While spectrum at millimeter-wave (mmWave) frequencies is less scarce than at traditional frequencies below 6 GHz, still it is not unlimited, in particular if we consider the requirements from other services using the same band and the need to license mmWave bands to multiple mobile operators. Therefore, an efficient use of the spectrum is critical to harvest the maximum benefit from emerging mmWave technologies.

 

Example of the hybrid spectrum paradigm: three operators share 0.9 GHz in the 70 GHz range, while having each exclusive access to 300 MHz in the 20/30 GHz range.

 

In this section, we discuss resource sharing, a key dimension in mmWave network design in which spectrum, access and/or network infrastructure resources can be shared by multiple operators. It is argued that this
sharing paradigm will be essential to fully exploit the tremendous amounts of bandwidth and the large number of antenna degrees of freedom available in these bands, and to provide statistical multiplexing to accommodate the highly variable nature of the traffic.

In our works, we have investigated and compared various sharing configurations in order to capture the enhanced potential of mmWave communications.

Our results reflect both the technical and the economical aspects of the various sharing paradigms. We deliver a number of key insights, corroborated by detailed simulations, which include an analysis of the effects of the distinctive propagation characteristics of the mmWave channel, along with a rigorous multi-antenna characterization. Key findings of our study include: firstly the strong dependence of the comparative results on channel propagation and antenna characteristics, and therefore the need to accurately model them, and second the desirability of a full spectrum and infrastructure sharing configuration, which may result in increased user rate as well as in economical advantages for both service provider.

We have also introduce a new hybrid spectrum access scheme for mmWave networks, where data packets are scheduled through two mmWave carriers with different characteristics. In particular, we consider the case of a hybrid spectrum scheme between a mmWave band with exclusive access and a mmWave band where spectrum is pooled between multiple operators. This approach provides advantages with respect to traditional fully licensed or fully pooled spectrum access schemes.

Title  DateArea
H. Shokri-Ghadikolaei et al., "The impact of beamforming and coordination on spectrum pooling in mmWave cellular networks," 2016 50th Asilomar Conference on Signals, Systems and Computers, Pacific Grove, CA, 2016, pp. 21-26.
IEEE Xplore
2016/11Spectrum Sharing
F. Boccardi et al., "Spectrum Pooling in MmWave Networks: Opportunities, Challenges, and Enablers," in IEEE Communications Magazine, vol. 54, no. 11, pp. 33-39, November 2016.
IEEE Xplore
2016/11Spectrum Sharing
M. Rebato, F. Boccardi, M. Mezzavilla, S. Rangan, and M. Zorzi, "Hybrid Spectrum Sharing in mmWave Cellular Networks", in IEEE Transactions on Cognitive Communications and Networking.
IEEE Xplore
2016/10Spectrum Sharing
H. Shokri-Ghadikolaei, F. Boccardi, C. Fischione, G. Fodor and M. Zorzi, "Spectrum Sharing in mmWave Cellular Networks via Cell Association, Coordination, and Beamforming," in IEEE Journal on Selected Areas in Communications, vol. 34, no. 11, pp. 2902-2917, Nov. 2016.
IEEE Xplore
2016/10Spectrum Sharing
Rebato, M., Mezzavilla, M., Rangan, S. and Zorzi, M., "Resource sharing in 5G mmwave cellular networks" in IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS), (pp. 271-276), IEEE, 2016.
IEEE Xplore

arXiv
2016/04Spectrum Sharing