Briefly discuss the Network Slice Admission Control Function (NSACF) and the related charging functions?
The charging functions specified for Network Slice Admission Control Function, are based on following functionalities supported by NSACF:
- monitoring and controlling the number of registered UEs per network slice
- monitoring and controlling the number of established PDU Sessions per network slice.
The 3GPP 5G Release 17 brings in a new feature, i.e. NSAC to better manage and operate network slices. An NSAC Function (NSACF) can monitor and control the number of registered UEs and established Protocol Data Unit (PDU) sessions per network slice and feed the information to an Application Function (AF) for analysis and further processing. Since the AF could be deployed outside the operator domain, additional security measures are put in place in order to mitigate potential security risks.
On top of securing the application-layer interface between the AF and the 3GPP network, the identifier of the network slice is masked to prevent leakage of the sensitive information. In addition, the AF is authorized to access only specific network slices in order to prevent the AF from accessing information for other network slices unauthorized.
The following are high-level charging requirements specific to Network Slice Admission Control Function:
- The NSACF shall support converged charging using service-based interface.
- The NSACF shall support converged charging for number of UEs per S-NSSAI.
- The NSACF shall support converged charging for number of PDU Sessions per S-NSSAI
Architectural options of below figure can apply to any Network Slice Admission Control converged charging architecture.
