# US 2025/0097792 A1 · Enabling direct connectivity between distributed units of radio-based applications to improve post-handover retransmission performance > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0097792 A1 - Document ID: US20250097792A1 - Status: Published application - Kind: A1 - Application number: 18/959,353 - Filed: 2024-11-25 - Published: 2025-03-20 - Earliest claimed: 2022-06-23 - Assignees: Amazon Technologies, Inc. - Applicants: Amazon Technologies, Inc. - Inventors: Ozgur Dural - Web page: https://patentgrep.com/patent/US20250097792A1 ## CPC - H04W 36/0069: {in case of dual connectivity, e.g. decoupled uplink/downlink} - H04W 36/023: {Buffering or recovering information during reselection} - H04W 36/087: {between radio units of access points} - H04W 76/14: Direct-mode setup - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A first distributed unit (DU) of a radio-based application determines that traffic associated with a particular user equipment device (UED) is to be handed over to a second DU. The first DU transmits contents of a buffer, including a data block transmitted from the UED, to the second DU using a direct network channel established between the DUs. The second DU stores the contents in a second buffer, and uses the contents to perform a retransmission operation associated with the traffic of the UED. ## Claims ### Claim at position 1 -20. (canceled) ### Claim 21 A computer-implemented method, comprising: storing, by a first distributed unit (DU) of a radio access network (RAN) of a radio-based application, a set of user data at a first network function accelerator card attached to a first virtualization server at an edge location of a cloud computing environment, wherein the set of user data is part of a data transfer between a pair of devices utilizing the radio-based application; receiving, by a second DU of the RAN from the first DU, the set of user data via a local path at the edge location, wherein the local path does not include a centralized unit (CU) of the RAN as an intermediary; and utilizing, by the second DU, the set of user data to perform a retransmission operation pertaining to the data transfer. ### Claim 22 (depends on 21) The computer-implemented method as recited in claim 21, wherein the first DU runs at the first virtualization server, and wherein the second DU runs at a second virtualization server at the edge location. ### Claim 23 (depends on 21) The computer-implemented method as recited in claim 21, further comprising: storing, by the second DU, the set of user data at a second network function accelerator card after receiving the set of user data via the local path. ### Claim 24 (depends on 21) The computer-implemented method as recited in claim 21, further comprising: receiving, at the first DU, from the CU, an indication of a handover of the data transfer; and based at least in part on receiving the indication of the handover, establishing connectivity between the first DU and the second DU; and initiating transmission of the set of user data, via the local path, from the first DU to the second DU. ### Claim 25 (depends on 24) The computer-implemented method as recited in claim 24, wherein at least a portion of the CU runs at a data center of cloud computing environment. ### Claim 26 (depends on 24) The computer-implemented method as recited in claim 24, wherein at least a portion of the CU runs at the edge location. ### Claim 27 (depends on 21) The computer-implemented method as recited in claim 21, further comprising: transmitting the set of user data from the first DU to the second DU using a layer-2 protocol of the Open Systems Interconnection (OSI) model, without utilizing a layer-3 protocol of the OSI model. ### Claim 28 A system, comprising: one or more computing devices; wherein the one or more computing devices include instructions that upon execution on or across the one or more computing devices cause: a first distributed unit (DU) of a radio access network (RAN) of a radio-based application to store a set of user data at a first network function accelerator card attached to a first virtualization server at an edge location of a cloud computing environment, wherein the set of user data is part of a data transfer between a pair of devices utilizing the radio-based application; a second DU of the RAN to receive, from the first DU, the set of user data via a local path at the edge location, wherein the local path does not include a centralized unit (CU) of the RAN as an intermediary; and the second DU to utilize the set of user data to perform a retransmission operation pertaining to the data transfer. ### Claim 29 (depends on 28) The system as recited in claim 28, wherein the first DU runs at the first virtualization server, and wherein the second DU runs at a second virtualization server at the edge location. ### Claim 30 (depends on 28) The system as recited in claim 28, wherein the one or more computing devices include further instructions that upon execution on or across the one or more computing devices further cause: the second DU to store the set of user data at a second network function accelerator card after receiving the set of user data via the local path. ### Claim 31 (depends on 28) The system as recited in claim 28, wherein the one or more computing devices include further instructions that upon execution on or across the one or more computing devices further cause: the first DU to receive, from the CU, an indication of a handover of the data transfer; and based at least in part on receiving the indication of the handover, establishment of connectivity between the first DU and the second DU; and initiation of transmission of the set of user data, via the local path, from the first DU to the second DU. ### Claim 32 (depends on 31) The system as recited in claim 31, wherein at least a portion of the CU runs at a data center of cloud computing environment. ### Claim 33 (depends on 31) The system as recited in claim 31, wherein at least a portion of the CU runs at the edge location. ### Claim 34 (depends on 28) The system as recited in claim 28, wherein the one or more computing devices include further instructions that upon execution on or across the one or more computing devices further cause: the set of user data to be sent from the first DU to the second DU using a layer-2 protocol of the Open Systems Interconnection (OSI) model, without utilizing a layer-3 protocol of the OSI model. ### Claim 35 One or more non-transitory computer-accessible storage media storing program instructions that when executed on or across one or more processors cause: a first distributed unit (DU) of a radio access network (RAN) of a radio-based application to store a set of user data at a first network function accelerator card attached to a first virtualization server at an edge location of a cloud computing environment, wherein the set of user data is part of a data transfer between a pair of devices utilizing the radio-based application; a second DU of the RAN to receive, from the first DU, the set of user data via a local path at the edge location, wherein the local path does not include a centralized unit (CU) of the RAN as an intermediary; and the second DU to utilize the set of user data to perform a retransmission operation pertaining to the data transfer. ### Claim 36 (depends on 35) The one or more non-transitory computer-accessible storage media as recited in claim 35, wherein the first DU runs at the first virtualization server, and wherein the second DU runs at a second virtualization server at the edge location. ### Claim 37 (depends on 35) The one or more non-transitory computer-accessible storage media as recited in claim 35, storing further program instructions that when executed on or across the one or more processors further cause: the second DU to store the set of user data at a second network function accelerator card after receiving the set of user data via the local path. ### Claim 38 (depends on 35) The one or more non-transitory computer-accessible storage media as recited in claim 35, storing further program instructions that when executed on or across the one or more processors further cause: the first DU to receive, from the CU, an indication of a handover of the data transfer; and based at least in part on receiving the indication of the handover, establishment of connectivity between the first DU and the second DU; and initiation of transmission of the set of user data, via the local path, from the first DU to the second DU. ### Claim 39 (depends on 38) The one or more non-transitory computer-accessible storage media as recited in claim 38, wherein at least a portion of the CU runs at a data center of cloud computing environment. ### Claim 40 (depends on 38) The one or more non-transitory computer-accessible storage media as recited in claim 38, wherein at least a portion of the CU runs at the edge location.