On radio resource sharing in multi-antenna virtualized wireless networks

Virtualizing wireless networks has the potential to improve resource usage efficiency (system capacity) through spectrum sharing while allowing for isolation between users and customization of applications {9}. In most work related to wireless network virtualization, the sharing of spectrum is considered at the level of chunks of frequency that do not interfere. Such spectrum sharing, where service provider SPA can use the spectrum allocated to SPB when SPB does not use it, results in multiplexing gains improving the resource usage (see for example, [12]). We argue that sharing radio resources that are a function of geography and signal strength, rather than slices of spectrum is also possible. When we consider sharing of radio resources, the transmit power, the interference, and the usage scenario (capabilities/needs of devices) become important in determining what can be shared. In this paper, the potential gain from sharing such radio resources while using MIMO for combating interference and exploiting spatial degrees of freedom is investigated in a two service provider collaboration scenario. The metric used is the capacity of the system (with a large cell and a small cell) as a function of separation distance, transmit power, cell range, and various MIMO settings. We show that radio resource sharing is feasible, but it has implications on isolation between users of different SPs and MIMO settings are an important factor.