JP2006295495A - Optical network system and information distribution board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve working executability, and to reduce working execution cost, by decreasing the number of wiring media and by suppressing complexity in a wiring pattern. <P>SOLUTION: One optical fiber on optical networks 14-1 to 14-3 is used for assigning a plurality of light signals related to different service to different wavelengths for each service, and wavelength division multiplexing is performed for transmitting to optical multiplex distributors 21-1 to 21-3 of respective rooms R1-R3, from an information distribution board 11. The information distribution board 11 has a B-ONU 114 for converting a broadcast signal from an electric signal into a light signal. Additionally, the information distribution board 11 converts the light signal of IP service, arriving from an access network 13 into an electrical signal by the B-ONU 114 for dividing into the electrical signal to personal computers PC1, PC2 and an IP telephone IPT by a router 115, and the time division multiplexing of each electrical signal is performed by an OHT 116 for converting into a light signal having wavelength of λ1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical network system that assigns wavelengths to services and users, and performs wavelength division multiplex transmission via a single optical fiber, mainly in user homes such as small-scale houses or detached houses.

  The optical network system of the present invention is applied to, for example, a case where WDM transmission is performed by assigning different wavelengths to optical signals of a broadcast service and an IP (Internet Protocol) service (Internet connection service) transmitted to each room.

  In recent years, IP services (Internet connection services) using optical fibers can be used in small-scale houses and detached houses. Also, different broadcast services such as VHF broadcast, UHF broadcast, BS broadcast, CS broadcast, CS110 degree broadcast, CATV broadcast, etc. can be used.

  In this case, the optical signal of the IP service from the access network is converted into an electrical signal using an ONU (Optical Termination Device) in a room in the user's home. Wiring is performed from the ONU to a terminal such as a personal computer using a UTP cable (untwisted pair cable). When there is a terminal in each room, an IP address is assigned using a router or the like and wired using a UTP cable or the like.

  On the other hand, an information distribution board is used that concentrates a plurality of signal transmission paths in which a plurality of broadcasting services are mixed in one place. This information distribution board is placed behind the ceiling or wall of the house, and from there, VHF / UHF combined coaxial cable, BS / CS combined coaxial cable, CATV coaxial cable are laid in each room. A broadcasting outlet corresponding to a connection device such as a tuner required in each room is attached to the terminal.

The information distribution board includes an amplifier and a distributor, amplifies the input signal to a level at which a sufficient distribution signal can be obtained by the amplifier, distributes the amplified signal by the distributor, and outputs the amplified signal to each coaxial cable. Here, there is a wiring system (for example, Patent Document 1) as an example of the prior art. This system uses a head end including a broadcast signal channel selection unit and a switching unit to reduce the number of coaxial cables.
Patent No. 3042336.

  By the way, when the IP service is wired using the UTP cable, the transmission band is determined by the type of the UTP cable. For this reason, when the transmission rate is changed, the burden increases from the viewpoint of flexibility and expandability. In addition, since the UTP cable has low workability including workability of connector termination and bending resistance, the cost of application increases.

  On the other hand, when a plurality of different broadcast signals are wired using a coaxial cable, the number of coaxial cables is required according to the number of broadcast services. Therefore, when a coaxial cable is laid, a burden increases from the viewpoint of cost and workability.

  Also, it is possible to transmit a broadcast service having different transmission bands as in the case of VHF broadcasting and BS broadcasting using a single coaxial cable, but in this case, transmission loss differs depending on each transmission band. The amplifiers and distributors must be arranged according to the transmission distance and the number of branches.

  Furthermore, in Patent Document 1, a device such as a terminal controller is required to share the cable with other services. In addition, since an electric signal is used, there are problems such as generation of noise to the periphery and the influence of ambient noise.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an optical network system and an information distribution board that can improve the workability and reduce the cost of processing by reducing the number of wiring media and suppressing the complexity of the wiring form. There is to do.

In order to achieve the above object, the present invention is configured as follows.
(1) An optical network that is placed indoors and that wavelength-division-multiplexes a plurality of optical signals corresponding to a plurality of different broadcasting / communication services, and is connected to one end of the optical network. In addition, a plurality of transmission paths corresponding to a plurality of broadcasting / communication services are connected, and a plurality of optical signals arriving from the plurality of transmission paths are assigned to different wavelengths for each broadcasting / communication service and wavelength division multiplexed to perform optical networking. And an information distribution board that outputs an optical signal coming from the optical network to the corresponding transmission line, and a plurality of wavelength components that are connected to the other end of the optical network and are wavelength division multiplexed from the optical network And a terminal device that extracts an optical signal having a wavelength component corresponding to the connected device.

  According to the invention of (1), since a plurality of optical signals related to different services are wavelength-division multiplexed and transmitted from the information distribution board to the terminal device using one optical fiber on the optical network, the service is provided. Therefore, it is not necessary to separately install each transmission line, and the transmission line connecting between the information distribution board and the terminal device can be reduced correspondingly to simplify the system wiring structure. Thereby, the complexity of the wiring form by the difference in the kind and speed of a service can be suppressed, Furthermore, improvement of workability and reduction of construction cost can be implement | achieved. In addition, since there are an infinite number of wavelengths that can be transmitted through the optical fiber, it can be used without limiting the number of wavelengths.

(2) A plurality of terminal devices are provided, and an optical splitter for distributing and connecting the optical network to each of the plurality of terminal devices is further provided.
According to the invention of (2), a plurality of optical signals related to different services are wavelength-division multiplexed using one optical fiber on the optical network and transmitted from the information distribution board to a plurality of terminal devices. One optical fiber can be shared by a plurality of terminal devices, thereby further improving the workability and reducing the construction cost.

(3) The optical signal transmitted through the optical fiber of the optical network is a wavelength belonging to at least one of a wavelength band of a CWDM (Coarse Wavelength Division multiplex) system and a wavelength band used by a known light source. It is characterized by having.
According to the invention of (3), as a light source for converting an electric signal into an optical signal, a distributed feedback laser (DFB-LD) or a Fabry-Perot laser (FP-LD) used in a CWDM transmission system, and a 650 nm band An economical system with significantly reduced costs by using a DVD pickup light source for DVDs, a CD pickup light source for 780 nm band, a LAN light source for 850 nm band, especially a surface emitting laser (VCSEL). Can do.

(4) Each of the plurality of terminal devices corresponds to a plurality of broadcast / communication services in advance, and an arbitrary wavelength component out of a plurality of wavelength components that have arrived from the optical network and are wavelength-division-multiplexed according to connected devices It has the function to extract the optical signal of.
According to the invention of (4), each of the plurality of terminal devices is made to correspond to a plurality of broadcasting / communication services in advance, and can be selected and set according to the connected device. An arbitrary wavelength can be extracted from a signal transmitted through an optical fiber according to the type, speed, and terminal.

(5) When the signal transmitted through the transmission path and corresponding to the broadcast service is an electrical signal, the information distribution board converts the electrical signal corresponding to the broadcast service into an optical signal, and the optical signal corresponding to the communication service And a function of wavelength division multiplexing and outputting to an optical network.
According to the invention of (5), since the information distribution board has a function of converting an electric signal into an optical signal, it is not necessary to prepare a separate electric / optical converter, and the information is received by an existing antenna. Broadcast signals can be handled.

(6) The information distribution board converts a plurality of optical signals corresponding to the communication service into a plurality of electrical signals, analyzes the transmission destination or signal format of each of the plurality of electrical signals, and based on the analysis result A plurality of electrical signals are time-division multiplexed at different time positions for each destination or signal format, converted into optical signals, and sent to a transmission line corresponding to an optical network or communication service.
According to the invention of (6), the information distribution board recognizes the signal format of the communication signal to the connected device connected to each terminal device, the transmission destination of the communication signal from the connected device, and the signal format. It becomes possible to make it. In addition, a communication signal addressed to the connected device to each terminal device is transmitted on the optical network at different time positions on the same wavelength.

  As described above in detail, according to the present invention, for example, an optical network system and an information distribution circuit capable of WDM transmission via a single optical fiber by assigning different wavelengths to optical signals transmitted to each room, for example. A board can be provided.

  In addition, an optical network system and an information distribution unit that can assign different wavelengths to optical signals of IP service and broadcasting service, perform WDM transmission via a single optical fiber, and optically wire each room using an optical splitter. A board can be provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a configuration of an optical network system applied to a house HM as an embodiment of the present invention, and 11 is an information distribution board. Here, in order to simplify the description, the information distribution board 11 has one input terminal and four input / output terminals.

  In this embodiment, a booster 12 is connected to an input terminal of the information distribution board 11, an access network 13 made of an optical fiber is connected to a first input / output terminal, and an optical network 14 is connected to a second input / output terminal. The optical network 14-1 distributed in the above is connected, the optical network 14-2 is connected to the third input / output terminal, and the optical network 14-3 is connected to the fourth input / output terminal.

  The booster 12 connects the BS / CS 110 degree broadcast antenna 15 and a U / V mixer 18 that mixes the broadcast signal received by the VHF antenna 16 and the broadcast signal received by the UHF antenna 17. . Broadcast signals received by the BS / CS 110-degree broadcasting antenna 15, the VHF antenna 16, and the UHF antenna 17 are supplied to the information distribution board 11 via the booster 12.

  The access network 13 is pulled out from the information distribution board 11 through an outdoor cabinet 19 arranged outside the house HM, and transmits an optical signal corresponding to the IP service.

  The optical networks 14-1 to 14-3 are laid from the information distribution board 11 to the rooms R 1 to R 3, respectively. Distributors 21-1 to 21-3 are connected. In each of the rooms R1 to R3, optical outlets 22-1 to 22-3 are connected to the optical multiplexers / distributors 21-1 to 21-3.

  The optical multiplexer / distributor 21-1 includes, for example, optical filters for extracting different wavelengths λ1 and λ3, and outputs optical signals having wavelengths λ1 and λ3 from optical signals arriving from the optical network 14-1. The optical signal is extracted and output to the optical outlet 22-1, and the optical signal having the wavelength λ2 transmitted from the optical outlet 22-1 is transmitted to the optical network 14-1. The optical multiplexer / distributors 21-2 and 21-3 are the same as the optical multiplexer / distributor 21-1.

  The optical outlet 22-1 includes an IP connection connector 22a and a television connection connector 22b. For example, in the room R1, the personal computer PC1 is connected to the IP connection connector 22a, and the optical signal having the wavelength λ1 sent from the optical multiplexer / distributor 21-1 is output to the personal computer PC1. The optical signal of wavelength λ2 sent from the PC 1 is output to the optical multiplexer / distributor 21-1. Further, the television receiver TV1 is connected to the television connector 22b, and the optical signal having the wavelength λ3 sent from the optical multiplexer / distributor 21-1 is converted into an electric signal to the television receiver TV1. Output.

  The optical outlets 22-2 and 22-3 are the same as the optical outlet 22-1. The personal computers PC1 and PC2 and the IP telephone IPT provided in each of the rooms R1 to R3 receive the optical signal of the IP service at different assigned time intervals and convert it into an electrical signal. ) Is provided.

  By the way, in the information distribution board 11, the broadcast signal output from the booster 12 is converted from an electrical signal to an optical signal having a wavelength λ 3 by a V-MC (Video-Media Converter) 112 and is transmitted to the optical distributor / multiplexer 113. Supplied.

  On the other hand, the optical signal of the IP service transmitted from the outside by the access network 13 is converted from an optical signal to an electric signal by a B-0NU (Broadband-Optical Network Unit) 114, and each personal computer PC1, PC2 is converted by the router 115. To the electric signal to the IP phone IPT. Thereafter, each electrical signal to the personal computers PC1, PC2 and IP telephone IPT is time-division multiplexed by an OHT (Optical Home Terminal) 116 and converted into an optical signal of wavelength λ1, and then supplied to the optical distributor / multiplexer 113. The

  The router 115 stores routing information indicating IP addresses and signal formats respectively assigned to the personal computers PC1 and PC2 and the IP telephone set IPT. That is, the router 115 can determine whether or not the electrical signal from the B-0NU 114 is an electrical signal to the personal computers PC1 and PC2 and the IP telephone set IPT by referring to the routing information.

  The optical distributor / multiplexer 113 wavelength-division-multiplexes the IP downstream optical signal and the optical signal corresponding to the broadcast service, and transmits the result to each of the rooms R1 to R3 through one optical fiber of the optical network 14.

  Further, in the information distribution board 11, the IP upstream optical signal (wavelength λ 2) sent by the optical network 14 is distributed for each wavelength by the optical distributor / multiplexer 113, sent to the OHT 116, and converted into an electrical signal. After being converted and routed to the upper network by the router 115, that is, converted to the IP address of the router 115 itself, the B-ONU 114 converts the electrical signal into an optical signal and sends it to the access network 13.

  In this case, since the upper and lower wavelengths assigned to the IP service belong to the wavelength band of a CWDM (Coarse Wavelength Division Multiplex) transmission system, it is possible to use a CWDM LD as a light source and a CWDM filter as a multiplexer / demultiplexer.

Next, the operation of the system configured as described above will be described.
First, the information distribution board 11 is arranged at an appropriate location in the house HM, and from there, optical networks 14-1 to 14-3 are laid in the rooms R1 to R3, and each of the rooms R1 to R3 is connected to the terminal. Optical multiplexers / distributors 21-1 to 21-3 and optical outlets 22-1 to 22-3 corresponding to necessary connection devices are connected.

  For example, in the room R3, the IP telephone IPT and the television receiver TV3 are connected to the optical outlet 22-3. In this optical outlet 22-3, the optical signal having the wavelength λ3 that has arrived from the information distribution board 11 through the optical network 14-3 and the optical multiplexer / distributor 21-3 is converted into an electrical signal to be converted into the television receiver TV3. Output to.

  Further, when a communication link is established between the IP telephone set IPT and an external telephone set on the access network 13, the optical outlet 22-3 transmits from the information distribution board 11 to the optical network 14-3 and the optical multiplexing / The optical signal having the wavelength λ1 that has arrived via the distributor 21-3 is output to the IP telephone IPT, and the optical signal having the wavelength λ2 from the IP telephone IPT is transmitted via the optical multiplexer / distributor 21-3 and the optical network 14-3. To the information distribution board 11. In the information distribution board 11, the optical signal of wavelength λ 2 is once converted into an electrical signal by the OHT 116, the IP address of the IP telephone IPT added to the electrical signal by the router 115 is converted into the IP address of the router 115, and B− It is converted into an optical signal by the ONU 114 and sent to the access network 13.

  Here, conventionally, as shown in FIG. 2, it is necessary to lay separate communication infrastructures in the broadcasting system, the data communication system, and the voice communication system between the information distribution board 31 and the rooms R1 to R3. there were. For this reason, the information distribution board 31 must be provided with the distributor 311 and the multi-connection device 312, and the system configuration is large. Moreover, the number of connectors of the outlets 41-1 to 41-3 provided in the rooms R1 to R3 will also increase. In FIG. 2, the same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  Therefore, according to the present embodiment, signals having different signal formats can be shared by the same optical networks 14-1 to 14-3.

  When receiving a new service, conventionally, it has been necessary to lay a cable corresponding to the new service between the information distribution board 11 and each of the rooms R1 to R3. Optical multiplexing / distribution devices 21-1 to 21-3 and optical outlets 22-1 to 22-3 provided at terminals of the networks 14-1 to 14-3 are replaced with new optical multiplexing / distribution devices and optical outlets for service. The optical networks 14-1 to 14-3 can be used as they are.

  Further, if there is an empty line in the optical splitter 111, the addition of the optical network 14 can be easily handled.

  As described above, in the above-described embodiment, a plurality of optical signals related to different services are wavelength-division multiplexed using one optical fiber on the optical networks 14-1 to 14-3, and the information distribution board 11 The data is transmitted to the optical multiplex distributors 21-1 to 21-3 in the rooms R1 to R3.

  Accordingly, there is no need to separately lay transmission cables for each service, and transmission cables for connecting the information distribution board 11 and the optical multiplex distributors 21-1 to 21-3 in the rooms R1 to R3 accordingly. It can be reduced and the wiring structure of the system can be simplified. Thereby, the complexity of the wiring form by the difference in the kind and speed of a service can be suppressed, Furthermore, improvement of workability and reduction of construction cost can be implement | achieved. In addition, since there are an infinite number of wavelengths that can be transmitted through the optical fiber, it can be used without limiting the number of wavelengths. Furthermore, since the optical splitter 111 is used, the cost of the system can be reduced by sharing the light emitting element incorporated in the OHT 116 and the optical fiber up to the optical splitter 111.

  In the above embodiment, the OHT 116 of the information distribution board 11 uses a distributed feedback laser (DFB-LD) or a Fabry-Perot laser (FP) used in a CWDM transmission system as a light source for converting an electrical signal into an optical signal. -LD) can be used, so that an economical system can be constructed with greatly reduced costs.

  Further, in the above embodiment, the information distribution board 11 is provided with the B-ONU 114 that converts a broadcast signal from an electric signal to an optical signal. Therefore, the BS / CS 110-degree broadcasting antenna already installed in the house HM. 15, the broadcast signal received by the VHF antenna 16 and the UHF antenna 17 can be directly handled by the information distribution board 11.

  Furthermore, in the above-described embodiment, the information distribution board 11 temporarily converts the IP service optical signal arriving from the access network 13 into an electrical signal by the B-ONU 114 and the router 115 for the personal computers PC1, PC2 and IP telephone IPT. The electric signals are divided into electric signals, and each electric signal is time-division multiplexed by the OHT 116 to be converted into an optical signal having a wavelength λ1.

  Accordingly, optical signals to the personal computers PC1, PC2 and IP telephone IPT are transmitted on the optical networks 14-1 to 14-3 at different time positions on the same wavelength λ1, so that each personal computer Even when optical signals of a plurality of IP services addressed to the computers PC1 and PC2 and the IP telephone set IPT arrive at the information distribution board 11 in the same time zone, the optical signals of these IP services can be transmitted in parallel. Note that the same can be applied to an optical signal having an upstream wavelength λ2 from the optical networks 14-1 to 14-3.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the example in which the optical networks 14-1 to 14-3 are laid from the information distribution board 11 to the rooms R1 to R3 has been described. However, a plurality of optical multiplexing / distributors and optical outlets are provided in each room. If an optical network is provided, an optical network may be laid for each optical multiplexer / distributor. Further, in the case of a house having only one room, one optical network 14 may be laid. Furthermore, it goes without saying that the present invention can be applied not only to a house but also to a company or a business office.

  In the above embodiment, an example in which a broadcast signal received by the BS / CS 110 degree broadcasting antenna 15, the VHF antenna 16, and the UHF antenna 17 is converted from an electrical signal to an optical signal by the information distribution board 11 will be described. did. However, the present invention is not limited to this. For example, an optical signal from another broadcast service may be input to the information distribution board 11 from the outside.

  In the above embodiment, the OHT 116 of the information distribution board 11 uses a distributed feedback laser (DFB-LD) or a Fabry-Perot laser (FP) used in a CWDM transmission system as a light source for converting an electrical signal into an optical signal. However, the present invention is not limited to this. For example, a DVD pickup light source for 650 nm band, a CD pickup light source for 780 nm band, a LAN light source for 850 nm band, particularly a surface emitting laser (VCSEL) Such an existing light source may be used.

  Moreover, although the said embodiment demonstrated the example provided with OHU in each of personal computer PC1, PC2, and IP telephone set IPT, you may equip the optical outlets 22-1 to 22-3 with OHU. In this way, even a personal computer or IP telephone that does not include an OHU can be easily connected to the optical outlets 22-1 to 22-3.

  Further, in the above embodiment, the optical multiplexer / distributors 21-1 to 21-3 and the optical outlets 22-1 to 22-3 are connected in correspondence with services other than the IP service and the broadcast service. It is versatile and convenient to be able to select and set according to the device.

  In addition, the system configuration, the configuration of the information distribution board, the types of optical signals to be handled, and the like can be variously modified and implemented without departing from the gist of the present invention.

The block diagram which shows the structure of the optical network system applied in a house as one Embodiment of this invention. The block diagram which shows the example at the time of using the conventional information wiring system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11,31 ... Information distribution board, 12 ... Booster, 13 ... Access network, 14, 14-1 to 14-3 ... Optical network, 15 ... BS / CS110 degree broadcasting antenna, 16 ... VHF antenna, 17 ... UHF 18 ... U / V mixer, 19 ... outdoor cabinet, 211-1 to 21-3 ... optical multiplexer / distributor, 22-1 to 22-3 ... optical outlet, 22a ... IP connection connector, 22b ... Connector for television connection, 111 ... optical splitter, 112 ... V-MC, 113 ... optical distributor / multiplexer, 114 ... B-ONU, 115 ... router, 116 ... OHT, 311 ... distributor, 312 ... multi-connector, 41-1 to 41-3 ... Outlet, HM ... Residential, PC1, PC2 ... Personal computer, IPT ... IP phone, TV1-TV3 ... TV Receiver.

Claims (10)

An optical network that is arranged indoors and that wavelength-division-multiplexes a plurality of optical signals corresponding to a plurality of different broadcasting / communication services, respectively, and transmits the signals through one optical fiber;
Connected to one end of the optical network and connected to a plurality of transmission paths corresponding to the plurality of broadcasting / communication services, and a plurality of optical signals arriving from the plurality of transmission paths are different in wavelength for each broadcasting / communication service. And an information distribution board that outputs the optical signal arriving from the optical network to a corresponding transmission line, and wavelength division multiplexing and assigning to the optical network,
A terminal device connected to the other end of the optical network and extracting an optical signal having a wavelength component corresponding to the connected device from a plurality of wavelength components that have arrived from the optical network and are wavelength division multiplexed. An optical network system characterized by A plurality of the terminal devices are provided,
The optical network system according to claim 1, further comprising an optical splitter for distributing and connecting the optical network to the plurality of terminal devices. The optical signal transmitted through the optical fiber of the optical network has a wavelength belonging to at least one of a wavelength band of a CWDM (Coarse Wavelength Division Multiplex) system and a wavelength band used by a known light source. The optical network system according to claim 1 or 2, The plurality of terminal devices respectively correspond to a plurality of broadcasting / communication services in advance, and depending on connected devices, the plurality of terminal devices can receive arbitrary wavelength components from a plurality of wavelength components that have arrived from the optical network and are wavelength division multiplexed. 3. The optical network system according to claim 2, having a function of extracting an optical signal. When the signal transmitted through the transmission path and corresponding to the broadcast service is an electrical signal,
The information distribution board has a function of converting an electrical signal corresponding to the broadcasting service into an optical signal, wavelength division multiplexing with the optical signal corresponding to the communication service, and outputting the optical signal to the optical network. The optical network system according to claim 1. The information distribution board converts a plurality of optical signals corresponding to a communication service into a plurality of electrical signals, analyzes a transmission destination or a signal format of each of the plurality of electrical signals, and based on the analysis result, a plurality of 2. An electric signal having a function of time-division multiplexing at different time positions for each destination or signal format, converting the electric signal into an optical signal, and transmitting the optical signal to a transmission line corresponding to the optical network or the communication service. Or the optical network system of 2. The terminal device has a function of converting an optical signal from the optical network into an electrical signal and sending it to a connected device, and converting an electrical signal from the connected device into an optical signal and sending it to the optical network. The optical network system according to claim 1. A first terminal for connecting an optical network for wavelength-division-multiplexing a plurality of optical signals corresponding to a plurality of different broadcasting / communication services, respectively, and transmitting the optical signal through one optical fiber;
A second terminal for connecting a plurality of transmission paths corresponding to the plurality of broadcasting / communication services;
A plurality of optical signals arriving from the plurality of transmission paths are assigned to different wavelengths for each broadcasting / communication service, wavelength division multiplexed and output to the optical network, and an optical signal arriving from the optical network is associated with the transmission path. An information distribution board comprising a signal processing means for outputting to the information distribution board. When the signal corresponding to the broadcast service transmitted through the transmission path is an electrical signal,
The signal processing means has a function of converting an electrical signal corresponding to the broadcast service into an optical signal, wavelength division multiplexing with the optical signal corresponding to the communication service, and outputting the result to the optical network. The information distribution board according to Item 8. The signal processing means converts a plurality of optical signals corresponding to a communication service into a plurality of electrical signals, analyzes a transmission destination and a signal format of each of the plurality of electrical signals, and a plurality of electrical signals based on the analysis result. 9. The function of transmitting a signal to a transmission line corresponding to the optical network or the communication service by time-division multiplexing at different time positions for each destination and signal format, converting the signal into an optical signal. Information distribution board.

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