Search

US-12628108-B2 - Avoiding redundant voice capability updates from the AMF to the UDM

US12628108B2US 12628108 B2US12628108 B2US 12628108B2US-12628108-B2

Abstract

An access and mobility management function (AMF) configured to send a registration message with an initial registration flag set to false to a unified data management node (UDM) and refrain from sending an update message to the UDM is described herein. The AMF receives 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 and determines that the registration request is not for an initial registration. In response to determining that the registration request is not for an initial registration, the AMF sends the registration message to the UDM with an initial registration flag set to false and refrains from sending the update message to the UDM.

Inventors

  • Subramania Kaushik
  • Anil Kumar Mariyani

Assignees

  • T-MOBILE USA, INC.

Dates

Publication Date
20260512
Application Date
20230801

Claims (20)

  1. 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. 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. 3 . The method of claim 1 , wherein the registration request includes an imsVoPS indication.
  4. 4 . The method of claim 3 , wherein sending the registration message further comprises sending the imsVoPS indication to the UDM.
  5. 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. 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. 7 . The method of claim 1 , wherein the AMF is part of pool of AMFs sharing an initial registration status for the UE.
  8. 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. 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. 10 . The system of claim 8 , wherein the registration request includes an imsVoPS indication.
  11. 11 . The system of claim 10 , wherein sending the registration message further comprises sending the imsVoPS indication to the UDM.
  12. 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. 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. 14 . The system of claim 8 , wherein the AMF is part of pool of AMFs sharing an initial registration status for the UE.
  15. 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. 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. 17 . The non-transitory computer storage medium of claim 15 , wherein the registration request includes an imsVoPS indication.
  18. 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. 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. 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.

Description

BACKGROUND The increased availability and performance characteristics of fifth generation (5G) networks have greatly enhanced the communication experiences of users. In some environments, however, the relative capabilities of fourth generation (4G) networks and 5G networks may result in handovers from 5G to 4G and, as environment, use, and characteristics vary, handovers back from 4G to 5G. The frequency of handovers has greatly increased signaling among core network nodes, including signaling to the unified data management node (UDM) and the associated unified data repository (UDR). Handovers to 5G may result, for example, in registration messages from an access and mobility management function (AMF) to the UDM, update messages to the UDM, subscribe messages to the UDM, each of these in turn causing a request and response between the UDM and UDR. Handovers away from 5G may result in loss of information obtained by the AMF from these messages, requiring their repetition with each return to 5G. BRIEF DESCRIPTION OF THE DRAWINGS The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same reference numbers in different figures indicate similar or identical items. FIG. 1 is a diagram of a telecommunication network having a combined 4G/5G core network (“core network”) and 4G and 5G radio access technologies (RATs) available to user equipment (UE) via access networks, the nodes of the core network engaging in signaling and data retention to handle handovers in a manner that optimizes user experience and resource usage. FIG. 2 is a message flow diagram showing a subset of core network nodes and a UE and the messages among these nodes and devices to ensure knowledge of voice capabilities while avoiding unnecessary/redundant signaling. FIG. 3 is a flow diagrams of an illustrative process at an AMF for determining that a handover-triggered registration request is not for an initial registration and, in response, providing a registration message with an initial registration flag set to false and refraining from sending an update message. FIG. 4 is a schematic diagram of a computing device capable of implement functionality of one or more nodes of the core network. DETAILED DESCRIPTION This disclosure is directed in part to an AMF configured to send a registration message with an initial registration flag set to false to a UDM and refrain from sending an update message to the UDM. The AMF receives a registration request from a UE associated with a handover of the UE from a 4G network to a 5G network and determines that the registration request is not for an initial registration. In response to determining that the registration request is not for an initial registration, the AMF sends the registration message to the UDM with an initial registration flag set to false and refrains from sending the update message to the UDM. The registration request from the UE may include an indication of the voice capabilities associated with the UE, such as an imsVoPS indication, and when the request is not for an initial registration, the imsVoPS indication may be included with the registration message sent from the AMF to UDM. By providing the imsVoPS indication in the registration message, the need for an update message from AMF to UDM to convey the imsVoPS indication is obviated. In an initial registration, the AMF may store the imsVoPS indication and other UE context information, either in itself or in an unstructured data storage function (UDSF) shared by a pool of AMFs including the AMF that received the initial registration request. In some implementations, the imsVoPS indication may arrive in a subsequent message or request, and the AMF may store the imsVoPS indication at that time. The AMF may also include the imsVoPS indication in the registration message from the AMF to the UDM (e.g., a Nudm_UECM_Registration sent over an N8 interface between the AMF and UDM) conditionally, based on whether it is included in the initial registration request, or may simply forgo including it, leaving that to the update message. The registration message may also set the initial registration flag to true to inform the UDM of the messaging context. Then, because the registration is an initial registration, the AMF may send an update message, such as a Nudm_UECM_Update, over the N8 interface to the UDM. The update message will include the imsVoPS indication. In subsequent registrations associated with a return from a 4G network to the 5G network, an update message may only be sent if the AMF discovers that the imsVoPS indication has changed. Such a discovery may be made by comparing an imsVoPS indication returned in a response to the registration message from the UDM to the imsVoPS indication received in the registration request. If there is not a match, the AMF may send an update message w