Open RAN, challenges and opportunities

Telecom operators globally are either already in the process of launching 5G services, or planning to upgrade their networks from 4G to 5G. Apart from high speed and low latency in 5G, another important driver toward upgradation is the move to cloud based, disaggregated Open RAN solutions.

In the past, 2G/3G/4G RAN networks were closed, proprietary designs. Interoperability challenges made it tough to deploy multi-vendor RAN equipment. In addition, the hardware-based appliances rapidly reached end-of-life and required long design cycles, resulting in little or no revenue benefit for operators. This put constraints on innovation in today’s dynamic, network-centric connected world. Open RAN is increasingly making telco networks work like IT cloud networks. Scaling benefits accrued in an IT cloud network are being brought to the telco cloud, thereby simplifying deployment, provisioning and automation with the application of AI/ML. Open RAN solutions are allowing MNOs to move away from dependency on single vendor.

Challenges in Open RAN implementation
The flexibility afforded by a multi-vendor RAN ecosystem makes Open RAN solutions very attractive to MNOs, but this comes with certain challenges as well.

Backward compatibility. The first major challenge is compatibility with legacy networks. Brownfield MNOs have existing 2G, 3G, and 4G networks. Legacy networks will co-exist with 5G networks, with some dynamic spectrum sharing. The Open RAN based solution must ensure connectivity with legacy networks, as well as scale up to meet increasing data demands for 5G.

Scalability. Open RAN solutions need to be scalable across multiple deployment scenarios. The DUs deployed at the cell site-based mobile tower cater to lesser number of RUs and are more sensitive to power consumption and cost, While the DU at the data center needs to scale to support multiple RUs.

Interoperability. Disaggregation of RAN into multiple parts increases the number of interfaces between components. With increased virtualization, there are multiple software vendors whose software may not be easily portable across different COTS hardware in data centres. This multi-vendor, multi-layered RAN increases the challenge of interoperability across all these various combinations.

Problem resolution. Troubleshooting the network will also be a challenge. If there is an issue in the network, it may be difficult to identify and isolate the specific cause to a specific vendor’s equipment or software due to the increased number of vendors and interfaces. This may also increase the downtime of the network.

Security. Network security is a major challenge as different vendors follow different security protocols. An MNO will have to balance the various security protocols to ensure robust security for the network.

Opportunities for the new vendors
These challenges are not insur­mountable. On the contrary, they provide an opportunity for newer vendors to bring innovative solutions. There are already some solutions on the horizon from multiple players. Saankhya Labs is working on bringing a portable RAN framework, RANWiser that addresses the problem of portability of RAN software between multiple RAN hardware platforms.

It acts as a hardware abstraction layer and also increases the security of RAN software. Increased portability helps in opening the RAN hardware ecosystem and encourages bring differentiated offerings that make the RAN more power-efficient and reduce the total cost of ownership (TCO). Newer specialized hardware platforms such as the one Saankhya is deve­loping address the issues of scalability, power efficiency and TCO by building on chipsets that are elastic and optimized to run RAN workloads. This results not only in reduced power and cost but also scales in both directions from a cell site deployment to a data centre deployment. By addressing these issues, Open RAN solutions can enable future-proofing of the network. This will also help in large scale adoption of Open RAN.