What Is Open RAN?

Open RAN (Open Radio Access Network) is a telecommunications network architecture that allows hardware and software intercommunication in mobile networks using standardized interfaces. Traditional RAN systems use proprietary equipment with interconnected hardware and software. Open RAN separates these components so that wireless network operators can combine different equipment from different vendors, with the ability to use software-based network functions. An Open RAN architecture lowers costs and allows mobile network operators to scale quickly.

Here are the main components of Open RAN that work together to allow it to function. As modular components, you can deploy each of these independently, effectively scaling or changing your management system at a functional level.

Radio Unit (RU)

The RU manages radio frequency transmission and reception. All low-level physical layer processing, such as beamforming, occurs in the RU component. Because the RU works with radio frequencies, you mostly deploy this near the cell site.

Distributed Unit (DU)

The DU is for latency-sensitive functions that need to meet strict timing requirements. The DU also manages Medium Access Control (MAC) layer functions. Due to high performance expectations, network operators typically deploy the DU at the network edge to help minimize latency.

Centralized Unit (CU)

The CU is for any non-time-sensitive functions, and is split into the CU-CP for the control plane and the CU-UP for the user plane. Network operators usually choose to deploy the CU in stable and scalable environments, such as cloud data centers.

RAN Intelligent Controller (RIC)

The RAN intelligent controller (RIC) acts as an optimization engine for RAN resources. There are two parts to the RIC: the Near Real Time RIC (Near RT RIC) and the Non-RT RIC. The Near RT RIC component is deployed at the edge, whereas the Non-RT RIC is deployed in the cloud. Combined, the RIC gives adaptation recommendations to distribute RAN resources better and improve overall performance. Like Open RAN, the RIC is defined by the O-RAN Alliance’s specification.

Open interfaces for mobile network connectivity

Open interfaces are the communication protocols that allow the separate Open RAN hardware components to communicate with one another. These interfaces are non-vendor specific, allowing operators to use components from different suppliers and still have each component function correctly.

By decoupling hardware and software, Open Radio Access Network offers numerous benefits for operators.

Multi-vendor flexibility

The move away from fixed architecture to Open RAN allows network operators to source control applications, software, and radios from multiple vendors. By using a standardized, open interface, operators can avoid vendor lock-in and optimize their infrastructure on a function-by-function basis.

Programmability and automation

With standardized control interfaces, Open RAN allows network operators to use software-based automation frameworks. By working on the same standard system, network operators can use software to automatically adjust the radio network performance without manual intervention.

Edge computing integration

Separating the individual RAN functional components means that operators can deploy specific components within the edge computing infrastructure. Especially for RAN functions such as the DU that require low latency, this helps to further enhance the speed and efficiency of this architecturally distributed approach to networking.

Reduced capital expenditure

Open RAN removes the need for proprietary hardware. This allows network operators to choose competitors that offer the best deal, instead of being locked into the same vendor’s products across the entire architecture.

Faster feature deployment

By moving to a cloud-native model, network operators can easily upgrade their software whenever patches become available. Instead of dealing with monolithic systems, the cloud-native approach improves innovation speed, as network operators can rapidly adopt new features into their networks.

Depending on your existing infrastructure and objectives, there are a few different deployment models for Open RAN.

Greenfield deployment

Greenfield deployment for Open RAN is where you build an all-new mobile network infrastructure instead of using any existing RAN infrastructure. Although this is a fully customizable approach with lots of flexibility, it does require a larger up-front investment.

Brownfield migration

A brownfield migration or approach is where you instead replace or upgrade existing RAN environments to facilitate Open RAN. As a form of modernization, brownfield migration helps to build upon what you already have access to, but requires careful planning to work around legacy components.

Hybrid approach

A hybrid approach uses both RAN and Open RAN within the same network. Typically, you deploy Open RAN to cover specific frequency bands or help with certain use cases. A hybrid approach is cost-effective and lets network operators take advantage of Open RAN where they need it most, while decreasing new infrastructural costs and limiting migration risks.

By being flexible, efficient, and helping to avoid vendor lock-in, Open RAN is an effective choice for a number of radio access network use cases.

5G network deployment

The modular approach of Open RAN allows network operators to optimize RAN functions, helping to meet the higher performance requirements that 5G demands. Cloud RAN or virtualized RAN also makes it flexible and effective for 5G rollouts and ongoing upgrades.

Private networks

Enterprises or settings that need a private cellular network can use Open RAN to meet that requirement. The modular nature of Open RAN lets you create networks that meet exact business needs, while also prioritizing security and privacy.

Rural connectivity

By using existing off-the-shelf hardware, enterprises can extend their network reach to rural areas to boost mobile coverage. Open RAN’s more flexible deployment structure saves costs over a traditional RAN deployment approach, while facilitating the network’s expanding reach.

Network densification

By allowing edge-based Radio Access Network (RAN) functions and modular deployment, Open RAN solutions help network operators to scale their networks iteratively. Incremental scaling on a network helps improve coverage and densify capacity over time by deploying additional units to better service high-traffic areas.

AWS offers infrastructure and services to support Open RAN deployment, testing, and operations:

• AWS for Telecommunications provides the technologies, solutions, and support to help telcos modernize their network and business operations, enhance customer experiences, and create new service offerings.
• AWS Outposts is a family of fully managed solutions delivering AWS infrastructure and services to virtually any on-premises or edge location for a truly consistent hybrid experience.
• AWS Wavelength allows you to run applications using AWS Infrastructure and services in AWS telco partners’ data centers to meet low latency, data residency, and resiliency needs.

Get started with Open RAN on AWS by creating a free account today.