# US 11,452,020 B2 · Maintaining internet protocol address for network traffic during handover procedure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,452,020 B2 - Document ID: US11452020B2 - Status: Granted - Kind: B2 - Application number: 16/518,140 - Filed: 2019-07-22 - Published: 2021-01-28 - Granted: 2022-09-20 - Earliest claimed: 2019-07-22 - Assignees: Cisco Technology, Inc. - Applicants: Cisco Technology, Inc. - Inventors: Aeneas Dodd-Noble; Raghavendra Suryanarayanarao Vidyashankar; Om Prakash Suthar - Web page: https://patentgrep.com/patent/US11452020B2 ## CPC - H04W 36/22: for handling the traffic - H04W 8/26: Network addressing or numbering for mobility support - H04W 36/0033: {with transfer of context information} - H04W 36/0066: {of control information between different types of networks in order to establish a new radio link in the target network} - H04W 40/36: due to handover - H04L 61/5007: Internet protocol [IP] addresses - H04W 36/0022: {for transferring data sessions between adjacent core network technologies} - H04W 36/14: Reselecting a network or an air interface - H04W 84/042: {Public Land Mobile systems, e.g. cellular systems} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract In one example, a User Plane Function (UPF) in a Visited Public Land Mobile Network (V-PLMN) that includes a first network and a second network obtains network traffic from user equipment via the first network. The UPF provides the network traffic obtained via the first network to a data network with an Internet Protocol (IP) address allocated to the network traffic obtained from the user equipment. In response to a handover of the user equipment from the first network to the second network, the UPF obtains the network traffic from the user equipment via the second network. The UPF provides the network traffic obtained via the second network to the data network with the IP address. ## Claims ### Claim 1 A method comprising: at a user plane function in a visited public land mobile network that includes a first network and a second network, wherein the user plane function is in the first network: obtaining network traffic from user equipment via the first network; providing the network traffic obtained via the first network to a data network with an Internet Protocol (IP) address allocated to the network traffic obtained from the user equipment; in response to a handover of the user equipment from the first network to the second network, obtaining the network traffic from the user equipment via the second network from a serving gateway in the second network of the visited public land mobile network via an intermediate user plane function located in and selected by a home public land mobile network; and providing the network traffic obtained via the second network to the data network with the IP address. ### Claim 2 (depends on 1) The method of claim 1, wherein the serving gateway obtains, from the home public land mobile network, an indication to provide the network traffic to the user plane function. ### Claim 3 (depends on 2) The method of claim 2, further comprising: at the user plane function: providing an identification of the user plane function to the home public land mobile network. ### Claim 4 (depends on 2) The method of claim 2, wherein an identification of the user plane function is provided to the home public land mobile network from a session management function in the visited public land mobile network. ### Claim 5 (depends on 2) The method of claim 2, wherein an identification of the user plane function is provided to the home public land mobile network from an access and mobility management function in the visited public land mobile network. ### Claim 6 (depends on 1) The method of claim 1, wherein the serving gateway obtains, from the home public land mobile network, an indication to provide the network traffic to the intermediate user plane function. ### Claim 7 (depends on 1) The method of claim 1, further comprising: at the user plane function: in response to a handover of the user equipment from the second network to the first network, obtaining, from a session management function in the visited public land mobile network, an indication to establish a session with another user plane function in the visited public land mobile network, wherein the other user plane function obtains the network traffic via the second network and provides the network traffic to the data network with the IP address; establishing the session with the other user plane function; obtaining the network traffic from the user equipment via the first network; and providing the network traffic obtained via the first network to the data network with the IP address. ### Claim 8 (depends on 1) The method of claim 1, wherein the first network is a fifth generation network and the second network is a fourth generation network. ### Claim 9 An apparatus comprising: a network interface configured to provide/obtain network traffic to/from user equipment; and one or more processors of a user plane function in a visited public land mobile network that includes a first network and a second network, wherein the user plane function is in the first network, wherein the one or more processors are coupled to the network interface and are configured to: obtain the network traffic from the user equipment via the first network; provide the network traffic obtained via the first network to a data network with an Internet Protocol (IP) address allocated to the network traffic obtained from the user equipment; in response to a handover of the user equipment from the first network to the second network, obtain the network traffic from the user equipment via the second network from a serving gateway in the second network of the visited public land mobile network via an intermediate user plane function located in and selected by a home public land mobile network; and provide the network traffic obtained via the second network to the data network with the IP address. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the serving gateway obtains, from the home public land mobile network, an indication to provide the network traffic to the user plane function. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the one or more processors are further configured to: provide an identification of the user plane function to the home public land mobile network. ### Claim 12 (depends on 10) The apparatus of claim 10, wherein an identification of the user plane function is provided to the home public land mobile network from a session management function in the visited public land mobile network. ### Claim 13 (depends on 10) The apparatus of claim 10, wherein an identification of the user plane function is provided to the home public land mobile network from an access and mobility management function in the visited public land mobile network. ### Claim 14 (depends on 9) The apparatus of claim 9, wherein the serving gateway obtains, from the home public land mobile network, an indication to provide the network traffic to the intermediate user plane function. ### Claim 15 (depends on 9) The apparatus of claim 9, wherein the one or more processors are further configured to: in response to a handover of the user equipment from the second network to the first network, obtain, from a session management function in the visited public land mobile network, an indication to establish a session with another user plane function in the visited public land mobile network, wherein the other user plane function obtains the network traffic via the second network and provides the network traffic to the data network with the IP address; establish the session with the other user plane function; obtain the network traffic from the user equipment via the first network; and provide the network traffic obtained via the first network to the data network with the IP address. ### Claim 16 (depends on 9) The apparatus of claim 9, wherein the first network is a fifth generation network and the second network is a fourth generation network. ### Claim 17 One or more non-transitory computer readable storage media encoded with instructions that, when executed by a processor of a user plane function in a visited public land mobile network that includes a first network and a second network, wherein the user plane function is in the first network, cause the processor to: obtain network traffic from user equipment via the first network; provide the network traffic obtained via the first network to a data network with an Internet Protocol (IP) address allocated to the network traffic obtained from the user equipment; in response to a handover of the user equipment from the first network to the second network, obtain the network traffic from the user equipment via the second network from a serving gateway in the second network of the visited public land mobile network via an intermediate user plane function located in and selected by a home public land mobile network; and provide the network traffic obtained via the second network to the data network with the IP address. ### Claim 18 (depends on 17) The one or more non-transitory computer readable storage media of claim 17, wherein the serving gateway obtains, from the home public land mobile network, an indication to provide the network traffic to the user plane function. ### Claim 19 (depends on 17) The one or more non-transitory computer readable storage media of claim 17, wherein the serving gateway obtains, from the home public land mobile network, an indication to provide the network traffic to the intermediate user plane function. ### Claim 20 (depends on 17) The one or more non-transitory computer readable storage media of claim 17, wherein the instructions further cause the processor to: in response to a handover of the user equipment from the second network to the first network, obtain, from a session management function in the visited public land mobile network, an indication to establish a session with another user plane function in the visited public land mobile network, wherein the other user plane function obtains the network traffic via the second network and provides the network traffic to the data network with the IP address; establish the session with the other user plane function; obtain the network traffic from the user equipment via the first network; and provide the network traffic obtained via the first network to the data network with the IP address.