Common Framework for 5G Northbound APIs
3rd Generation Partnership Project (3GPP), a global standards forum for cellular communication technologies, exposed the core network capabilities as Northbound APIs for consumption by 3rd parties outside Mobile Network Operator (MNO) domain such as enterprise domain Application Servers (AS) or Application Function (AF). However, the common supporting capabilities like onboarding, discovery, publishing, authentication, logging, auditing etc., applicable for all Northbound APIs, were not specified in 3GPP until Rel-14. In addition, with the advent of 5G networks, it is natural that more vertical industries look to enable their communications on 5G networks, and so the increase in 3rd parties ecosystem consuming the 5G Northbound APIs. In Rel15, 3GPP specified Common API Framework (CAPIF), to avoid duplication in being specified at multiple places and bring in consistency of approach between different API specifications, and to ease the development and deployment of 3rd party applications invoking 3GPP Northbound APIs for Evolved Packet System (EPS) and 5G System (5GS). In this technical paper, the CAPIF standard for 3GPP Northbound APIs including the common supporting capabilities enabled by the framework are explained. The paper also elaborates how CAPIF can be leveraged to quickly develop and deploy different 3GPP Northbound APIs and the vertical industry applications in unified and harmonized manner over the 5G Network.