Vodafone turns on first Open RAN macro site

It's not full Open RAN, yet.

Vodafone’s previous Open RAN rural trial.

Vodafone UK has turned on its first commercial macro Open RAN site in the UK. The site is the first of a targeted 2,500 Huawei sites that are due to be swapped out with Open RAN technology over the coming years. Located near Bath, it is now a live part of the operator’s production network, handing traffic in and out of nearby cells.

The site has been built using a range of hardware and software technology partners, announced by Vodafone in July 2021. Samsung provides the all important vRAN CU-DU software. Wind River, acquired last week by automotive software company Aptiv,  is providing the cloud management and orchestration aspects. Hardware is from Dell, based on Intel Xeon Server and accelerators. HPE is also involved, TMN understands.

However, one element of the build is not yet O-RAN compliant. The current radio antenna unit at the live site is a proprietary unit from Samsung, connected to the virtualised baseband via a CPRI interface.

The vCU-DU function (the Central Unit and Distributed Unit make up the elements of a virtualised baseband in the O-RAN architecture) that Samsung has provided is Open Fronthaul compatible, so at the moment Vodafone is connecting the Samsung CU-DU to the Samsung RU via a switch to convert the baseband’s Open Fronthaul interface to CPRI to connect on to the RU.

The O-RAN compatible RUs from Samsung and NEC are still being verified as O-RAN compliant in Vodafone’s lab by test partners Keysight and CapGemini. The aim is to then swap out the current proprietary RU for the O-RAN RU when the lab has given it the all clear, dispensing with the need for the fronthaul switch.

The temporary use of the proprietary RU and protocol conversion, while no big deal in the long term, shows that Vodafone was keen to get up and running with a public deployment, even if that was before it had fully tested out RU-DU-CU interoperability from Samsung (and NEC). And while it may also be a surprise to some that Samsung and NEC’s RU are still being given the once over in the Vodafone lab – especially as NEC already has units working in a multi vendor 5G network in Japan – it also shows what other vRAN vendors have been saying for a while, that there is a need to accelerate the development of available RUs in the market.

A Vodafone spokesperson said the next phase of the Open RAN rollout would be to identify a “golden cluster” of around ten sites on the country’s south coast, and implement learnings on handover and mobility management, as well as site design, from the Bath site. After that trial, the operator intends to move Open RAN rollout to a more industrialised process.

As has been covered in the past, Vodafone’s Open RAN sites only provide 4G and 5G technology using the new kit, with 2G/3G being provided by the legacy radios. That means two sets of everything at the sites in question.

Additionally, a Vodafone spokesperson said that the company is still evaluating its Evenstar RU – the product it is developing in alignment with the Facebook Connectivity Open RAN initiative that Vodafone also sponsors. Evenstar has been designed to give manufacturers a template for RU manufacturer, to hit an operator use case “sweet spot”.  In the short to mid term, however, the focus would be on the NEC and Samsung units.

Vodafone’s spokesperson also described the launch schedule of Massive MIMO Open RAN RUs, trailed in its July 2021 announcement, as commercially sensitive, but reiterated previous guidance that such units were more likely to be deployed in dense urban scenarios.