Towards a Virtual Cellular Network with Variable Grade Spectrum: Challenges and Opportunities

This position paper presents vision of a bold future for wireless networking research where wireless networks exploit many variable grade spectrum bands. The transformation we envision will be fueled by a fundamental change in the way networks use spectrum. The mix of spectrum options will include existing exclusively licensed and unlicensed bands and new shared spectrum bands where incumbent primary transmitters with interruptible, exclusive access share the band with cooperating (secondary) users. Such bands used in small cell deployments will be key to creating enormous wireless capacity. The nascent spectrum database technologies will morph into more dynamic spectrum databases and provide essential interference coordination, channel management and monetization. This trend when combined with virtualization of Radio Access Network (RAN) will gradually lead to new deployment models where entire wireless network control and data paths are collapsed into virtual machines in a data center. Such implosion of network and democratization of spectrum access can fuel innovative business models and new regulatory regimes for wireless networks. We illustrate the new architecture and component radio, database and security technologies using concrete example of incorporating shared S-band radar spectrum in a virtualized small cell network. We also identify new business models, major research challenges and potential roadblocks that can slow down realization of this vision into reality.