Radio Base-Stations in the Cloud

During past years, architectures for cellular radio networks like 3GPP LTE evolved towards flatter topologies with less centralized nodes, shifting more and more radio-related processing towards the Base Station or even further into so-called Remote Radio Heads near the antennas. With IP traffic growth, user traffic has lost its predictability, which resulted in the need for over-dimensioning of processing and forwarding resources in the radio path. This is especially true for upcoming pico and femto cell configurations in heterogeneous cellular architecture. To constrain the costs resulting from the emerging architectures and deployments, we develop a concept of a Cloud Base Station as a candidate for a Light Radio (TM) evolution, which uses virtualization techniques such as dynamic and elastic allocation of base-band processing resources between small and large cell sites, as well as load balancing between temporarily overloaded sites and their less utilized neighbors. The Cloud Base Station in a virtualized RAN eases a smooth standards migration towards LTE-Advanced with the same deployed equipment, and in future, more and more transformation of dedicated baseband hardware into general purpose processing platforms. In this article, we discuss the tight networking requirements of a Cloud Base Station in a virtual Radio Access Network (RAN), its architecture challenges and our cloud management solutions. Moreover we show research results on the concept validation based on simulations and discuss business-case related implications.