Is open RAN attractive for private and venue mobile networks? At first look, no. Enterprises want to buy integrated private mobile network solutions – possibly delivered as a service – and have little appetite to create their own mobile networks using open RAN subsystems.

Yet, the idea of open RAN for smaller-scale private and venue networks is of interest to mobile operators, systems integrators, cloud companies and RAN technology developers. A quick look on Light Reading, for example, shows the following: AT&T to take open RAN indoors first, Amazon, Dish peddle 5G products for the enterprise and Cohere CEO: Open RAN ideal for enterprise applications.

Private networks and venue networks are also backed in the latest Heavy Reading Open RAN Operator Survey as among the leading use cases for open RAN technology. There are likely several reasons for this, including the following:

Digging into this topic, Heavy Reading's survey asked operator respondents to identify a preferred RAN split option for private 5G mobile networks. The figure below shows that an integrated CU+DU+RU (respectively, centralized unit, distributed unit, radio unit) is most popular for both sub-6GHz (59%) and mmWave (39%) spectrum. This, in effect, means a small cell solution. Using integrated small cells is a familiar indoor deployment model for enterprises and venues and reflects the current LTE private network market and vendor ecosystem. In this type of scenario, to make this "open RAN" would require opening E2 and/or O1 interfaces to a service management and orchestration (SMO) system.

Another way to look at integrated small cells as "open RAN" is as networks created from open RAN subsystems and components provided by different vendors, with telco operators, systems integrators or cloud companies acting to provide enterprise and venue customers with a pre-integrated solution. This may be stretching the definition of "open" a little, but it offers organizations with expertise in enterprise networking and applications the potential to create mobile networks that are customized for the deployment scenario and yet are still inexpensive to deploy and operate.

Among the other RAN split options offered in the question, the absence of a clear favorite probably indicates the market is in an exploratory phase, with Option 2, Option 6 and Option 7 all still in play. Over time, it is possible operator preferences will favor one or another split option, but for now, this is an area to watch closely.

Figure 1: For private 5G networks, which RAN split option(s) is your company likely to deploy? Select all that apply. (Source: Heavy Reading)

Virtualized RAN for private networks

Where a RAN split is used, an interesting question is the extent to which operators think private network solutions will be virtualized. This is important because the virtualization (or containerization) of CU and DU software enables integration with edge cloud infrastructure deployed at the enterprise location, which can enable a simpler operating model and closer integration with enterprise applications. The figure below shows a large 40% of respondents expect "both the CU and DU to be virtualized," ahead of the 31% that expect to see "only the CU virtualized." Therefore, a combined 60% do not expect to virtualize the DU in private 5G open RAN networks (which is consistent with the integrated small cell preference identified above).

Figure 2: To what extent will virtualized RAN (vRAN) be present in your company's O-RAN 5G private network deployments? n=81 (Source: Heavy Reading)

The difference between virtual CU and virtual DU is significant. In simple terms, a hardware DU (i.e., a DU based on an SoC) trades performance for lower flexibility; only virtualizing the CU is simpler but reduces the potential gains from edge cloud integration. Note, however, that this is a fast evolving area of technology. There are many performance enhancements to edge cloud infrastructure and open RAN silicon in development that may change the picture in the next year or two. It is anticipated, for example, that virtual RAN using SoC accelerators that are addressable by cloud management software will emerge as a competitive way to deliver cloud native RAN to private enterprise and venue networks.

To download a copy of the 2021 Heavy Reading Open RAN Operator Survey, click here.

This blog is sponsored by Qualcomm.

— Gabriel Brown, Principal Analyst, Heavy Reading