Granted Patent B2

US 12,628,108 · App. 18/229,160 · Granted May 12, 2026

Inventors: Subramania Kaushik (Bellevue, WA); Anil Kumar Mariyani (Ashburn, VA)

Assignee: T-Mobile USA, Inc.

H04W60/04H04W36/00226

Abstract

Claims (37)

1 . A method comprising:

receiving, by an access and mobility management function (AMF), a registration request from a user equipment (UE) associated with a handover of the UE from a fourth generation (4G) network to a fifth generation (5G) network;

determining, by the AMF, that the registration request is not for an initial registration; and

in response to the determining:

sending, by the AMF, a registration message to a unified data management node (UDM) with an initial registration flag set to false, and

refraining, by the AMF, from sending an update message to the UDM.

2 . The method of claim 1 , further comprising maintaining, by the AMF, an imsVoPS indication received in the initial registration while the UE is on the 4G network.

3 . The method of claim 1 , wherein the registration request includes an imsVoPS indication.

4 . The method of claim 3 , wherein sending the registration message further comprises sending the imsVoPS indication to the UDM.

5 . The method of claim 4 , further comprising determining that the imsVoPS indication does not match a stored imsVoPS indication and updating the stored imsVoPS indication with the imsVoPS indication received from the UE in the registration request.

6 . The method of claim 1 , further comprising receiving another registration request associated with another handover, determining that the other registration request is an initial registration, sending another registration message with an initial registration flag set to true, and sending an update message to the UDM.

7 . The method of claim 1 , wherein the AMF is part of pool of AMFs sharing an initial registration status for the UE.

8 . A system comprising:

one or more processors; and

a plurality of programming instructions that, when executed by the one or more processors, program an access and mobility management function (AMF) to perform operations including:

receiving a registration request from a user equipment (UE) associated with a handover of the UE from a fourth generation (4G) network to a fifth generation (5G) network;

determining that the registration request is not an initial registration; and

in response to the determining:

sending a registration message to a unified data management node (UDM) with an initial registration flag set to false, and

refraining from sending an update message to the UDM.

9 . The system of claim 8 , wherein the operations further include maintaining an imsVoPS indication received in the initial registration while the UE is on the 4G network.

10 . The system of claim 8 , wherein the registration request includes an imsVoPS indication.

11 . The system of claim 10 , wherein sending the registration message further comprises sending the imsVoPS indication to the UDM.

12 . The system of claim 11 , wherein the operations further include determining that the imsVoPS indication does not match a stored imsVoPS indication and updating the stored imsVoPS indication with the imsVoPS indication received from the UE in the registration request.

13 . The system of claim 8 , wherein the operations further include receiving another registration request associated with another handover, determining that the other registration request is an initial registration, sending another registration message with an initial registration flag set to true, and sending an update message to the UDM.

14 . The system of claim 8 , wherein the AMF is part of pool of AMFs sharing an initial registration status for the UE.

15 . A non-transitory computer storage medium having a plurality of programming instructions stored thereon that, when executed by one or more processors, program an access and mobility management function (AMF) to perform operations comprising:

receiving a registration request from a user equipment (UE) associated with a handover of the UE from a fourth generation (4G) network to a fifth generation (5G) network;

determining that the registration request is not an initial registration; and

in response to the determining:

sending a registration message to a unified data management node (UDM) with an initial registration flag set to false, and

refraining from sending an update message to the UDM.

16 . The non-transitory computer storage medium of claim 15 , wherein the operations further comprise maintaining an imsVoPS indication received in the initial registration while the UE is on the 4G network.

17 . The non-transitory computer storage medium of claim 15 , wherein the registration request includes an imsVoPS indication.

18 . The non-transitory computer storage medium of claim 17 , wherein sending the registration message further comprises sending the imsVoPS indication to the UDM.

19 . The non-transitory computer storage medium of claim 18 , wherein the operations further comprise determining that the imsVoPS indication does not match a stored imsVoPS indication and updating the stored imsVoPS indication with the imsVoPS indication received from the UE in the registration request.

20 . The non-transitory computer storage medium of claim 15 , wherein the operations further comprise receiving another registration request associated with another handover, determining that the other registration request is an initial registration, sending another registration message with an initial registration flag set to true, and sending an update message to the UDM.

Assignments (1)

Continuity (1)

References Cited (29)