# US 2020/0396643 A1 · Dual connectivity flow control > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0396643 A1 - Document ID: US20200396643A1 - Status: Published application - Kind: A1 - Application number: 16/442,314 - Filed: 2019-06-14 - Published: 2020-12-17 - Earliest claimed: 2019-06-14 - Assignees: T-Mobile USA, Inc. - Applicants: T-Mobile USA, Inc. - Inventors: Ming Shan Kwok; Wafik Abdel Shahid - Web page: https://patentgrep.com/patent/US20200396643A1 ## CPC - H04W 28/082: among bearers or channels - H04L 1/1887: {Scheduling and prioritising arrangements} - H04L 45/24: Multipath - H04L 47/125: by balancing the load, e.g. traffic engineering - H04L 47/283: in response to processing delays, e.g. caused by jitter or round trip time [RTT] - H04L 47/286: {Time to live} - H04W 28/0236: {radio quality, e.g. interference, losses or delay} - H04W 28/0268: {using specific QoS parameters for wireless networks, e.g. QoS class identifier [QCI] or guaranteed bit rate [GBR] (negotiating SLA or negotiating QoS H04W28/24)} - H04W 28/0273: {adapting protocols for flow control or congestion control to wireless environment, e.g. adapting transmission control protocol [TCP] (wireless network protocols or protocol adaptations to wireless operation, e.g. wireless application protocol H04W80/00)} - H04W 28/0278: {using buffer status reports (dynamic wireless traffic scheduling definition H04W72/12)} - H04W 28/0284: {detecting congestion or overload during communication (monitoring arrangements H04L43/00)} - H04W 28/0861: {between base stations} - H04W 28/0975: {for reducing delays} - H04W 76/15: Setup of multiple wireless link connections - H04W 80/08: Upper layer protocols {(network arrangements or communication protocols for networked applications H04L67/00)} - H04W 76/16: Involving different core network technologies, e.g. a packet-switched [PS] bearer in combination with a circuit-switched [CS] bearer - 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 User equipment (UE) can be connected to both a first base station and a second base station. A flow controller at the first base station can determine packet latency goals associated with packets. The flow controller can also determine connection latencies associated with a first connection from the first base station to the UE and a second connection from the second base station to the UE, where one leg of a split bearer passes from the first base station to the UE over the first connection and another leg of the split bearer passes from the first base station to the second base station and then to the UE over the second connection. The flow controller can route packets with lower packet latency goals via the leg of the lower-latency connection, and route other packets with higher packet latency goals over the leg of the higher-latency connection. ## Claims ### Claim 1 A method comprising: receiving, by a flow controller operating on a first base station, a set of data packets for a user equipment (UE) from a core network over a split bearer, wherein the split bearer divides at the first base station into a first leg that passes through the first base station to the UE and a second leg that passes from the first base station to the UE via a second base station; determining, by the flow controller, packet latency goals associated with data packets of the set of data packets; determining, by the flow controller, a first connection latency associated with a first connection from the first base station to the UE and a second connection latency associated with a second connection from the second base station to the UE; determining, by the flow controller, that one of the first leg and the second leg is a lower-latency leg and a second one of the first leg and the second leg is a higher-latency leg based on a comparison of the first connection latency and the second connection latency; grouping, by the flow controller, the set of data packets into a first subset associated with lower packet latency goals and a second subset associated with higher packet latency goals; and routing, by the flow controller, the first subset to the UE via the lower-latency leg and the second subset to the UE via the higher-latency leg. ### Claim 2 (depends on 1) The method of claim 1, wherein the flow controller operates on the first base station at a Packet Data Convergence Protocol (PDCP) layer. ### Claim 3 (depends on 2) The method of claim 2, wherein the grouping and the routing is based on PDCP aggregation. ### Claim 4 (depends on 1) The method of claim 1, wherein the flow controller determines the packet latency goals by inspecting the data packets for information about at least one of a priority level, a service type, a Quality of Service (QoS) value, or a Class of Service (CoS) value. ### Claim 5 (depends on 4) The method of claim 4, wherein the information is indicated by a Differentiated Services Code Point (DSCP) field in headers of the data packets. ### Claim 6 (depends on 4) The method of claim 4, wherein the information is indicated by Service Data Adaptation Protocol (SDAP) headers of the data packets. ### Claim 7 (depends on 1) The method of claim 1, wherein one of the first base station and the second base station is a fifth generation (5G) base station and another one of the first base station and the second base station is a Long-Term Evolution (LTE) base station linked to the 5G base station in a dual connectivity configuration. ### Claim 8 (depends on 1) The method of claim 1, wherein the flow controller determines at least one of the first connection latency and the second connection latency at least in part based on measuring a round-trip time associated with a data transmission between the first base station and the UE over the first connection or between the second base station and the UE over the second connection. ### Claim 9 (depends on 1) The method of claim 1, wherein the flow controller determines at least one of the first connection latency and the second connection latency at least in part based on at least one of radio conditions, available bandwidth, network congestion levels, numbers of connections to the first base station or the second base station, or a buffer fullness level at the first base station or the second base station. ### Claim 10 A base station, comprising: one or more processors; transmission interfaces associated with a first connection to a user equipment (UE), a second connection to a second base station, and a third connection to a core network of a telecommunication network; memory storing computer-executable instructions for a flow controller that, when executed by the one or more processors, cause the flow controller to: receive a set of data packets for the UE from the core network via a split bearer over the third connection, wherein the split bearer divides into a first leg that passes over the first connection to the UE and a second leg that passes over the second connection to the second base station and from the second base station to the UE; determine packet latency goals associated with data packets of the set of data packets; determine a first connection latency associated with the first connection and a second connection latency associated with the second connection; determine that one of the first leg and the second leg is a lower-latency leg and a second one of the first leg and the second leg is a higher-latency leg based on a comparison of the first connection latency and the second connection latency; group the set of data packets into a first subset associated with lower packet latency goals and a second subset associated with higher packet latency goals; and route the first subset to the UE via the lower-latency leg and the second subset to the UE via the higher-latency leg. ### Claim 11 (depends on 10) The base station of claim 10, wherein the flow controller operates on the base station at a Packet Data Convergence Protocol (PDCP) layer. ### Claim 12 (depends on 10) The base station of claim 10, wherein the flow controller determines the packet latency goals by inspecting the data packets for information about at least one of a priority level, a service type, a Quality of Service (QoS) value, or a Class of Service (CoS) value. ### Claim 13 (depends on 10) The base station of claim 10, wherein one of the base station and the second base station is a fifth generation (5G) base station and another one of the base station and the second base station is a Long-Term Evolution (LTE) base station linked to the 5G base station in a dual connectivity configuration. ### Claim 14 (depends on 10) The base station of claim 10, wherein the flow controller determines at least one of the first connection latency and the second connection latency at least in part based on measuring a round-trip time associated with a data transmission between the base station and the UE over the first connection or between the second base station and the UE over the second connection. ### Claim 15 (depends on 10) The base station of claim 10, wherein the flow controller determines at least one of the first connection latency and the second connection latency at least in part based on at least one of radio conditions, available bandwidth, network congestion levels, numbers of connections to the base station or the second base station, or a buffer fullness level at the base station or the second base station. ### Claim 16 One or more non-transitory computer-readable media storing computer-executable instructions that, when executed by one or more processors of a base station of a telecommunication network, cause the base station to perform operations comprising: receive a set of data packets for a user equipment (UE) from a core network via a split bearer, wherein the split bearer divides into a first leg that passes over a first connection from the base station to the UE and a second leg that passes over a second connection from the base station to a second base station and from the second base station to the UE; determine packet latency goals associated with data packets of the set of data packets; determine a first connection latency associated with the first connection and a second connection latency associated with the second connection; determine that one of the first leg and the second leg is a lower-latency leg and a second one of the first leg and the second leg is a higher-latency leg based on a comparison of the first connection latency and the second connection latency; group the set of data packets into a first subset associated with lower packet latency goals and a second subset associated with higher packet latency goals; and route the first subset to the UE via the lower-latency leg and the second subset to the UE via the higher-latency leg. ### Claim 17 (depends on 16) The one or more non-transitory computer-readable media of claim 16, wherein the operations are executed on the base station at a Packet Data Convergence Protocol (PDCP) layer. ### Claim 18 (depends on 16) The one or more non-transitory computer-readable media of claim 16, wherein the packet latency goals are determined by inspecting the data packets for information about at least one of a priority level, a service type, a Quality of Service (QoS) value, or a Class of Service (CoS) value. ### Claim 19 (depends on 16) The one or more non-transitory computer-readable media of claim 16, wherein one of the base station and the second base station is a fifth generation (5G) base station and another one of the base station and the second base station is a Long-Term Evolution (LTE) base station linked to the 5G base station in a dual connectivity configuration. ### Claim 20 (depends on 16) The one or more non-transitory computer-readable media of claim 16, wherein at least one of the first connection latency and the second connection latency is determined at least in part based on one of measuring a round-trip time associated with a data transmission between the base station and the UE over the first connection or between the second base station and the UE over the second connection, radio conditions, available bandwidth, network congestion levels, numbers of connections to the base station or the second base station, or a buffer fullness level at the base station or the second base station.