5G network exposure concept: AF → NEF → PCF/AMF/UDM

Opening the Network to Applications

Historically, telecom networks were closed systems. Applications had no way to request specific network behavior like guaranteed bandwidth or device location. 5G changes this through network exposure, a framework that lets external Application Functions communicate with core network functions via standardized APIs. The Network Exposure Function acts as the secure gateway between the outside world and the 5G core. When an AF needs QoS modification, location data, or event subscriptions, it sends API requests to the NEF rather than contacting PCF, AMF, or UDM directly.