It’s widely expected that 5G will bring immense benefits to Communication Service Providers, with many new service opportunities. To make the most of this potential, the 5G core architecture has significantly changed from its 3G and 4G predecessors. Network functions have been largely disaggregated, moving from a small number of monolithic black boxes to many smaller microservices cooperating in a service-based architecture.

The approach for how these microservices co-ordinate with one another – known as signaling – becomes supremely important. Get the signaling right and a CSP can enjoy top-class performance and a highly reliable network. Get it wrong, and the result could be bottlenecks, low performance and even an outage across the whole network.

Further complicating the picture is the trend toward cloud deployment of these networks. The 5G architecture was designed with cloud principles in mind by the standards organizations. This introduces new challenges for signaling.

Don’t treat signaling as an add on

Signaling is so important that CSPs need to treat it as a fundamental part of their initial network design. The signaling strategy defines how important elements for the service-based architecture interact. This can’t be separated from the 5G core design – it needs to be integrated into the network from the start.

While it is possible to connect network functions to one another without an up-front signaling strategy, the result is increased costs. If the signaling design is implemented from the very beginning, only a single integration is needed. But trying to add a signaling overlay at a later stage results in an exponentially more complex integration, and a higher total deployment cost.

More importantly, signaling provides observability that is essential to the deployment itself, aiding in the rollout and operations of the network. During network rollout, the signaling component facilitates integration efforts and smooths over compatibility problems between elements. Later, while operating the network, it allows the monitoring of traffic statistics, network performance, and failure and success rates.

Signaling also aids risk mitigation during failures and overload conditions. When signaling is included in the design from the start, the overall deployment proceeds more smoothly and the network operation is improved.

Three signaling ‘must haves’

Network architecture requires a series of tradeoffs, so it’s critical to know what requirements are important. When planning a 5G signaling architecture, CSPs will want to bear these in mind – Flexibility, Performance and Cloud-native design.

The signaling solution must have the flexibility to observe and control all parts of a 5G core network. It must provide observability of core network functions in a vendor agnostic way. The CSP must also be able to fine tune operations and address any problems that arise, and since these cannot be predicted in advance, the signaling system must have a very flexible message filtering system.

When it comes to performance, one of the essentials is low latency combined with high throughput, whichever service is being provided. The signaling must also be scalable, up or down, to deal with changes in traffic and network elasticity in cloud deployments. Further, that agile message filtering system mentioned above must not impact performance – it needs to work at line rates.

Being Cloud-native is another vital characteristic. Signaling must be software based, designed to cloud-native principles, and be able to use web-scale IT infrastructure – regardless of the underlying cloud implementation. Much of the benefit 5G brings comes from web-scale design patterns, such as service-based architecture – so without a cloud-native design, the signaling system will struggle to realize the benefits of 5G.

5G signaling made easy

Whatever network strategy a CSP is following, deploying the solution at the very start of their 5G project gains numerous benefits. These include the ability to fine tune the signaling to meet the needs of each service, faster integration with the core, lower risk of network outage, simplified network operations, and an overall lower total cost of ownership.

Nokia Cloud Signaling Director (CSD) meets these needs, functioning as the SCP, BSF, and SEPP in the 5G core architecture. It supports all standard signaling models, as well as non-standard choices. Nokia’s Agile Rules Technology (A.R.T.) rules engine provides the most flexible, highly performant rules engine in the industry, filtering and modifying messages at line rate. CSD provides a single point for tracing and probing, working with both Nokia and 3rd party vendor elements. And the CSD’s unique forwarding approach delivers high throughput and low latency – regardless of the end user service mix.

To discover more about 5G signaling and Nokia CSD, go to:

https://www.nokia.com/networks/products/cloud-signaling-director/
or visit our 5G Signaling page at https://www.nokia.com/networks/5g/5g-signaling/.