CN101442374A - Time division multiplexing optical network system, device and method for preventing signal collision - Google Patents

Abstract

A device for preventing the collision of the up stream signal is suitable for the time-division multiplexing passive optical network and comprises an optical coupling device, an optical-electrical converter, a control system and an optical-electrical signal switching module. The photoelectric converter is coupled to the optical coupling device, the control system is coupled to the photoelectric converter, and the optical signal switching module is coupled to the optical coupling device and the control system. The optical coupling device is used for receiving the first optical signal and dividing the first optical signal into a second optical signal and a third optical signal. The photoelectric converter is used for converting the second optical signal into a first electric signal, and the control system generates a control signal according to the first electric signal. The optical signal switching module determines whether to block the third optical signal from passing through the device according to the control signal.

Description

Time division multiplexing optical network system, device and method for preventing signal collision

technical field

The present invention relates to a time division multiplexing (Time Division Multiplexing, TDM) optical network system, device and method for preventing signal collisions, and in particular to a time division multiplexing optical passive optical network (TDM Passive Optical Network, TDMPON) system, device and method thereof.

Background technique

With the increase of network users, the amount of data transmission also increases. The traditional technology of using electrical signals for communication will cause network congestion due to the bandwidth limitation of electrical signals. Therefore, many network service providers use optical fiber communication to provide network services to various network users with different needs.

The bandwidth of optical fiber communication technology is larger than that of wireless communication or wired communication using electrical signals, so it can transmit a larger amount of data and provide users with better network services. Current optical fiber communication systems mostly use passive optical networks. Passive optical networks use passive components and do not require a large number of switching devices. Therefore, maintenance is relatively easy, and use is relatively power-saving. At present, many countries are more committed to using optical fiber communication technology to develop passive optical networks such as Fiber to the Home (FFTH), Fiber to the Curb (FFTC) and Fiber to the Building (FFTB). , so that network users can send and receive data quickly and in large quantities. Therefore, passive optical networks play an important role in current communication technologies.

In a passive optical network, the distance between each optical network unit (Optical Network Unit, ONU) and the optical line terminal (Optical Line Termination, OLT) at the central office is different, so the upload signal can be controlled by time division multiplexing (generally Use 1310 nanometer optical signal) for transmission to avoid the signal collision problem. Therefore, the optical transceiver (Optical Transceiver) of the optical network unit must be a laser light source in burst mode (Burst Mode) to meet the transmission mode of time division multiplexing. If the burst mode of any optical network unit in the network becomes continuous mode (Continuous Wave Mode, CW Mode) due to module problems, it will paralyze the entire passive optical network. Due to the problem of collision, it will not be possible to upload all upload signals.

Please refer to FIG. 1A . FIG. 1A shows a schematic diagram of a traditional time-division multiplexing passive optical network 100 operating in a normal state. As shown in FIG. 1A , a time division multiplexing passive optical network 100 includes an optical terminal 101 , a plurality of optical fibers 102 , an optical coupling device 103 and a plurality of optical network units 1041 - 1044 . The optical terminal 101 is coupled to an optical coupling device 103 through an optical fiber 102 , and the optical coupling device 103 is coupled to a plurality of network units 1041 - 1044 through an optical fiber 102 . For the downlink signal, the optical coupling device 103 is used to split the downlink signal, so that each optical network unit 1041-1044 can receive the downlink signal; The uploading signal of each optical network unit 1041 - 1044 is coupled, so that the uploading signal of each optical network unit 1041 - 1044 can be successfully uploaded to the optical path terminal 102 .

Each optical network unit 1041-1044 is allocated to a time slot ts_1-ts_4 (timeslot). When the optical network unit 1041 has uploaded data, the optical network unit 1041 must transmit it to the optical path terminal 101 within the time slot ts_1, and other optical network units The network units 1042-1044 can be deduced by analogy. Therefore, the laser light sources of the ONUs 1041-1044 must be operated in a burst mode.

Please refer to FIG. 1B . FIG. 1B shows a schematic diagram of a traditional time-division multiplexing passive optical network 100 in a collision state. When external factors or other factors, such as earthquakes, damage to optical fiber modules, or other environmental problems cause the laser light source of the optical network unit 1043 to change from a burst state to a continuous state, it will cause different optical network units 1041 , 1042, 1044 collide with the ONU 1043 upload signal, so the time division multiplexing transmission mode will be destroyed, and the passive optical network 100 with time division multiplexing will be completely paralyzed.

In order to avoid the paralysis of the entire time-division multiplexed passive optical network, U.S. Patent Publication 2005/0244160 A1 discloses a method and device for using an optical terminal to transmit control signals to control the on or off of each optical network unit. However, the above method must redesign the circuit of the optical terminal, and the hardware complexity is high, which is not cost-effective.

Contents of the invention

The invention provides a device for preventing upload signal collision, which is suitable for time-division multiplexing passive optical network. The device has a simple structure and low cost, and can prevent the time-division multiplexing passive optical network from paralyzing the optical network due to signal collision.

The invention provides a method for preventing upload signal collision, which is suitable for time division multiplexing passive optical network, and the device using the method can prevent the time division multiplexing passive optical network from paralyzing the optical network due to signal collision.

The present invention also provides a time-division multiplexing passive optical network system for preventing collision of uploaded signals. The structure of the network system can be completed by slightly modifying the traditional time-division multiplexing passive optical network. And this network system will not have the situation that the traditional passive optical network will cause the entire network system to be paralyzed due to signal collision.

The present invention proposes a device for preventing collision of uploaded signals, which is suitable for time-division multiplexing passive optical network. Switch modules. Wherein, the photoelectric converter is coupled to the optical coupling device, the control system is coupled to the photoelectric converter, and the optical signal switching module is coupled to the optical coupling device and the control system. The optical coupling device is used for receiving the first optical signal and dividing the first optical signal into a second optical signal and a third optical signal. The photoelectric converter is used to convert the second optical signal into a first electrical signal, and the control system generates a control signal according to the first electrical signal. The optical signal switching module determines whether to block the third optical signal from passing through the device according to the control signal.

According to the device for preventing upload signal collisions according to the embodiment of the present invention, if the time for which the first electrical signal is greater than the threshold exceeds the set time, the optical signal switching module blocks the third optical signal from passing through the device; if the first electrical signal If the time when the signal is greater than the threshold does not exceed the set time, the optical signal switching module allows the third optical signal to pass through the device.

According to the device for preventing collision of uploaded signals described in the embodiment of the present invention, the above-mentioned optical signal switching module includes an optical switch (Optical Switch) and a light blocking component. The optical switch has a first output end and a second output end, and outputs a third optical signal at the first output end or the second output end according to the control signal. The light-blocking component is coupled to the second output end and is used for blocking the third light signal from passing through the device.

The invention proposes a method for preventing collision of uploaded signals, which is suitable for time-division multiplexing passive optical network. Firstly, the first optical signal is divided into a second optical signal and a third optical signal. Afterwards, the second optical signal is converted into the first electrical signal. Next, a control signal is generated according to the first electrical signal. Finally, it is determined whether to output the third optical signal according to the control signal.

According to the method for preventing upload signal collisions according to the embodiments of the present invention, if the time for which the first electrical signal is greater than the threshold exceeds the set time, it is decided not to output the third optical signal; if the time for the first electrical signal is greater than the threshold If the set time is not exceeded, it is decided to output the third optical signal.

The invention provides a time-division multiplexing passive optical network system for preventing collision of uploaded signals. The network system includes an optical path terminal, a first optical coupling device, multiple user terminal equipment and multiple optical fibers. Wherein, the plurality of optical fibers are used to connect the optical path terminal and the first optical coupling device, and to connect the first optical coupling device to multiple user terminal equipment. Each user terminal equipment includes an optical network unit and a signal collision prevention device. Wherein, the signal collision preventing device is coupled to the optical network unit, and is used for receiving the first optical signal from the optical network unit, dividing the first optical signal into a second optical signal and a third optical signal, and according to the second optical signal Determine whether to output the third optical signal.

According to the network system described in the embodiment of the present invention, the above-mentioned signal collision prevention device includes a second optical coupling device, a photoelectric converter, a control system, and a photoelectric signal switching module. Wherein, the photoelectric converter is coupled to the second optical coupling device, the control system is coupled to the photoelectric converter, and the optical signal switching module is coupled to the second optical coupling device and the control system. The second optical coupling device is used for receiving the first optical signal and dividing the first optical signal into a second optical signal and a third optical signal. The photoelectric converter is used to convert the second optical signal into a first electrical signal, and the control system generates a control signal according to the first electrical signal. The optical signal switching module determines whether to block the third optical signal from passing through the signal collision preventing device according to the control signal.

According to the network system described in the embodiment of the present invention, if the time for which the first electrical signal is greater than the threshold exceeds the set time, the optical signal switching module blocks the third optical signal from passing through the signal collision prevention device; if the first electrical signal is greater than If the threshold time does not exceed the set time, the optical signal switching module allows the third optical signal to pass through the signal collision prevention device.

According to the network system described in the embodiment of the present invention, the above optical signal switching module includes an optical switch and a light blocking component. The optical switch has a first output end and a second output end, and outputs a third optical signal at the first output end or the second output end according to the control signal. The light blocking component is coupled to the second output end, and is used for blocking the third light signal from passing through the signal collision prevention device.

The invention utilizes the device for preventing collision of uploaded signals to control the optical network unit, thus avoiding the situation that the entire optical network is paralyzed due to the collision of uploaded signals. In addition, the above-mentioned device for preventing signal uploading has the advantages of simple structure, low cost, low hardware complexity and easy integration into the optical network unit.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments are specifically cited below and described in detail with reference to the accompanying drawings.

Description of drawings

FIG. 1A shows a schematic diagram of the architecture of a traditional time-division multiplexing passive optical network 100 operating in a normal state.

FIG. 1B shows a schematic diagram of the architecture of a traditional time-division multiplexing passive optical network 100 in a collision state.

FIG. 2A shows a system architecture diagram of an embodiment of a time division multiplexing optical network system 200 for preventing upload signal collisions.

FIG. 2B shows a structural diagram of the signal collision prevention device 2030 in FIG. 2A .

FIG. 2C shows a schematic diagram of optical signals when the ONU 2031 in FIG. 2A is operating in the burst mode.

FIG. 2D shows a schematic diagram of the operation of the optical switch 203A when the ONU 2031 in FIG. 2A is operating in the continuous mode.

FIG. 2E shows a schematic diagram of optical signals when the ONU 2031 in FIG. 2A operates in a continuous mode.

FIG. 3A shows a structural diagram of an embodiment of an optical switch 203A.

FIG. 3B shows a schematic diagram of an optical signal output to the second output terminal 2 of the optical switch 203A.

FIG. 3C shows a schematic diagram of outputting an optical signal to the first output terminal 1 of the optical switch 203A.

Fig. 4 shows a flow chart of a method for preventing upload signal collisions according to an embodiment of the present invention.

FIG. 5A shows an eye diagram of an optical signal when no ONU is in continuous mode in an optical network according to an embodiment of the present invention.

FIG. 5B shows an eye diagram of an optical signal when any optical network unit is in a continuous mode and the optical network is paralyzed according to an embodiment of the present invention.

FIG. 5C shows an eye diagram of an optical signal using the apparatus and method of the present invention when any optical network unit is in a continuous mode according to an embodiment of the present invention.

Fig. 6 shows a schematic diagram of switching time of an optical switch according to an embodiment of the present invention.

FIG. 7 shows a graph of downlink signal error probability versus received power according to an embodiment of the present invention.

Description of reference symbols

100: Passive optical network with time division multiplexing

101: Optical path terminal

102: optical fiber

103: Optical coupling device

1041～1044: optical network unit

200: Time division multiplexing optical network system

201: Optical path terminal

202: Optical coupling device

203~206: user terminal equipment

207: optical fiber

2031, 2041, 2051, 2061: Optical Network Units

2030, 2040, 2050, 2060: Signal collision prevention device

2035: Optocouplers

2036: Photoelectric Converters

2037: Control systems

2038: Optical signal switching module

203A: Optical switch

203B: light blocking component

300: Latching Optical Switches for MEMS

301: Mirror that can move up and down

S400～S403: step process

Detailed ways

Embodiments of the present invention provide a time-division multiplexing optical network, device and method for preventing collision of uploaded signals.

Please refer to FIG. 2A . FIG. 2A shows a system architecture diagram of an embodiment of a time division multiplexing optical network system 200 for preventing upload signal collisions. The network system 200 includes an optical terminal 201 , an optical coupling device 202 , multiple user terminal devices 203 - 206 and multiple optical fibers 207 . Wherein, the plurality of optical fibers 207 are used to connect the optical terminal 201 and the optical coupling device 202 , and connect the optical coupling device 202 to a plurality of user terminal devices 203 - 206 . The optical coupling device 202 can be an optical coupler (Optical Coupler, OCP) or an optical splitter (Optical Splitter, OS). Simply put, the optical coupling device can be any component that achieves the functions of light splitting and optical coupling, and the above-mentioned optical coupling The embodiment of the optical device or optical splitter is not intended to limit the present invention.

For the downlink signal, the optical coupling device 202 is used to split the downlink signal, so that each user terminal equipment 203-206 can receive the downlink signal; for the uplink signal, the optical coupling device 202 The uploading signal of each user terminal device 203 - 206 is coupled so that the uploading signal of each user terminal device 203 - 206 can be successfully uploaded to the optical path terminal 201 . In the network system 200, the user terminal devices 203-206 are allocated to corresponding time slots ts_1-ts_4, and the user terminal devices 203-206 can transmit the data to be transmitted in the allocated time slots ts_1-ts_4.

The user terminal equipment 203 includes an optical network unit 2031 and a signal collision prevention device 2030 . Wherein, the signal collision prevention device 2030 is coupled to the optical network unit 2031 for receiving the optical signal transmitted by the optical network unit 2031, and divides the optical signal transmitted by the optical network unit 2031 into a detection optical signal and a data optical signal , and decide whether to output a data optical signal according to the detected optical signal. The structures of the user terminal devices 204-206 are the same as those of the user terminal device 203, so they are not described in detail.

If the optical network unit 2051 of the user terminal device 205 is abnormal, so that its transceiver is in continuous mode, the entire optical network 200 will not be paralyzed due to the abnormal occurrence of the optical network unit 2051 . Because, when the optical network unit 2051 is abnormal, the signal collision prevention device 2050 will prevent the optical network unit 2051 from continuously transmitting optical signals, so the optical network units 2031, 2041 and 2061 can respectively operate in their corresponding time slots ts_1, ts_2 and ts_4 Send the data to be sent.

Next, please refer to FIG. 2B , which shows a structural diagram of the signal collision prevention device 2030 . Here, only the signal collision prevention device 2030 is taken as an example, and the structures of other signal collision prevention devices 2040-2060 are also the same. The signal collision prevention device 2030 includes an optical coupling device 2035 , an optical-electron converter (Optic-Electron Converter, O/E) 2036 , a control system 2037 , and an optical signal switching module 2038 . Wherein, the photoelectric converter 2036 is coupled to the optical coupling device 2035 , the control system 2037 is coupled to the photoelectric converter 2036 , and the optical signal switching module 2038 is coupled to the optical coupling device 2035 and the control system 2037 .

The optical coupling device 2035 receives the optical signal transmitted from the optical network unit 2031 and divides the optical signal transmitted by the optical network unit 2031 into a detection optical signal and a data optical signal. The photoelectric converter 2036 is used to convert the detected optical signal into a detected electrical signal, and the control system 2037 generates a control signal according to the detected electrical signal. The optical signal switching module 2038 determines whether to block the data optical signal from passing through the signal collision prevention device 2030 according to the control signal.

As shown in FIG. 2B , the optical signal switching module 2038 includes an optical switch (Optical Switch, OS) 203A and a light blocking component 203B. The optical switch 203A has an input terminal 0, a first output terminal 1 and a second output terminal 2, the input terminal 0 is coupled to the optical coupling device 2035, the second output terminal 2 is coupled to the light blocking component 2038, and the first output terminal 1 is coupled to connected to the optical fiber 207. The optical switch 203A outputs the data optical signal to the first output end 1 or the second output end 2 according to the control signal, and the light blocking component 203B is used to block the data optical signal. In addition, in this embodiment, the data optical signal is an upload signal of 1310 nanometers, however, the wavelength of the data optical signal is not used to limit the present invention.

Under normal circumstances, the optical network unit 2031 in FIG. 2B operates in burst mode, and the data optical signal should be smoothly output to the optical fiber 207, so the optical switch 203A sends the optical data signal from the input terminal 0 to the first output terminal 1 of. In addition, the above-mentioned optical coupling device 2035 may be an optical coupler (Optical Coupler, OCP) or an optical splitter (Optical Splitter) implemented using a planar waveguide process (PLC) or a waveguide (Waveguide). The photoelectric conversion device 2036 can be realized by a photodiode, and a general photodiode includes a positive-intrinsic-negative junction photodiode (Positive-Intrinsic-Negative Photodiode, PIN Photodiode), an accumulative avalanche photodiode (Avalanche Photodiode, APD) There are three types of metal-semiconductor-metal junction photodiodes (Metal-Semiconductor-Metal Photodiode, MAM Photodiode).

The above implementations of the photoelectric conversion device 2036, the optical coupling device 2035 and the optical signal switching module 2038 are not intended to limit the present invention. There are other implementations of the photoelectric conversion device 2036, the optical coupling device 2035 and the optical signal switching module 2038 to achieve same function. In short, the above-mentioned FIG. 2B is only an embodiment, and is not used to limit the present invention. Anything within the spirit of the present invention shall be within the scope of protection of the present invention.

Please refer to FIG. 2C . FIG. 2C shows a schematic diagram of optical signals when the ONU 2031 operates in the burst mode. When the ONU 2031 operates in the burst mode, the time τ during which the optical signal occupies the channel is the sum of the laser turn-on time C00, turn-on time C02 and data transmission time C01. Generally speaking, as far as the current passive optical network standard is concerned, τ is usually less than several microseconds, and at this time the above-mentioned optical switch 203A will send the data optical signal to the first output port 1 to the optical fiber 207, so that it The optical network 200 can be connected normally.

Please refer to FIGS. 2D and 2E. FIG. 2D shows a schematic diagram of the operation of the optical switch 203A when the ONU 2031 is operating in the continuous mode; FIG. 2E shows the optical signal of the ONU 2031 operating in the continuous mode schematic diagram. When the optical network unit 2031 is operating in the continuous mode, its laser will not be turned off after it is turned on, so the time τ' for its optical signal to occupy the channel is the sum of the turn-on time E00 of its laser and the continuous turn-on time E01 of the laser , at this time τ' will be much longer than several microseconds. The signal collision prevention device 2030 will block the data optical signal from passing through, and the entire optical network 200 will not be paralyzed. Therefore, the optical switch 203A will send the data optical signal to its second output terminal 2, and the light blocking component 203B can transmit the data. The light signal is blocked. The principle of preventing the paralysis of the optical network 200 is that the control system 2037 judges whether the time when the received detection electrical signal is greater than the threshold exceeds the set time. The time when the electrical signal is greater than the threshold will exceed the set time, then the optical signal switching module 2038 will block the output of the data optical signal to the optical fiber 207 according to the control signal, wherein the set time will be greater than τ; when the optical network unit 2031 is in the bursting mode , at this time, the laser will only emit the upload signal within the time of τ, so the time when the detected electrical signal is greater than the threshold will be less than the set time, and the optical signal switching module 2038 will allow the data optical signal to be output to the optical fiber 207 .

The optical switch 203A may be a micro-electromechanical system latch optical switch or a semiconductor optical amplifier switch (Semiconductor Optical Amplifier Switch, SOA Switch). Please refer to FIGS. 3A, 3B and 3C. FIG. 3A shows a structural diagram of an embodiment of an optical switch 203A, FIG. 3B shows a schematic diagram of an optical signal output to the second output terminal 2, and FIG. Schematic diagram of output 1. The optical switch 203A in FIGS. 3A-3B is implemented by a MEMS latch optical switch 300 . The optical switch 300 includes a reflector 301 that can move up and down. The control signal can control the movement of the reflector 301 . Please refer to FIG. 3B, when the control signal controls the reflector 301 to move upward, the reflector 301 will reflect the data optical signal to the second output terminal 2; please refer to FIG. 3C, when the control signal controls the reflector 301 to move downward, The data optical signal will be directly transmitted to the first output terminal 1 .

Although the above-mentioned optical switch 203A is implemented by the latching optical switch 300 of MEMS, it is not intended to limit the present invention. In other words, other implementations that can achieve the function of the optical switch 203A should also fall within the protection scope of the present invention.

Please refer to FIG. 4 . FIG. 4 shows a flow chart of a method for preventing collisions of uploaded signals according to an embodiment of the present invention, and the method is applicable to a time-division multiplexing passive optical network. The method first divides the optical signal transmitted by the ONU into a data optical signal and a detection optical signal (step S400). Afterwards, the detection optical signal is converted into a detection electrical signal (step S401). Next, a control signal is generated according to the detected electrical signal (step S402). Finally, it is determined whether to output the data optical signal according to the control signal (step S403). Wherein, if the time for which the intensity of the detected electrical signal is greater than the threshold exceeds the set time, the data optical signal will be blocked and not output to the optical network, thus realizing a mechanism for preventing collision of uploaded signals. In addition, the above-mentioned setting time and threshold can be adjusted according to different requirements and systems.

Next, please refer to FIGS. 5A, 5B and 5C. FIG. 5A shows an eye diagram of an optical signal when no optical network unit is in a continuous mode in an optical network according to an embodiment of the present invention; FIG. 5B shows an optical signal in this embodiment When any optical network unit is in the continuous mode and the optical network is paralyzed, the eye diagram of the optical signal; FIG. 5C shows the eye diagram of the optical signal using the device and method of the present invention when any optical network unit is in the continuous mode in this embodiment graphic. In the above-mentioned optical network, the total distance from the optical terminal to the optical network unit is about 20 kilometers, and the optical signals uploaded and uploaded there will go through a 1×8 optical splitter. Laser light sources with wavelengths of 1490 nm and 1310 nm are respectively used as laser light sources for downlink and uplink signals. This optical network uses 1.25Gbps direct modulation for optical signal modulation, and uses non-return-to-zero (Non-Return-to-Zero, NRZ) pseudo-random binary sequence (Pseudo Random BinarySequence, PRBS) mode to generate 231-1 One bit to measure the bit error rate (BitError Rate, BER) of the entire optical network.

As shown in FIG. 5A , when no optical network unit is in continuous mode, the Eye Diagram displayed is quite complete and its extinction coefficient (Extinction Ratio, ED) value is greater than 10dB. When a certain optical network unit is in the continuous mode, the uploaded signal received by the optical terminal will be seriously distorted after receiving the signal due to signal collision. As shown in FIG. 5B , at this time, due to signal collision, the eye diagram is very poor, and the extinction coefficient is hardly measurable. The input power of the ONU in FIG. 5B in continuous mode is about -30dBm, and its power is already very small. If it exceeds this power, the eye diagram of the signal will become worse. If the optical network of the above-mentioned device and method for preventing upload signal collisions is used, the optical signals of the optical network units in a continuous state cannot be uploaded to the optical network to avoid the paralysis of the optical network. As shown in FIG. 5C , since the optical signal of the ONU in the continuous state cannot be uploaded to the optical network, the eye diagram of the uploaded signal received by the optical terminal is very perfect.

Next, please refer to FIG. 6 and FIG. 7. FIG. 6 shows a schematic diagram of the switching time of an optical switch according to an embodiment of the present invention, and FIG. Power) graph. As shown in FIG. 6, in FIGS. 5A-5C, the response time of the optical switch in the optical network system is about 7 milliseconds. As shown in Figure 7, the curve of the circular mark represents the error rate curve of back-to-back transmission (back to back); the curve of the diamond mark represents the error rate curve of the upload signal collision, but no upload signal collision prevention; and The curve with square marks indicates that there is an upload signal collision, and the error rate curve using the device or method for preventing upload signal collision of this embodiment. It can be seen from Fig. 7 that no matter whether the protection mechanism is activated or not, for the downlink signal at 1490nm, the power penalty does not increase much when the BER is equal to 10 ^-9 , about Less than 0.2dB. Therefore, the device, network system and method proposed by the present invention will not significantly reduce the performance of the downlink signal.

To sum up, the upload signal collision prevention device, optical network system and method thereof provided by the present invention can avoid the situation that the entire optical network is paralyzed due to upload signal collision. In addition, the above-mentioned device has the advantages of simple structure, low cost, low hardware complexity and easy integration into the optical network unit.

Although the present invention has been disclosed above with the embodiments, it is not intended to limit the present invention. Those skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection should be based on the claims of the present invention.

Claims (20)

1. A device for preventing collisions of uploaded signals, suitable for time-division multiplexing passive optical networks, comprising: An optical coupling device for receiving a first optical signal and dividing the first optical signal into a second optical signal and a third optical signal; a photoelectric converter, coupled to the photocoupling device, for converting the second optical signal into a first electrical signal; a control system, coupled to the photoelectric converter, for generating a control signal according to the first electrical signal; and An optical signal switching module, coupled to the optical coupling device and the control system, determines whether to block the third optical signal from passing through the device for preventing collision of uploaded signals according to the control signal. 2. The device for preventing upload signal collisions as claimed in claim 1, wherein if the first electrical signal is greater than a threshold for more than a set time, the optical signal switching module blocks the third optical signal from passing through the preventive upload A device for signal collision; if the time for which the first electrical signal is greater than the threshold does not exceed the set time, the optical signal switching module allows the third optical signal to pass through the device for preventing upload signal collision. 3. The device for preventing collision of uploaded signals as claimed in claim 1, further comprising an optical network unit coupled to the optical coupling device for providing the first optical signal. 4. The device for preventing collision of uploaded signals as claimed in claim 1, wherein the photoelectric conversion device comprises a photodiode. 5. The device for preventing upload signal collisions as claimed in claim 4, wherein the photodiode comprises a positive-pure-negative junction photodiode, a cumulative avalanche photodiode or a metal-semiconductor-metal junction photodiode . 6. The device for preventing upload signal collisions according to claim 1, wherein the optical signal switching module comprises: An optical switch having a first output terminal and a second output terminal, outputting the third optical signal at the first output terminal or the second output terminal according to the control signal; and A light-blocking component, coupled to the second output end, is used to block the third light signal from passing through the device for preventing collision of uploaded signals. 7. The device for preventing collision of uploaded signals as claimed in claim 6, wherein the optical switch is a MEMS latch optical switch or a semiconductor optical amplifier switch. 8. A method for preventing upload signal collisions, suitable for time-division multiplexing passive optical networks, comprising: dividing a first optical signal into a second optical signal and a third optical signal; converting the second optical signal into a first electrical signal; generating a control signal according to the first electrical signal; and Whether to output the third optical signal is determined according to the control signal. 9. The method for preventing upload signal collisions as claimed in claim 8, wherein if the time for which the first electrical signal is greater than a threshold exceeds a set time, it is decided not to output the third optical signal; if the first electrical signal If the time that the signal is greater than the threshold does not exceed the set time, it is determined to output the third optical signal. 10. The method for preventing collision of uploaded signals as claimed in claim 8, wherein dividing a first optical signal into a second optical signal and a third optical signal is to divide the first signal into a second optical signal through an optical coupling device The second optical signal and the third optical signal. 11. The method for preventing collision of uploaded signals as claimed in claim 8, wherein converting the second optical signal into a first electrical signal is converting the second optical signal into the first electrical signal through a photodiode. 12. The method for preventing upload signal collisions as claimed in claim 8, wherein generating a control signal according to the first electrical signal is a control system generating the control signal according to the first signal. 13. The method for preventing collision of uploaded signals as claimed in claim 8, wherein determining whether to output the third optical signal according to the control signal is to use an optical signal switching module to determine whether to output the third optical signal according to the control signal. 14. A time-division multiplexing passive optical network system for preventing upload signal collisions, comprising: an optical path terminal; A first optical coupling device, used for light splitting and coupling; A plurality of user terminal devices, wherein each user terminal device includes: an optical network unit; and an upload signal collision prevention device, coupled to the optical network unit, for receiving a first optical signal from the optical network unit, and dividing the first optical signal into a second optical signal and a third optical signal, and determining whether to output the third optical signal according to the second optical signal; and A plurality of optical fibers are used to connect the optical path terminal and the first optical coupling device, and to connect the first optical coupling device to the user terminal equipment. 15. The time division multiplexing passive optical network system for preventing upload signal collision as claimed in claim 14, wherein the device for preventing upload signal collision comprises: a second optical coupling device, coupled to the optical network unit, for receiving the first optical signal and dividing the first optical signal into the second optical signal and the third optical signal; a photoelectric converter, coupled to the second photocoupling device, for converting the second optical signal into a first electrical signal; a control system, coupled to the photoelectric converter, for generating a control signal according to the first electrical signal; and An optical signal switching module, coupled to the second optical coupling device and the control system, determines whether to output the third optical signal according to the control signal. 16. The time-division multiplexing passive optical network system for preventing upload signal collisions as claimed in claim 15, wherein if the first electrical signal is greater than a threshold for more than a set time, the optical signal switching module blocks the preventive upload The signal collision device outputs the third optical signal; if the first electrical signal is greater than the threshold for less than the set time, the optical signal switching module allows the third signal to pass through the upload signal collision prevention device. 17. The time-division multiplexing passive optical network system for preventing upload signal collisions as claimed in claim 15, wherein the photoelectric conversion device comprises a photodiode. 18. The time-division multiplexing passive optical network system for preventing upload signal collisions as claimed in claim 17, wherein the photodiode comprises an anode-pure-cathode junction photodiode, an accumulative avalanche photodiode or a metal-semiconductor - Metal junction photodiodes. 19. The time-division multiplexing passive optical network system for preventing upload signal collisions as claimed in claim 15, wherein the optical signal switching module comprises: An optical switch having a first output terminal and a second output terminal, outputting the third optical signal at the first output terminal or the second output terminal according to the control signal; and A light blocking component, coupled to the second output end, is used to block the third light signal from passing through the device. 20. The time-division multiplexing passive optical network system for preventing collision of uploaded signals as claimed in claim 19, wherein the optical switch is a MEMS latching optical switch.

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