# US 10,374,727 B2 · Optical link management > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,727 B2 - Document ID: US10374727B2 - Status: Granted - Kind: B2 - Application number: 16/297,112 - Filed: 2019-03-08 - Published: 2019-07-04 - Granted: 2019-08-06 - Earliest claimed: 2016-04-27 - Assignees: Magseis FF LLC - Applicants: Magseis FF LLC - Inventors: Michael Morris; Thomas O'Brien; Philip Navratil - Web page: https://patentgrep.com/patent/US10374727B2 ## CPC - H04B 13/02: Transmission systems in which the medium consists of the earth or a large mass of water thereon, e.g. earth telegraphy - G01V 1/226: {Optoseismic systems} - H04B 10/11: Arrangements specific to free-space transmission, i.e. transmission through air or vacuum - H04B 10/112: Line-of-sight transmission over an extended range - H04B 10/50: Transmitters - H04L 1/0001: {Systems modifying transmission characteristics according to link quality, e.g. power backoff (adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04)} - H04L 1/08: by repeating transmission, e.g. Verdan system {(H04L1/1858 and H04L1/189 take precedence)} - G01V 1/3808: {Seismic data acquisition, e.g. survey design} - G08C 23/04: using light waves, e.g. infrared - H04B 10/80: Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups H04B10/03 - H04B10/70, e.g. optical power feeding or optical transmission through water - H04B: TRANSMISSION - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - G08C: TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS (fluid pressure transmitting systems F15B; mechanical means for transferring the output of a sensing member into a different variable G01D5/00; mechanical control systems G05G) ## Abstract The present disclosure provides optical link management in a marine seismic environment. A first device can transmit, to a second device, a first optical transmission at a first output level. The first optical transmission can include a first packet corresponding to a network protocol. The first device can determine that the second device failed to receive the first packet via the first optical transmission. The first device can transmit, responsive to failure of the first optical transmission, a second optical transmission at a second output level different than the first output level. The second optical transmission can include a second packet corresponding to the network protocol. The first device can identify that the second packet was successfully received by the second link manager agent. The first device can establish, responsive to the identification that the second packet was successfully received, the second output level as a transmission output level for the first device. ## Claims ### Claim 1 A system to manage an optical link in free-space to communicate data via an aqueous medium, comprising: a seismic data acquisition unit positioned on a seabed in the aqueous medium, the seismic data acquisition unit comprising: one or more sensors to detect acoustic waves that indicate subsurface lithologic formations or hydrocarbon deposits; a seismic data recorder to record seismic data corresponding to the acoustic waves detected by the one or more sensors; and a first link manager agent of the seismic data acquisition unit to: receive, through the aqueous medium from a second link manager agent of an underwater vehicle, a default optical transmission; transmit, responsive to receipt of the default optical transmission, to the second link manager agent of the underwater vehicle, a first optical transmission at a first output level, the first optical transmission comprising a first packet corresponding to a network protocol; receive, subsequent to transmission of the first optical transmission at the first output level, one or more additional default transmissions from the underwater vehicle having a same parameter as the default optical transmission previously received from the underwater vehicle; determine, responsive to receipt of the one or more additional default transmissions having the same parameter, that the second link manager agent failed to receive the first packet via the first optical transmission; determine, based on one or more optical signals comprising at least a portion of the first optical transmission transmitted between the seismic data acquisition unit and the underwater vehicle, a distance between the seismic data acquisition unit and the underwater vehicle based on a phase error in the one or more optical signals; and transmit, responsive to failure of the first optical transmission, a second optical transmission at a second output level different than the first output level over the distance between the seismic data acquisition unit and the underwater vehicle and establish the second output level as a transmission output level for the seismic data acquisition unit. ### Claim 2 (depends on 1) The system of claim 1, comprising: the second link manager agent configured to disable an optical transmitter of the seismic data acquisition unit responsive to a determination that the second link manager agent successfully received a second packet. ### Claim 3 (depends on 1) The system of claim 1, comprising: the first link manager agent configured to determine that the second link manager agent failed to receive the first packet via the first optical transmission based on receipt by the underwater vehicle of one or more optical transmissions from the seismic data acquisition unit at a predetermined time interval, wherein the first link manager agent fails to receive one or more packets of the one or more optical transmissions. ### Claim 4 (depends on 1) The system of claim 1, comprising: the first link manager agent configured to increase the first output level to the second output level in accordance with a sinusoidal wave. ### Claim 5 (depends on 1) The system of claim 1, comprising: the first link manager agent configured to use a half-duplex communication technique to identify that a second packet was successfully received by the second link manager agent. ### Claim 6 (depends on 1) The system of claim 1, comprising: the second link manager agent configured to: transmit to the first link manager agent of the seismic data acquisition unit, a third optical transmission at a third output level, the third optical transmission comprising a third packet corresponding to the network protocol; determine that the first link manager agent failed to receive the third packet via the third optical transmission; transmit, responsive to failure of the third optical transmission, a fourth optical transmission at a fourth output level different than the third output level, the fourth optical transmission comprising a fourth packet corresponding to the network protocol; identify that the fourth packet was successfully received by the first link manager agent; and establish responsive to a determination of successful receipt of a second packet and the fourth packet, an optical link between the seismic data acquisition unit and the underwater vehicle. ### Claim 7 (depends on 1) The system of claim 1, comprising: the first link manager agent configured to identify that a second packet was successfully received by the second link manager agent prior to successful receipt by the first link manager agent of one or more data packets via one or more optical transmissions from the second link manager agent. ### Claim 8 (depends on 1) The system of claim 1, comprising: the first link manager agent configured to: determine that the second link manager agent failed to receive the first packet via the first optical transmission based on receipt by the seismic data acquisition unit of a first one or more optical transmissions from the seismic data acquisition unit at a first predetermined time interval; and identify that a second packet was successfully received by the second link manager agent based on receipt by the underwater vehicle of a second one or more optical transmissions from the seismic data acquisition unit at a second predetermined time interval. ### Claim 9 (depends on 1) The system of claim 1, comprising: the first link manager agent and the second link manager agent configured to establish an optical link between the seismic data acquisition unit and the underwater vehicle; and the first link manager agent configured to provide, for inclusion in a third optical transmission, status data used to maintain a level of quality of the optical link. ### Claim 10 (depends on 1) The system of claim 1, comprising: an automatic gain control unit of the seismic data acquisition unit to increase a gain level based on a measurement of at least one of an alternating current component or direct current component of one or more optical transmissions received by the seismic data acquisition unit; an overdrive protection system of the seismic data acquisition unit to detect a signal level greater than or equal to a threshold and, responsive to detection of the signal level greater than or equal to the threshold, turn off a receiver of the seismic data acquisition unit. ### Claim 11 (depends on 1) The system of claim 1, comprising: the first link manager agent and the second link manager agent configured to establish an optical link between the seismic data acquisition unit and the underwater vehicle; the first link manager agent configured to provide, for inclusion in a third optical transmission, status data used to maintain a level of quality of the optical link; and the second link manager agent configured to adjust an output level of an optical transmitter of the seismic data acquisition unit based on the level of quality of the optical link. ### Claim 12 (depends on 1) The system of claim 1, comprising: the first link manager agent configured to increase the first output level to the second output level in accordance with a ramp function. ### Claim 13 A method of managing an optical link to communicate data via an aqueous medium, comprising: providing a seismic data acquisition unit on a seabed in the aqueous medium, the seismic data acquisition unit comprising one or more sensor to detect acoustic waves that indicate subsurface lithologic formations or hydrocarbon deposits, and a seismic data recorder to record seismic data corresponding to the acoustic waves detected by one or more sensors; receiving, by a first link manager agent of the seismic data acquisition unit, through the aqueous medium from a second link manager agent of an underwater vehicle, a default optical transmission transmitting, by the first link manager agent of the seismic data acquisition unit responsive to receipt of the default optical transmission through the aqueous medium, to the second link manager agent of the underwater vehicle, a first optical transmission at a first output level, the first optical transmission comprising a first packet corresponding to a network protocol; receiving, by the first link manager agent of the seismic data acquisition unit subsequent to transmission of the first optical transmission at the first output level, one or more additional default transmissions from the underwater vehicle having a same parameter as the default optical transmission previously received from the underwater vehicle; determining, by the first link manager agent, responsive to receipt of the one or more additional default transmissions having the same parameter, that the second link manager agent failed to receive the first packet via the first optical transmission; determining, based on one or more optical signals comprising at least a portion of the first optical transmission transmitted between the seismic data acquisition unit and the underwater vehicle, a distance between the seismic data acquisition unit and the underwater vehicle based on a phase error in the one or more optical signals; and transmitting, responsive to failure of the first optical transmission, a second optical transmission at a second output level different than the first output level over the distance between the seismic data acquisition unit and the underwater vehicle and establish the second output level as a transmission output level for the seismic data acquisition unit. ### Claim 14 (depends on 13) The method of claim 13, comprising: identifying, by the first link manager agent, that a second packet was successfully received by the second link manager agent prior to the first link manager agent successfully receiving one or more data packets via one or more optical transmissions from the second link manager agent. ### Claim 15 (depends on 13) The method of claim 13, comprising: using a half-duplex communication technique to identify that a second packet was successfully received by the second link manager agent. ### Claim 16 (depends on 13) The method of claim 13, comprising: providing, by the second link manager agent, for inclusion in a third optical transmission to the first link manager agent, status data used to maintain a level of quality of the optical link. ### Claim 17 (depends on 13) The method of claim 13, comprising: providing, by the first link manager agent, for inclusion in a third optical transmission to the second link manager agent, status data used to maintain a level of quality of the optical link, the status data comprising at least one of an automatic gain control value, receiver control setting, transmitter control setting, receiver clock lock, framing error, bit error, bit error rate, network packet errors received, distance measurement, or packet retries; and adjusting, by the second link manager agent, output level of an optical transmitter of the underwater vehicle based on the level of quality of the optical link. ### Claim 18 (depends on 13) The method of claim 13, comprising: turning off, by the second link manager agent, an optical transmitter of the underwater vehicle responsive to determining that the second link manager agent successfully received a second packet, the second link manager agent disabling the optical transmitter to indicate to the first link manager agent that the second link manager agent successfully received the second packet. ### Claim 19 (depends on 13) The method of claim 13, comprising: increasing, by the first link manager agent, the first output level to the second output level in accordance with a sinusoidal wave. ### Claim 20 (depends on 13) The method of claim 13, comprising: increasing, by the first link manager agent, the first output level to the second output level in accordance with a ramp function.