Abstract: A system for wavelength control in a passive optical network (PON) with point to multi-point (P2MP) topology comprising a central node and end node. The system comprises a central node transceiver configured for broadcasting to end nodes a reference signal carrying a management information, wherein the management information indicates a target frequency assigned to each end node, and an end node transceiver in each end node configured for determining the target frequency by extracting the management information from the reference signal. The system comprises generating a beating frequency by beating the reference signal with an uplink laser signal, and controlling a wavelength of the uplink laser signal to lock to the target frequency based on the beating frequency. The system is compatible with existing power-split optical distribution networks (ODN), with tolerance to an uplink reflection, and has high power sensitivity.

Abstract: The reflection-asymmetric metal grating polarization beam splitter comprises a substrate, and a first grating composed of first mediums and first metals, and first light-absorbing materials are provided on the upper surfaces or side surfaces of the first metals. A plurality of second materials are provided at equal intervals longitudinally along the upper surfaces of the first metals to form a second grating. The first light-absorbing materials are closely provided on the upper surfaces of the first metals between two adjacent second materials, and second light-absorbing materials are closely provided on the upper surfaces and/or side surfaces of the second materials. The second materials have a greater thickness than the first light-absorbing materials. Second mediums are filled in spaces between adjacent second materials above the first light-absorbing materials.

Abstract: The present disclosure relates to information transmission methods in a passive optical network (PON) system. One example method includes sending, by an optical line terminal (OLT), a first power range and time indication to an unregistered optical network unit (ONU), where the first power range and the time indication indicate the ONU to send a serial number of the ONU to the OLT at a time indicated by the time indication in case a downlink receive power of the ONU is within the first power range, and receiving, by the OLT, the serial number of the ONU.

Abstract: A sub-wavelength grating optical film comprises a plurality of one-dimensional periodic grating units repeatedly arranged side by side. Each grating unit with a period of p comprises a first medium, a second medium, a third material, a fourth material, a fifth material, a sixth medium and a seventh medium, wherein the sixth medium serving as a substrate and the seventh medium serving as a covering layer are respectively arranged on bottom and top of each grating unit periodically arranged side by side. By controlling grating period and refractive index, incident blue-violet light meets condition that a diffraction angle in a layer with highest refractive index is smaller than 90 degrees; and by adjusting duty ratio of the grating and the thickness of each layer of material, transmitted light energy of the blue-violet light wave band is the lowest so that harmful blue-violet light is isolated.

Abstract: A grating touch screen based on lattice structure distribution comprises a laser light source, an optical waveguide layer, a grating and a photoelectric detector. In the present invention, the grating with the lattice structure distribution is reasonably arranged on the optical waveguide layer, so that the efficiency of detection light from the laser light source reaching the photoelectric detector at a periphery through the grating touch screen is maximized, and the sensitivity of the touch screen is effectively improved.

Abstract: The present disclosure relates to information transmission methods in a passive optical network (PON) system. One example method includes sending, by an optical line terminal (OLT), a first power range and time indication to an unregistered optical network unit (ONU), where the first power range and the time indication indicate the ONU to send a serial number of the ONU to the OLT at a time indicated by the time indication in case a downlink receive power of the ONU is within the first power range, and receiving, by the OLT, the serial number of the ONU.

Abstract: The present disclosure relates to message transmission methods in a PON system. One example method includes sending, by an optical line terminal (OLT), a first message to an unregistered optical network unit (ONU), where the first message includes at least one piece of indication message, and one piece of indication message of the at least one piece of indication message indicates a first power range and a first time range associated with the first power range, and receiving, by the OLT in the first time range, a registration message sent by the ONU, where a downstream receive power of the ONU falls within the first power range.

Abstract: A grating touch screen based on lattice structure distribution comprises a laser light source, an optical waveguide layer, a grating and a photoelectric detector. In the present invention, the grating with the lattice structure distribution is reasonably arranged on the optical waveguide layer, so that the efficiency of detection light from the laser light source reaching the photoelectric detector at a periphery through the grating touch screen is maximized, and the sensitivity of the touch screen is effectively improved.

Abstract: The present disclosure relates to message transmission methods in a PON system. One example method includes sending, by an optical line terminal (OLT), a first message to an unregistered optical network unit (ONU), where the first message includes at least one piece of indication message, and one piece of indication message of the at least one piece of indication message indicates a first power range and a first time range associated with the first power range, and receiving, by the OLT in the first time range, a registration message sent by the ONU, where a downstream receive power of the ONU falls within the first power range.

Abstract: Embodiments of the present disclosure provide a passive optical network communications method and apparatus, and a system. The method includes: determining a wavelength channel group of an optical network unit (ONU) and a wavelength channel in the wavelength channel group; and sending a first message to the ONU, where the first message carries identification information of the wavelength channel group and identification information of the wavelength channel in the wavelength channel group. In the embodiments of the present disclosure, such a logical channel group as a wavelength channel group is established, and when a channel in a channel group is faulty, a scheduling module of an OLT can rapidly and easily reallocate a service to another member in the channel group, so that channel interaction is avoided. Therefore, bandwidth scheduling efficiency and bandwidth utilization of a PON system are higher.

Abstract: Embodiments of the present invention disclose a method for switching a modulation format of a passive optical network, an apparatus, and a system. The method includes: separately delivering, by an OLT, a registration message to an optical network unit in all supported upstream modulation formats and/or downstream modulation formats; receiving, by the OLT, a first message reported by the optical network unit, where the first message includes an upstream modulation format capability and/or a downstream modulation format capability; and determining, by the OLT, a target upstream modulation format and/or a target downstream modulation format of the optical network unit according to the first message, and instructing the optical network unit to switch to the target upstream modulation format and/or the target downstream modulation format. Therefore, in a PON system that supports a plurality of modulation formats, a modulation format reporting capability of the ONU is improved.

Abstract: Embodiments relate to the field of optical communications technologies. The bi-directional optical sub-assembly includes a transmitter optical path sub-assembly, a receiver optical sub-assembly, a wavelength division multiplexing sub-assembly, and an optical fiber interface.

Abstract: Embodiments of the present invention disclose a method for switching a modulation format of a passive optical network, an apparatus, and a system. The method includes: separately delivering, by an OLT, a registration message to an optical network unit in all supported upstream modulation formats and/or downstream modulation formats; receiving, by the OLT, a first message reported by the optical network unit, where the first message includes an upstream modulation format capability and/or a downstream modulation format capability; and determining, by the OLT, a target upstream modulation format and/or a target downstream modulation format of the optical network unit according to the first message, and instructing the optical network unit to switch to the target upstream modulation format and/or the target downstream modulation format. Therefore, in a PON system that supports a plurality of modulation formats, a modulation format reporting capability of the ONU is improved.

Abstract: Embodiments of the invention disclose a communication method which includes: receiving, by the optical network unit (ONU) by using the first port or the second port, a wavelength switching request message delivered by the optical line terminal (OLT), where the wavelength switching request message carries second wavelength channel information and port information that is of the second port; switching, by the ONU, an operating wavelength channel of an optical module connected to the second port from a first wavelength channel to a second wavelength channel corresponding to the second wavelength channel information; and sending, by the ONU, a wavelength switching complete message to the OLT by using the first port. According to the communication method provided in embodiments of the present invention, quick wavelength switching is performed based on the second port, so that a service is not interrupted in a wavelength switching process, and user experience is better.

Abstract: Embodiments of the present disclosure provide a passive optical network communications method and apparatus, and a system. The method includes: determining a wavelength channel group of an optical network unit (ONU) and a wavelength channel in the wavelength channel group; and sending a first message to the ONU, where the first message carries identification information of the wavelength channel group and identification information of the wavelength channel in the wavelength channel group. In the embodiments of the present disclosure, such a logical channel group as a wavelength channel group is established, and when a channel in a channel group is faulty, a scheduling module of an OLT can rapidly and easily reallocate a service to another member in the channel group, so that channel interaction is avoided. Therefore, bandwidth scheduling efficiency and bandwidth utilization of a PON system are higher.

Abstract: An adaptive heat dissipation apparatus is provided, including two or more chamber walls forming a chamber volume having a first open side and a second open side, a heat source positioned at the first open side of the chamber volume, a heat conducting surface positioned at the second open side of the chamber volume, and a thermally-expansive material occupying a predetermined portion of the chamber volume. The thermally-expansive material expands to substantially fill the chamber volume at an ambient temperature above a predetermined temperature threshold and conducts heat from the heat source to the heat conducting surface. The thermally-expansive material contracts to leave an air gap when the ambient temperature is below the predetermined temperature threshold.

Abstract: The invention discloses a communication method includes: receiving, by the ONU by using the first port or the second port, a wavelength switching request message delivered by the OLT, where the wavelength switching request message carries second wavelength channel information and port information that is of the second port; switching, by the ONU, an operating wavelength channel of an optical module connected to the second port from a first wavelength channel to a second wavelength channel corresponding to the second wavelength channel information; and sending, by the ONU, a wavelength switching complete message to the OLT by using the first port. According to the communication method provided in embodiments of the present invention, quick wavelength switching is performed based on the second port, so that a service is not interrupted in a wavelength switching process, and user experience is better.

Abstract: A method and an apparatus for sending and receiving audio data, so as to solve the problem that in the prior art, a simulating audio and video transmission system is complex in cable connection structure. The audio data is overlaid at a preset position of a video blanking interval of video data, sending and receiving of audio signals are carried out, and co-cable transmission of the audio and video data can be achieved.

Abstract: Disclosed are a video signal attenuation equalization circuit, a video signal processing apparatus, and a control device and method, which are used for solving the problem that the transmission of an analog video signal is distorted after the analog video signal is transmitted by a coaxial cable, so as to guarantee low signal distortion after the video signal is transmitted at a long distance.

Abstract: Disclosed are a high-definition digital video signal transmission method and device, a high-definition digital video camera and a video acquisition device. The technical solution provided in the embodiments of the present invention comprises: transcoding a high-definition digital video signal in accordance with a line-by-line sequence at a sending end to obtain an analogue video line signal, and sending analogue video line data which is obtained by conversion; and receiving the analogue video line data at a receiving end, and conducting decoding conversion on the received analogue video line data to obtain high-definition digital video line data. The present invention can convert a high-definition digital video signal into an analogue video signal to conduct transmission, thereby being able to solve the problem that a high-definition digital video signal cannot be transmitted for a long distance in the existing high-definition digital video monitoring technology.