Network nodes and methods therein for secondary RAT usage reporting

1 . A method in an Access and Mobility Management Function, AMF, comprising, in a 5th Generation System, 5GS, to Evolved Packet System, EPS, handover procedure of a User Equipment, UE:

receiving, from a Next Generation Radio Access Network, NG-RAN, node, a secondary Radio Access Technology, RAT, usage data report message including a Secondary RAT Usage Data Report Transfer Information Element, IE, containing secondary RAT usage data associated with the UE; and

transmitting, to a Mobility Management Entity, MME, a message including a first IE containing the secondary RAT usage data, wherein the first IE contains a field encoded with content of the Secondary RAT Usage Data Report Transfer IE, and wherein the first IE further contains an EPS Bearer Identifier, EBI, associated with a Protocol Data Unit, PDU, session for the UE.

2 . The method of claim 1 , wherein the message is a Forward Relocation Complete Acknowledge message.

3 . The method of claim 1 , wherein the first IE further contains an indication indicating presence of the field.

4 . The method of claim 1 , wherein the first IE is of a type Secondary RAT Usage Data Report.

5 . The method of claim 1 , wherein the first IE is defined as a container containing the Secondary RAT Usage Data Report Transfer IE.

6 . The method of claim 1 , wherein the secondary RAT usage data report message further contains a handover flag.

7 . A method in a Mobility Management Entity, MME, comprising, in a 5th Generation System, 5GS, to Evolved Packet System, EPS, handover procedure of a User Equipment, UE:

receiving, from an Access and Mobility Management Function, AMF, a first message including a first Information Element, IE, containing secondary Radio Access Technology, RAT, usage data associated with the UE; and

transmitting, to a Session Management Function and Packet Data Network Gateway-Control, SMF+PGW-C, a second message including the first IE, wherein the first IE contains a field encoded with content of a Secondary RAT Usage Data Report Transfer IE, the Secondary RAT Usage Data Report Transfer IE containing the secondary RAT usage data, and wherein the first IE further contains an EPS Bearer Identifier, EBI, associated with a Protocol Data Unit, PDU, session for the UE.

8 . The method of claim 7 , wherein the first message is a Forward Relocation Complete Acknowledge message, and/or the second message is a Modify Bearer Request message.

9 . The method of claim 7 , wherein the first IE further contains an indication indicating presence of the field.

10 . The method of claim 7 , wherein the SMF+PGW-C serves a Packet Data Network, PDN, connection to which the PDU session is mapped.

11 . The method of claim 7 , wherein the first IE is of a type Secondary RAT Usage Data Report.

12 . The method of claim 7 , wherein the first IE is defined as a container containing the Secondary RAT Usage Data Report Transfer IE.

13 . A method in a Session Management Function and Packet Data Network Gateway-Control, SMF+PGW-C, comprising, in a 5th Generation System, 5GS, to Evolved Packet System, EPS, handover procedure of a User Equipment, UE:

receiving, from a Mobility Management Entity, MME, a message including a first Information Element, IE, containing secondary Radio Access Technology, RAT, usage data associated with the UE, wherein the first IE contains a field encoded with content of a Secondary RAT Usage Data Report Transfer IE, the Secondary RAT Usage Data Report Transfer IE containing the secondary RAT usage data, and wherein the first IE further contains an EPS Bearer Identifier, EBI, associated with a Protocol Data Unit, PDU, session for the UE.

14 . The method of claim 13 , wherein the message is a Modify Bearer Request message.

15 . The method of claim 13 , wherein the first IE further contains an indication indicating presence of the field.

16 . The method of claim 13 , wherein the SMF+PGW-C serves a Packet Data Network, PDN, connection to which the PDU session is mapped.

17 . The method of claim 13 , wherein the first IE is of a type Secondary RAT Usage Data Report.

18 . The method of claim 13 , wherein the first IE is defined as a container containing the Secondary RAT Usage Data Report Transfer IE.

19 . The method of claim 13 , further comprising:

transmitting the secondary RAT usage data to a management system associated with the 5GS.

20 . A network node implementing an Access and Mobility Management Function, AME, comprising:

a communication interface,

a processor, and

a memory, the memory comprising instructions that when executed by the processor configure the network node, to facilitate a handover procedure of a User Equipment, UE, by:

receiving, from a Next Generation Radio Access Network, NG-RAN, node, a secondary Radio Access Technology, RAT, usage data report message including a Secondary RAT Usage Data Report Transfer Information Element, IE, containing secondary RAT usage data associated with the UE; and

transmitting, to a Mobility Management Entity, MME, a message including a first IE containing the secondary RAT usage data, wherein the first IE contains a field encoded with content of the Secondary RAT Usage Data Report Transfer IE, and wherein the first IE further contains an EPS Bearer Identifier, EBI, associated with a Protocol Data Unit, PDU, session for the UE.

21 . The network node of claim 20 , wherein the message is a Forward Relocation Complete Acknowledge message.

22 . The network node of claim 20 , wherein the secondary RAT usage data report message further contains a handover flag.