Monitoring an attribute of a network slice

An apparatus comprising:

• a memory;
• and
• a processor coupled with the memory and configured to cause the apparatus to:
• receive a first request from an application function (AF) or a network exposure function (NEF), wherein the first request comprises Single Network Slice Selection Assistance Information (“S-NSSAI”) that identifies a network slice and an event identifier that indicates a reporting event corresponding to a number of user equipments (UEs) registered to the network slice or a number of data connections established for the network slice, and wherein the first request comprises event reporting information indicating a reporting condition, wherein the reporting condition comprises the number of UEs registered to the network slice or the number of data connections established for the network slice satisfying exceeding a respective threshold value or underrunning the respective threshold value by being below the respective threshold value;
• transmit, to the AF or NEF, a confirmation message in response to the first request;
• and
• transmit a first notification message to the AF or NEF in response to the reporting condition being fulfilled, the first notification message comprising the event identifier and an event report corresponding to the reporting condition, wherein the event report comprises a confirmation that the respective threshold value is exceeded or a confirmation that the respective threshold value is underrun.

An apparatus comprising a network exposure function (NEF), the apparatus comprising:

• a memory;
• and
• a processor coupled with the memory and configured to cause the NEF to:
• receive, from an application function (AF), a first subscribe request for network slice notification reporting,
• wherein the first subscribe request comprises Single Network Slice Selection Assistance Information (“S-NSSAI”) that identifies a network slice and an event identifier that indicates a reporting event corresponding to a number of user equipments (UEs) registered to the network slice or a number of data connections established for the network slice, and
• wherein the first subscribe request comprises event reporting information indicating a reporting condition, wherein the reporting condition comprises the number of UEs registered to the network slice or the number of data connections established for the network slice exceeding a respective threshold value or underrunning the respective threshold value by being below the respective threshold value;
• discover a network function that supports network slice notification reporting;
• transmit a second subscribe request to the network function, the second subscribe request comprising the event identifier and the event reporting information;
• receive a first notification message from the network function, the first notification message comprising the event identifier and an event report corresponding to the reporting condition,
• wherein the event report comprises a confirmation that the respective threshold value is exceeded or a confirmation that the respective threshold value is underrun;
• and
• send a second notification message to the AF, the second notification message comprising the event identifier and the event report.