Methods and apparatuses for network function discovery

1. A method performed by a network entity, the method comprising:

the network entity generating a discovery request, wherein the discovery request comprises a set of query parameters, the set of query parameters comprising a first candidate network entity identifier (ID) that identifies a first candidate network entity and a set of search parameters for use by a network repository entity (NRE) to determine network entities that match one or more of the search parameters, where the first candidate network entity ID is not one of the search parameters and the set of search parameters comprises a first search parameter;

the network entity transmitting the discovery request to the NRE; and

the network entity receiving from the NRE a discovery response responsive to the discovery request, wherein the discovery response comprises a SearchResult data object that comprises: i) a first information element comprising an array of one or more network function (NF) profiles, wherein each NF profile in the array matches at least one of the search parameters and ii) a second information element comprising a match indicator information element comprising a Boolean indicator that indicates whether or not at least one of the one or more NF profiles in the array matches the first search parameter.

2. The method of claim 1 , wherein

the set of query parameters further comprises a second candidate network entity ID, and

the second candidate network entity ID is not one of the search parameters.

3. The method of claim 2 , wherein

the first candidate network entity ID identifies a first session management function (SMF).

4. The method of claim 3 , wherein

the second candidate network entity ID identifies a second SMF.

5. The method of claim 4 , wherein the second SMF is an intermediate SMF (I-SMF).

6. The method of claim 1 , wherein the set of query parameters further includes an inclusion indicator value that indicates whether or not a network entity profile corresponding to the first candidate network entity ID should be included in an array of query results even if the first candidate network entity ID does not identify a network entity that matches the search parameters.

7. The method of claim 1 , wherein

the set of query parameters includes an array of tuples,

each of the tuples included in the array consists of: i) one of the candidate network entity IDs and ii) and a value indicating whether or not the network entity profile corresponding to the candidate network entity ID included in the tuple should be included in an array of query results even if the candidate network entity ID does not identify a network entity that matches the search parameters.

8. The method of claim 1 , further comprising network entity receiving from another network entity user equipment (UE) context information for a UE that has initiated a registration procedure and that has a protocol data unit (PDU) session, wherein

the UE context information comprises PDU context information associated with the PDU session, and

the PDU context information comprises a first Session Management Function, SMF, ID identifying an anchor SMF for the PDU session and a second SMF ID identifying an intermediate SMF (I-SMF) for the PDU session.

9. The method of claim 1 , wherein the network entity is an instance of an Access and Mobility Management Function.

10. A method performed by a network repository entity (NRE), the method comprising:

the NRE receiving a discovery request transmitted by a network entity, wherein the received discovery request comprises a set of query parameters, the set of query parameters comprising a first candidate network entity identifier (ID) that identifies a first candidate network entity and a set of search parameters for use by a network repository entity (NRE) to determine network entities that match one or more of the search parameters, where the first candidate network entity ID is not one of the search parameters and the set of search parameters comprises a first search parameter; and

the NRE transmitting to the network entity a discovery response responding to the discovery request, wherein the discovery response comprises a SearchResult data object that comprises: i) a first information element comprising an array of one or more network function (NF) profiles, wherein each NF profile in the array matches at least one of the search parameters and ii) a second information element comprising a match indicator information element comprising a Boolean indicator that indicates whether or not at least one of the one or more NF profiles in the array matches the first search parameter.

11. The method of claim 10 , wherein

the set of query parameters further comprises a second candidate network entity ID, and

the second candidate network entity ID is not one of the search parameters.

12. The method of claim 11 , wherein

the first candidate network entity ID identifies a first session management function (SMF), and

the second candidate network entity ID identifies an intermediate SMF (I-SMF).

13. The method of claim 10 , wherein the set of query parameters further includes an inclusion indicator value that indicates whether or not a network entity profile corresponding to the first candidate network entity ID should be included in an array of query results even if the first candidate network entity ID does not identify a network entity that matches the search parameters.

14. The method of claim 10 , wherein

the set of query parameters includes an array of tuples,

each of the tuples included in the array consists of: i) one of the candidate network entity IDs and ii) and a value indicating whether or not the network entity profile corresponding to the candidate network entity ID included in the tuple should be included in an array of query results even if the candidate network entity ID does not identify a network entity that matches the search parameters.

15. A non-transitory computer readable medium storing a computer program comprising instructions which when executed by processing circuitry of an apparatus causes the apparatus to perform the method of claim 1 .

16. A non-transitory computer readable medium storing a computer program comprising instructions which when executed by processing circuitry of an apparatus causes the apparatus to perform the method of claim 10 .

17. A network entity (NE), the network entity comprising:

processing circuitry configured to generate a discovery request, wherein the discovery request comprises a set of query parameters, the set of query parameters comprising a first candidate network entity identifier (ID) that identifies a first candidate network entity and a set of search parameters for use by a network repository entity (NRE) to determine network entities that match one or more of the search parameters, where the first candidate network entity ID is not one of the search parameters and the set of search parameters comprises a first search parameter;

a transmitter for transmitting the discovery request to the NRE; and

a receiver for receiving a response to the discovery request, wherein the response to the discovery request comprises a SearchResult data object that comprises: i) a first information element comprising an array of one or more network function (NF) profiles, wherein each NF profile in the array matches at least one of the search parameters and ii) a second information element comprising a match indicator information element comprising a Boolean indicator that indicates whether or not at least one of the one or more NF profiles in the array matches the first search parameter.

18. A network repository entity (NRE), the NRE comprising:

a receiver for receiving a discovery request transmitted by a network entity (NE), wherein the received discovery request comprises a set of query parameters, the set of query parameters comprising a first candidate network entity identifier (ID) that identifies a first candidate network entity and a set of search parameters for use by a network repository entity (NRE) to determine network entities that match one or more of the search parameters, where the first candidate network entity ID is not one of the search parameters and the set of search parameters comprises a first search parameter; and

a transmitter for transmitting a discovery response responding to the discovery request wherein the discovery response comprises a SearchResult data object that comprises: i) a first information element comprising an array of one or more network function (NF) profiles, wherein each NF profile in the array matches at least one of the search parameters and ii) a second information element comprising a match indicator information element comprising a Boolean indicator that indicates whether or not at least one of the one or more NF profiles in the array matches the first search parameter.