In this article, Mike Murphy CTO, Nokia North America, outlines key areas that need to be developed to enable true Open RAN deployments at scale.

Michael Murphy, CTO for North America, Nokia Networks

April 19, 2021

5 Min Read
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The dream of an open RAN ecosystem is to broaden the vendor landscape so that service providers can mix and match best-of-breed suppliers with ease. That requires rigorous standardization and the only accepted authority to do that is the O-RAN Alliance. Some would suggest standardization is not required; however, such approaches inevitably imply complex pairwise contracts and interoperability efforts – resulting in a different form of lock-in and counter to the fundamental stated objectives.

Standardization and Closed RAN 2.0

This leads us to a long-overdue clarification of terminology. Since open RAN is highly ambiguous, a more precise and appropriate term is O-RAN compliant system. Similarly, the term legacy is inappropriate. Every major provider in the world today is deploying bespoke solutions and thus, by definition, they are not legacy, rather they are integrated vs open.

Work within the O-RAN Alliance is being developed by subject matter experts spread across nine different Working Groups (WGs) [and a tenth to be added], as shown below. While progress is admirable, specifications are at different levels of maturity. For example, the Fronthaul Control, User and Synchronization Specification, developed by WG4, is at Version 5.0 and considered stable.

O-RAN Alliance Working Groups

However, the O1 SMO data models, O2 cloud management interface and security specifications haven't even been specified yet! For this reason, it is factually correct to say that it is literally impossible to build an end-to-end, standardized O-RAN compliant system today. Could you build a partially compliant system? Yes, but it would have proprietary components (requiring pairwise agreements).

Even when specifications exist, further tuning may be required. For example, the CUS plane specifications cover a broad array of capabilities. Actual deployments require only a subset of those defined. Those subsets are called profiles, specifying things like usage of 3.7-3.98GHz spectrum, 20MHz carriers, dynamic PRACH and so on. More than 100 profiles have been defined to date. That proliferation has resulted in an exercise to collapse those down into a more reasonable and generalized set of 10-20 IOT Profiles. A work in progress.

Finally, while O-RAN is broad in its coverage, 3GPP specifications are even greater in breadth and constantly evolving. It is quite natural then that some 3GPP capabilities haven't been fully analyzed by the O-RAN Alliance. One example is RF sharing.

O-RAN Alliance Specification Status

From this, it should be clear that O-RAN interoperability between vendors today may not be as seamless as one would hope. That is why some operators who have gone through this somewhat painful process have packaged fixed line-ups of components from different vendors and are offering them globally. Iain Morris of Light Reading adroitly referred to them as Closed RAN 2.0.


Above and beyond the need to align with mature specifications, is the requirement parity. Simply put, the set of features or capabilities available with O-RAN compliant products should, minimally, be the same as those deployed today and in the future with incumbent, integrated solutions. Parity applies to features, performance (KPIs), security and other factors. Think of the alternative. Does it make sense to degrade a network for the sole purpose of being open? This is flawed thinking in the extreme, as it could lead to reduced competitiveness at a country or service provider level, or equally disgraceful, an increase in the digital divide if enforced on rural providers as a prerequisite for receiving government funds.

It is true that some use cases do not require full feature parity, such as in private networks, however, one would guess performance and security parity are non-negotiable. Even then, history has shown enterprise feature creep tends to lead towards content like that available on public networks.

Parity is challenging. Nokia received requests for 327 CU/DU features, 35 custom KPIs and 52 new Radio Units (RUs) – to be delivered across multiple 5G platforms, in 2021. Multiplied across ten to 15 years and one can appreciate the breadth of content available on incumbent products today. Parity is not the home of the meek. It requires significant scale.

Infrastructure readiness

The O-RAN Alliance specifications do not mandate virtualized implementations. Traditional or classic solutions with vendor-specific hardware can also be O-RAN compliant. Classic solutions do not require new infrastructure and can be deployed in tandem or adjacent to existing systems today. Conversely, virtualized DU solutions do require new infrastructure with significant capital investment and changes to operational procedures. Few providers have implemented such changes. Those that have, have taken many years to do so.

The only possible exception to this might be virtualized CU or RAN Intelligent Controller (RIC) functions, having less stringent latency demands. They could in principle coexist with existing virtualized core network sites.

Replacement technology vs. new value

All of this leads to the discussion of value. Why are we doing this?

The RIC, enabled by the E2 interface, enables the development of xApps by third-party, independent vendors. Examples include admission control, traffic steering and power consumption optimization. The RIC thus provides net new value. Arguably, the O1 and O2 interfaces also provide new value by enabling vendor-independent network and lifecycle management. The open fronthaul interface, however, offers no new network capabilities. It is a replacement technology that enables a wider choice of vendors, for the purpose of price competition and, in theory, innovation.

Service providers thus need to consider the complexity that comes with multivendor O-RAN solutions with no increase in competitiveness versus working with incumbents on pricing and content, or, looking at net new services enabled by the RIC, O1 and O2 interfaces.

To close, the O-RAN Alliance suite of specifications is progressing well, but with different levels of maturity. Deployment of end-to-end solutions needs to also consider service provider infrastructure readiness, parity with existing integrated product capabilities and whether net new value is introduced.

— Mike Murphy, CTO, Nokia North America

About the Author(s)

Michael Murphy

CTO for North America, Nokia Networks

Mike is an international technology expert with extensive experience in running technology development programs on a global scale for some of the top companies in the telecommunications industry. He has an extensive background in both Research & Development and P&L ownership globally.

 In 2014, Mike moved to Dallas, Texas and assumed his current role, CTO for North America for Nokia Networks. In this capacity, Mike is responsible for supporting senior customer engagements and influencing corporate strategy in both product direction and roadmaps. As such, Mike has been a key presenter for strategic vision both within and outside the region.

Mike joined Nokia in 2005 as Japan country manager, where he was responsible for P&L and led the formation of a senior team during the Softbank takeover of Vodafone.

He then moved to the role of Head of Technology for the Asia-Pacific region, managing activities in Asia, the Middle East and Africa. In this role, his focus was roadmap planning for the region, LTE entry and development, as well as communicating the telecom vision with a focus on broadband profitability.

 Prior to joining Nokia, Mike was the former head of WCDMA development for Nortel Networks.  Mike had primary responsibility for delivering that technology in 2001 to European customers. He then moved to Asia where he was instrumental in establishing the LG-Nortel joint venture in Korea. After that, Mike headed the Nortel Networks Asia-Pacific Wireless sales business, covering all countries in the region.

 Mike has a master's degree in Mathematics from the University of Waterloo in Canada. He has lived in Turkey, China, Korea, France, Canada, Japan, Thailand, and is now based in Irving Texas. Mike is fluent in English and French. He is a semi-professional photographer and holds a black belt in Tae Kwon Do.

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