US-12627965-B2 - Reduced messaging to the UDM during an AMF handover

Abstract

An access and mobility management function (AMF) configured to obtain subscriber profile information without sending a get message and a subscribe message to a unified data management node (UDM) is described herein. The AMF is a new AMF that receives a registration request as part of a handover from an old AMF and receives user equipment (UE) context information from the old AMF. Without sending a get message to the UDM, the AMF obtains subscriber profile information by either fetching the subscriber profile information from an unstructured data storage function (UDSF) shared by a pool of AMFs, when the UDSF is available, or receiving the subscriber profile information from old AMF, when the UDSF is not available. Also, without sending a subscribe message to the UDM, the AMF receives notification of changes to the subscriber profile information from 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 a new access and mobility management function (AMF), a registration request as part of a handover from an old AMF to the new AMF; receiving, by the new AMF, user equipment (UE) context information from the old AMF; without sending a get message to a unified data management node (UDM), obtaining, by the new AMF, subscriber profile information, the obtaining including either: when an unstructured data storage function (UDSF) shared by a pool of AMFs that includes at least the old AMF and new AMF is available, fetching the subscriber profile information from the UDSF, and when the UDSF is not available, receiving the subscriber profile information from old AMF; and without sending a subscribe message to the UDM, receiving from the UDM, by the new AMF, notification of changes to the subscriber profile information.
2. 2 . The method of claim 1 , wherein the subscriber profile information includes at least one of access management information, session management information, or subscriber data.
3. 3 . The method of claim 1 , wherein the UE context information includes at least one of UE mobility management information, security context information, a subscription permanent identifier (SUPI), 5G global unique temporary identifier (5G GUTI), or UE capabilities.
4. 4 . The method of claim 1 , further comprising, in response to receiving the registration request, sending, by the new AMF, a registration message to the UDM.
5. 5 . The method of claim 4 , wherein the UDM, upon receiving the registration message, sends to the new AMF the notification of changes to the subscriber profile information.
6. 6 . The method of claim 5 , wherein the UDM tracks changes to the subscriber profile information and obtains an identifier of the new AMF from information received from the new AMF or stored by a unified data repository (UDR) to enable the UDM to send the notification of changes to the new AMF.
7. 7 . The method of claim 1 , wherein the UDSF is shared across AMFs of multiple locations or multiple AMF pools.
8. 8 . A system comprising: one or more processors; and a plurality of programming instructions that, when executed by the one or more processors, configure a new access and mobility management function (AMF) to perform operations including: receiving a registration request as part of a handover from an old AMF to the new AMF; receiving user equipment (UE) context information from the old AMF; without sending a get message to a unified data management node (UDM), obtaining subscriber profile information, the obtaining including either: when an unstructured data storage function (UDSF) shared by a pool of AMFs that includes at least the old AMF and new AMF is available, fetching the subscriber profile information from the UDSF, and when the UDSF is not available, receiving the subscriber profile information from old AMF; and without sending a subscribe message to the UDM, receiving from the UDM notification of changes to the subscriber profile information.
9. 9 . The system of claim 8 , wherein the subscriber profile information includes at least one of access management information, session management information, or subscriber data.
10. 10 . The system of claim 8 , wherein the UE context information includes at least one of UE mobility management information, security context information, a subscription permanent identifier (SUPI), 5G global unique temporary identifier (5G GUTI), or UE capabilities.
11. 11 . The system of claim 8 , wherein the operations further include in response to receiving the registration request, sending, by the new AMF, a registration message to the UDM.
12. 12 . The system of claim 11 , wherein the UDM, upon receiving the registration message, sends to the new AMF the notification of changes to the subscriber profile information.
13. 13 . The system of claim 12 , wherein the UDM tracks changes to the subscriber profile information and obtains an identifier of the new AMF from information received from the new AMF or stored by a unified data repository (UDR) to enable the UDM to send the notification of changes to the new AMF.
14. 14 . The system of claim 8 , wherein the UDSF is shared across AMFs of multiple locations or multiple AMF pools.
15. 15 . A non-transitory computer storage medium having a plurality of programming instructions stored thereon that, when executed by one or more processors, configure a new access and mobility management function (AMF) to perform operations comprising: receiving a registration request as part of a handover from an old AMF to the new AMF; receiving user equipment (UE) context information from the old AMF; without sending a get message to a unified data management node (UDM), obtaining subscriber profile information, the obtaining including either: when an unstructured data storage function (UDSF) shared by a pool of AMFs that includes at least the old AMF and new AMF is available, fetching the subscriber profile information from the UDSF, and when the UDSF is not available, receiving the subscriber profile information from old AMF; and without sending a subscribe message to the UDM, receiving from the UDM notification of changes to the subscriber profile information.
16. 16 . The non-transitory computer storage medium of claim 15 , wherein the subscriber profile information includes at least one of access management information, session management information, or subscriber data.
17. 17 . The non-transitory computer storage medium of claim 15 , wherein the UE context information includes at least one of UE mobility management information, security context information, a subscription permanent identifier (SUPI), 5G global unique temporary identifier (5G GUTI), or UE capabilities.
18. 18 . The non-transitory computer storage medium of claim 15 , wherein the operations further comprise, in response to receiving the registration request, sending, by the new AMF, a registration message to the UDM.
19. 19 . The non-transitory computer storage medium of claim 18 , wherein the UDM, upon receiving the registration message, sends to the new AMF the notification of changes to the subscriber profile information.
20. 20 . The non-transitory computer storage medium of claim 19 , wherein the UDM tracks changes to the subscriber profile information and obtains an identifier of the new AMF from information received from the new AMF or stored by a unified data repository (UDR) to enable the UDM to send the notification of changes to the new AMF.

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, get 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 obtain subscriber profile information for the AMF during an AMF-to-AMF handover while optimizing signaling between the new AMF and the UDM. FIG. 3 is a flow diagrams of an illustrative process at an AMF for obtaining subscriber profile information for the AMF during an AMF-to-AMF handover while optimizing signaling between the new AMF and the UDM. 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 obtain subscriber profile information without sending a get message and a subscribe message to a UDM. The AMF is a new AMF that receives a registration request as part of a handover from an old AMF and receives UE context information from the old AMF. Without sending a get message to the UDM, the AMF obtains subscriber profile information either by fetching the subscriber profile information from an unstructured data storage function (UDSF) shared by a pool of AMFs, when the UDSF is available, or receiving the subscriber profile information from old AMF, when the UDSF is not available. Also, without sending a subscribe message to the UDM, the AMF receives notification of changes to the subscriber profile information from the UDM. As used herein, the terms “new AMF” and “old AMF” refer to the recipient and source of a handover between AMFs, respectively. They do not refer to an “age” of the AMF (e.g., time since implementation) or any other relative roles. In various implementations, the subscriber profile information received from the old AMF or from a UDSF common to the new AMF and old AMF may include at least one of access management information, session management information, or subscriber data. Along with the retrieval or reception of the subscriber profile data, the new AMF may receive UE context information from the old AMF as part of a UE context transfer. Such UE context information may include at least one of UE mobility management information, security context information, a subscription permanent identifier (SUPI), 5G global unique temporary identifier (5G GUTI), or UE capabilities. By obtaining this information, the new AMF removes the need for a get message from itself to the UDM. In further implementations, the UDM may be configured to maintain the subscriber profile information, too, and send notification of changes to the subscriber profile information to the new AMF without the new AMF subscribing for change notifications. By the UDM behaving as if it received a subscribe message (without actually receiving one), the need for a subscribe message from the new AMF to the UDM is also removed. FIG. 1 is a diagram of a telecommunication network having a combined 4G/5G core network (“core network”) and 4G and 5G RATs available to UEs 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. As illustrated, a UE 102 may connect to a 5G RAT 104 or a 4G RAT 106 of one or more access networks and may be directed from one to the other through han