Integration with 5G networks

The 5G Core (5GC) consists of Network Functions (NFs) that communicate via REST APIs over HTTP.

PortaBilling communicates with the following 5G network components:

• UDR (User Data Repository) – stores subscriber profiles and policy-related data. When a subscriber is activated in PortaBilling and assigned a SIM card, the data is provisioned to the UDR so the subscriber can register on the network. UDR is the 5G equivalent of HSS in 4G.
• SMF (Session Management Function) – manages user internet sessions and IP address allocation. It authorizes and reports service usage to CHF. SMF is the 5G equivalent of P-GW in 4G.
• PCF (Policy Control Function) – enforces QoS and policy rules based on subscriber plans. PCF is the 5G equivalent of PCRF in 4G.
• AF (Application Function) – communicates with PCF for QoS enforcement for multimedia services such as voice and video calls. Voice calls in 5G use Voice over New Radio (VoNR), managed by the IMS working with the AF.
• SMSF (SMS Function) – manages SMS delivery, routing messages through the SMSC.

In 4G networks, real-time and offline charging are handled separately by the OCS and OFCS. In 5G, these are combined into a single entity – the Convergent Charging Function (CHF). PortaBilling functions as the CHF in 5G networks.

As a CHF, PortaBilling integrates with other NFs as follows:

• With SMF – via the Nchf_ConvergedCharging interface for real-time data charging. This integration requires a dedicated Add-on Mart adapter module.
• With PCF – via the Nchf_SpendingLimitControl interface, to notify PCF when a subscriber reaches a spending or data consumption limit. This integration is available via PortaOne Workflows.
  Voice calls and SMS are charged using the same Diameter Ro interface as in 4G.

Many 5G network elements maintain backward compatibility with 4G charging interfaces. If the operator runs 4G and 5G simultaneously, PortaBilling supports 4G Diameter interfaces (Gy and Ro) alongside the native 5G interfaces.