5G presents network operators with a new framework that lends itself to open source technologies that can play an important and defining role in how services are architected, maintained, and operated. While open source is making an impact on the software layer of 5G networks, the vision for open source networking is much more grandiose.

Open source’s ultimate impact on 5G will likely fall somewhere in the middle — heralding new ways for operators to piece together networks and services, but well short of the utopian, completely disaggregated future some have envisioned.

Operators have long complained about the lack of choice and vendor lock-in that results from having a small group of entrenched vendors to buy equipment and networking services. Open source will change that dynamic in small areas of the radio access network (RAN), but its mark will be much greater in the services layer or what many call the “softwarization” of the network — service orchestration, automation, network slicing, and mobile edge computing.

Open Source Role in 5G Networks

“The system architecture [of 5G] is a real opportunity for operators to look at open source because there’s a real openness to the 5G architecture that’s been developed at 3GPP,” says Chris Pearson, president of 5G Americas, referring to the organization that develops and defines standards for mobile telecommunications. “Open source is complementary to the standards process at this point, in my mind, and it will be one of the enablers for 5G.”

Much has been learned about the relationship between formal standards and software implementations of those standards of late, says Adrian Scrase, head of 3GPP’s Mobile Competence Center and CTO at ETSI. The standards body is developing several standards relevant to 5G and recently partnered with the Linux Foundation to work more closely on the development of open networking technologies. “If you want to ensure interoperability and a multi-vendor environment then you need both,” he said. “One does not replace the other. A software-only approach is not sufficient for infrastructure.”

As operators move to 5G, some roadblocks are starting to be taken down or circumvented altogether, explains Pearson. “In the past you’ve seen a lot of proprietary software in the interfaces that were tied to the underlying hardware,” he said. Some of those interfaces that send commands to network hardware are now untethered from vendor control and ripe for open source innovation.

The packet core is also becoming increasingly disaggregated, explains Guru Parulkar, executive director at the Open Networking Foundation (ONF). “When it comes to radio access networks, there isn’t anything that is real open source right now,” but controllers for RAN are gaining autonomy in the 5G framework, he says. “We are still in the very early days of having open source in mobile cellular networks.”

Traditionally, cellular networks are defined by RAN and core networks, but 5G standards introduce cloud computing principles and new capabilities like virtualization, densification, distribution, and disaggregation, explains Oguz Sunay, chief architect of mobile networking at ONF. This effectively brings software into networking, cloud control management, and automation, he said.

From that angle “open source is starting to have an impact. Going top to bottom, telcos have pretty much aligned themselves around ONAP (the Open Networking Automation Platform),” which he describes as a completely open source architecture that can improve carriers’ operations and business support systems.

Many telco providers are talking about open source and some have “moved aggressively with some stacks in particular use cases,” says Tom Burns, senior vice president of Dell EMC Networking Solutions. “Lots of interest in open source, lots of discussion, but I do think that there needs to be some level of consolidation and focus to a fewer set of priorities… so that we can gain further traction. In a multi-cloud world it will probably be a combination of traditional stacks and open-source stacks.”

Challenges that Open Source Could Help Operators Overcome

The concept and objective of open source is to provide mobile operators with more capabilities in a much faster manner, explains Pearson of 5G Americas. “It’s really about doing things more efficiently, complementary to the standards obviously.”

The proprietary hold over telcos hasn’t been effectively challenged by standards to date, but operators are trying to overcome that barrier as they move to 5G and use open source technology to enable new opportunities.

“If you go through disaggregation and open source, [operators] will have a lot more control of their own infrastructure, and then they will be able to provide much better optimization and services to their customers,” says Parulkar of ONF. “All of that becomes possible if it is disaggregated and open source.”

Decentralizing networks at a functional level and the user or control plane is an important aspect of open source, explains Sunay of ONF. “The latter disaggregation brings in SDN principles and that’s where even in the RAN space we are talking about a programmable RAN and in that context it is the control plane of that RAN,” he says. “Open hardware is going to be the first step and then we’ll slowly start seeing, at least on a functional level, components to be open sourced.”

Network Components That Are Ripe for Open Source

Indeed, certain parts of the 5G network are ripe for open source involvement. It will start with small cells during the next 18 months, followed by macro cells and the control plane, according to Parulkar.

“The [component] that comes to light with a fair amount of enthusiasm is on the 5G core network,” says Pearson. “If you start thinking about the core network and the softwarization of telecommunications networks … there’s obviously opportunity there.”

Greater contributions from the open source community will also open up the ecosystem, explains Sunay. “We have a very tight, closed ecosystem today that is composed of maybe just a handful of incumbent vendors.”

Roughly 80% of what’s inside an expensive network component like a base station or macro cell is common, whether it comes from Ericsson, Nokia, Huawei, or Samsung, according to Sunay. “The real differentiating intelligent component is going to be 20% or so. Open source helps by letting the non-differentiating part be contributed to across the board,” he says.

Companies that focus on a subset of that intelligent layer can have a tremendous impact by introducing features like network slicing, for example, Sunay explains. “If you have an open source foundation with APIs, operators can just select that small company potentially as one of their vendors. And a systems integrator can pick and choose from these different components and end up with a highly customized solution that an operator wants and needs.”

Scrase of 3GPP and ETSI says reaching a critical mass of adopters is essential in any format. Multiple initiatives have been established around NFV that have fragmented the market further and effectively slowed down NFV adoption, he says.

“Standards bodies and open-source initiatives are all created and supported by industry,” Scrase says. “This means that any inter-relationship is in the hands of industry. Where we see fragmentation, it is because industry has driven that fragmentation.”

Experiences gained from seeing how open source and formal standards can conflict or complement each should be recognized and adopted in the standards-writing process, Scrase explains. ETSI is taking that path to reduce development time and increase functionality, he says.

“There is no value in standards bodies trying to become open source foundations, and no value in open source foundations trying to become standards bodies,” Scrase concludes. “Their respective roles are complementary, but different.”