissionin mmWave, which reduces the interference caused by one network on the othernetworks sharing the same resources. In this paper, we model a mmWave cellularsystem where an operator that primarily owns an exclusive-use license of acertain band can sell a restricted secondary license of the same band toanother operator. This secondary network has a restriction on the maximuminterference it can cause to the original network. Using stochastic geometry,we derive expressions for the coverage and rate of both networks, and establishthe feasibility of secondary licensing in licensed mmWave bands. To explaineconomic trade-offs, we consider a revenue-pricing model for both operators inthe presence of a central licensing authority. Our results show that theoriginal operator and central network authority can benefit from secondarylicensing when the maximum interference threshold is properly adjusted. Thismeans that the original operator and central licensing authority have anincentive to permit a secondary network to restrictively share the spectrum.Our results also illustrate that the spectrum sharing gains increase withnarrow beams and when the network densifies.