CN-122027922-A - Passive optical network monitoring system and passive optical network architecture

Abstract

The embodiment of the application relates to the technical field of optical fiber sensing, and discloses a passive optical network monitoring system and a passive optical network system. The passive optical network monitoring system comprises a sensing optical signal component, a passive round-trip structure and a controller, wherein the sensing optical signal component is configured at an optical line terminal of a passive optical network and is used for generating a sensing optical signal, the optical line terminal is connected with an optical network unit of the passive optical network through an optical distribution link, the passive round-trip structure is configured at the optical network unit and is used for receiving the sensing optical signal transmitted by the optical line terminal through the optical distribution link and reflecting the back sensing optical signal to the optical line terminal, and the controller is used for determining fluctuation characteristics with correlation caused by polarization disturbance in the reflected back sensing optical signal and positioning disturbance positions in the optical distribution link according to the fluctuation characteristics. The application can accurately locate the disturbance in the passive optical network scene.

Inventors

• YANG MING
• XIAO XIAO

Assignees

• 众瑞速联（武汉）科技有限公司
• 芯速联光电科技(杭州)有限公司

Dates

Publication Date

20260512

Application Date

20260414

Claims (10)

1. 1. A passive optical network monitoring system, comprising: A sensing optical signal component, configured at an optical line terminal of the passive optical network, for generating a sensing optical signal, the optical line terminal is connected with an optical network unit of the passive optical network through an optical distribution link; The passive round trip structure is configured in the optical network unit and is used for receiving the sensing optical signal transmitted by the optical line terminal through the optical distribution link and reflecting the sensing optical signal back to the optical line terminal; And the controller is used for determining fluctuation characteristics with correlation caused by polarization disturbance in the reflected and returned sensing optical signals so as to position disturbance positions in the optical distribution link according to the fluctuation characteristics.
2. 2. The passive optical network monitoring system of claim 1, wherein the controller is specifically configured to: Determining a time difference between the correlated wave features; And determining the disturbance position according to the time difference.
3. 3. The passive optical network monitoring system of claim 1, further comprising: the Stokes vector receiver is configured at the optical line terminal and is used for receiving the reflected and returned sensing optical signals and extracting Stokes parameters of multiple dimensions in the sensing optical signals; the controller is specifically configured to determine a fluctuation feature having a correlation in the reflected back-transmitted sensor light signal according to the stokes parameter.
4. 4. A passive optical network monitoring system according to claim 3, wherein the controller is further specifically configured to: Preprocessing an initial Stokes parameter by a denoising algorithm based on wavelet transformation; and determining fluctuation characteristics with correlation in the sensing optical signals according to the preprocessed Stokes parameters.
5. 5. The passive optical network monitoring system of claim 3, wherein the stokes vector receiver comprises a polarizing beam splitter, a 90 ° optical mixer, and a photo-balance detector; The polarization beam splitter is used for decomposing the sensing optical signal into an orthogonal X polarization component and an orthogonal Y polarization component, and dividing the X polarization component and the Y polarization component into two paths of signals respectively; the 90 DEG optical mixer is used for carrying out coherent mixing on one X polarization component and one Y polarization component, The photoelectric balance detector is used for carrying out balanced differential detection on the sub-signals after coherent mixing, and carrying out balanced differential detection on the other path of X polarization component and the other path of Y polarization component so as to extract and obtain the Stokes parameters.
6. 6. The passive optical network monitoring system of any of claims 3-5, wherein the physical mapping formula of stokes parameters comprises: ; Wherein, the For the stokes parameters mentioned above, And Representing the real and imaginary parts of the complex signal respectively, The polarization component of the light is transmitted, Representation of The polarization component of the light is transmitted, Representing a conjugate operation.
7. 7. The passive optical network monitoring system according to any one of claims 3 to 5, further comprising an erbium-doped fiber amplifier, wherein the erbium-doped fiber amplifier is disposed at the optical line terminal and is located at the front end of the stokes vector receiver, and the erbium-doped fiber amplifier is configured to compensate for the loss of the reflected back sensing optical signal, and send the sensing optical signal after compensating for the loss to the stokes vector receiver.
8. 8. The passive optical network monitoring system of any of claims 1-5, further comprising: The first coupler is configured at the optical line terminal and is used for coupling the sensing optical signal generated by the sensing optical signal component with the downlink optical communication signal generated by the optical line terminal to obtain a first mixed optical signal, and transmitting the first mixed optical signal to the optical network unit through the optical distribution link; And the second coupler is configured in the optical network unit and is used for receiving and separating the first mixed optical signal and transmitting the separated signal to the passive round-trip structure and the first data recovery component of the optical network unit respectively.
9. 9. The passive optical network monitoring system according to claim 8, wherein the second coupler is further specifically configured to couple the sensing optical signal reflected by the passive round trip structure and the uplink optical communication signal generated by the optical network unit to obtain a second mixed optical signal, and transmit the second mixed optical signal to the optical line terminal through the optical distribution link; The first coupler is specifically further configured to receive and separate the second mixed optical signal, and transmit the separated signal to the stokes vector receiver and the second data recovery component of the optical line terminal, respectively.
10. 10. A passive optical network architecture comprising the passive optical network monitoring system of any of claims 1-9.

Description

Passive optical network monitoring system and passive optical network architecture Technical Field The embodiment of the application relates to the technical field of optical fiber sensing, in particular to a passive optical network monitoring system and a passive optical network architecture. Background As 50G passive optical network (Passive Optical Network, PON) technology enters standardized and scaled deployments, optical access networks are evolving from a single service-carrying platform to a comprehensive information infrastructure with "universal-sensing integration" capability. The combination of the distributed optical fiber sensing technology (Distributed Fiber Optic Sensing, DFOS) and the existing telecom optical fiber infrastructure can realize real-time monitoring of external environment evolution, mechanical vibration and link health state while guaranteeing high throughput data transmission, and the paradigm conversion becomes a key technology for supporting future smart cities and digital economy, and opens up a new business opportunity for telecom operators under deployed PON networks. Conventional PON sensing schemes are mainly based on amplitude or phase demodulation of rayleigh backscattered light. Because PON adopts a typical point-to-multipoint topology structure, the broadcasting characteristics of a high-splitting ratio power divider in an optical distribution network (Optical Distribution Network, ODN) of PON cause extremely dispersed sensing downlink energy, and the conventional sensing method is difficult to effectively monitor a distribution optical fiber section, so that the coverage range and reliability perceived by the optical network are severely limited. In the related art, the optical fiber link loss is compensated for or the detection mechanism is improved through various approaches. Some schemes attempt to deploy reflective semiconductor optical amplifiers (Semiconductor Optical Amplifier, SOA) at optical network units (Optical Network Unit, ONUs) to achieve active gain of the sensing pulse, or to employ special enhanced scattering fibers to boost the scattered echo power. However, the scheme has significant limitation in practical application, namely, the introduction of an active device significantly increases the power consumption cost and the operation and maintenance complexity of an ONU end, and deviates from the design original purpose of 'fully passive' of a PON system, and the special optical fiber scheme is difficult to realize low-cost large-scale substitution due to the lack of compatibility with huge existing network stock optical fibers. In addition, the schemes generally lack an effective space positioning mechanism, physical coordinates of disturbance are difficult to judge in multi-branch scattered topology, accurate positioning of disturbance cannot be performed, and follow-up maintenance is inconvenient. Disclosure of Invention The embodiment of the application aims to provide a passive optical network monitoring system and a passive optical network system, which are used for accurately positioning disturbance appearing in a passive optical network scene. To solve the above technical problem, an embodiment of the present application provides a passive optical network monitoring system, including: A sensing optical signal component, configured at an optical line terminal of the passive optical network, for generating a sensing optical signal, the optical line terminal is connected with an optical network unit of the passive optical network through an optical distribution link; The passive round trip structure is configured in the optical network unit and is used for receiving the sensing optical signal transmitted by the optical line terminal through the optical distribution link and reflecting the sensing optical signal back to the optical line terminal; And the controller is used for determining fluctuation characteristics with correlation caused by polarization disturbance in the reflected and returned sensing optical signals so as to position disturbance positions in the optical distribution link according to the fluctuation characteristics. In some embodiments, the controller is specifically configured to: Determining a time difference between the correlated wave features; And determining the disturbance position according to the time difference. In some embodiments, the passive optical network monitoring system further comprises: the Stokes vector receiver is configured at the optical line terminal and is used for receiving the reflected and returned sensing optical signals and extracting Stokes parameters of multiple dimensions in the sensing optical signals; the controller is specifically configured to determine a fluctuation feature having a correlation in the reflected back-transmitted sensor light signal according to the stokes parameter. In some embodiments, the controller is specifically further configured to: Preprocessing an initial Sto