JP6412358B2 - Communications system - Google Patents

Description

The present invention relates to a communication system for an apartment house that operates a plurality of communication services .

  In recent CATV systems, telephone services, high-speed Internet services, and the like have been provided, and FTTH (Fiber to the Home) has been adopted because of merits such as improvement of communication speed and suppression of inflow noise. FTTH is a method of constructing an optical fiber network from the center to each subscriber's house.

  In the case of apartment houses such as condominiums, FTTB (Fiber to the Building) is often used, and optical fiber is laid from the entrance to the apartment house, but the communication network in the apartment house from the entrance to each house is a coaxial cable. Since it is constructed, there is a problem that inflow noise occurs on the premises and it is difficult to increase the speed of uplink communication.

  In order to solve such a problem, the communication system of Patent Document 1 has been proposed. In Patent Document 1, a CMTS (Cable Modem Termination System) is arranged in the premises of an apartment house, and a cable from the CM (Cable Modem) of each apartment house to the CMTS in the apartment house is connected by a coaxial cable. Is demodulated into a data signal in the CMTS. The data signal from the CMTS is converted into an optical signal and transmitted to the center via an optical fiber. As described above, since the data signal is once demodulated in the apartment house, the inflow noise can be eliminated, and the communication quality deterioration due to the inflow noise can be suppressed.

JP 2001-53764 A

  However, the communication system of Patent Document 1 has the following problems when trying to operate both the data communication service such as the Internet and the primary telephone service.

  First, since high reliability is required for telephone services, CMTS used for telephones must have a redundant configuration. Therefore, if such a CMTS for telephones is provided for each apartment house, the cost increases. In addition, since it is necessary to maintain the telephone CMTS for each apartment house, the operation and management costs also increase.

  Therefore, a communication system that can operate both a high-speed Internet service and a telephone service at a lower cost than that of Patent Document 1 has been demanded.

  Accordingly, an object of the present invention is to realize a low-cost communication system for an apartment house that operates a plurality of communication services.

The present invention includes a first terminal control device and a second terminal control device arranged on the center side, and arranged in an apartment house and connected to the first terminal control device and the second terminal control device via an optical transmission line network. The communication terminal device is connected to the communication terminal device via the electrical transmission line network installed in each house of the apartment house and built in the apartment house, and communicates the primary telephone service with the first terminal control device. A first terminal device to perform communication and a second terminal device to perform data communication service communication with the second terminal control device. The communication terminal device includes a first optical terminal and a second optical terminal. And a third terminal control device, wherein the first optical terminal is connected to the first terminal control device and the first terminal device, converts the optical signal from the first terminal control device into an electrical signal, and Output to one terminal device, and the electrical signal from the first terminal device is an optical signal The second optical terminal is connected to the second terminal control device and the third terminal control device, and converts the optical signal from the second terminal control device into an electrical signal. Output to the third terminal control device, convert the electrical signal from the third terminal control device into an optical signal and output to the second terminal control device, the third terminal control device, the second optical terminal and the second terminal The data signal is demodulated from the electrical signal from the second terminal device and output to the second optical terminal, and the modulation method of the upstream electrical signal of the data communication service is multi-level modulation of 64QAM or more This is a communication system characterized in that the modulation method of the upstream electrical signal of the primary telephone service is a binary or quaternary modulation method .

  A filter for limiting the band of the electric signal may be provided on the electric signal input side of the first optical terminal. The influence of inflow noise generated in the apartment house is reduced, and higher quality communication can be performed.

  The first optical terminal may output optical signals having different wavelengths for each apartment house. OBI (optical beat interference) is prevented from occurring, and higher quality communication can be realized.

  The connection between the first terminal control device and the first optical terminal and the connection between the second terminal control device and the communication terminal device may be performed through the same optical transmission line network, or separate optical transmissions. It may be performed via a route network (first and second optical transmission route networks). When the same optical transmission line network is used, the first wavelength multiplexing device for wavelength multiplexing the optical signal input / output to / from the first terminal control device and the optical signal input / output to / from the second terminal control device is the center. The communication terminal apparatus may be provided with a second wavelength multiplexing apparatus that wavelength-multiplexes the optical signal input / output to / from the first optical terminal and the optical signal input / output to / from the second optical terminal. .

  The third terminal control device may convert the electrical signal from the second optical terminal again into another electrical signal and output it to the second terminal device.

  The communication between the first terminal control device and the first terminal device and the communication between the second terminal control device and the second terminal device may be any communication service. For example, high-speed data communication services such as a primary telephone service and an Internet connection service. Communication between the first terminal control device and the first terminal device and between the third terminal control device and the second terminal device is a DOCSIS method, and between the second terminal control device and the second optical terminal. The communication can be a GE-PON system. In particular, a communication service in which the uplink electrical signal modulation scheme from the second terminal apparatus to the third terminal control apparatus is faster than the uplink electrical signal modulation scheme from the first terminal apparatus to the first optical terminal. It is suitable for operation.

  According to another aspect of the present invention, a communication terminal device connected to an optical transmission line network and an electric transmission line network includes a first optical terminal, a second optical terminal, and a terminal control device. The machine converts the first optical signal input through the optical transmission line network into a first electric signal and outputs the first electric signal, and converts the first electric signal input through the electric transmission line network into the first optical signal. The second optical terminal converts the second optical signal input via the optical transmission line network into a second electric signal, outputs the second electric signal, and outputs the second electric signal input from the terminal controller. The terminal control device demodulates the data signal from the third electric signal input via the electric transmission line network, converts it again into the second electric signal, and outputs the second optical signal. It is a communication terminal device characterized by being output to a machine.

  The communication system of the present invention can be constructed at a low cost, and the communication between the second terminal control device and the second terminal device suppresses deterioration of communication quality due to inflow noise, which is a problem in an apartment house. be able to. In addition, for communication between the first terminal control device and the first terminal device, the first terminal control device is not provided for each communication terminal device of each apartment house, but is provided in the center. Operation and management can be performed efficiently, and operation and management costs can be reduced.

1 is a diagram illustrating a configuration of a communication system according to a first embodiment. The figure which showed the structure of the communication system of the modification of Example 1. FIG. The figure which showed the modification of the communication terminal device 31. FIG. The figure which showed the structure of the communication system of the modification of Example 1. FIG. The figure which showed the structure of the communication system of the modification of Example 1. FIG.

  Hereinafter, specific examples of the present invention will be described with reference to the drawings. However, the present invention is not limited to the examples.

  FIG. 1 is a diagram illustrating a communication system according to the first embodiment. As shown in FIG. 1, in the communication system of the first embodiment, the telephone CMTS 10, the optical transmitter 11 and the optical receiver 12 connected to the telephone CMTS 10, and the optical transmitter 11 and the optical receiver 12 are connected. A WDM (wavelength multiplexing apparatus) 13 and an OLT (Optical Line Terminal) 20 are arranged on the center side. A communication terminal device 31 is arranged in the apartment house 30. A CM 32 for telephone and a CM 33 for data communication are arranged in each house of the apartment house 30. The telephone CM 32 is connected to a telephone (not shown) or a FAX, and the data communication CM 33 is connected to a PC (personal computer) (not shown).

  As illustrated in FIG. 1, the communication terminal device 31 includes an R-ONU (Optical Network Unit) 34 connected to the WDM 13 via the first optical fiber network 40 and a D connected to the OLT 20 via the second optical fiber network 41. -ONU 35, a data communication CMTS 36 connected to the D-ONU 35, and a distributor 37 connected to the R-ONU 34 and the data communication CMTS 36. Yes. Such integration makes it easy to introduce the communication system of the first embodiment into an existing communication system, and facilitates maintenance and management of the communication system.

  Note that all the components of the communication terminal device 31 do not necessarily have to be integrated, and each component may be a single device or a combination of several components. For example, only the D-ONU 35 and the data communication CMTS 36 may be configured integrally. In the first embodiment, the communication terminal device 31 is arranged in the apartment house 30, but may be arranged outside the apartment house 30 and in the vicinity thereof. In addition, it is not necessary that all the configurations of the communication terminal device 31 are arranged inside or outside the apartment house 30, only a part of the configuration is arranged inside the apartment house 30, and other configurations are arranged outside the apartment house 30. You may do it.

  The first optical fiber network 40 connects the optical transmitter 11 and the optical receiver 12 of the center to the R-ONU 34 of the communication terminal device 31 of each apartment house 30. The OLT 20 of the center and the D-ONU 35 of the communication terminal device 31 of each apartment house 30 are connected by a second optical fiber network 41. The first optical fiber network 40 and the second optical fiber network 41 have a double star network topology branched into a plurality by an optical coupler 42. Of course, other network topologies such as a star type, a ring type, and a tree type may be used.

  The coaxial cable network 50 connects the R-ONU 34 and the data communication CMTS 36 of the communication terminal device 31 to the telephone CM 32 and the data communication CM 33 of each unit of the apartment 30. A coaxial cable network 50 is configured by branching a coaxial cable for each door by a branching device 51.

  Hereinafter, each configuration and its operation will be described in more detail. First, details of each component on the center side will be described.

  The telephone CMTS 10 is used for telephone service, and communication using the DOCSIS protocol is performed between the telephone CMTS 10 and each telephone CM 32 in the apartment 30. The telephone CMTS 10 includes a working card 10A that is normally used and a spare card 10B that is used as a spare. In the primary telephone service, it is essential to make the CMTS redundant in order to ensure reliability. Two telephone CMTSs 10 may be provided so that one is active and the other is reserved.

  The telephone CMTS 10 outputs a downstream telephone signal and an upstream telephone signal. The downlink telephone signal from the telephone CMTS 10 is input to the optical transmitter 11, and the upstream telephone signal from the optical receiver 12 is input to the telephone CMTS 10. The upstream telephone signal is an electrical signal having a frequency of 10 to 60 MHz, and the downstream telephone signal is an electrical signal having a frequency of 70 to 770 MHz.

  The optical transmitter 11 converts the downlink telephone signal from the telephone CMTS 10 into an optical signal and outputs it. The wavelength of the optical signal is 1550 nm, for example. The optical signal output from the optical transmitter 11 passes through the WDM 13 and then is input to the communication terminal device 31 in the apartment house 30 via the first optical fiber network 40.

  In addition, the optical receiver 12 converts the optical signal output from the communication terminal device 31 in the apartment house 30 through the first optical fiber network 40 into an uplink telephone signal and outputs it. The wavelength of the received optical signal is different from that of the optical signal output from the optical transmitter 11, and is, for example, 1610 nm.

  The WDM 13 is provided so that a downstream optical signal output from the optical transmitter 11 and an upstream optical signal input to the optical receiver 12 can be wavelength-multiplexed and transmitted through a single optical fiber. As shown in FIG. 2, a two-core optical fiber cable may be used without providing the WDM 13, and the downstream optical signal and the upstream optical signal may be transmitted separately by the first optical fiber networks 40A and 40B. In this case, instead of the R-ONU 34, an R-ONU 134 in which optical signals are input / output through different cores is used. The R-ONU 34 performs optical signal input / output with one core using WDM, while the R-ONU 134 performs optical signal input / output with separate hearts without using WDM. There are other internal configurations similar to those of the R-ONU 34. In addition, when using separate core wires for upstream and downstream, the upstream optical signal and downstream optical signal may have the same wavelength.

  The OLT 20 is connected to the communication terminal device 31 in the apartment house 30 via the second optical fiber network 41. Data communication by the GE-PON method is performed between the OLT 20 and the D-ONU 35 of the communication terminal device 31. Other than the GE-PON system, a G-PON system, a 10G-EPON system, an E-PON system, a media converter system (communication system using a media converter), and the like can be used. The OLT 20 transmits an optical signal (for example, wavelength 1490 nm) according to the GE-PON system to the communication terminal apparatus 31 and receives an optical signal (for example, wavelength 1310 nm) from the communication terminal apparatus 31.

  The R-ONU 34 of the communication terminal device 31 is connected to the first optical fiber network 40, and an optical signal from the optical transmitter 11 is input via the first optical fiber network 40. Then, the optical signal is converted into a downlink telephone signal which is an electric signal and output. The R-ONU 34 receives an upstream telephone signal from the coaxial cable network 50 through a distributor 37, converts the upstream telephone signal, which is an electrical signal, into an optical signal and outputs the optical signal. The optical signal is transmitted to the optical receiver 12 at the center via the first optical fiber network 40.

  The R-ONU 34 for each apartment 30 may use the same output optical signal, but may output an optical signal having a wavelength different from the predetermined wavelength for each apartment 30. Such an R-ONU 34 having a different wavelength for each housing complex 30 is also called an in-building node.

  Assuming that the output wavelengths of the R-ONUs 34 for the respective housing complexes 30 are the same, in the center optical receiver 12, the upstream optical signal from one housing complex 30 and the upstream optical signal from another housing complex 30 are simultaneously transmitted. If it reaches, OBI (Optical Beat Interference) occurs and the communication quality deteriorates. Even if the LD (semiconductor laser) of the R-ONU 34 has the same wavelength, there is a slight variation in wavelength due to product error, temperature, etc., and noise is generated during light reception by the optical receiver 12 due to interference due to the wavelength difference. Because. Therefore, if an R-ONU 34 for each housing complex 30 that outputs optical signals having different wavelengths by a predetermined wavelength or more is used, OBI does not occur and deterioration of communication quality can be prevented. In a band of 1600 to 1620 nm, OBI can be sufficiently suppressed if there is a wavelength difference of 0.05 nm or more.

  The D-ONU 35 of the communication terminal device 31 is connected to the second optical fiber network 41, and an optical signal according to the GE-PON system from the OLT 20 is input via the second optical fiber network 41. Then, the optical signal is converted into a downlink data communication signal (baseband signal) which is an electrical signal and output. The D-ONU 35 receives an uplink data communication signal (baseband signal) from the data communication CMTS 36, converts the uplink data communication signal into an optical signal, and outputs the optical signal. Then, the optical signal is transmitted to the center OLT 20 via the second optical fiber network 41.

  The data communication CMTS 36 of the communication terminal device 31 outputs a downlink data communication signal and an uplink data communication signal. The downlink data communication signal is an electric signal having a frequency of 70 to 770 MHz (a signal obtained by modulating a high frequency with a baseband signal), and the uplink data communication signal is an electric signal having a frequency of 10 to 60 MHz (a signal obtained by modulating a high frequency with a baseband signal). ).

  The data communication CMTS 36 receives a downlink data communication signal (baseband signal) from the D-ONU 35. The data communication CMTS 36 converts the downlink data communication signal into a signal conforming to the DOCSIS protocol and outputs the signal. Further, the data communication CMTS 36 receives an uplink data communication signal in accordance with the DOCSIS protocol from the coaxial cable network 50 via the distributor 37, and after demodulating data (baseband signal) from the uplink data communication signal, The baseband signal is output to the D-ONU 35.

  The distributor 37 distributes the electric signal from the coaxial cable network 50 and inputs the electric signal to the R-ONU 34 and the data communication CMTS 36, respectively, and the downlink telephone signal from the R-ONU 34 and the downlink data communication from the data communication CMTS 36. The signal is transmitted through one coaxial cable network 50. As shown in FIG. 3, a filter 38 may be provided between the R-ONU 34 and the distributor 37 to narrow the transmission band. The filter 38 is a BPF, HPF, LPF, or the like, and may have a characteristic that transmits the band of the downstream telephone signal and the upstream telephone signal. By providing the filter 38, the influence of inflow noise generated in the apartment house 30 can be reduced, and the communication quality can be further improved. Further, a duplexer may be provided in place of the distributor 37.

  The telephone CM 32 is connected to a coaxial cable network 50 built in the apartment house 30, and a downstream telephone signal from the R-ONU 34 is input via the coaxial cable network 50. The telephone CM 32 outputs an upstream telephone signal in accordance with the DOCSIS protocol.

  The data communication CM 33 is connected to the coaxial cable network 50, and a downlink data communication signal in accordance with the DOCSIS protocol from the data communication CMTS 36 is input via the coaxial cable network 50. Further, the data communication CM 33 outputs an upstream data communication signal according to the DOCSIS protocol.

  Next, a communication operation in the communication system according to the first embodiment will be described. In the communication system of the first embodiment, a telephone service and a high-speed data communication service are provided to each house in the apartment house 30. First, communication on the telephone service side will be described.

  Communication in the telephone service is performed by the normal RFoG system from the center telephone CMTS 10 to the telephone CM 32 of each house in the apartment 30. The RFoG method is a method for performing communication in the DOCSIS method via an optical fiber. Further, transmission from the center telephone CMTS 10 to the communication terminal device 31 of the housing complex 30 is performed by the first optical fiber network 40, and communication within the housing complex 30 from the communication terminal device 31 to the telephone CM 32 is performed by the coaxial cable network 50. It is as transmission. In the modulation scheme, the downlink telephone signal is 256QAM, and the upstream telephone signal is QPSK. Since the upstream telephone signal is a low-speed modulation method, it is more resistant to ingress noise than a high-speed modulation method. Therefore, even if inflow noise occurs in the apartment house 30, the influence is small and communication quality can be maintained.

  Next, communication on the high-speed data communication service side will be described.

  The communication in the high-speed data communication service is based on the DOCSIS protocol from the center OLT 20 to the D-ONU 35 in the housing complex 30 by the GE-PON system communication, and from the data communication CMTS 36 to the data communication CM 33 of each house in the housing complex 30. Communication. Communication within the housing complex 30, that is, communication between the data communication CMTS 36 and the data communication CM 33 of the communication terminal device 31 is transmitted through the coaxial cable network 50 similar to the telephone service. On the other hand, transmission from the center OLT 20 to the communication terminal device 31 of the housing complex 30 is performed by the second optical fiber network 41 different from the telephone service.

  The modulation scheme for communication of the high-speed data communication service is 256QAM for the downlink data communication signal and 64QAM for the uplink data communication signal. The modulation method of the uplink data communication signal employs a modulation method that is faster than the modulation method of the uplink telephone signal, and is easily affected by inflow noise. Therefore, a CMTS 36 for data communication is provided for each housing complex 30, and the inflow noise is removed by demodulating data (baseband signal) once from the upstream data communication signal, and transmitted to the center by the GE-PON system. .

  As described above, on the high-speed data communication service side, the communication terminal device 31 of each housing complex 30 has the data communication CMTS 36 which is a DOCSIS communication termination device. On the other hand, the telephone service side has a telephone CMTS 10 as a DOCSIS communication termination device at the center. Since the telephone CMTS 10 is not required for each communication terminal apparatus 31, the communication system of the first embodiment can be constructed at low cost. In the communication system of the first embodiment, the telephone CMTS 10 may be maintained and managed only at the center for telephone service, and it is not necessary to maintain and manage each apartment house 30. Therefore, the operation and management cost of the communication system of the first embodiment can be suppressed.

  In the communication of the high-speed data communication service, the downlink communication is performed without passing through the data communication CMTS 36 by providing another route, using the communication route on the telephone service side, or providing another CMTS. Also good.

  As described above, the communication system according to the first embodiment can be constructed at a low cost, and the high-speed data communication service can suppress deterioration in communication quality due to inflow noise, which is a problem in the housing complex 30. The telephone service can be efficiently operated and managed by the center.

  Hereinafter, various modifications of the communication system according to the first embodiment will be described.

  In the communication system according to the first embodiment, the first optical fiber network 40 that is a communication network on the telephone service side and the communication network that is the high-speed data communication service side are used as communication networks from the center to the communication terminal device 31 of the apartment house 30. Although two optical fiber networks 41 are provided separately, the same optical fiber network 140 can be used on the telephone service side and the high-speed data communication service side by the following configuration. As shown in FIG. 4, the WDM 130 is provided in place of the WDM 13 in the communication system of the first embodiment, and the WDM 131 is provided in the communication terminal device 31.

  The WDM 130 is a device that wavelength-multiplexes optical signals input and output by the optical transmitter 11, the optical receiver 12, and the OLT 20. The WDM 130 transmits the optical signal output from the OLT 20 to the optical fiber network 140 via the WDM 130, and separates the upstream optical signal of the high-speed data communication service from the optical signals from the optical fiber network 140 and inputs the optical signal to the OLT 20. I am doing so.

  The WDM 131 is a device that is provided in the communication terminal device 31 and wavelength-multiplexes optical signals input and output by the R-ONU 34 and the D-ONU 35. Of the optical signals transmitted from the center via the optical fiber network 140 by the WDM 131, the downstream optical signal of the telephone service is input to the R-ONU 34, and the downstream optical signal of the high-speed data communication service is input to the D-ONU 35. The The upstream optical signal from the R-ONU 34 and the upstream optical signal from the D-ONU 35 are multiplexed and transmitted by the optical fiber network 140.

  By configuring as described above, the same optical fiber network 140 can be used on the telephone service side and the high-speed data communication service side, and the system can be constructed at a lower cost.

  Further, the communication system of the present invention is not limited to one that operates two communication services, a telephone service and a high-speed data communication service. The present invention can be applied to a communication system that operates any two or more communication services. In particular, the communication system according to the present invention includes a communication service that performs uplink communication using a low-speed modulation method (for example, binary or quaternary modulation such as BPSK or QPSK) that is less affected by inflow noise, as in the first embodiment. This is suitable when both communication services that perform uplink communication using a higher-speed modulation method (for example, multi-level modulation of 64 QAM or more) that has a large influence of combined noise are used. For example, the present invention can be applied to a case where a low-speed Internet service and a high-speed Internet service are operated.

  For example, in addition to the telephone service and the high-speed data communication service of the first embodiment, the broadcast service is operated as follows.

  As shown in FIG. 5, a broadcasting facility 14 is provided at the center and connected to the optical transmitter 11 so that a broadcast signal from the broadcasting facility 14 is input to the optical transmitter 11. Further, an STB (set top box) 39 that is connected to the coaxial cable network 50 is provided in each house of the apartment house 30. A TV receiver (not shown) is connected to the STB. Thereby, a broadcast signal can be transmitted to the communication terminal device 31 of the housing complex 30 via the first optical fiber network 40 and transmitted from the communication terminal device 31 to the STB of each house via the coaxial cable network 50.

  Naturally, the various modified examples described above can be applied not only to the first embodiment, but also in combination. Further, the communication system according to the first embodiment can be applied not only to the apartment house 30 but also to a detached house, so that there is a problem even if the apartment house 30 and the detached house are mixed in the communication service providing area. There is no.

  The present invention is suitable for a CATV system that provides both a data communication service such as the Internet and a telephone service.

10: CMTS for telephone
11: Optical transmitter 12: Optical receiver 13: WDM
20: OLT
30: Apartment house 31: Communication terminal device 32: Telephone CM
33: CM for data communication
34: R-ONU
35: D-ONU
36: CMTS for data communication
37: distributor 40: first optical fiber network 41: second optical fiber network 50: coaxial cable network

Claims (7)

A first terminal control device and a second terminal control device arranged on the center side;
A communication terminal device disposed in an apartment house and connected to the first terminal control device and the second terminal control device via an optical transmission line network;
A first telephone service that communicates with the first terminal control device and is connected to the communication terminal device via an electrical transmission line network that is disposed in each house of the apartment house and is constructed in the apartment house. A second terminal device that performs communication of a data communication service between the one terminal device and the second terminal control device;
Have
The communication terminal device includes a first optical terminal, a second optical terminal, and a third terminal control device,
The first optical terminal is connected to the first terminal control device and the first terminal device, converts an optical signal from the first terminal control device into an electrical signal, and outputs the electrical signal to the first terminal device; An electrical signal from the first terminal device is converted into an optical signal and output to the first terminal control device;
The second optical terminal is connected to the second terminal control device and the third terminal control device, converts an optical signal from the second terminal control device into an electrical signal, and outputs the electrical signal to the third terminal control device The electrical signal from the third terminal control device is converted into an optical signal and output to the second terminal control device,
The third terminal control device is connected to the second optical terminal and the second terminal device, demodulates a data signal from an electrical signal from the second terminal device, and outputs the data signal to the second optical terminal ,
The upstream electrical signal modulation scheme of the data communication service is a multi-level modulation scheme of 64QAM or more, and the upstream electrical signal modulation scheme of the primary telephone service is a binary or quaternary modulation scheme. ,
A communication system characterized by the above.   The communication system according to claim 1, wherein a filter for limiting a band of the electric signal is provided on an electric signal input side of the first optical terminal.   The communication system according to claim 1 or 2, wherein the first optical terminal outputs optical signals having different wavelengths for each apartment house.   The optical transmission line network includes a first optical transmission line network that connects the first terminal control apparatus and the first optical terminal, the second terminal control apparatus, and a second optical terminal of the communication terminal apparatus. The communication system according to any one of claims 1 to 3, wherein the communication system is configured by a second optical transmission line network connecting the two. A first wavelength multiplexing device arranged on the center side and wavelength-multiplexing an optical signal input / output to / from the first terminal control device and an optical signal input / output to / from the second terminal control device;
The communication terminal device includes a second wavelength multiplexing device that wavelength-multiplexes an optical signal input / output to / from the first optical terminal and an optical signal input / output to / from the second optical terminal,
Connecting between the first terminal control device and the first optical terminal and between the second terminal control device and the second optical terminal via the same optical transmission line network; The communication system according to any one of claims 1 to 4, wherein the communication system is characterized. Said third terminal controller, and outputs the converted back other electrical signals electrical signals from the second optical terminal to the second terminal device, of claims 1 to 5, characterized in that The communication system according to any one of the above. Communication between the first terminal control device and the first terminal device, and communication between the third terminal control device and the second terminal device is a DOCSIS method,
The communication system according to any one of claims 1 to 6 , wherein communication between the second terminal control device and the second optical terminal is a GE-PON system.

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