Adaptive Control Channels Allocation for 5G Virtualized Radio Access Networks

Network virtualization in 5G wireless networks aims to enable efficient sharing of the physical Radio Access Network (RAN) among multiple virtual mobile networks operators (vMNOs). To realize virtualization, a hypervisor layer assimilates and abstracts the physical radio resources into a pool of virtual network resources, which then can be allocated to virtualized RANs belonging to different vMNOs. A challenging task here is achieving low-level isolation between vMNOs sharing the same physical RAN especially during the initial access and registration process. The shared nature of the physical control channels that are used by the User Equipment (UE) to connect to the network may cause a congested vMNO to block or delay access to other vMNOs. A static Common Control Channel (CCC) scheme that shares all physical control channels among all virtual RAN (vRAN) instances can reduce the control overhead but may cause the load of one vRAN to negatively impact the other vRANs that are running on the same physical RAN. On the other hand, a Dedicated Control Channel (DCC) scheme will achieve perfect load isolation among vRANs but at the expense of extra control overhead and unbalanced resource utilization. To this end, we propose a layered hypervisor design that dynamically adapts the control channel allocation according to the current access load in each vRAN. This Adaptive Control Channel (ACC) allocation improves the performance of the initial random access procedure especially for vRANs with unbalanced distribution of UEs in their coverage area.