This blog post considers what can be done to accelerate the uptake of O-RAN infrastructure.
How to Expedite the Adoption of O-RAN Infrastructure
From reduced cost and improved performance to faster implementation and greater flexibility, the benefits of O-RAN are clear. However, there are issues that must be addressed if we are to see faster adoption of this infrastructure built on interoperable hardware from multiple vendors. In this blog post, we consider some of the challenges that are preventing faster O-RAN uptake and what can be done to address those challenges.
O-RAN—The Story So Far
An O-RAN, or Open Radio Access Network, is an open, intelligent, virtualized and fully interoperable RAN in which, as Figure 1 illustrates, the key functions are conceptually disaggregated into four distinct categories: Radio Units (RUs), Distributed Units (DUs), Centralized Units (CUs) and RAN Intelligent Controllers (RICs).
Figure 1: Disaggregated O-RAN infrastructure as defined by the O-RAN Alliance
O-RANs are based on the individual functional blocks communicating with each other via standardized, open interfaces and protocols and the concept supports and encourages virtualization in which the DUs, CUs and RICs can be implemented as cloud-based services.
The combination of improved interoperability and potential for virtualization means that, on paper, O-RAN infrastructures offer many advantages over conventional, closed radio access networks built around proprietary technologies.
Among these are:
Reduced dependence of the mobile network operator on individual manufacturers and technologies
Use of lower cost and freely available standard, off-the-shelf components and platforms.
The ability to mix hardware and software from different manufacturers to quickly build optimized and more cost-effective solutions
Increased competition and innovation
More flexibility in RAN implementation, including programmability of the RAN through a software-defined approach and the ability to serve smaller, tightly defined 5G networks
Minimizing the number of complex conversions of base stations through software rather than hardware
Lower total cost of ownership (TCO)
Addressing the Challenges to Speed Adoption
While the benefits are clear, there are some barriers that are slowing global uptake of O-RAN, meaning the number of implementations remains relatively low, and, to date, largely confined to small and greenfield sites.
So, what are the challenges and what can be done to improve the rate of adoption?
Figure 2: Challenges slowing O-RAN adoption
1. The Standards are Still Evolving
The first challenge is that the O-RAN concept is still relatively immature, which is reflected in the fact that the standards continue to evolve. Moreover, at this stage O-RAN does not fully comply with World Trade Organization (WTO) rules, which is why ETSI—a fully WTO-compliant standards body—is being used to adopt and release its recommendations.
As well as limited O-RAN expertise in the industry, one implication of this is that different varieties of O-RAN could emerge as vendors look to gain competitive advantage by bringing products with their own proprietary interpretations to market as quickly as possible. This, in turn, fuels fears of integration overheads as operators seek ways to make these “quasi-O-RAN” solutions successfully work together.
Ensuring technologies are fully harmonized in line with the direction of the evolving standards makes it imperative that system architects and network operators demand suppliers are contractually committed to meeting the standards as they emerge and to working closely with (and being informed by) key bodies such as the O-RAN Alliance, the Telecom Infra Project (TIP), the Open RAN Policy Coalition and ETSI.
2. Timing and Synchronization
O-RAN sees the network synchronization requirements for RUs and DUs become much more stringent—in some cases as tight as +/-130 ns. This demands as much as a tenfold improvement in performance over previous 3GPP-based systems if network operators are to be fully compliant with the terms of their frequency licenses while minimizing system costs.
The good news is that addressing this challenge is made much easier by choosing the latest advanced semiconductor timing devices and platforms designed for time division multiplexing (TDD) based on the IEEE 1588 Precision Timing Protocol (PTP), which is used to ensure the most efficient use of the channel.
Among the off-the-shelf components that Microchip offers hardware designers, for example, are high-accuracy PLLs and buffers, “grandmaster” clocks, primary reference time clocks (pRTCs) and precision oscillators. We also provide platform solutions including Precise Time Scale Systems (PTSS) for robust and resilient sources for UTC-class time and flexible gateway clock hardware that provides secure and accurate IEEE 1588-compliant time and synchronization.
To discover Microchip’s clock and timing solutions, visit our web page.
3. Security
Creating disaggregated networks around products from multiple vendors makes O-RANs more vulnerable to cyber-attacks including passive (e.g. eavesdropping) and active (e.g. man-in-the-middle or MiTM) attacks than conventional, proprietary RANs.
These threats are highlighted in an “Open Radio Access Network Security Considerations” paper developed by NSA and CISA1 that states “in addition to addressing security considerations related to integrating components from multiple vendors, service providers will continue to deal with other considerations related to use of open-source applications and new 5G network functions and interfaces whose standards are still under development. Additionally, MNOs will need to address security considerations related, but not unique to Open RAN, such as cloud infrastructure, virtualization, containerization and Distributed Denial of Service attacks.”
What’s more, the attack surface will only increase as the number of connected devices grows.
Once again, a number of off-the-shelf semiconductor and platform technologies can help system architects incorporate (and network operators maintain) the cyber protection that O-RANs will need. Our customers, for instance, can access a comprehensive family of security solutions. These include embedded processors with hardware-based security such as secure boot (or root of trust) functionality that meets the protection and detection requirements of NIST Platform Firmware Resiliency Guidelines as well as certified “Trusted Platform Modules” built on Trusted Computing Group (TCG) specifications.
At the same time, as the opportunities for virtualization move RANs towards cloud-based implementations, O-RANs could potentially leverage the robust security features available in cloud computing architectures.
4. Complexity of Implementation and Management
Multi-vendor O-RANs are still likely to be more complex to implement and manage than conventional, proprietary systems based on technologies from a single supplier. Such complexity puts the onus on the operator to create an integration team or to employ additional resources to manage system set-up.
Once the RAN is up and running, operational teams will have to contend with understanding how to identify and isolate network problems in a multi-vendor environment and who should take ownership and responsibility for resolving any issues.
To ensure that this complexity does not erode the potential TCO benefits of choosing an O-RAN deployment, operators will need to adopt more automated and less manually intensive processes for system design, deployment and management. Automating tasks to provide “zero-touch” provisioning, for example, facilitates network management and scaling without the need for more staff, while the O-RAN architecture’s support for machine learning (ML) will allow performance and efficiency to be automatically optimized through predictive artificial intelligence (AI) models
5. Testing and Validation
Making O-RAN work as intended requires the adoption of a different approach to testing and validation to ensure that (1) all elements of the ecosystem conform to the relevant standards in isolation and (2) interoperability of the various platforms and components when they are incorporated into an O-RAN architecture is guaranteed. This means that all parties—from equipment vendors and system integrators to service providers and cloud vendors—have important testing and validation responsibilities.
For manufacturers, O-RAN conformance testing—which is more complicated than for conventional RANs and requires a more comprehensive range of test equipment—must validate that their technologies are standards-compliant, deliver expected operation and performance and meet requirements for interoperability. Systems integrators must take responsibility for end-to-end operability, and service providers must perform appropriate performance validation of everything from the core network to the end points.
Moving Forward
The O-RAN Alliance has defined a disaggregated model that is being adopted by both traditional vendors and new entrants to the market who see opportunities to provide hardware and software. As ever, cost benefits (both initial and ongoing TCO) are likely to be the most significant factor in the uptake of O-RAN and the specific implementations that emerge over time. Just because virtualization is possible, for example, does not mean that every operator will take this approach. They are much more likely to seek out the most cost-effective, bundled solution, which will mean we see both virtualized and non-virtualized DUs and CUs in the near-term.
What is clear is that O-RAN has opened up a new market for semiconductor vendors such as Microchip who combine a variety of proven technologies and platforms with the resources to work closely with engineers, system architects, network operators, standards bodies and a variety of other stakeholders to overcome O-RAN challenges. This, plus not insignificant political will—most notably with the announcement that the U.S. CHIPS Act of 2022 has allocated $1.5 billion of funding to the development of O-RAN systems—leaves little doubt that predictions of a market (comprising hardware, software and services) increasing with a CAGR of over 70% and reaching a value of $15.6 billion by 20272 could well be realized.
References [1] https://www.cisa.gov/sites/default/files/publications/open-radio-access-network-security-considerations_508.pdf [2] https://www.marketsandmarkets.com/Market-Reports/open-ran-market-153445936.html?utm_source=Globenewswire&utm_medium=referral&utm_campaign=paidpr
Thomas Gleiter, May 23, 2023
Tags/Keywords: Communications
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