# US 9,882,820 B2 · Communication apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,882,820 B2 - Document ID: US9882820B2 - Status: Granted - Kind: B2 - Application number: 15/106,183 - Filed: 2014-12-10 - Published: 2017-02-09 - Granted: 2018-01-30 - Earliest claimed: 2014-01-15 - Assignees: Hitachi, Ltd. - Applicants: Hitachi, Ltd. - Inventors: Naoki Tanida; Takashi Isobe; Takeki Yazaki; Tetsuya Oohashi - Web page: https://patentgrep.com/patent/US9882820B2 ## CPC - H04L 47/27: Evaluation or update of window size, e.g. using information derived from acknowledged [ACK] packets - H04L 12/6418: {Hybrid transport} - H04L 47/82: {Miscellaneous aspects} - H04L 47/11: Identifying congestion - H04L 47/36: by determining packet size, e.g. maximum transfer unit [MTU] - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A transmission apparatus includes: a sending unit configured to send data to a receiver apparatus via the network; a receiving unit configured to receive acknowledgement data including an acknowledgement and information on a receive window size from the receiver apparatus via the network; a transmission bandwidth controller configured to control a bandwidth for data to be sent from the sending unit; a transmission bandwidth restriction unit configured to restrict the bandwidth controlled by the transmission bandwidth controller in such a manner that a data size of data for which no acknowledgement is received from the receiver apparatus among data which is sent is equal to or smaller than an upper limit size determined from the receive window size; and a switching controller configured to switch activation and inactivation of the transmission bandwidth restriction unit based on the data size and the receive window size. ## Claims ### Claim 1 A transmission apparatus connectable to a network, the transmission apparatus comprising: a sending unit configured to send data to a receiver apparatus via the network; a receiving unit configured to receive acknowledgement data including an acknowledgement and information on a receive window size from the receiver apparatus via the network; a transmission bandwidth controller configured to control a bandwidth for data to be sent from the sending unit; a transmission bandwidth restriction unit configured to restrict the bandwidth controlled by the transmission bandwidth controller in such a manner that a data size of data for which no acknowledgement is received from the receiver apparatus among data which has been from the sending unit is equal to or smaller than an upper limit size determined from the receive window size; and a switching controller configured to enable the transmission bandwidth restriction unit in a case where the data size is smaller than the receive window size and to disable the transmission bandwidth restriction unit in a case where the data size is equal to or larger than the receive window size. ### Claim 2 (depends on 1) The transmission apparatus according to claim 1, wherein the switching controller is configured to determine whether to switch the transmission bandwidth restriction unit from active to inactive based on whether the data size is larger than a threshold, the threshold being equal to or smaller than the upper limit size. ### Claim 3 (depends on 2) The transmission apparatus according to claim 2, wherein the switching controller is configured to determine whether to switch the transmission bandwidth restriction unit from active to inactive based on whether a state where the data size is equal to or larger than the threshold has lasted for a predetermined time. ### Claim 4 (depends on 1) The transmission apparatus according to claim 1, wherein the switching controller is configured to determine whether to switch the transmission bandwidth restriction unit from active to inactive based on whether a variation in the receive window size is less than a threshold. ### Claim 5 (depends on 1) The transmission apparatus according to claim 1, wherein the switching controller is configured to determine whether to switch the transmission bandwidth restriction unit from active to inactive based on whether a variation in loss rate of data sent from the sending unit is less than a threshold. ### Claim 6 (depends on 1) The transmission apparatus according to claim 1, wherein the switching controller is configured to determine whether to switch the transmission bandwidth restriction unit from active to inactive based on whether an average loss rate of data sent from the sending unit is lower than a threshold. ### Claim 7 (depends on 2) The transmission apparatus according to claim 2, wherein the switching controller is configured to determine whether to switch the transmission bandwidth restriction unit from inactive to active based on whether the data size is smaller than the threshold. ### Claim 8 (depends on 7) The transmission apparatus according to claim 7, wherein the switching controller is configured to determine whether to switch the transmission bandwidth restriction unit from inactive to active in a case where a state where the data size is smaller than the threshold has lasted for a predetermined time. ### Claim 9 (depends on 1) The transmission apparatus according to claim 1, wherein the switching controller is configured to determine whether to switch the transmission bandwidth restriction unit from inactive to active in a case where a variation in the receive window size is not less than a threshold. ### Claim 10 (depends on 1) The transmission apparatus according to claim 1, wherein the switching controller is configured to determine whether to switch the transmission bandwidth restriction unit from inactive to active in a case where a variation in loss rate of data sent from the sending unit is not less than a threshold. ### Claim 11 (depends on 1) The transmission apparatus according to claim 1, wherein the switching controller is configured to determine whether to switch the transmission bandwidth restriction unit from inactive to active in a case where an average loss rate of data sent from the sending unit is not lower than a threshold. ### Claim 12 (depends on 1) The transmission apparatus according to claim 1, wherein the transmission bandwidth controller is configured to control the bandwidth depending on tokens determined from a loss rate of data sent from the sending unit. ### Claim 13 A control method for a transmission apparatus connectable to a network, the control method comprising: sending data to a receiver apparatus via the network; receiving acknowledgement data including an acknowledgement and information on a receive window size from the receiver apparatus via the network; controlling a bandwidth for data to be sent from the transmission apparatus; restricting the controlled bandwidth in such a manner that a data size of data for which no acknowledgement is received from the receiver apparatus among data which is sent is equal to or smaller than an upper limit size determined from the receive window size; and switching on the restricting the bandwidth in a case where the data size is smaller than the receive window size and switching off the restricting the bandwidth in a case where the data size is equal to or larger than the receive window size. ### Claim 14 A non-transitory computer-readable storage medium storing commands for controlling a transmission apparatus including an interface, a processor, and a primary storage, the commands being to be executed by the processor to make the processor perform the following processing of: sending data to a receiver apparatus from the interface; receiving acknowledgement data including an acknowledgement and information on a receive window size from the receiver apparatus via the interface; controlling a bandwidth for data to be sent from the interface; restricting the controlled bandwidth in such a manner that a data size of data for which no acknowledgement is received from the receiver apparatus among data which is sent is equal to or smaller than an upper limit size determined from the receive window size; and switching on the restricting the bandwidth in a case where the data size is smaller than the receive window size and switching off the restricting the bandwidth in a case where the data size is equal to or larger than the receive window size.