There is no doubt that Rakuten Mobile’s greenfield roll-out in Japan has been the most-watched network deployment in the world over the past year. The new MNO set out its plans with a great fanfare at Mobile World Congress 2019 and proceeded to select more than 20 vendors to help it roll out an end-to-end, open, cloud-native 4G network (soon to include 5G). A year later, and with inevitable delays and setbacks along the way, the first commercial services were announced and the first phase of the build-out completed.
In the spirit of the open networks it espouses, Rakuten has not been secretive about its suppliers, and all of them have been able to use their involvement to raise their profile and kudos with other operators – especially the smaller ones like RAN virtual network function (VNF) provider Altiostar. Rakuten is seen as a vital proof point that open networks are deployable, are capable of supporting carrier-grade services and quality of experience, and are dramatically cheaper to roll out. It is too early to make a full judgement on this, but despite scepticism in some quarters about Rakuten’s low capex claims, it is ticking several boxes in terms of interoperability.
The next step, for the operator itself (see separate item), and its suppliers, is to take the lessons learned and use them to generate business elsewhere. Various combinations of vendors within the Rakuten supply chain are forming alliances to punch above their weight in targeting procurements in other parts of the world.
The latest is between Altiostar and Airspan, which aim to commercialize the pre-integrated combination of the former’s virtualized baseband network functions, and the latter’s millimeter wave radio units.
In theory, of course, open fronthaul interfaces between shared baseband units and the radio/antennas should ensure that multivendor offerings interoperate anyway, but to achieve the optimized performance and tuning that MNOs require from their networks, a degree of integration is likely always to be required – even when those open interfaces are widely supported and mature.
Airspan’s VP of strategy and marketing, Damiano Coletti, commented that the combined solution would have to be customized for each operator because of different spectrum bands, and different scenarios in terms of access to backhaul and sites. But he insisted that the end-to-end platform that Airspan and Altiostar developed with Rakuten is compliant with both O-RAN and 3GPP specifications, and is highly modular and software-based, all of which will significantly reduce cost and complexity to deploy.
The Altiostar/Airspan partnership will be looking for operators which want to emulate some aspects of the Rakuten roll-out, including its cloud-native baseband, its openness, and its density. In the last category, Rakuten is deploying tens of thousands of small cells, as well as 4,400 macro sites. The small cells include a mixture of indoor and outdoor units, and 4G and 5G. Many of the latter run in the operator’s 28 GHz mmWave spectrum, which has limited range but very high capacity, and so is good for densification and laying foundations for 5G.
Coletti told FierceWireless there were “already thousands of 4G hotspots, mostly pole-mounted or wall-mounted outdoors. Ultra-dense architectures are a fundamental complement to that macro network.”
Airspan’s 25-year history and its practical expertise of deploying such large numbers of units – for Sprint and Reliance Jio as well as Rakuten – will be important to Altiostar, which is a new company and, being software-based, not versed in challenges like gaining access to sites and power. But it brings a virtualized RAN solution to the partnership, at a time when operators are just starting to take that architecture seriously for at-scale roll-outs.
Altiostar was an early mover in RAN VNFs, and can now offer a fully containerized, cloud-native RAN, partly based on its developments for Rakuten. It also has investment from its flagship customer, whose CTO, Tareq Amin, said recently: “We wanted to protect the company from being acquired because we need a disrupter in this industry that could challenge incumbents.”
Now Altiostar is developing an ecosystem of its own, adding partners which will help it to scale up, and accelerate vRAN deployments. As well as Airspan, it has announced a development and marketing alliance with NEC, which makes Rakuten’s 5G macro radio units, as well as with NEC’s OSS subsidiary, Netcracker. This partnership will combine NEC’s IT, radio and systems integration skills with Netcracker’s orchestration and Altiostar’s vRAN to provide the foundations for an end-to-end cloud-based network.
NEC and Altiostar have a joint deal with the United Arab Emirates’ Etisalat, which recently announced plans to launch a network using virtualized, disaggregated and open RAN technologies, a project which also includes Cisco (as does the Rakuten roll-out).
Altiostar’s most recent technical milestone was to containerize its radio software, using container management frameworks from Robin.io. In its existing deployments with Rakuten and others, Altiostar had delivered a fully virtualized 4G PHY layer. Now the next step, moving towards cloud-native 5G, is to break the RAN into smaller, mix-and-match components via containers.