JPH07177491A - Interconnection device between different transmission media - Google Patents

Abstract

PURPOSE:To use a coaxial transmission line for a CATV for a distribution automation system by interconnecting an optical fiber transmission line and a coaxial transmission line. CONSTITUTION:A CATV signal from a coaxial CATV transmission line 42 passes through a different transmission medium interconnection device 31 and propagates through a CATV use coaxial transmission line 45 installed in a block of a high building and is given to a television receiver 65. An outgoing optical signal from a line controller 53 is given to the different transmission medium interconnection device 31 through an optical fiber 61 and converted into a coaxial signal. The coaxial signal as a distribution control signal is led to the CATV use coaxial transmission line 45. The distribution control signal propagated through the CATV use coaxial transmission line 45 is received by terminal equipment 67. The distribution control signal corresponding to the information to be given to the line controller 53 from the terminal equipment 67 propagates through the CATV use coaxial transmission line 45 and is converted into a optical signal and sent to an optical fiber 62 as an incoming optical signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used by being inserted between transmission media of different types such as an optical fiber transmission line and a coaxial transmission line, and enables data communication between different types of transmission media. And an interconnection device between heterogeneous transmission media.

[0002]

2. Description of the Related Art It has been proposed in the past to apply an optical communication system to construct an automated distribution system. The configuration of the optical communication system for distribution automation is shown in FIG.
Is shown in. The master stations 1 and 2 for centrally managing information are connected to the line control device 3. The line control device 3 is connected with optical transmission lines 11 and 12 formed in a tree shape by branching a transmission line made of an optical fiber by tree type optical couplers 5, 6, 7, 8, 9, and 10. ing. The optical fiber 13 at the end of the optical transmission line 11 and the optical fiber 14 at the end of the optical transmission line 12 are connected to an optical communication unit 15 as a terminal device. A power meter 17 and a gas meter 18 are connected to the optical communication unit 15. In this way, the optical multi-drop network is constructed.

With this configuration, data to be given from the master stations 1 and 2 to the terminal device propagates through the optical transmission line 11 as a downlink signal. The data to be given from the terminal device to the master stations 1 and 2 propagates through the optical transmission line 12 as an upstream signal. FIG. 4 shows an example in which the distribution automation system is applied to each house in the ridge of a high-rise house 20 such as an apartment. In this case, the optical fibers 13 and 14 at the ends are laid down to each door in the building.

Reference numeral 25 is a CATV coaxial transmission line. The CATV transmitted from the head end 27 through the coaxial CATV transmission line 29 to the coaxial transmission line 25.
A signal is given. At the end of the coaxial transmission line 25 in the building,
A television receiver 30 is connected. It is also possible to transmit predetermined information from the CATV terminal device (not shown) provided in association with the television receiver 30 toward the head end 27. That is, the transmission line 25,
29 is used for two-way communication by multiplexing by frequency division.

[0005]

In the structure shown in FIG. 4, it is necessary to lay the optical fibers 13 and 14 to each house in the ridge of the high-rise house 20, which is economically problematic. In addition, if the optical fibers 13 and 14 are laid in addition to the CATV coaxial transmission line 25, there is a problem in that the wiring is inevitably complicated.

It is considered that such a problem can be solved if the coaxial transmission line 25 can be shared for an automatic distribution system using an optical multi-drop network. However, conventionally, there is no means for performing mutual communication between different types of transmission media such as an optical fiber transmission line and a coaxial transmission line, and the coaxial transmission line 25 cannot be shared for a distribution automation system. could not.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above technical problems and to provide an interconnection device between heterogeneous transmission media capable of communicating between different transmission media.

[0008]

According to a first aspect of the present invention, there is provided an interconnection device between heterogeneous transmission media, which is connected to a first transmission medium for propagating a signal of a first type. A first connection part, a second connection part connected to a second transmission medium for propagating a second type signal different from the first type signal, and a signal from the first connection part Is converted into the signal of the second type and given to the second connection portion.

According to this structure, the first type signal input from the first transmission medium to the first connection portion is converted into the second type signal by the first signal converting means. Then, this second type of signal is given to the second transmission medium from the second connection portion. Thereby, interconnection of the first transmission medium and the second transmission medium is achieved. 3. The interconnection device between heterogeneous transmission media according to claim 2, further comprising second signal conversion means for converting the signal from the second connection unit into the signal of the first type and supplying the signal to the first connection unit. Characterize.

According to this structure, the second type signal input to the second connection section is converted into the first type signal by the second signal converting means, and the first type signal is converted into the first connection section. To the first transmission medium. Accordingly, bidirectional communication can be performed between the first transmission medium and the second transmission medium. The first transmission medium may be an optical fiber transmission line and the second transmission medium may be a coaxial transmission line (claim 3).

In this case, the interconnection device between different types of transmission media further includes a television signal input section for receiving a television signal, and the coaxial transmission path is the second type from the second connection section. If it is a transmission path for propagating the television signal input from the television signal input section together with the signal of (claim 4), it is possible to share the transmission path of the television signal with the transmission path of the signal through the optical fiber transmission path. You can do it.

[0012]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 2 is a conceptual diagram for explaining a mode of use of the interconnection device between heterogeneous transmission media according to an embodiment of the present invention. The interconnection device 31 between different kinds of transmission media is applied when the distribution automation system is applied to each house in the ridge of the high-rise house 32 such as an apartment. In FIG. 2, the distribution automation system is composed of an optical multi-drop network.

In the building of the high-rise house 32, the head end 4
C for propagating a CATV signal as a television signal transmitted from the first unit via the coaxial CATV transmission line 42.
The ATV coaxial transmission line 45 is laid up to each house. C
The ATV coaxial transmission line 45 corresponds to a second transmission medium. On the other hand, the optical multi-drop network that constitutes the distribution automation system has master stations 51 and 52, a line control device 53, and optical transmission lines 54 and 55. The optical transmission line 54 is for transmitting a downlink signal for giving data from the master stations 51 and 52 to each terminal device, and the transmission line formed by an optical fiber is branched by the tree type optical couplers 56 and 57. By doing so, it is formed in a tree shape. The optical transmission line 55 is for transmitting an upstream signal for giving data from each terminal device to the master stations 51 and 52. The tree type optical couplers 58 and 59 are used to form a transmission line composed of optical fibers. The tree shape is formed by branching.

Each of the optical fibers 61 and 62 of the plurality of optical fibers connected to the tree type optical couplers 57 and 59, respectively, is connected to the interconnection device 31 of different transmission media. The optical fibers 61 and 62 correspond to the first transmission medium. The interconnection device 31 between heterogeneous transmission media converts the optical signal from the optical fiber 61 into a coaxial signal, and sends this coaxial signal to the CATV coaxial transmission line 45 as a power distribution control signal. In addition, a coaxial signal corresponding to a power distribution control signal to be given to the master stations 51 and 52 is extracted from the signal propagating through the CATV coaxial transmission line 45, the coaxial signal is converted into an optical signal, and the optical signal is sent to the optical fiber 62. To do.

A television receiver 65 and a terminal device 67 having a built-in RF modem are connected to the end of the CATV coaxial transmission line 45.
1 and the gas meter 72 are connected. 68 is a branching filter. With this configuration, the CATV signal from the head end 41 is received by the television receiver 65, and mutual communication is performed between the master stations 51 and 52 and the terminal device 67.

FIG. 1 shows an interconnection device 31 between heterogeneous transmission media.
3 is a block diagram showing the internal configuration of FIG. The interconnection device 31 between different types of transmission media includes a coaxial transmission line connection unit T0 as a television signal input unit connected to the coaxial CATV transmission line 42,
It has optical fiber connection parts T11 and T12 as first connection parts connected to the optical fibers 61 and 62, and a coaxial transmission line connection part T2 as a second connection part connected to the CATV coaxial transmission line 45. ing.

Further, an interconnection device 31 between heterogeneous transmission media is provided.
In the interior of the, the first to perform mutual conversion between optical signals and coaxial signals
A signal converter 81 as a signal converter and a second signal converter, a multiplexer / demultiplexer 85 for multiplexing and demultiplexing signals, and a power supply 8 for supplying operating power to the signal converter 81.
And 8 are provided. The multiplexer / demultiplexer 85 includes a multiplexer / demultiplexer 8
6 and a notch filter (NF) 87. The multiplexer 86 is the CAT from the coaxial transmission line connection section T0.
The V signal and the power distribution control signal supplied from the signal conversion unit 81 are merged and supplied to the coaxial transmission line connection unit T2. The multiplexer / demultiplexer 86 also branches the coaxial signal from the coaxial transmission line connection unit T2 into a CATV signal and a power distribution control signal, and supplies the branched signals to the coaxial transmission line connection unit T0 and the signal conversion unit 81, respectively. .. The notch filter 87 is a filter for preventing the power distribution control signal from being given to the coaxial transmission line connecting portion T0.

The signal conversion unit 81 includes an optical communication unit 83 that receives a downstream optical signal input from the optical fiber 61 via the optical fiber connection unit T11, performs a process such as photoelectric conversion, and converts it into received data. ing. The received data is
It is given to the CPU unit 82. Data to be transmitted to the line control device 53 is given from the CPU section 82 to the optical communication unit 83. The optical communication unit 83 creates an optical signal corresponding to the transmission data, and sends this optical signal as an upstream optical signal from the optical fiber connection section T12 to the optical fiber 62.

The optical signal propagating through the optical fibers 61 and 62 is a packet type signal including a source address SA, a destination address DA and data to be transmitted. The optical signal from the optical fiber 61 includes the address of the line controller 53 (or the line controller 53 and the master station 51 or 52) as the source address SA, and the terminal device to which the optical signal (packet) should be given. The address 67 is included as the destination address DA. Further, regarding the data to be transmitted from the terminal device 67 to the line control device 53, the optical communication unit 8 in the signal conversion unit 81
3 creates a packet including the address of the terminal device 67 as the source address SA and the address of the line control device 53 (or the line control device 53 and the master station 51 or 52) as the destination address DA.

The CPU section 82 extracts a necessary part from the signal given from the optical communication unit 83, and the RF modem 8
Give to 4. The necessary part is the destination address SA and the data. The RF modem 84 modulates the signal from the CPU section 82 and gives it to the multiplexer / demultiplexer 86. Further, the signal transmitted from the terminal device 67 via the CATV coaxial transmission line 45 (this signal includes the address of the terminal device 67 as the source address SA) is sent to the multiplexer / demultiplexer 86. It is demultiplexed and demodulated in the RF modem 84.
The demodulated signal is given to the CPU section 82. CPU
The unit 82 extracts the source address SA and the data from the signal given from the RF modem 84, and the optical communication unit 8
Enter in 3.

FIG. 3 is a diagram for explaining a used frequency band of a signal propagating through the CATV coaxial transmission line 45.
3 (a) shows the frequency band of the CATV signal, and FIG. 3 (b)
Indicates a frequency band of a power distribution control signal for exchanging information between the terminal device 67 and the line control device 53. C
Regarding the ATV signal, the band of 10 MHz to 50 MHz is allocated to the upstream signal to be transmitted to the head end 41, and the band of 70 MHz or more is allocated to the downstream signal which is the signal from the head end 41. The frequency band of the downlink signal is the first band B of 70 MHz to 228 MHz.
1 and a second band B2 of 234 MHz to 450 MHz.

Regarding the power distribution control signal, an unused band of the band of the CATV upstream signal is used for the upstream signal. That is, 39 is included in the upstream signal of the power distribution control signal.
A frequency band centered around MHz is used. Further, the downlink signal of the power distribution control signal includes the above-mentioned first band B1.
And a frequency band between the second band B2 is used. That is, a signal modulated with a center frequency of 231 MHz is used.

With the above configuration, the coaxial CATV transmission line 4
The CATV downstream signal from 2 passes through the interconnection device 31 between different transmission media, and is laid in the ridge of the high-rise house 32 by C.
It is given to the ATV coaxial transmission line 45. In addition, a CATV upstream signal from a CATV terminal device (not shown) arranged in association with the television receiver 65 receives the coaxial transmission line 4
5, propagates through the coaxial CATV transmission path 42 through the interconnection device 31 between different types of transmission media, and is given to the head end 41.

On the other hand, from the line controller 53 to the optical transmission line 54
An optical signal given from the optical fiber 61 to the interconnection device 31 between different types of transmission media via the optical fiber 61 is converted into data by the optical communication unit 83, and then the CPU 82 unit causes the RF modem 8 to operate.
4 is input. The RF modem 84 frequency-modulates the input data with a center frequency of 231 MHz to create a power distribution control signal. This power distribution control signal is multiplexed by the multiplexer / demultiplexer 86 and is guided to the coaxial transmission line 45 together with the CATV signal. The signal guided to the coaxial transmission line 45 is received by the terminal device 67 and demodulated into data. However,
The terminal device 67 takes in only the signal including the address given to itself as the destination address SA.

When terminal device 67 transmits data relating to, for example, power meter 71 or gas meter 72, data corresponding to the data to be transmitted and its own address is created. And this data is center frequency 3
The frequency is modulated at 9 MHz. The power distribution control signal obtained by this frequency modulation is led to the CATV coaxial transmission line 45. The signal propagated through the CATV coaxial transmission line 45 is demultiplexed by the multiplexer / demultiplexer 86, and demodulated into data by the RF modem 84. This data is given from the CPU section 82 to the optical communication unit 83, and a packet including the address of the terminal device 67 as the source address SA is created. The optical signal corresponding to this packet is transmitted to the optical fiber 62.

The multiplexer / demultiplexer 86 and the coaxial line connecting portion T0
The notch filter NF interposed between and blocks the passage of a signal in the frequency band of 38.75 MHz to 39.25 MHz, for example. Therefore, the terminal device 67
The signal sent from the coaxial transmission line 45 to the coaxial CATV
It is not led to the transmission line 42. The signal blocking amount in the notch filter NF is preferably 30 dB or more.

As described above, according to this embodiment, the CATV
The coaxial transmission line 45 laid in the ridge of the high-rise house 32 for transmitting a signal can be shared for transmission of a power distribution control signal. Therefore, it is not necessary to lay an optical fiber transmission line separately from the coaxial transmission line 45, which is extremely economical and wiring is not complicated. The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. For example, in the above embodiment, the CATV coaxial transmission line 45 is shared for transmission of the distribution control signal. However, the coaxial transmission line for transmitting the distribution control signal is not necessarily shared with the transmission of the CATV signal. do not have to. That is, when the CATV coaxial transmission line is not laid, a new coaxial transmission line for transmitting the power distribution control signal may be newly laid.

Further, in the above embodiment, the downstream optical signal is converted into the coaxial signal and sent to the coaxial transmission line 45, and the upstream coaxial signal guided to the coaxial transmission line 45 is converted into the optical signal and the optical signal is converted into the optical signal. The configuration for sending to the fiber 62 has been described,
Only one of the conversions may be performed. That is,
If it is sufficient to transmit only the downlink signal, it is not necessary to convert the coaxial signal into an optical signal, and if it is sufficient to transmit only the uplink signal, there is no need to convert the optical signal into the coaxial signal.

Further, in the above embodiment, the interconnection device between different kinds of transmission media for connecting the optical fiber transmission line and the coaxial transmission line has been described, but the present invention is also applied to any other combination of different kinds of transmission media. can do. The combination of transmission lines other than the optical fiber transmission line and the coaxial transmission line includes a combination of the coaxial transmission line and the pair transmission line, a combination of the NTT line and the coaxial transmission line, and the like.

In addition, various design changes can be made without changing the gist of the present invention.

[0031]

According to the first aspect of the present invention, since the signal from the first transmission medium can be converted and given to the second transmission medium, interconnection of different types of transmission medium can be achieved. . According to the second aspect of the present invention, since the signal from the second transmission medium can be converted and given to the first transmission medium, bidirectional communication can be performed between different types of transmission media.

If the first transmission medium is an optical fiber transmission line and the second transmission medium is a coaxial transmission line capable of propagating a television signal (claims 3 and 4), the television signal is It is possible to share the signal transmission line via the optical fiber transmission line and the transmission line of the signal. As a result, the cost for laying the transmission path can be reduced and the wiring can be simplified.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an interconnection device between heterogeneous transmission media according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing an example of use of the interconnection device between heterogeneous transmission media of the above embodiment.

FIG. 3 is a diagram for explaining a used frequency band.
(a) shows the used frequency of the CATV signal, and (b) shows the used frequency of the power distribution control signal.

FIG. 4 is a conceptual diagram showing a configuration example in which an automated power distribution system configured by an optical multi-drop network is applied to each house in a high-rise residential building.

[Explanation of symbols]

 31 Interconnection device between different types of transmission media 42 Coaxial CATV transmission line 45 CATV coaxial transmission line 51, 52 Master station 53 Line control device 54, 55 Optical transmission line 61, 62 Optical fiber 65 Television receiver 67 Terminal device 71 Power meter 72 Gas Meter 81 Signal Converter 82 CPU Unit 83 Optical Communication Unit 84 RF Modem 85 Combiner / Demultiplexer 86 Combiner / Demultiplexer 87 Notch Filter T0 Coaxial Transmission Line Connection T11, T12 Optical Fiber Connection T2 Coaxial Transmission Line Connection

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location H04B 10/12 (72) Inventor Fudo Hiroyuki 3-3-22 Nakanoshima, Kita-ku, Osaka Kansai Denryoku Co., Ltd. (72) Inventor Naoyuki Nozaki 3-3-22 Nakanoshima, Kita-ku, Osaka City Kansai Electric Power Co., Inc.

Claims (4)

[Claims] 1. A first connection unit connected to a first transmission medium for propagating a first type signal, and a first connection unit for propagating a second type signal different from the first type signal. A second connection part connected to the second transmission medium, and a first signal conversion means for converting the signal from the first connection part into the second type signal and giving the second connection part. A device for interconnecting different types of transmission media. 2. The heterogeneous device according to claim 1, further comprising second signal converting means for converting the signal from the second connecting portion into the signal of the first type and applying the signal to the first connecting portion. Interconnection device between transmission media. 3. The interconnection device between heterogeneous transmission media according to claim 1, wherein the first transmission medium is an optical fiber transmission line, and the second transmission medium is a coaxial transmission line. . 4. A television signal input section for inputting a television signal is further included, wherein the coaxial transmission path is a television signal input from the television signal input section together with the second type signal from the second connection section. 4. The interconnection device between heterogeneous transmission media according to claim 3, which is a transmission line that also propagates.