The move to 5G standalone (SA) networks is now underway around the world as operators seek to modernize their core network infrastructure and introduce services such as network slicing and low latency edge applications. By December 2021, 47 operators were actively deploying public 5G SA networks, according to the Global Mobile Suppliers Association (GSA).

Decisions about how to deploy 5G core will have far-reaching and long-term implications for how 5G networks perform and for the operator's service offer, according to a Heavy Reading white paper, Multi-Vendor 5G Core Networks: The Case for a Disaggregated Control Plane. The paper references the 3GPP service-based architecture (SBA) and cloud native infrastructure as important enablers for multi-vendor 5G core.

A multi-vendor 5G core is strategic to operators in two main ways, as discussed below.

Supplier diversity and network resiliency

High availability — making sure the service works consistently with minimal downtime — is the most important priority for mobile operators. Even seemingly small problems in the mobile core can result in widespread outages and brownouts. In 5G networks, availability will become ever more important as more devices, more services — and more critical services — are deployed on the network. By definition, a single-supplier dependency, in the most critical part of the network, is a risk.

A multi-vendor 5G core provides a degree of resiliency because it helps build the operational capability needed to adapt and react to challenges. For example, if an existing vendor is not meeting requirements or delivering features as needed, the operator should be able to respond and take control to resolve the situation.

Creation of 5G SA services

The ability to create services that respond to market demand, or that stimulate and enable new applications, is one of the important ways operators can serve customers with 5G. A 5G SA network is required for advanced service types such as edge applications, network slicing and mission-critical communications. This makes the 5G core (a prerequisite for 5G SA) more than a critical connectivity layer; it is also important to service creation in operator networks.

A multi-vendor core can decouple service creation from connectivity. This allows operators to source the best independent suppliers to support different service types. Where the 5G core connects to external services — for example, using service exposure APIs — suppliers that are more cloud native, with deeper and wider support for open APIs, may be better able to integrate with external cloud applications.

Heavy Reading research, including operator surveys and our one-to-one interactions with core network professionals, strongly supports the view that a new 5G core should be a multi-vendor deployment. But while there are many benefits to this approach, multi-vendor core comes with its own set of challenges, including increased systems integration costs, interoperability testing, extra training, vendor management and more. The SBA and cloud native infrastructure help alleviate these challenges to an extent, but there is nevertheless a limit on how many vendors it is practical for an operator to work with.

As of 3GPP Release 16, the SBA specifies 22 discrete 5G core functions and an associated service-based management architecture (SBMA). Clearly, it is impractical for operators to use large numbers of discrete suppliers and take on extensive, custom integration work. Pre-integration is required.

For this reason, Heavy Reading's paper advocates that two to four 5G core suppliers — each providing clusters of related network functions — are optimal for a multi-vendor strategy. This gives operators substantial benefits but with manageable integration costs.

For more information on multi-vendor 5G core, download the full report.

— Gabriel Brown, Principal Analyst, Heavy Reading

This blog is sponsored by Oracle Communications.