JP4700337B2 - Hearing system and apparatus therefor - Google Patents

Description

  The present invention relates to a common hearing system for distributing broadcast signals to each house in a predetermined facility and an apparatus therefor.

  An example of a broadcasting form is terrestrial broadcasting. In order to receive this terrestrial broadcast signal, it was necessary to install a receiving facility such as an antenna for each household. However, in collective housing facilities where a plurality of households live, installation of receiving equipment for each resident household causes inconveniences such as increased equipment costs. Has been introduced. In this system, instead of installing an antenna in each household, a single shared antenna is provided, and electrical signals received through this shared antenna are distributed to each household through a plurality of distributors. It was.

  Recently, as another example of the broadcast form, there is an optical communication CATV broadcast that transmits an optical signal via an optical cable. In this optical communication CATV broadcasting, the CATV transmitting station converts an electrical signal into an optical signal using an external modulation type optical transmitter capable of long-distance transmission, and this optical signal is transmitted to each household via an optical cable. It was transmitted (for example, patent document 1).

  On the other hand, since the receiver side receives the optical signal in the apartment building facility, the distributor group in the terrestrial broadcasting common hearing system cannot distribute the optical signal. A separate hearing system for optical communication CATV broadcasting was separately provided, and an optical signal was distributed via this common hearing system. That is, the optical signal transmitted from the CATV transmitting station is received through one shared optical cable, and then distributed to each household through a group of optical signal distributors.

JP-A-8-274712

  However, since the common hearing system is constructed independently for each of the electrical signal and the optical signal, there is a problem that the equipment cost and installation cost of the common hearing system are increased. For example, in a housing complex housing 64 households, it is necessary to provide nine distributors for eight distributions as a terrestrial broadcasting common hearing system, and further, as a common hearing system for optical communication CATV broadcasting, Since it was necessary to provide nine distributors for eight distributions, it was necessary to install a total of 18 distributors.

  The present invention has been made in view of the above, and provides a common hearing system capable of distributing both terrestrial broadcasts and optical communication CATV broadcasts and a device therefor. The purpose is to reduce costs and installation costs.

In order to solve the above-described problems and achieve the object, the hearing system according to claim 1 is a hearing system that receives a communication signal and distributes the received communication signal to each house in a predetermined facility. Photoelectric conversion means for converting the first optical communication signal into a second electric communication signal among the two types of signals of the first optical communication signal and the first electric communication signal received in a predetermined device; and the first An integration unit that integrates a single integrated signal by outputting the telecommunication signal and the second telecommunication signal converted by the photoelectric conversion unit while switching, and the one integration unit integrated by the integration unit signal, to the electro-optic conversion means for converting the optical communication signal, the one integrated signal converted into an optical communication signal by said electro-optic conversion means, characterized in that a distributing means for distributing the said door to door .

Further, in the common hearing system according to claim 2, in the common hearing system according to claim 1, the integration unit determines whether the first telecommunication signal or the second telecommunication signal is greater than a reference voltage. And switching between the first telecommunication signal and the second telecommunication signal .

Further, the hearing system according to claim 3 is characterized in that, in the hearing system according to claim 1 or 2, the electro-optic conversion means is an electro-optic conversion means of a direct modulation system.

The signal switching device according to claim 4 is a signal switching device that receives a communication signal and distributes the received communication signal to each house in a predetermined facility. The first optical communication signal received by a predetermined device. Switching the photoelectric conversion means for converting the second electric communication signal into the second electric communication signal, the first electric communication signal received by the predetermined device, and the second electric communication signal converted by the photoelectric conversion means. Thus, there is provided an integration unit that integrates into one integrated signal, and an electro-optical conversion unit that converts the one integrated signal integrated by the integration unit into an optical communication signal .

  The hearing system according to the present invention first converts one type of signal from two types of received optical communication signal and telecommunication signal into the other type of signal, and then one type of signal. Since the optical communication signal and the telecommunications signal converted into signals are integrated into one integrated signal, two different types of signals can be converted into one type of signal within a predetermined facility and integrated to be distributed to each house. The equipment cost and installation cost of the hearing system can be reduced.

  The hearing system according to the present invention first converts the received first optical communication signal into a second telecommunication signal, and then converts the second telecommunication signal and the received first telecommunication signal. Since it is integrated into one integrated signal, the equipment cost and installation cost of the common hearing system can be reduced.

  In the hearing system according to the present invention, the received first telecommunication signal is first converted into the second optical communication signal, and then the second optical communication signal and the received first optical communication signal are converted. Since it integrates into the one integrated signal, the equipment cost and installation cost of the hearing system can be reduced.

  In the hearing system according to the present invention, since the electro-optic conversion means is a direct modulation type electro-optic conversion means, a wide-band electrical communication signal including a high-frequency band can be converted into an optical communication signal.

  The signal switching device according to the present invention first integrates the received first telecommunication signal and the received second telecommunication signal into one integrated signal, and then integrates the one integrated signal. By using this signal switching device to convert a signal into an optical communication signal, it is possible to provide a hearing system that can distribute both terrestrial broadcasting and optical communication CATV broadcasting.

  Further, the signal switching device according to the present invention realizes a common hearing system capable of distributing both terrestrial broadcasting and optical communication CATV broadcasting in order to convert the received first optical communication signal into the second telecommunication signal. Therefore, main functions that must be newly added to the existing hearing system can be integrated into the signal switching device. Therefore, the equipment cost and installation cost of a common hearing system can be reduced.

  Further, the signal switching device according to the present invention outputs the first telecommunication signal and the second telecommunication signal by alternately outputting the first telecommunication signal and the second telecommunication signal. In order to integrate into one integrated signal, it is possible to provide a signal switching device that realizes a common hearing system capable of distributing both terrestrial broadcasting and optical communication CATV broadcasting.

  Exemplary embodiments of a hearing system and an apparatus therefor according to the present invention will be described below in detail with reference to the accompanying drawings. First, [I] the basic concept of the present invention will be described, then [II] each embodiment of the present invention will be described, and [III] Finally, a modification to the embodiment of the present invention will be described.

[I] Basic concept of the present invention First, the basic concept of the present invention will be described. The present invention relates to a hearing system and an apparatus therefor. Here, the facility to which the common hearing system and the apparatus therefor are to be installed, the facility to which the broadcast signal (communication signal) is distributed within the facility, and the type of broadcast to be distributed are arbitrary, but the following implementation In this embodiment, a case where a television broadcast is distributed to each household in an apartment house facility will be described as an example. More specifically, regarding television broadcasting, it is assumed that three types of broadcast signals, terrestrial broadcast signals, satellite broadcast signals, and CATV broadcast signals, are received. Here, the terrestrial broadcast and the satellite broadcast are wireless broadcasts using radio waves (electric communication signals), and the CATV broadcast is a wired broadcast performed by transmitting an optical communication signal via an optical cable.

  Here, one of the features of the hearing system and the apparatus therefor according to the present invention is not provided independently for two types of signals, that is, an electric communication signal and an optical communication signal. It can be used as one system common to signals. Schematically, a hearing system and an apparatus therefor according to the present invention integrate two kinds of signals such as an electric communication signal and an optical communication signal into one integrated signal, and then pass through a set of distributors. Distribute this integrated signal to each household. Thereby, since an electric communication signal and an optical communication signal can be distributed to each household using one set of distributor groups, an effect of reducing the number of distributors to be used can be obtained.

[II] Embodiments of the Present Invention Next, embodiments of the hearing system and the apparatus therefor according to the present invention will be described. However, the present invention is not limited by these embodiments.

[Embodiment 1]
First, the first embodiment will be described. The common hearing system and the apparatus therefor according to the first embodiment are roughly as follows: (1) One type of two types of signals, that is, an optical communication signal and an electric communication signal received by a predetermined device. Conversion means for converting the signal into the other type of signal, integration means for integrating the optical communication signal and the telecommunication signal converted into this one type of signal into one integrated signal, and one integrated integrated signal And (2) a conversion means for converting the first optical communication signal received by the predetermined device into a second electric communication signal. The integrating means integrates the second telecommunication signal and the first telecommunication signal received at a predetermined device into the one integrated signal; and (3) the electro-optic converting means directly modulates the second telecommunication signal. The main feature is that it is a system .

(Outline of communication signal)
Here, a communication signal received by the common hearing system and the apparatus therefor according to the first embodiment will be described. A hearing system and an apparatus therefor provided in an apartment house facility receive a CATV broadcast signal, a terrestrial broadcast signal, and a satellite broadcast signal from outside the apartment house facility. The CATV broadcast signal is an optical communication signal with a bandwidth of 70 to 770 MHz. Hereinafter, the optical communication signal that is the CATV broadcast signal is referred to as a “first optical communication signal”. The terrestrial broadcast signal is an electric communication signal in the VHF band (470 to 770 MHz) and the UHF band (90 to 108 MHz, 170 to 222 MHz). The satellite broadcast signal is an electric communication signal with a bandwidth of 1000 to 2602 MHz. Hereinafter, the telecommunications signal obtained by mixing the terrestrial broadcast telecommunications signal and the satellite broadcast telecommunications signal is referred to as a “first telecommunications signal”.

  Furthermore, the hearing system and the apparatus therefor receive an in-house broadcast signal, which is an electric communication signal, from an in-facility broadcast station provided inside the apartment house facility. Hereinafter, the telecommunications signal which is the in-house broadcast signal is referred to as “in-house telecommunications signal”. The band of the hall broadcast signal is arbitrary, but a band that is not used in any of the CATV broadcast signal, the terrestrial broadcast signal, and the satellite broadcast signal is used.

(Outline of the hearing system)
Next, the configuration of the common hearing system according to Embodiment 1 will be described. FIG. 1 is a functional block diagram illustrating a functional concept of the configuration of the hearing system 1 according to the first embodiment. The common hearing system 1 is generally configured to include a photoelectric conversion unit 2, a signal switching device 3, a distributor group 4, and antennas 5, 6, and 7 (here, the photoelectric conversion unit 2, The signal switching device 3 and the distributor group 4 respectively correspond to the photoelectric conversion means, the signal switching device, and the distribution means in the claims).

  Among these, the photoelectric conversion unit 2 is a photoelectric conversion unit that converts an optical communication signal received by the hearing system 1 into an electric communication signal. For example, a pin photodiode (PIN) or an avalanche photodiode (APD) is used. An ONU (Optical Network Unit) configured using such a light receiving element.

  The signal switching device 3 switches and integrates a plurality of telecommunication signals. The signal switching device 3 includes a switching unit 8 and an electro-optic conversion unit 9 (here, the switching unit 8 and the electro-optic conversion unit 9 are integrated with the integration unit and the electro-optic conversion unit in the claims). Respectively). Among these, the switching unit 8 is an integration unit that integrates a plurality of telecommunication signals into one integrated signal by alternately switching and outputting the plurality of input telecommunication signals, for example, a relay, a comparator, etc. Etc. are provided. The electro-optic conversion unit 9 is electro-optic conversion means for converting an electrical communication signal into an optical communication signal, and is, for example, an optical transmitter configured using an electro-optic conversion element such as a laser diode.

  Here, the electro-optic conversion unit 9 is electro-optic conversion means of a direct modulation method. The reason why the direct modulation type electro-optic conversion means is used is as follows. That is, the integrated signal that the electro-optic conversion unit 9 performs electro-optical conversion has a very wide band of 70 to 2060 MHz. For this reason, it is not easy for the external modulation type electro-optical conversion means to electro-optically convert such a broadband signal, particularly a high-frequency band signal, and there is currently no such product. Therefore, as the electro-optic conversion unit 9, a direct modulation type electro-optic conversion means capable of electro-optic conversion of a broadband signal is used. Other configurations of the signal switching device 3 will be described later.

  The distributor group 4 is a distribution unit that distributes one signal to a plurality of signals, and includes, for example, a plurality of distributors and amplifiers. Antennas 5, 6, and 7 are receiving means for receiving a telecommunication signal. Among these, the antennas 5 and 6 receive terrestrial broadcast signals (VHF band and UHF band), and the antenna 7 receives satellite broadcast signals (BS and CS). The above is the configuration of the common hearing system 1 according to the first embodiment.

(Communication signal distribution processing)
Next, the outline of the communication signal distribution process of the common hearing system 1 will be described. In the hearing system 1 shown in FIG. 1, the terrestrial broadcast signal received via the antennas 5 and 6 and the satellite broadcast signal received via the antenna 7 are mixed by a known mixer to obtain the first. This becomes a telecommunication signal, and this first telecommunication signal is input to the signal switching device 3. Further, the first optical communication signal transmitted from the CATV broadcasting station equipment (simply called CATV in the figure) 11 through the optical cable is converted into an electric communication signal by the photoelectric conversion unit 2 (here, this conversion is performed). The telecommunications signal is referred to as a “second telecommunications signal”) and is input to the signal switching device 3. In the switching unit 8 described later of the signal switching device 3, the first telecommunication signal and the second telecommunication signal are integrated into one signal (here, a signal obtained by integrating a plurality of signals is referred to as “integrated signal”). In addition, the in-house telecommunications signal received from the in-facility broadcasting station is integrated with the integrated signal. This integrated signal is converted again into an optical communication signal by an electro-optic conversion unit 9 to be described later of the signal switching device 3. The integrated signal thus converted into the optical communication signal is distributed by the distributor group 4 and distributed to each household 13.

  Each household 13 is provided with a photoelectric conversion unit 14 such as an ONU, an STB (Set Top Box) 15, and a TV (TV terminal) 16. The integrated signal distributed to each household 13 is first converted into an electric communication signal by the photoelectric conversion unit 14. The integrated signal converted into the telecommunication signal is supplied to the TV 16 directly via the STB 15 or not via the STB 15. The above is the outline of the communication signal distribution processing by the common hearing system 1.

(Configuration of signal switching device)
Here, a specific configuration example of the signal switching device 3 will be described. FIG. 2 is a functional block diagram illustrating functionally conceptually the configuration of the signal switching device 3 according to the first embodiment. As shown in FIG. 2, the signal switching device 3 is configured by connecting a switching unit 8, a SLOPE 20, a GC (Gain Control) 21, an amplifier 22, and an electro-optic conversion unit 9 as illustrated. The electro-optic conversion unit 9 includes an LD (Laser Diode) 17, an APC (Auto Power Control) 18, and an ATC (Auto Thermo Control) 19.

  FIG. 3 is a functional block diagram illustrating a functional concept of the configuration of the switching unit 8 according to the first embodiment. As shown in FIG. 3, the switching unit 8 is configured by connecting a high frequency relay 23, an AGC (Auto Gain Control) 24, an amplifier 25, comparators 26 and 27, and detection circuits 28 and 29 as shown. ing. A second telecommunication signal, a first telecommunication signal, and an in-house telecommunication signal are inputted to the input 1, the input 2, and the input 3, respectively. The above is a specific configuration example of the signal switching device 3. The function of each part of the signal switching device 3 will be described below.

(Communication signal switching processing of signal switching device)
Next, communication signal switching processing by the signal switching device 3 will be described. In the high-frequency relay 23 provided in the switching unit 8 shown in FIG. 3, the second telecommunication signal input to the input 1 and the first telecommunication signal input to the input 2 correspond to the output from the comparator 26. Are alternately switched and output as one integrated signal. Specifically, the second telecommunication signal is output when the output from the comparator 26 is high, and the first telecommunication signal is output when the output from the comparator 26 is Lo. At this time, the comparator 26 outputs High or Lo based on whether or not the second telecommunication signal detected by the detection circuit 28 is greater than the reference voltage V1. That is, Lo is output from the comparator 26 and the first telecommunication signal input to the input 2 is output from the high frequency relay 23 only when the second telecommunication signal input to the input 1 is interrupted. Next, the output integrated signal is output after the level is adjusted and amplified by the AGC 24 and the amplifier 25. At this time, the level adjustment by the AGC 24 is performed by feeding back the monitoring results of the outputs from the AGC 24 and the amplifier 25 by the detection circuit 29 and the comparator 27.

  Next, as shown in FIG. 2, the in-house telecommunication signal input from the input 3 is further integrated with the integrated signal thus integrated. The integrated signal obtained by integrating the in-house telecommunications signal is then adjusted in slope characteristics by the SLOPE 20, adjusted in level by the GC 21 and the amplifier 22, and then output. The integrated signal output in this way is converted from an electrical communication signal into an optical communication signal by the electro-optic conversion unit 9. Specifically, this electrical communication signal is converted into an optical communication signal by the LD 17 provided in the electro-optic conversion unit 9. At this time, the APC 18 protects the LD 17 by adjusting the output of the LD 17 and further stabilizes the output of the LD 17. The ATC 19 controls the temperature of the LD 17 to be constant. The telecommunication signal whose level is adjusted and amplified by the GC 21 and the amplifier 22 is output to the modulation degree monitor terminal and can be monitored by a predetermined device. Since this is direct modulation in which an RF signal is directly input into light and modulated, it is necessary to match an aptitude level determined according to the number of channels. The optimum total modulation factor is 30-40%. When overmodulation occurs, a beat failure or the like occurs. As described above, the integrated signal converted into the optical communication signal in the electro-optic conversion unit 9 is distributed to each household 13 via the distributor group 4 as shown in FIG. The above is the communication signal switching process by the signal switching device 3.

(Effect of Embodiment 1)
Thus, according to the hearing system 1 according to the first embodiment, the first telecommunication signal and the first optical communication signal are unified into the form of the telecommunication signal, and then integrated into one integrated signal. Since the integrated signal is distributed in the state of being converted into the optical communication signal, two different types of signals can be converted into one type of signal in the apartment building 10 and integrated and distributed, thereby reducing the equipment cost and installation cost of the common hearing system. Can be reduced.

[Embodiment 2]
Hereinafter, a hearing system according to Embodiment 2 of the present invention will be described. In the hearing system according to the second embodiment, the conversion means is an electro-optic conversion means for converting the first telecommunication signal received by the predetermined device into the second optical communication signal, and the integrating means is the second The optical communication signal and the first optical communication signal received by a predetermined device are integrated into one integrated signal. On the other hand, in the hearing system according to the first embodiment, the conversion means is a photoelectric conversion means for converting the first optical communication signal received by the predetermined device into the second electrical communication signal, and the integration means is The second telecommunication signal and the first telecommunication signal received at a predetermined device are integrated into the one integrated signal. In this respect, the common hearing system according to the second embodiment is different from the common hearing system according to the first embodiment.

(Outline of the hearing system)
First, the outline of the common hearing system according to the second embodiment will be described. FIG. 4 is a functional block diagram illustrating a functional concept of the configuration of the common hearing system 31 according to the second embodiment. This common hearing system 31 is generally configured to include an electro-optic conversion unit 9, a multiplexing unit 32, a distributor group 4, and an antenna 7. Note that structures and processes that are not particularly described are the same as those in the first embodiment described above, and the same structures and processes will be described with the same reference numerals.

  Among these, the multiplexing unit 32 is an integration unit that combines a plurality of optical communication signals (here, the multiplexing unit 32 corresponds to the integration unit in the claims), for example, a plurality of lights having different wavelengths. It is configured with a multiplexer that outputs one signal. The above is the outline of the common hearing system 31 according to the second embodiment.

(Outline of communication signal)
Here, a communication signal received by the common hearing system 31 will be described. The hearing system 31 provided in the apartment house facility 10 receives a CATV broadcast signal and a satellite broadcast signal from the outside of the apartment house facility 10. Hereinafter, the optical communication signal that is the CATV broadcast signal is referred to as “first optical communication signal”, and the telecommunication signal that is the satellite broadcast signal is referred to as “first telecommunication signal”.

(Communication signal distribution processing)
Next, communication signal distribution processing of the common hearing system 31 will be described. 4, the first telecommunication signal received via the antenna 7 is converted into an optical communication signal by the electro-optic conversion unit 9 (here, the converted optical communication signal is converted into an optical communication signal). Referred to as “second optical communication signal”). The second optical communication signal and the first optical communication signal received from the CATV 11 via the optical cable are integrated into one signal in the multiplexing unit 32 (here, a signal in which a plurality of signals are integrated) Referred to as "integrated signal"). The integrated signal is divided into a plurality of communication signals by the distributor group 4 and then distributed to each household 13. Here, the wavelength of the second optical communication signal is different from the wavelength of the first optical communication signal. The above is the communication signal distribution processing by the common hearing system 31.

(Effect of Embodiment 2)
Thus, according to the hearing system 31 according to the second embodiment, the first telecommunication signal and the first optical communication signal are unified into the form of the optical communication signal, and then integrated into one integrated signal for distribution. Therefore, two different types of signals can be converted into one type of signals in the apartment house facility 10 and can be integrated and distributed, and the equipment cost and installation cost of the common hearing system can be reduced.

[III] Modifications to Embodiments Although the embodiments of the present invention have been described above, the specific configuration and method of the present invention are within the scope of the technical idea of each invention described in the claims. Can be arbitrarily modified and improved. Hereinafter, such a modification will be described.

(About facilities and each house in the facility)
The plurality of doors in the facility according to the present invention may be a plurality of terminals in the facility. Moreover, when only one unit exists in one facility, the present invention may be a hearing system that distributes communication signals to a plurality of terminals included in the one unit. Further, the present invention may be a hearing system that distributes communication signals to a single terminal or a plurality of terminals of each house even when there are a plurality of houses in the facility.

(About the types of signals to be integrated)
In the first embodiment, the signal integrated by the switching unit 8 is an electric communication signal, but is not limited thereto, and may be an optical communication signal. In that case, the switching unit 8 is configured to realize switching of a plurality of optical communication signals. Further, in this case, since the integrated signal is already an optical communication signal, the electro-optic conversion unit 9 can be omitted. However, this integrated signal may be distributed to each household 13 using the distributor group 4 after being converted into an electric communication signal by the photoelectric conversion unit 2. In that case, the photoelectric conversion unit 14 can be omitted.

(About the types of signals to be distributed)
In the first and second embodiments, the integrated signal distributed by the distributor group 4 is an optical communication signal. However, the integrated signal is not limited to this and may be an electric communication signal. In that case, the electro-optic conversion unit 9 and the photoelectric conversion unit 14 can be omitted in the first embodiment, and the integrated signal is converted into an electric communication signal by the photoelectric conversion unit 2 in the second embodiment, and the photoelectric conversion unit 14 can be omitted.

  In addition, although the broadcast signals are distributed in the first and second embodiments, the present invention is not limited thereto, and may be communication signals such as the Internet or telephone.

(Signal switching device)
In the first embodiment, the components of the signal switching device 3 are the switching unit 8 and the electro-optic conversion unit 9. However, the signal switching device 3 is not limited to this, and the signal switching device 3 may further include the photoelectric conversion unit 2. Good. As a result, the main functions that must be newly added to the existing common hearing system in order to realize a common hearing system that can distribute both terrestrial broadcasting and optical communication CATV broadcasting are consolidated in the signal switching device. it can. Therefore, the equipment cost and installation cost of a common hearing system can be reduced.

(About switching unit)
The switching unit 8 is configured to preferentially output the CATV broadcast signal as compared with the integrated signal of the terrestrial broadcast signal and the satellite broadcast signal, but is not limited thereto, and compared with the CATV broadcast signal, The configuration may be such that the integrated signal of the terrestrial broadcast signal and the satellite broadcast signal is output with priority.

  The switching unit 8 is switched by the high-frequency relay 23 because the frequency bands of the electrical signals input from the input 1 and the input 2 overlap. In the case of only broadcasting, since it does not overlap with CATV broadcasting, the high frequency relay 23 may be changed to a mixer.

It is a functional block diagram which illustrates the structure of the common hearing system which concerns on this Embodiment 1 functionally conceptually. It is a figure which shows the structure of the signal switching apparatus which concerns on this Embodiment 1. FIG. It is a figure which shows the structure of the switching part which concerns on this Embodiment 1. FIG. It is a functional block diagram which illustrates the structure of the common hearing system which concerns on this Embodiment 2 functionally conceptually.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,31 Hearing system 2,14 Photoelectric conversion part 3 Signal switching device 4 Divider group 5, 6, 7 Antenna 8 Switching part 9 Lightning conversion part 10 Apartment house facilities 11 CATV
12 On-site broadcasting stations 13 Households 15 STB
16 TV
17 LD
18 APC
19 ATC
20 SLOPE
21 GC
22, 25 Amplifier 23 High frequency relay 24 AGC
26, 27 Comparator 28, 29 Detection circuit 32 Multiplexing unit V1, V2 Reference voltage

Claims (4)

In a hearing system that receives a communication signal and distributes the received communication signal to each house in a predetermined facility.
Photoelectric conversion means for converting the first optical communication signal into the second electric communication signal among the two types of signals of the first optical communication signal and the first electric communication signal received by the predetermined device;
Integration means for integrating the first telecommunication signal and the second telecommunication signal converted by the photoelectric conversion means into one integrated signal by switching and outputting;
Electro-optic conversion means for converting the one integrated signal integrated by the integrating means into an optical communication signal;
Distribution means for distributing the one integrated signal converted into an optical communication signal by the electro-optic conversion means to each of the doors;
A hearing system characterized by comprising: The integration means outputs the first telecommunication signal and the second telecommunication signal while switching based on whether the first telecommunication signal or the second telecommunication signal is larger than a reference voltage.
The common hearing system according to claim 1. The electro-optic conversion means is a direct-modulation electro-optic conversion means;
The hearing system according to claim 1 or 2. In a signal switching device that receives a communication signal and distributes the received communication signal to each house in a predetermined facility,
Photoelectric conversion means for converting a first optical communication signal received in a predetermined device into a second telecommunication signal;
Integration means for integrating the first telecommunication signal received at a predetermined device and the second telecommunication signal converted by the photoelectric conversion means into one integrated signal by switching and outputting;
Electro-optic conversion means for converting the one integrated signal integrated by the integrating means into an optical communication signal;
A signal switching device comprising:

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