# US 12,193,090 B2 · First base station, second base station, method, program, and recording medium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,193,090 B2 - Document ID: US12193090B2 - Status: Granted - Kind: B2 - Application number: 17/626,583 - Filed: 2020-07-30 - Published: 2022-07-28 - Granted: 2025-01-07 - Earliest claimed: 2019-08-08 - Assignees: NEC Corporation - Applicants: NEC Corporation - Inventors: Shiro Asada - Web page: https://patentgrep.com/patent/US12193090B2 ## CPC - H04W 76/15: Setup of multiple wireless link connections - H04W 16/32: Hierarchical cell structures - H04W 28/0862: {of same hierarchy level} - H04W 28/0864: {of different hierarchy levels, e.g. Master Evolved Node B [MeNB] or Secondary Evolved node B [SeNB]} - H04W 28/0867: {among entities in the downlink} - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04W 92/20: between access points - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract In order to start transmission of downlink data to an RLC layer with an appropriate data amount from a base station that performs Packet Data Convergence Protocol (PDCP) layer processing to another base station that performs Radio Link Control (RLC) layer processing, a base station 100 (MN) includes: an information obtaining unit configured to obtain information for controlling a downlink data flow in a Radio Link Control (RLC) layer for a terminal apparatus 300; and a communication processing unit 143 configured to transmit, to a base station 200 (SN) performing processing for a PDCP layer for the terminal apparatus 300, the information for controlling the downlink data flow, before the base station 100 (MN) detects a correct random access channel access. ## Claims ### Claim 1 A first base station comprising: a memory storing instructions; and one or more processors configured to execute the instructions to: an information obtaining unit configured to obtain information for controlling a downlink data flow in a Radio Link Control (RLC) layer for a terminal apparatus; a communication processing unit configured to transmit, to a second base station performing processing for a Packet Data Convergence Protocol (PDCP) layer for the terminal apparatus, the information for controlling the downlink data flow, before a connection between the first base station and the terminal apparatus is performed; and coordinate processing of obtaining the information and processing of transmitting the information, with the second base station. ### Claim 2 (depends on 1) The first base station according to claim 1, wherein the information for controlling the downlink data flow includes information related to a buffer size for downlink data in the RLC layer. ### Claim 3 (depends on 1) The first base station according to claim 1, wherein the information for controlling the downlink data flow includes information related to a data rate for downlink data in the RLC layer. ### Claim 4 (depends on 1) The first base station according to claim 1, wherein the random access channel access is performed by the terminal apparatus for a bearer for the second base station. ### Claim 5 (depends on 1) The first base station according to claim 1, wherein the first base station is a master node for dual connectivity for the terminal apparatus, and the second base station is a secondary node for the dual connectivity for the terminal apparatus. ### Claim 6 (depends on 5) The first base station according to claim 5, wherein the one or more processors are configured to execute the instructions to transmit, to the second base station, a Secondary Node Reconfiguration Complete message during a Secondary Node Addition procedure for the terminal apparatus, and the information for controlling the downlink data flow is included in the Secondary Node Reconfiguration Complete message. ### Claim 7 (depends on 1) The first base station according to claim 1, wherein the first base station is a secondary node for dual connectivity for the terminal apparatus, and the second base station is a master node for the dual connectivity for the terminal apparatus. ### Claim 8 (depends on 7) The first base station according to claim 7, wherein the one or more processors are configured to execute the instructions to transmit, to the second base station, a response message to a Secondary Node Addition Request message from the second base station during a secondary node addition procedure for the terminal apparatus, and the information for controlling the downlink data flow is included in the response message to the Secondary Node Addition Request message. ### Claim 9 (depends on 1) The first base station according to claim 1, wherein the first base station is a master node for dual connectivity for the terminal apparatus, and the second base station is a central unit included in a secondary node for the dual connectivity for the terminal apparatus. ### Claim 10 (depends on 9) The first base station according to claim 9, wherein the one or more processors are configured to execute the instructions to transmit, to the second base station, a Secondary Node Reconfiguration Complete message during a Secondary Node Addition procedure for the terminal apparatus, and the information for controlling the downlink data flow is included in the Secondary Node Reconfiguration Complete message. ### Claim 11 (depends on 1) The first base station according to claim 1, wherein the first base station is a distributed unit included in a secondary node for dual connectivity for the terminal apparatus, and the second base station is a master node for the dual connectivity for the terminal apparatus. ### Claim 12 (depends on 11) The first base station according to claim 11, wherein the one or more processors are configured to execute the instructions to transmit, to the second base station, a response message to a Secondary Node Addition Request message from the second base station via a central unit included in the secondary node, during a secondary node addition procedure for the terminal apparatus, and the information for controlling the downlink data flow is included in the response message to the Secondary Node Addition Request message. ### Claim 13 A second base station comprising: a memory storing instructions; and one or more processors configured to execute the instructions to: execute processing for a Packet Data Convergence Protocol (PDCP) layer; receive, from a first base station performing processing in a Radio Link Control (RLC) layer for the terminal apparatus, information for controlling a downlink data flow in the RLC, before a connection between the first base station detects and the terminal apparatus is performed; and coordinate the processing for the PDCP layer and processing of receiving the information, with the first base station. ### Claim 14 A method comprising: obtaining information for controlling a downlink data flow in a Radio Link Control (RLC) layer for a terminal apparatus; and transmitting the information for controlling the downlink data flow to a second base station performing processing for a Packet Data Convergence Protocol (PDCP) layer for the terminal apparatus, before a connection between the first base station and the terminal apparatus is performed; and coordinating processing of obtaining the information and processing of transmitting the information, with the second base station.