Telecom Italia (TIM) has been one of the more active MNOs in trialling virtualized RAN (vRAN) architectures in its macro RAN as a precursor to 5G. It has conducted trials with Ericsson, Huawei Nokia and Altiostar at various points in the past and is now reporting encouraging results on the cost side.
Lucy Lombardi, Telecom Italia’s SVP of digital and ecosystem innovation, told the 5G Core Summit in Madrid that TIM had saved up to 50% on software resources by using an architecture in which numerous radio/antenna units could share a centralized baseband processor, with the flexibility increased further by virtualizing the baseband functions. Most of the cost savings came from the ability to allocate network resources dynamically to any cell in the cluster as required, rather than fully provisioning each cell for peak traffic.
Like most early movers in trialling vRAN, TIM started with vendor-specific systems and focused its efforts on adapting to a software-driven, disaggregated architecture, with all the differences of management and operations compared to a traditional integrated base station. Now it is looking at taking the next step, towards a vRAN in which virtual network functions (VNFs), radio units and cloud infrastructure from different vendors can be integrated using open interfaces.
It is working with the specs from the ORAN Alliance (see lead article), which is rapidly gaining ground among advanced MNOs and starting to look likely to be the dominant open platform for a multivendor vRAN in future.
However, deploying vRAN on a wide-scale basis will be challenging for TIM because of the active network sharing deal it recently announced with Vodafone Italia. This is designed to cut RAN costs by about 40%, and so, together with the savings associated with vRAN, TIM could be in far better shape in terms of its 5G TCO than its 4G cost base. However, a shared network means the two operators will need to cooperate, to some extent at least, on architecture and suppliers, which could greatly delay the roll-out of a complex new network, especially as Vodafone has not yet shown the same level of near term interest in vRAN as its partner.
TIM’s most recent vRAN trial started late last year in the city of Turin, where it said it deployed the largest LTE vRAN so far in a major city. It deployed cloud-based NFV infrastructure and virtualized 40 network functions, for instance, those concerned with mobile traffic optimization and VoLTE management.
In February, TIM and Ericsson announced they would digitalize TIM’s nationwide RAN, starting in Turin, to improve cost efficiency and customer experience. In tandem with virtualizing RAN functions, they are working on automation, especially self-organizing network (SON) technology, to reduce TCO and, in the specific case of voice, reduce the number of servers to support VoLTE services.
The Turin deployment is part of TIM’s DigiTIM digital transformation project. It will form the basis of an eventual migration to 5G, which will be used, in particular, to extend the RAN’s services to machine-to-machine applications, from a unified network database.