5G Core Transformation Is Key to Private Network Evolution

The 5G core is the brain of a 5G mobile network, establishing reliable connectivity and services access, handling mobility management, authentication and authorization, subscriber data management and policy management, among other functions. It means that network functions are fully software-based and cloud-native, allowing for higher deployment agility and flexibility.

This is no less true for private mobile networks, but because different deployment models have emerged — based on options for enterprises to integrate their private 5G network with the public mobile network or build their own separate network — there are various ways of accessing the 5G core. The basic deployment models for private mobile networks are depicted below.

The first model shows a private 5G network in which there’s no demand at the network edge. Radio coverage provided by 5G radios is the only privately added element, with all infrastructure and user plane and control plane functions provided by the public 5G network, managed by the operator using end-to-end network slicing.

The second, a hybrid model, is similar — designed for enterprise scenarios with higher demand for offloading and multiaccess edge computing. In this model, the RAN and some control plane elements are shared with the public 5G network, but the private mobile network has its own local services too — a dedicated user plane function deployed in the enterprise campus to achieve local offloading. Here, the private mobile network is integrated with the public network, and is often an option if the enterprise needs roaming between the two.

The third model is a fully private network in which the whole network, including a dedicated 5G core, is deployed on-premises as a standalone system. This is either fully independent of the operator’s public 5G network using dedicated industry spectrum, or with shared RAN infrastructure managed by the operator.

5G connectivity is the building block for these networks, and even though private mobile networks are tiny mobile networks in terms of scale, they’re still demanding environments with complex networking and performance needs. This means the mobile core solution has a lot of heavy lifting to do to offer functionality.

The 5G core is based on service-based architecture, which combines IT network principles and cloud-native design. In this type of architecture, network functions offer services to each other through APIs, with each function formed by small blocks of software code called microservices. Some microservices can be reused for different network functions, easing implementation and supporting life-cycle management, such as helping with deployment of new functions and upgrades with minimal impact on live services.

Clearly, not all private networks are the same, so no single equipment solution will be a universal fit — indeed, it’s an indicator of a maturing market when different solutions and equipment designs are commercially available, giving businesses more choice about the type of deployment to meet their current and future needs. In terms of RAN equipment, there’s already a range of 5G base station designs, from macro to pico (small) cells, aligned with the type of coverage and capacity requirements of public 5G networks. But what of mobile core solutions for deployments of private mobile networks?

As an example, we can look at the core portfolio of Chinese firm ZTE, which has been highly active in the private 5G market to date, to see how its solutions align with different private mobile network deployment applications.

For general, larger-scale industrial deployments that need to keep corporate data more secure, ZTE has its iCube. This is a dual-cabinet solution in which the private mobile network asset — the 5G core, baseband unit, IP multimedia system, optical line terminals and cloud platform — is separate from the enterprise cloud cabinet — the mobile edge platform, transparent computing, and applications.

For medium to large deployments involving integration of the private network and the edge cloud, ZTE offers an all-in-one version of the compact iCube — also cloud-based — in which carrier and enterprise IT network resources and functions are combined in a single cabinet solution.

For simpler, smaller-scale deployments, there’s the i5GC, a small and customizable dedicated core product. This is a commercial off-the-shelf server solution made up of two units with a solid feature set, including unified data management and server-based architecture functionality such as 5G core access and mobility management functions. These functions receive all connection and session-related information from devices on the private mobile network, handling connection and mobility management tasks. There’s also a session management function, which interacts with the decoupled data plane and manages session context with the user plane function.

ZTE’s mini i5GC is an even more scaled-down version: a single off-the-shelf server unit based on 5 Gbps throughput, compared with 5 to 20 Gbps for the i5GC. This might serve as an entry-level solution for smaller enterprises needing less scale in terms of user, device and application volume, but still seeking the benefits of 5G private mobile network functionality. In my opinion, this type of solution will play a notable role in growing the lower end of the private mobile network market, exploiting the potential of small and medium enterprises worldwide.

Industrial and enterprise customers don’t necessarily understand complex mobile-led communications networks, but they shouldn’t need to employ private 5G network services — if they provide application road maps and cost budgets, operators need to be able to use templates to design private networks tailored to the needs of these customers and deliver automatic and accurate deployment.

ZTE’s range of core solutions is diversified to support a broad spectrum of private 5G network uses, whether as a sliced provision of the public mobile network, a hybrid private network or standalone private network, with a one-stop order-to-service offering. Enhanced functions such as time-sensitive networking and 5G local area networks are available on demand to meet deterministic network requirements in industrial control scenarios.

5G connectivity is the fundamental building block for these networks, but private mobile networks are complex and demanding environments that are just as much about artificial intelligence, automation, analytics, edge computing, data security and more. The core is the brain of a mobile network and a key domain of interaction with these technologies, so the transition to 5G core is fundamental to employing cloud-native, service-based architecture. This is, in turn, critical to meeting the needs of different deployment models, network functionality and 5G uses. The market for private 5G networks needs a diverse range of 5G core solutions to drive its evolution.