# US 11,309,974 B2 · Quantum channel routing utilizing a quantum channel measurement service > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,309,974 B2 - Document ID: US11309974B2 - Status: Granted - Kind: B2 - Application number: 16/407,362 - Filed: 2019-05-09 - Published: 2020-11-12 - Granted: 2022-04-19 - Earliest claimed: 2019-05-09 - Assignees: Red Hat, Inc. - Applicants: Red Hat, Inc. - Inventors: Leigh Griffin; Stephen Coady - Web page: https://patentgrep.com/patent/US11309974B2 ## CPC - H04B 10/70: Photonic quantum communication - B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic - H04B 10/07: Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems - H04L 9/0855: {involving additional nodes, e.g. quantum relays, repeaters, intermediate nodes or remote nodes} - H04B 10/07957: {Monitoring or measuring wavelength} - H04B 10/25: Arrangements specific to fibre transmission - H04B: TRANSMISSION - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Quantum channel routing utilizing a quantum channel measurement service is disclosed. A quantum channel router that is communicatively coupled to a plurality of quantum channels receives a message from a sender that is directed to a receiver. Each quantum channel is configured to convey a quantum message from a sender to a receiver. The quantum channel router identifies a quantum channel to which the receiver listens. The quantum channel router determines a message size of the message. It is determined that transmission of the message would exceed a maximum channel capacity of the quantum channel at a current point in time, and in response, the quantum channel router does not transmit the first message onto the first quantum channel at the current point in time. ## Claims ### Claim 1 A method comprising: receiving, by a quantum channel router communicatively coupled to a plurality of quantum channels, a first message from a first sender of a plurality of senders, the first message directed to a first receiver of a plurality of receivers, wherein each quantum channel is configured to convey a quantum message from a sender to a receiver; identifying, by the quantum channel router, a first quantum channel to which the first receiver listens; determining, by the quantum channel router, a first message size of the first message; determining that transmission of the first message would exceed a maximum channel capacity of the first quantum channel at a current point in time; and in response to determining that transmission of the first message would exceed the maximum channel capacity of the first quantum channel, not transmitting the first message onto the first quantum channel at the current point in time. ### Claim 2 (depends on 1) The method of claim 1 wherein the first message comprises a quantum message comprising one or more qubits. ### Claim 3 (depends on 1) The method of claim 1 wherein identifying the first quantum channel comprises accessing a table that identifies each quantum channel of the plurality of quantum channels to which each receiver of the plurality of receivers listens. ### Claim 4 (depends on 1) The method of claim 1 further comprising determining a current available capacity of the first quantum channel, comprising: determining the maximum channel capacity of the first quantum channel; determining a current channel usage of the first quantum channel; and determining the current available capacity to be a difference between the maximum channel capacity of the first quantum channel and the current channel usage of the first quantum channel. ### Claim 5 (depends on 1) The method of claim 1 wherein the first message comprises a quantum message, and wherein determining the first message size comprises accessing header information that identifies the first message size of the first quantum message. ### Claim 6 (depends on 1) The method of claim 1 wherein the first message comprises a quantum message, and wherein determining the first message size comprises performing a von Neumann measurement on the quantum message. ### Claim 7 (depends on 1) The method of claim 1 wherein the first message comprises a quantum message, and further comprising: storing the first message in a plurality of qubits; waiting a period of time; determining that transmission of the first message would not exceed the maximum channel capacity of the first quantum channel at a current point in time; and in response to determining that transmission of the first message would not exceed the maximum channel capacity of the first quantum channel, transmitting the first message onto the first quantum channel. ### Claim 8 (depends on 1) The method of claim 1 wherein the first message comprises a quantum message, and further comprising sending a message to the first sender to retry sending the first message to the quantum channel router at a future point in time. ### Claim 9 (depends on 1) The method of claim 1 wherein the first message comprises a quantum message, and further comprising: in response to determining that transmission of the first message would exceed the maximum channel capacity of the first quantum channel: identifying, by the quantum channel router, a second quantum channel to which the first receiver listens; determining that transmission of the first message would not exceed a maximum channel capacity of the second quantum channel at the current point in time; and transmitting the first message onto the second quantum channel. ### Claim 10 (depends on 1) The method of claim 1 further comprising: identifying, by the quantum channel router, a second quantum channel to which the first receiver listens; determining that a most recent message sent to the first receiver was sent on the second quantum channel; and based on determining that the most recent message sent to the first receiver was sent on the second quantum channel, selecting the first quantum channel to use to send the first message to the first receiver. ### Claim 11 A quantum computing system comprising: one or more memories; and one or more processor devices coupled to the one or more memories to: receive, by a quantum channel router communicatively coupled to a plurality of quantum channels, a first message from a first sender of a plurality of senders, the first message directed to a first receiver of a plurality of receivers, wherein each quantum channel is configured to convey a quantum message from a sender to a receiver; identify, by the quantum channel router, a first quantum channel to which the first receiver listens; determine, by the quantum channel router, a first message size of the first message; determine that transmission of the first message would exceed a maximum channel capacity of the first quantum channel at a current point in time; and in response to determining that transmission of the first message would exceed the maximum channel capacity of the first quantum channel, not transmit the first message onto the first quantum channel at the current point in time. ### Claim 12 (depends on 11) The quantum computing system of claim 11 wherein to identify the first quantum channel, the one or more processor devices are further to access a table that identifies each quantum channel of the plurality of quantum channels to which each receiver of the plurality of receivers listens. ### Claim 13 (depends on 11) The quantum computing system of claim 11 wherein the one or more processor devices are further to determine a current available capacity of the first quantum channel, and wherein to determine the current available capacity, the one or more processor devices are further to: determine the maximum channel capacity of the first quantum channel; determine a current channel usage of the first quantum channel; and determine the current available capacity to be a difference between the maximum channel capacity of the first quantum channel and the current channel usage of the first quantum channel. ### Claim 14 (depends on 11) The quantum computing system of claim 11 wherein the first message comprises a quantum message, and wherein to determine the first message size, the one or more processor devices are further to perform a von Neumann measurement on the quantum message. ### Claim 15 (depends on 11) The quantum computing system of claim 11 wherein the first message comprises a quantum message, and wherein the one or more processor devices are further to: store the first message in a plurality of qubits; wait a period of time; determine that transmission of the first message would not exceed the maximum channel capacity of the first quantum channel at a current point in time; and in response to determining that transmission of the first message would not exceed the maximum channel capacity of the first quantum channel, transmit the first message onto the first quantum channel. ### Claim 16 A non-transitory computer-readable storage medium that includes executable instructions configured to cause one or more processor devices to: receive, by a quantum channel router communicatively coupled to a plurality of quantum channels, a first message from a first sender of a plurality of senders, the first message directed to a first receiver of a plurality of receivers, wherein each quantum channel is configured to convey a quantum message from a sender to a receiver; identify, by the quantum channel router, a first quantum channel to which the first receiver listens; determine, by the quantum channel router, a first message size of the first message; determine that transmission of the first message would exceed a maximum channel capacity of the first quantum channel at a current point in time; and in response to determining that transmission of the first message would exceed the maximum channel capacity of the first quantum channel, not transmit the first message onto the first quantum channel at the current point in time. ### Claim 17 (depends on 16) The non-transitory computer-readable storage medium of claim 16 wherein to identify the first quantum channel, the instructions further cause the one or more processor devices to access a table that identifies each quantum channel of the plurality of quantum channels to which each receiver of the plurality of receivers listens. ### Claim 18 (depends on 16) The non-transitory computer-readable storage medium of claim 16 wherein the instructions are further configured to cause the one or more processor devices to determine a current available capacity of the first quantum channel, and wherein to determine the current available capacity, the instructions further cause the one or more processor devices to: determine the maximum channel capacity of the first quantum channel; determine a current channel usage of the first quantum channel; and determine the current available capacity to be a difference between the maximum channel capacity of the first quantum channel and the current channel usage of the first quantum channel. ### Claim 19 (depends on 16) The non-transitory computer-readable storage medium of claim 16 wherein the first message comprises a quantum message, and wherein to determine the first message size, the instructions further cause the one or more processor devices to perform a von Neumann measurement on the quantum message. ### Claim 20 (depends on 16) The non-transitory computer-readable storage medium of claim 16 wherein the first message comprises a quantum message, and wherein the instructions further cause the one or more processor devices to: store the first message in a plurality of qubits; wait a period of time; determine that transmission of the first message would not exceed the maximum channel capacity of the first quantum channel at a current point in time; and in response to determining that transmission of the first message would not exceed the maximum channel capacity of the first quantum channel, transmit the first message onto the first quantum channel.