OPEN RAN

OPEN RAN

Open RAN (Open radio access network) is the industry term for the evolution of traditional RAN architecture to open interoperable interfaces, virtualization, and big data and AI-enabled intelligence. Open RAN consist of cloud RAN, O-RAN Alliance and other technologies. O-RAN Alliance is making specifications for O-RAN to make RAN disaggregated, open, intelligent, virtualized, and fully interoperable.

Open RAN Architecture

Open RAN architecture has been defined by O-RAN Alliance. Open RAN architecture disaggregates the radio unit (ORU) and the distributed unit (O-DU) interfaces and RAN Intelligent Controllers (RICs) leveraging AI/ML to make dynamic policy decisions and parameter settings for the radio access network.

Open RAN Radio Unit (O-RU)

Open RAN Radio Unit is responsible for processing the lower part of the physical layer.

Open RAN distributed unit (O-DU)

Open RAN distributed unit (O-DU) is responsible for baseband processing, scheduling, radio link control, medium access control, and the upper part of the physical layer.

Open RAN central unit (O-CU)

Open RAN central unit (O-CU) is responsible for the packet data convergence protocol layer.

Open RAN intelligent controller (O-RIC)

Open RAN intelligent controller (O-RIC) is responsible for gathering information from the network and performs the necessary optimization tasks.

Open RAN Key Benefits

Transformation

• Open RAN architectures consist of two different area “decomposition” that enables “modularity” and disaggregation that enables cloudification and virtualization.
• The mission of this architecture design is to remove the vendor monopoly and enable opportunities for new vendors and, therefore, promote increased competition, vendor diversity, and innovation.

Innovation

• One of the key benefits of deploying Open RAN is the creation of a robust multi-vendor ecosystem that drives competition and innovation.
• The establishment of a multi-vendor Open RAN ecosystem not only creates opportunities for new businesses, both small and large, to enter the previously closed market, but it also limits vendor “lock-in” that can occur under the traditional RAN environment in which the proprietary hardware and software are provided by a single vendor.
• Foundation for 6G innovation.

 Agility

• Open RAN has the potential to offer increased agility, resiliency, and flexibility in telecommunications networks by allowing service providers to select “best-of-breed” solutions from multiple vendors.

CAPEX and OPEX savings

• Open RAN enables transparency into the RAN. It will help operator to see all aspects of the network and diagnose, remedy, and prevent problems in real time. Automated remediation and optimization will reduce OPEX.
• Reduce 5G network deployment costs with a competitive supplier ecosystem.

Open RAN Security Consideration

Open RAN deployment require new security considerations for mobile network operators (MNO).

• As Open RAN follows disaggregated architecture, naturally attack surface is also increased. Multi-vendor echo-system needs specific consideration on changes to the threat surface area at the interfaces between technologies integrated via the architecture.
•  MNO will be using an open source applications and new 5G network functions and interfaces whose standards are still under development.
• MNOs will also need to consider security for cloud infrastructure, virtualization, containerization, and Distributed Denial of Service attacks.

Open RAN Challenges for MNO’s

• Open RAN multi-vendor management

Open RANs will introduce flexible and disaggregated architectures that support increasing data and service requirements of users. While traditional RANs are inherently single-vendor, Open RAN architecture will introduce more complexity due to the increased number of vendors and disaggregation of traditional network functions. These Open RANs are comprised of components that vary based on their specific function or use case they support. For example, a RAN could utilize small cells, Massive Input Massive Output devices, and macro towers to facilitate the communication needs of their users. These heterogeneous components, and the back-end networking components they connect to, may use open interfaces to enable integration with a variety of different components and vendors. While this openness enables vendors to maintain interoperability and functionality for the many components of a RAN, it can also exacerbate existing integration and security considerations for operators of the network.

• Open RAN Software and Hardware

Integration and compatibility between Open RAN components and functions from different vendors is critical to network security. A quick patch upgrade may be required due to discovery of new CVE or zero days CVE. It may delay the patch deployment in the network in case of one vendor delivering patch promptly and another vendor is taking time to deliver it. It may also lead to service outage due to compatibility issues. So, network becomes vulnerable until all the vendors are providing patch at the same time.

• Open RAN component lifecycle

MNO needs to test interoperability among the vendor in case of any software upgrade, new service implementation and addition of new component. It may lead to service outage if these interoperability and end to end service testing is not done prior to deploy in production network. On the other hand, traditional network requires only testing.

• Cooperation between vendor and operator

MNO need to coordinate and follow up rigorously between the vendors when an issue occurred in the open RAN network. It will be very difficult for the MNO’s to identify the issue belongs to which vendor. It is very simple for traditional network as it is belongs to same vendor who is responsible for providing fix. Specially, it will be more difficult to identify the issue in case of incompatibility between vendors. Operator need to sit with all vendors and fix the issue. It will be time consuming to identify and fix any issue.

• Open RAN specification support for device

It is become mandatory to support Open RAN standards and specifications for devices .It may support development of open interfaces, network flexibility, and multi-vendor network support. If any device does not support open RAN standards and specifications and try to communicate with another device, communication failure may happen and may introduce delays in transmission.