IP Library Granted Patent US 12,414,022
Granted Patent B2
US 12,414,022 · App. 18/738,733 · Granted Sep 9, 2025

Dynamic discovery of network functions in mobility interworking across radio access technologies

Inventors: Rajendra Prasad Kodaypak (Sammamish, WA); Vikram Seenappa (Sammamish, WA)
Assignee: AT&T Intellectual Property I, L.P.
H04W36/14H04W8/24H04W36/00222H04W36/144H04W48/16
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Quick Facts
Patent No.
US 12,414,022
App. No.
18/738,733
Granted
Sep 9, 2025
Kind
B2
Abstract

Aspects of the subject disclosure may include, for example, a machine-readable medium, comprising executable instructions that, when executed by a processing system including a processor, facilitate performance of operations including receiving a first message from a mobile management entity (MME) in a Long-Term Evolution (LTE) network indicating a handover of user equipment (UE) to a fifth generation (5G) network covering a first area in which the UE is located; discovering an access mobility management function (AMF) in the 5G network responsive to the second message; receiving a second message from the AMF indicating a handover of the UE to the LTE network; and discovering a second mobile management entity (MME) in the LTE network covering a second area in which the UE is located. Other embodiments are disclosed.

Claims (34)

1. A method, comprising:

discovering, by a processing system including a processor, an access mobility management function (AMF) in another radio technology network responsive to a message received by a network repository function (NRF) from a mobile management entity (MME) in a Long-Term Evolution (LTE) network that a user equipment (UE) has crossed a threshold and entered a coverage area of the another radio technology network, wherein the UE accesses a packet data network (PDN) through the LTE network;

transferring, by the processing system, metadata associated with the UE to the AMF responsive to discovering the AMF;

handing over, by the processing system, cellular services for the UE to the another radio technology network after the transferring; and

providing, by the processing system, the UE with access to the PDN through a user data plane function (UPF) of the another radio technology network after the handing over.

2. The method of claim 1 , wherein the AMF provides the cellular services to the coverage area of the another radio technology network, and wherein the another radio technology network is a fifth generation (5G) network.

3. The method of claim 2 , further comprising: checking, by the processing system, that the UE is authorized to access the 5G network before the handing over.

4. The method of claim 2 , wherein the NRF discovers the AMF.

5. The method of claim 4 , wherein the NRF discovers the AMF without using a domain name service (DNS) protocol.

6. The method of claim 5 , wherein the message is passed over a first Representational State Transfer (REST) Application Programming Interface (API).

7. The method of claim 6 , wherein the MME performs the transferring by passing a second message over an enhanced N26 interface to the AMF using a second REST API.

8. The method of claim 7 , wherein the NRF and the AMF are virtual network elements and wherein the metadata comprises status, heartbeat timer, Internet Protocol address, capacity, priority, load, locality, services supported, or a combination thereof.

9. A device, comprising:

a processing system including a processor; and

a memory that stores executable instructions that, when executed by the processing system, facilitate performance of operations, the operations comprising:

discovering an access mobility management function (AMF) in another radio technology network responsive to a message received by a network repository function (NRF) from a mobile management entity (MME) in a Long-Term Evolution (LTE) network that a user equipment (UE) has crossed a threshold and entered a coverage area of the another radio technology network, wherein the UE accesses a packet data network (PDN) through the LTE network;

transferring metadata associated with the UE to the AMF responsive to discovering the AMF;

handing over cellular services for the UE to the another radio technology network after the transferring; and

providing access to the PDN through a user data plane function (UPF) of the another radio technology network after the handing over.

10. The device of claim 9 , wherein the AMF provides services to the coverage area of the another radio technology network.

11. The device of claim 9 , wherein the NRF discovers the AMF.

12. The device of claim 11 , wherein the message is passed over a first Representational State Transfer (REST) Application Programming Interface (API).

13. The device of claim 11 , wherein the MME performs the transferring using a second REST API to the AMF over an enhanced N26 interface.

14. The device of claim 11 , wherein the NRF discovers the AMF without using a domain name service (DNS) protocol.

15. The device of claim 11 , wherein the NRF and the AMF are virtual network elements.

16. The device of claim 9 , wherein the processing system comprises a plurality of processors operating in a distributed computing environment.

17. A non-transitory, machine-readable medium, comprising executable instructions that, when executed by a processing system including a processor, facilitate performance of operations, the operations comprising:

discovering an access mobility management function (AMF) in another radio technology network responsive to a message received by a network repository function (NRF) from a mobile management entity (MME) in a Long-Term Evolution (LTE) network that a user equipment (UE) has crossed a threshold and entered a coverage area of the another radio technology network, wherein the UE accesses a packet data network (PDN) through the LTE network;

transferring metadata associated with the UE to the AMF responsive to discovering the AMF;

handing over cellular services for the UE to the another radio technology network after the transferring; and

providing access to the PDN through a user data plane function (UPF) of the another radio technology network after the handing over.

18. The non-transitory, machine-readable medium of claim 17 , wherein the processing system comprises a plurality of processors operating in a distributed computing environment.

19. The non-transitory, machine-readable medium of claim 17 , wherein the NRF discovers the AMF.

20. The non-transitory, machine-readable medium of claim 19 , wherein the message is passed over a first Representational State Transfer (REST) Application Programming Interface (API), and wherein the MME performs the transferring using a second REST API to the AMF over an enhanced N26 interface.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 18, 2024
From: KODAYPAK, RAJENDRA PRASAD; SEENAPPA, VIKRAM
To: AT&T INTELLECTUAL PROPERTY I, L.P.
Reel/Frame 067757/0421 →
Continuity (3)
Continuation 17974946 · Oct 27, 2022
Division 16924886 · Jul 9, 2020
Related Publication 20240334284A1 · Oct 3, 2024
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