Telecom core networks focus on optimising the performance and reliability of long-distance and large-scale data communications. Their functionality typically includes:
- Aggregation: Core nodes offer the highest level of aggregation—methods of combining multiple network connections in parallel to increase throughput—in a service provider network. This functionality also provides redundancy if any one link should fail.
- Authentication: Determines whether the user requesting a service from a telecom network is authorised to do so within the network.
- Call Control or Switching: Determines the future course of a call depending on call signalling processing. For instance, blocking a call from reaching a subscriber if it is deemed to be a robocall.
- Charging: Deals with the collation and processing of charging the data created by multiple network nodes.
- Service Invocation: The core commands service tasks based on either an action by a user i.e. a call transfer, or through implicit activity i.e. call waiting. The task itself can be executed at either the core or the third-party network level.
- Gateways: To allow the core network to access other networks.
- Subscriber database: Core networks house the subscriber database, which the core network nodes access for functions such as profiling, authentication, and service invocation.
- Operations & Maintenance (O&M): Operations support systems build up and provide the core network nodes, with configurations dependent on factors such as the peak hour call rate, number of subscribers, geographical preferences, and nature of services. Fault and performance management also happens here.
Core networks are critical infrastructure and new digital technologies and trends have the potential to disrupt and transform, ensuring capabilities, resilience and performance can meet emerging and future needs. The trend towards softwarisation and cloudification of the core over the last decade has been accelerated by the arrival of 5G. To achieve the full promise of high capacity and low latency, 5G networks must be supported by core and RAN architectures that are up to the challenge. Cloud-native core networks create opportunities for new services, revenue sources, the growth of open-source systems and change to hardware requirements as well as acting as a solution for new challenges such as how to integrate with legacy networks.