Vodafone is an operator with ambitious plans for open RAN – it has a target to run the technology at 30% of its more than 100,000 European sites by 2030 – and is a globally influential voice in mobile network technology.
The aim of the paper is to present Vodafone’s "vision of the system integration processes needed to deliver a truly interoperable RAN solution, ready for massive deployment, into a mobile operator network."
The premise, that a new system integration model is needed, identifies one of the major challenges to open RAN.
Whereas in a vendor-integrated RAN, a single company is accountable for the product and system lifecycle, in open RAN there are several companies involved without clear responsibility for system integration, acceptance testing, in-service updates, technical support, and so on.
Even physically shipping the various pieces of equipment to site and maintaining inventory can be a challenge to coordinate.
This is a well-known problem for open RAN and solving it in a way that will scale and sustain over the long-term is difficult. So, how does Vodafone propose to address open RAN system integration?
The company rejects porting the current single-vendor model to the open RAN scenario. For each vendor to maintain a lab that can perform conformance and interoperability verification for the overall RAN system is unnecessary and would result in duplication of effort.
The future model for open RAN system integration, according to my reading of the paper, has two major components:
1) A federation of different vendor labs connected to a central lab run by an operator-led consortium. Each vendor is responsible for their hardware or software (and runs their own lab for testing and verification), but the central lab coordinates these activities and verifies the overall system. The operator is responsible for governance of the consortium.
2) A physical facility that can configure field-ready multivendor basestations for shipment to site. According to the paper, "hardware parts will be assembled and firmware/software pre-commissioned, under a CI/CD framework. The ready for deployment solution will be then sent to the local market according to rollout milestones." This is, in effect, an advanced logistics operation.
A federated multivendor lab network
The new model must first integrate the various sub-systems that make up a radio basestation and verify the system against design goals. This is the task of the federated lab network, which Vodafone describes as follows:
"This [multi-vendor lab] network will act as a consortium, delivering the RAN product roadmap under supervision by [the] operator. The operator will govern the testing network addressing the growing complexity due to massive number of product specifications, suppliers, and configurations, compared to the traditional system integration model.”
The concept for the federated multivendor lab network is shown in the figure below:
An open RAN logistics hub
For efficient field operations, open RAN needs a logistics framework that can integrate equipment and software from diverse partners and ship ready-to-operate systems to the site. The paper proposes a "factory pre-staging HUB", described as follows:
"As a part of the OPEN RAN site build, our proposal for the future system integration model considers a factory pre-staging HUB."
"Once the solution is verified in vendors labs and E2E certified in operator´s premises, it will be delivered to this pre-staging facility. Each vendor will contribute to the product delivery, providing the already verified segment under its responsibility: RU Hardware and software, COTS servers, RAN software, CaaS layer and Orchestrator.
"Hardware parts will be assembled and firmware/software pre-commissioned, under a CI/CD framework. The ready for deployment solution will be then sent to the local market according to rollout milestones."
The idea is that this model delivers the logistics and fast site deployment that operators need to scale open RAN deployments. The concept is shown in the figure below:
Practical next steps
Vodafone has a pretty good idea about how it wants to approach the problem. It is working, for example, with Dell, NEC, Samsung and Wind River to build an open RAN system for large scale deployment in the UK and will move ahead with this new model.
"Preliminary activities include alignment in testing strategy, hardware/software transfer coordination between companies and trials for remote distribute tests.
"First phase is trialling a distributed / hybrid lab with the likes of Dell, NEC, Samsung and Wind River, in their own labs, and bring to our central lab for final security and core testing."
At face value, then, this all looks a useful and productive contribution to the open RAN system integration challenge. Vodafone is backing up its ambition with concrete actions to make it happen and this makes it a global leader in open RAN.
Nevertheless, questions remain
Assuming the operator is going ahead, some of the first questions that come to mind are:
- How is this model better than the operator paying an SI to do this work on its behalf? Could a vendor or SI run the central lab and hub facility and then ship pre-configured equipment to the operator site, just like an integrated vendor does today?
- Vodafone addresses the need for troubleshooting and technical support during the operating phase, but what does this mean in practice? In national telecom infrastructure, it is critical the right technical support is available at the right time and clearly this is a challenge when expertise is spread across companies. It would be useful to get further clarity on how this will work in practice over the long term.
- Does each operator run a central lab and/or sponsor a consortium? This might work for a Vodafone-sized company, but for many national operators it may not be commercially or practically viable. And how does this square with the objective of using open RAN to reduce cost?
- Finally, are other operators on board, or is Vodafone setting off in its own direction?
To its credit, Vodafone is open to input from outside – in fact, part of the reason for publishing the paper is to elicit views and contributions from the wider industry – and the company should be commended for taking an active lead. How else can the industry deliver pre-integrated open RAN solutions ready for massive rollout?
- Open RAN specialists are a dying breed
- The open RAN diversity mission is not going to plan
- Vodafone admits software rebirth will be hard to deliver
— Gabriel Brown, Senior Principal Analyst – Mobile Networks & 5G, Heavy Reading