Handling of IP multimedia subsystem VoPS indication
A solution of supporting IP multimedia subsystem (IMS) call setup in a next generation system (5GS) is proposed. During a registration procedure, the network sends indications to a user equipment (UE) indicating whether IMS voice over PS session (VoPS) over 3GPP access and over non-3GPP access is supported or not. The indications comprise two independent indicators, one indicator for indicating whether IMS VoPS is supported over 3GPP access, and the other indicator for indicating whether IMS VoPS is supported over non-3GPP access. In one example, the two independent indicators are included in a 5GS network feature support information element (IE) carried by a registration accept message sent from the network during the registration procedure.
1. A method of handling IP multimedia subsystem (IMS) Voice over Packet-Switched (VoPS) service indication, comprising:
transmitting a registration request message from a user equipment (UE) in mobile communication network, wherein the registration request message is sent over a 3GPP access or a non-3GPP access;
receiving a registration accept message from the network, wherein the accept message comprises an IMS VoPS service indications indicating whether IMS VoPS is supported over the 3GPP and the non-3GPP access;
determining, from the received IMS VoPS service indication, whether IMS VoPS is supported over the 3GPP access and the non-3GPP access; and
in response to receiving the IMS VoPS service indication sent over the 3GPP access indicating that the IMS VoPS is not supported over the 3GPP access and that the IMS VoPS is supported over the non-3GPP access, registering to the mobile communication network over the non-3GPP access or over another 3GPP access for voice service, and
at another time, in response to receiving the IMS VoPS service indication sent over the non-3GPP access, of ignoring the IMS VoPS service indication for the 3GPP access.
2. The method of claim 1 , wherein the registration request is an initial request, a periodic request, or a mobility request.
3. The method of claim 1 , wherein the IMS VoPS indications comprise a first bit indicating whether IMS VoPS is supported over 3GPP access.
4. The method of claim 1 , wherein the IMS VoPS indications comprise a second bit indicating whether IMS VoPS is supported over non-3GPP access.
5. The method of claim 1 , wherein the current RAT is 3GPP access, and wherein the IMS VoPS indication indicates that IMS VoPS is not supported over the current RAT.
6. The method of claim 5 , wherein the UE performs voice domain selection for voice service.
7. The method of claim 5 , wherein the IMS VoPS indications indicate that IMS VoPS is supported over non-3GPP access, and wherein the UE tries to register over non-3GPP access for voice service.
8. The method of claim 1 , wherein the current RAT is non-3GPP access, and wherein the IMS VoPS indication indicates that IMS VoPS is not supported over the current RAT.
9. The method of claim 8 , wherein the IMS VoPS indications indicate that IMS VoPS is supported over 3GPP access, and wherein the UE ignores the indications.
10. The method of claim 1 , wherein the registration accept message further carries information on whether IMS VoPS is supported over 5G new radio (NR), 4G LTE, and non-3GPP access independently.
11. A User Equipment (UE), comprising:
a transmitter that transmits a registration request message in mobile communication network, wherein the registration request message is sent over a 3GPP access or a non-3GPP access;
a receiver that receives a registration accept message from the network, wherein the accept message comprises an IP Multimedia Subsystem (IMS) voice over Packet-Switched (VoPS) service indications, wherein the IMS VoPS service indications comprises one or more bits indicating whether IMS VoPS is supported over the 3GPP and the non-3GPP access; and
a control and configuration circuit that determines whether IMS VoPS is supported over the 3GPP access and the non-3GPP access, and the UE
in response to, at a first time, receiving the IMS VoPS service indication sent over the 3GPP access indicating that the IMS VoPS is not supported over the 3GPP access and that the IMS VoPS is supported over the non-3GPP access, determines that the IMS VoPS service indication is correct and registers to the mobile communication network over the non-3GPP access or over another 3GPP radio access technology (RAT) for voice service, and
in response to, at a second time, receiving the IMS VoPS service indication sent over the non-3GPP access, determines that the IMS VoPS service indication for the 3GPP access is incorrect and ignores the IMS VoPS service indication for the 3GPP access.
12. The UE of claim 11 , wherein the registration request is an initial request, a periodic request, or a mobility request.
13. The UE of claim 11 , wherein the IMS VoPS indications comprise a first bit indicating whether IMS VoPS is supported over 3GPP access.
14. The UE of claim 11 , wherein the IMS VoPS indications comprise a second bit indicating whether IMS VoPS is supported over non-3GPP access.
15. The UE of claim 11 , wherein the current RAT is 3GPP access, and wherein the IMS VoPS indication indicates that IMS VoPS is not supported over the current RAT.
16. The UE of claim 15 , wherein the UE performs voice domain selection for voice service.
17. The UE of claim 15 , wherein the IMS VoPS indications indicate that IMS VoPS is supported over non-3GPP access, and wherein the UE tries to register over non-3GPP access for voice service.
18. The UE of claim 11 , wherein the current RAT is non-3GPP access, and wherein the IMS VoPS indication indicates that IMS VoPS is not supported over the current RAT.
19. The UE of claim 18 , wherein the IMS VoPS indications indicate that IMS VoPS is supported over 3GPP access, and wherein the UE ignores the indication.
20. The UE of claim 11 , wherein the registration accept message further carries information on whether IMS VoPS is supported over 5G new radio (NR), 4G LTE, and non-3GPP access independently.