# US 12,015,948 B2 · Small data transmission routing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,015,948 B2 - Document ID: US12015948B2 - Status: Granted - Kind: B2 - Application number: 17/485,975 - Filed: 2021-09-27 - Published: 2022-04-21 - Granted: 2024-06-18 - Earliest claimed: 2020-10-15 - Assignees: Nokia Technologies Oy - Applicants: Nokia Technologies Oy - Inventors: Philippe Godin; Subramanya Chandrashekar; Daniela Laselva - Web page: https://patentgrep.com/patent/US12015948B2 ## CPC - H04W 28/06: Optimizing {the usage of the radio link}, e.g. header compression, information sizing {, discarding information (system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365)} - H04W 76/12: Setup of transport tunnels - H04L 12/4633: {Interconnection of networks using encapsulation techniques, e.g. tunneling} - H04W 76/27: Transitions between radio resource control [RRC] states - 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 Systems, methods, apparatuses, and computer program products for inter-gNB small data transmission (SDT) routing at a radio access network (RAN). A method may include transmitting an initial request message from a first element in a first network node, to a second element in the first network node to obtain context information. The method may also include receiving, at the first element, a context setup request message based on the context information containing a transport layer information of a third element of a second network node and context information of a user equipment in the second network node. The method may further include processing a data packet according to the received context information. In addition, the method may include forwarding the data packet to the third element of the second network node according to the received transport layer information. ## Claims ### Claim 1 A method, comprising: transmitting an initial request message from a first element in a first network node, to a second element in the first network node to obtain context information; receiving, at the first element from the second element, a context setup request message comprising a transport layer information of a third element of a second network node and context information of a user equipment stored in the second network node; processing a data packet according to the received context information; and forwarding the data packet to the third element of the second network node according to the received transport layer information. ### Claim 2 (depends on 1) The method according to claim 1, wherein the transport layer information comprises at least one of an F1-U transport layer address and an F1-U general packet radio service tunneling protocol tunnel endpoint. ### Claim 3 (depends on 1) The method according to claim 1, wherein the context information is a radio link control context of the user equipment stored in the second network node. ### Claim 4 (depends on 1) The method according to claim 1, wherein the data packet is an uplink small data transmission packet. ### Claim 5 (depends on 1) The method according to claim 1, wherein the initial request message originates from the user equipment. ### Claim 6 (depends on 1) The method according to claim 1, further comprising transmitting a response message to the second element in response to receiving the context setup request message. ### Claim 7 (depends on 1) The method according to claim 1, wherein the initial request message comprises an inactive radio network temporary identifier. ### Claim 8 (depends on 1) The method according to claim 1, wherein the first element is a target base station distributed unit, wherein the second element is a control plane of a target base station central unit, and wherein the third element is a user plane of an anchor or source base station central unit. ### Claim 9 An apparatus, comprising: at least one processor; and at least one memory comprising computer program code, the at least one memory and computer program code are configured, with the at least one processor, to cause the apparatus at least to: transmit an initial request message from a first element in the apparatus, to a second element in the apparatus to obtain context information; receive, at the first element from the second element, a context setup request message comprising a transport layer information of a third element of a second network node and context information of a user equipment stored in the second network node; process a data packet according to the received context information; and forward the data packet to the third element of the second network node according to the received transport layer information. ### Claim 10 (depends on 9) The apparatus according to claim 9, wherein the transport layer information comprises at least one of an F1-U transport layer address and an F1-U general packet radio service tunneling protocol tunnel endpoint. ### Claim 11 (depends on 9) The apparatus according to claim 9, wherein the context information is a radio link control context of the user equipment stored in the second network node. ### Claim 12 (depends on 9) The apparatus according to claim 9, wherein the data packet is an uplink small data transmission packet. ### Claim 13 (depends on 9) The apparatus according to claim 9, wherein the initial request message originates from the user equipment. ### Claim 14 (depends on 9) The apparatus according to claim 9, wherein the apparatus is further caused to transmit a response message to the second element in response to receiving the context setup request message. ### Claim 15 (depends on 9) The apparatus according to claim 9, wherein the initial request message comprises an inactive radio network temporary identifier. ### Claim 16 (depends on 9) The apparatus according to claim 9, wherein the first element is a target base station distributed unit, wherein the second element is a control plane of a target base station central unit, and wherein the third element is a user plane of an anchor or source base station central unit. ### Claim 17 An apparatus, comprising: at least one processor; and at least one memory comprising computer program code, the at least one memory and computer program code are configured, with the at least one processor, to cause the apparatus at least to: receive a retrieve user equipment context request message from a second element of a first network node; send a response message comprising a context information of a user equipment stored in the apparatus and a transport layer information of a third element of the apparatus, to enable the user equipment to send one or more data packets to the apparatus based on the context information and the transport layer information; and receive the one or more data packets from the user equipment. ### Claim 18 (depends on 17) The apparatus according to claim 17, wherein the transport layer information comprises at least one of an F1-U transport layer address and an F1-U general packet radio service tunneling protocol tunnel endpoint. ### Claim 19 (depends on 17) The apparatus according to claim 17, wherein the context information is a radio link control context of the user equipment. ### Claim 20 (depends on 17) The apparatus according to claim 17, wherein the response message is one of a retrieve user equipment context response message or a retrieve user equipment context failure message.