Design Optimization of Wireless Access Virtualization Based on Cost & QoS Trade-Off Utility Maximization

Wireless access virtualization is an emerging avenue for research for future 5G networks. For its ability to augment network sharing and its subsequent impact on reducing network setup and operational costs, network virtualization is greatly sought after by telecommunications operators all over the world. This paper classifies virtual wireless access into three possible PHY-MAC models that differ in terms of the degree of segregation of baseband signal processing and radio access units. One of the models uses special purpose hardware while another leverages software defined networking (SDN) and cloud computing technologies for implementing virtual wireless access using general purpose hardware. The proposed models differ in terms of their associated network operational cost as well as in terms of the level of QoS they can provide. A new multi-criteria utility function is hence proposed in order to assess the tradeoffs between network cost & QoS of these models from a PHY-MAC layer perspective. The new utility function provides guidelines for a network designer to choose the optimal virtualization model that best fits an operator's budget constraint as well as the QoS requirement of the intended service. Analytical results show that a novel hybrid model that properly combines both special purpose and SDN & cloud computing technologies maximizes the newly introduced utility function by attaining the best balance between overall network cost and QoS. This occurs in most expected practical cases where precisely, one of the two does not relatively outweigh the other and viceversa.