On configuring radio resources in virtualized fractional frequency reuse cellular networks

Virtualization of wireless networks holds the promise of major gains in resource usage efficiency through spectrum/radio resources sharing. Unlike the case in wired networks, achieving high capacity, providing effective isolation, and customization of the network requires intelligent configuration of wireless resources due to the effects of interference. In this paper, we focus on how to configure the “over-the-air” part of virtual wireless networks to enable simultaneous use of radio resources that overlap geographically. A configuration framework is proposed based on an infrastructure cellular network that employs fractional frequency reuse (FFR) and Multiple-input Multiple-output (MIMO) to combat interference. Multiple scenarios are examined that include various network sizes and base station distances. Five radio resources configuration cases are developed and investigated with each of these scenarios for a number of parameter settings (e.g., transmit power, MIMO degree). From the analysis of capacity data obtained from simulations, we observe some general trends in the aggregate spectral efficiency, and more importantly, a variety of tradeoffs between service providers (SPs) or virtual network operators. Based on these tradeoffs, we create configuration maps using which, a network resource manager can select specific network configurations (transmit power, MIMO, etc.) to meet the demand and capabilities of SPs and their subscribers.