Wireless Network Virtualization – A New Approach for Enhancing Spectrum Utilization

The growth of wireless subscriptions is increasing exponentially with increasing mobile devices for Cyber-Physical Systems and Internet-of-Things applications.  Wireless network virtualization is envisioned to support billions of devices for wireless subscriptions and incorporate new wireless services for Cyber-Physical Systems and Internet-of-Things. Wireless network virtualization with the help of cognitive radio is a new approach for improving spectrum utilization where infrastructures, software and spectrum are combined into a single software-based virtual network entity, which then can be offered to different parties. Wireless network virtualization combines different wireless networks with different access technologies and network topologies (infrastructure-based and infrastructure-less) which makes the convergence, sharing and abstraction difficult to achieve. Furthermore, wireless networks operate in different spectrum bands ranging from MHz to GHz, unlicensed and licensed RF bands, and different geographic coverage (e.g., wide, local and personal areas). Thus far, there is no unified and universal architecture for wireless network virtualization available for commercial use. However, dynamic spectrum access is viewed as a sort of spectrum virtualization where cognitive radios can access underutilized licensed spectrum dynamically without creating harmful interference to licensed users. Some recent works have integrated game theory and auctioneer into the wireless model to incorporate heterogeneous wireless networks where auctioneer are responsible for allocating frequency bands to wireless devices within their geographic area. Furthermore, game theory based models can use bidding procedures between users and service providers, or between service providers and spectrum auctioneer. In addition, wireless virtualization could be performed using cross-infrastructures and intra-infrastructures in application level, spectrum level and (cloud) computing level. Thus, wireless network virtualization has the potential to relieve artificial spectrum scarcity problem and offer new services to support huge wireless subscriptions for Cyber-Physical Systems and Internet-of-Things.