JP3560882B2 - xDSL Optical Access System - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an xDSL-applied optical access system capable of applying the xDSL system to a system in which an optical line using an optical fiber is interposed in a transmission line, and more particularly, to a subscriber from an exchange via an optical fiber. XDSL capable of providing a high-speed xDSL data communication service by applying the xDSL system to a system connected to a terminal accommodation device and connected to a plurality of subscriber terminals from the subscriber terminal accommodation device via copper wires. The present invention relates to an applicable optical access system.
[0002]
[Prior art]
The xDSL system is an effective system for performing high-speed digital transmission using a copper wire cable for telephone subscribers, but conventionally, as shown in FIGS. 4 and 5, a system from a telephone exchange to a subscriber terminal is used. It can be applied only to a system in which the transmission line is made of copper wire.
[0003]
First, a system to which such a conventional xDSL system is applied will be described with reference to FIGS.
[0004]
FIG. 4 is a diagram showing a basic configuration of the xDSL application system. In the xDSL application system shown in the figure, an xDSL-related device is provided in each of a subscriber terminal 101 and a communication carrier device 105 provided with a telephone exchange 117 and the like connected by a telephone line 103 made of copper wire. This constitutes a system that enables high-speed transmission between devices.
[0005]
More specifically, the subscriber terminal 101 has a telephone terminal 107 and a data terminal 109 connected to the LAN. The telephone terminal 107 is directly connected to the xDSL home device 111, and the data terminal 109 is connected to the xDSL home device via the switch 113. The xDSL home device 111 is connected to a telephone line 103 made of copper wire.
[0006]
Further, the communication carrier apparatus 105 has an xDSL station apparatus 115 connected to the copper telephone line 103 and a telephone exchange 117 connected to the xDSL station apparatus 115. The xDSL station apparatus 115 is connected to the Internet. It is connected to a service provider (ISP) 119.
[0007]
FIG. 5 is a diagram showing the configuration of the xDSL application system similar to the xDSL application system shown in FIG. 4 in more detail. In FIG. 5, a subscriber terminal 201 is connected to a switching device 205 via a telephone line 203 made of copper wire, and a subscriber terminal 201 has an xDSL-related device including a splitter 211 and an xDSL modem 215 connected to the telephone line 203. The switching device 205 is provided with a plurality of splitters 217 and an xDSL aggregation modem 221 connected to each of the telephone lines 203 as xDSL-related devices. Note that the distance L between the subscriber terminal 201 and the switching device 205 is approximately 10 km or less.
[0008]
In the subscriber terminal 201, the splitter 211 is directly connected to the subscriber terminal 201, and is also connected to the data terminal 209 via the xDSL terminator 215 and the switch 213. In the switching device 205, the plurality of splitters 217 are connected to the telephone exchange 219 and to the Internet service provider 223 via the xDSL aggregation modem 221.
[0009]
FIG. 6 is a diagram illustrating carrier frequencies in the ADSL system, which is one of the representative xDSL systems. In the xDSL system including the ADSL system, in order to enable high-speed digital data transmission, a high-frequency region of 4 kHz or more, which has not been conventionally applied to a copper wire, is used. Specifically, in the ADSL (full rate G.dmt method) method, as shown in FIG. 6, a maximum of 8 Mbps transmission speed is realized by securing 256 channels of 4 kHz width in the 26 kHz to 1.1 MHz band. ing. In this manner, the existing copper wire is effectively utilized by the technology applied only to the existing copper wire.
[0010]
As described above, the xDSL system is conventionally applied only to a system in which a subscriber terminal is connected to a communication carrier device or a switching device with a copper wire. In the case where an optical transmission line composed of an optical fiber is interposed in the access network between the switching device and the switching device, the xDSL related device cannot be conventionally installed, and the speed of the copper line section in such a system cannot be increased. Was.
[0011]
FIG. 7 is a diagram illustrating a configuration of an optical transmission system when an optical cable made of an optical fiber is used for connection between a subscriber terminal and a communication carrier device. In this system, the communication carrier device 309 is connected to the optical network unit 305 via the optical cable 307, and is connected from the optical network unit 305 to each of the subscriber terminals 301 and 331 via the copper wires 303 and 333, respectively. ing.
[0012]
The telecommunications carrier device 309 includes an intra-office device 311 connected to the optical cable 307, a telephone exchange 313 and an ISDN exchange 315 connected to the intra-office device 311.
[0013]
The subscriber terminal 301 includes a digital service unit (DSU) 321 connected to the copper wire 303, a telephone terminal 317 connected to the digital service unit 321, a terminal adapter (TA) 323, and the terminal adapter via a LAN. It is composed of a data terminal 319 that is connected to the network.
[0014]
Further, the subscriber terminal 331 includes a telephone terminal 335 connected to a copper wire 333, a modem 339, and a data terminal 337 connected to the modem 339 via a LAN.
[0015]
Conventional examples of the above-described optical transmission system as shown in FIG. 7 include a CR / RT system, a π system, and an SBM / ASM system as shown in FIGS. 8 to 10, respectively. I do.
[0016]
The CR / RT optical transmission system shown in FIG. 8 has an optical fiber connected from a central terminal (CT) 417 provided in a communication carrier apparatus 415 to a remote terminal (RT) 409 constituting a multiplexing apparatus. The optical transmission line composed of 411 and 413 is configured so that it can be shared by a plurality of subscriber terminals 401 and 403 connected from the remote terminal 409 via copper wires 405 and 407, thereby realizing economy. . The central terminal 417 converts signals such as optical signals to electrical signals, electrical signals to optical signals, and optical signals to optical signals between the optical fibers 411 and 413 and the telephone exchanges 419 and 421. The remote terminal 409 converts signals such as optical signals to electric signals and electric signals to optical signals between the optical fibers 411 and 413 and the copper wires 405 and 407. The optical fibers 411 and 413 forming the optical transmission line are for upstream and downstream, respectively.
[0017]
Note that, in the communication company apparatus 415 of the CR / RT type optical transmission system shown in FIG. 8, a telephone exchange 419 and an ISDN exchange 421 are connected to the central terminal 417. The subscriber terminal 401 has a modem 427 connected to a remote terminal 409 via a copper wire 405, a telephone terminal 423 directly connected to the modem 427, and a data terminal 425 connected to the modem 427 via a LAN. The subscriber terminal 403 includes a digital service unit 431 connected to the remote terminal 409 via the copper wire 407, a terminal adapter 429 connected to the digital service unit 431, a telephone terminal 423 directly connected to the terminal adapter, And a data terminal 425 connected to the terminal adapter via the LAN.
[0018]
In the optical transmission system of the CR / RT system configured as described above, the subscriber terminal can use the analog telephone service, the INS64 service, and the low-speed leased line service.
[0019]
The π-type optical transmission system shown in FIG. 9 includes a subscriber line terminal (SLT) 509 and an optical wiring module (FTM) 507 provided in a communication carrier apparatus 505 to an optical line terminal (ONU) 501. The optical fiber 503 is used for connection, and several meters from the optical line terminal 501 to each of the subscriber terminals 401 and 403 are connected using copper wires 405 and 407. Note that the communication carrier apparatus 505 is provided with a telephone exchange 511 and an ISDN exchange 513 connected to the subscriber line terminal unit 509. The configuration of each of the subscriber terminals 401 and 403 is the same as in FIG.
[0020]
In the optical transmission system configured as described above, since the distance from the optical line terminal 501 to each subscriber terminal is about several meters, the FTTH (fiber / fiber) can be easily compared with the CR / RT system shown in FIG. To the home) can be realized.
[0021]
Even in the π-type optical transmission system thus configured, the subscriber terminal can use the analog telephone service, the INS64 service, and the low-speed leased line service.
[0022]
The SBM / ASM optical transmission system shown in FIG. 10 includes an optical transmission line including optical fibers 603 and 605 from an exchange (ASM) 609 provided in a communication carrier apparatus 607 to a subscriber accommodation module (SBM) 601. The configuration is such that a plurality of subscriber terminals 401 and 403 connected from the subscriber accommodating module 601 via copper wires 405 and 407 can be shared so as to achieve economy.
[0023]
In the configuration of the optical transmission system of the SBM / ASM system shown in FIG. 10, the subscriber accommodation module 601 is accommodated in the same building as the exchange 609, in another building, or remotely installed as a remote SBM (RSBM). And so on. The optical fibers 411 and 413 forming the optical transmission line are for upstream and downstream, respectively.
[0024]
Even in the SBM / ASM optical transmission system configured as described above, the subscriber terminal can use the analog telephone service, the INS64 service, and the low-speed leased line service.
[0025]
[Problems to be solved by the invention]
As described above, in various optical transmission systems in which the transmission path is an optical transmission path using an optical fiber, an xDSL-related device cannot be provided conventionally, and an optical transmission system to which the xDSL system is applied is realized. There is a problem that can not be.
[0026]
More specifically, since the xDSL technology is a technology that can be applied only to a copper wire that realizes high-speed transmission by effectively utilizing an unused high-band area on the copper wire, the above-described CR / RT method and π method are used. In the case where an optical transmission line composed of an optical fiber is interposed in a transmission line between a subscriber terminal and a communication carrier device as in the SBM / ASM system, communication utilizing the characteristics of the xDSL system becomes impossible. In addition, in each of the above-mentioned systems, since an optical fiber is laid from the exchange to the front of the subscriber terminal and a signal is transmitted, the xDSL system cannot be simply introduced, There is a problem that these subscriber terminals cannot provide a high-speed data communication service which is an advantage of the xDSL system.
[0027]
The present invention has been made in view of the above, and an object of the present invention is to provide an xDSL-applied optical access system that can effectively introduce the xDSL system even in a system including an optical transmission line where it is conventionally difficult to introduce the xDSL system. It is to provide a system.
[0028]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a plurality of subscriber terminals are connected to a subscriber terminal accommodating device from an exchange via an optical fiber, and from the subscriber terminal accommodating device via a copper wire. The subscriber terminal accommodating apparatus converts a multiplexed signal transmitted from the exchange side through a physically single optical fiber logically multiplexed into two lines into a voice band signal and a data. An optical splitter that multiplexes a voice band signal and a data band signal to the exchange side and transmits the multiplexed signal to an optical fiber, and an xDSL conversion that converts the data band signal separated by the optical splitter into an xDSL system. Means, and a data band signal and a voice band signal converted to the xDSL system are multiplexed for each subscriber terminal, and the multiplexed multiplexed signal is transmitted to each subscriber terminal via a copper wire. A plurality of splitters for delivering Beku Okusu
The gist is to have
[0029]
According to the first aspect of the present invention, the multiplexed signal transmitted from the exchange side through one physically optical fiber logically multiplexed into two lines is converted into a voice band signal and a data band signal. The separated data band signal is converted to the xDSL system by the xDSL conversion means, the data band signal converted to the xDSL system and the voice band signal are multiplexed by a splitter, and each subscriber is connected via a copper wire. Introduce the xDSL method using the existing optical fiber provided between the exchange side and the subscriber terminal accommodation equipment, even for the conventional optical transmission line with optical fiber, for transmission to the terminal. And a high-speed data communication service can be efficiently realized.
[0030]
According to a second aspect of the present invention, a plurality of subscribers are connected to a subscriber terminal accommodating device via an optical fiber from an exchange provided in a telecommunications carrier device and from the subscriber terminal accommodating device via a copper wire. In the system connected to the subscriber terminal, the communication carrier device, while concentrating the voice band signal from the exchange, and a concentrator distribution device for distributing the signal to the exchange, from the exchange concentrated in the concentrator distribution device An optical splitter for logically multiplexing a voice band signal and a data band signal from an external data device including an Internet service provider other than the switchboard and physically transmitting the signal to one optical fiber, The subscriber terminal accommodating device separates the multiplexed signal from the optical fiber into a voice band signal and a data band signal, and separates the voice band signal and the data band signal into the optical fiber. An optical splitter that multiplexes a signal and sends the multiplexed signal to the optical fiber; and an optical splitter that is provided corresponding to each subscriber terminal, separates a multiplex signal from the subscriber terminal into a voice band signal and a data band signal, and Multiplexing a voice band signal and a data band signal to the plurality of splitters to be sent out to the copper wire, and distributing the voice band signal separated by the optical splitter to the plurality of splitters, from the plurality of splitters A line concentrator that multiplexes the audio band signal of the optical splitter and sends the multiplexed signal to the optical splitter, and separates the data band signal from the optical splitter for a plurality of subscriber terminals, converts the signal into an xDSL format, and supplies the converted signal to the plurality of splitters. And an xDSL aggregation modem that multiplexes a plurality of data band signals from the plurality of splitters and supplies the multiplexed signals to the optical splitter. The subscriber terminal is connected to the copper wire, receives a multiplexed signal from a splitter of the subscriber terminal accommodating apparatus, separates the signal into a voice band signal and a data band signal, and transmits the voice band signal to the telephone terminal. And a splitter for multiplexing the voice band signal from the telephone terminal and the data band signal converted to the xDSL format from the data terminal, and transmitting the multiplexed multiplexed signal to the copper wire, and connecting to the splitter. The gist of the present invention is to have an xDSL terminator that outputs the data band signal from the splitter to the data terminal, converts the data band signal from the data terminal into the xDSL system, and supplies the xDSL system to the splitter.
[0031]
According to the second aspect of the present invention, the voice band signal from the exchange is collected by the concentrator distribution device in the communication carrier device, and the voice band signal and the data band signal from the external data device including the Internet service provider are combined. The multiplexed signal is multiplexed by an optical splitter and sent to one physical optical fiber which is logically multiplexed into two lines constituting an optical transmission line. The voice band signal and the data band signal are separated by a splitter, and the voice band signal is distributed to a plurality of splitters by a concentrator and the data band signal is separated by a xDSL aggregation modem for a plurality of subscriber terminals and converted into an xDSL system. To a plurality of splitters, and the plurality of splitters receive a voice band signal from a concentrator and a data band signal from an xDSL aggregation modem. Is multiplexed and transmitted to each subscriber terminal via a copper wire, and a multiplex signal transmitted from each subscriber terminal via a copper wire is separated into a voice band signal and a data band signal by each splitter, and the voice band signal Are multiplexed by a concentrator / distributor, data band signals are multiplexed by an xDSL aggregation modem, and the multiplexed voice band signal and data band signal are multiplexed by an optical splitter. To be transmitted. Therefore, the xDSL system can be introduced to a conventional optical transmission line having an optical fiber by using an existing optical fiber provided between the communication carrier device and the subscriber terminal accommodation device. Thus, a high-speed data communication service can be efficiently realized.
[0032]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of an xDSL optical access system according to an embodiment of the present invention. In the xDSL optical access system shown in FIG. 1, each subscriber terminal 1 is connected to a subscriber terminal accommodating device 5 via a copper wire 3 which is a normal telephone line, and the subscriber terminal accommodating device 5 is connected to an upstream optical fiber 7. In addition, it is connected to the communication carrier apparatus 11 through an optical transmission line composed of the downstream optical fiber 9, whereby the signal of each subscriber terminal 1 is multiplexed and transmitted through the optical transmission line composed of the optical fibers 7 and 9. I have. The distance of the copper wire 3 between each subscriber's other terminal 1 and the subscriber terminal accommodating device 5 is, for example, about 2 to 3 km. FTTH (fiber-to-the-home) can be realized relatively easily at the request of the subscriber. The distance between the subscriber terminal accommodation device 5 and the communication carrier device 11 is, for example, about 5 km to about 10 km.
[0033]
The subscriber terminal 1 has a telephone terminal 13 and a data terminal 15. The data terminal 15 is connected to an xDSL terminating device 21 via a switch 19 connected to a LAN, and transmits a data band signal from the data terminal 15 to the xDSL system. And supplies it to the splitter 17. The splitter 17 multiplexes a voice band signal from the telephone terminal 13 and a data band signal from the xDSL terminating device 21 and sends the multiplexed signal to the copper wire 3 for transmission to the subscriber terminal accommodation device 5. As the switch 19, specifically, a router, a hub, an ATM switch, or the like is appropriately used according to a communication method.
[0034]
In the subscriber terminal 1, the splitter 17 separates the multiplexed signal received from the subscriber terminal accommodating device 5 via the copper wire 3 into a voice band signal and a data band signal, and supplies the voice band signal to the telephone terminal 13. , A data band signal is supplied to the data terminal 15 via the xDSL terminator 21 and the switch 19.
[0035]
The subscriber terminal accommodating device 5 has a plurality of splitters 23 that receive multiplexed signals transmitted from the respective subscriber terminals 1 and separate the multiplexed signals into voice band signals and data band signals. The plurality of audio band signals separated by the plurality of splitters 23 are supplied to the concentrator / distributor 25, multiplexed as optical signals, and supplied to the optical splitter 29. The plurality of data band signals separated by the plurality of splitters 23 are multiplexed by the xDSL aggregation modem 27 and supplied to the optical splitter 29. The optical splitter 29 multiplexes the multiplexed voice band signal from the concentrator / distributor 25 and the multiplexed data band signal from the xDSL aggregation modem 27, and transmits the multiplexed data signal to the carrier 11. To send to.
[0036]
Further, in the subscriber terminal accommodation device 5, the optical splitter 31 separates the multiplexed signal received from the communication carrier device 11 via the downstream optical fiber 9 into a voice band signal and a data band signal, and concentrates and distributes the voice band signal. The data band signal is supplied to the xDSL aggregation modem 27. The line concentrator 25 separates the audio band signal from the optical splitter 31 for each subscriber terminal and supplies it to each splitter 23. Further, the xDSL aggregation modem 27 separates the data band signal from the optical splitter 31 for each subscriber terminal and supplies it to each splitter 23. Each splitter 23 multiplexes the voice band signal from the concentrator / distributor 25 and the data band signal from the xDSL aggregation modem 27, and sends the multiplexed signal to the copper wire 3 for transmission to each subscriber terminal 1.
[0037]
The communication carrier apparatus 11 has an optical splitter 33 that receives a multiplex signal transmitted from the subscriber terminal accommodating apparatus 5 via the upstream optical fiber 7 and separates the multiplex signal into a voice band signal and a data band signal. The voice band signal separated by the optical splitter 33 is supplied to a concentrator / distributor 37, separated for each subscriber terminal, and supplied to a telephone exchange 39 or an ISDN exchange 41. The data band signal separated by the optical splitter 33 is transmitted to an Internet service provider (ISP) 45 via the router 43.
[0038]
In the telecommunications carrier apparatus 11, the voice band signals from the telephone exchange 39 and the ISDN exchange 41 are multiplexed by the concentrator / distributor 37, converted into optical signals, and supplied to the optical splitter 35. Data band signals as various data from the Internet service provider 45 are supplied to the optical splitter 35 via the switch 43. The optical splitter 35 multiplexes the audio band signal composed of the multiplexed optical signal from the concentrator / distributor 37 and the data band signal supplied from the Internet service provider 45 via the switch 43, and To the downstream optical fiber 9 for transmission.
[0039]
FIG. 2 is a diagram showing a detailed configuration of the optical splitter 31 and the optical splitter 35 used in the xDSL optical access system shown in FIG. As shown in the figure, the optical splitter 35 provided in the communication carrier apparatus 11 has an OE converter 53 for converting a data band signal from the switch 43 into an optical signal. The converted data band signal is supplied to the optical demultiplexing circuit 51. The optical multiplexing / demultiplexing circuit 51 is also supplied with an audio band signal composed of an optical signal from the concentrator / distributor 37, whereby the optical multiplexing / demultiplexing circuit 51 multiplexes the audio band signal with the data band signal from the OE converter 53. And sends it to the downstream optical fiber 9.
[0040]
Further, the optical splitter 31 of the subscriber terminal accommodating apparatus 5 receives the multiplexed signal transmitted from the optical splitter 35 of the communication carrier apparatus 11 via the down optical fiber 9 by the optical multiplexing / demultiplexing circuit 47. The optical multiplexing / demultiplexing circuit 47 separates the received multiplexed signal into a voice band signal and a data band signal, and the voice band signal is supplied to the concentrator / distributor 25 as it is, and the data band signal is converted into an electric signal by the OE converter 49. And supplied to the xDSL aggregation modem 27.
[0041]
Although the downstream optical fiber 9 is physically composed of one optical fiber, it is logically multiplexed into two lines, and the optical fiber line indicated by a solid line in FIG. A line is configured to transmit a voice band signal, and an optical fiber line indicated by a broken line forms an optical line for xDSL data for downlink and transmits a data band signal.
[0042]
Although FIG. 2 describes the downstream optical fiber 9, the upstream optical fiber has the same configuration. In addition, as shown by a dotted line in FIG. 2, the line connected from the output of the OE converter 49 to the xDSL aggregation modem 27 constitutes an electrical signal line for xDSL aggregation modem / ATM router connection.
[0043]
Further, in the present embodiment, the case where the OE converter 49 is configured in the optical splitter 31 has been described with reference to FIG. 2, but the present invention is not limited to this. The same applies to the case of external connection or the case of being built in the xDSL aggregation modem 27.
[0044]
FIG. 3 is a diagram showing a configuration of the xDSL aggregation modem 27 used in the subscriber terminal accommodating device 5 of the xDSL optical access system shown in FIG. As shown in the figure, the xDSL aggregation modem 27 is connected to the plurality of subscriber circuits 57 connected to each of the plurality of splitters 23, and is connected to the plurality of subscriber circuits 57. Multiplexing and demultiplexing for multiplexing a plurality of data band signals and outputting the multiplexed signals to the upstream optical fiber 7, receiving the multiplexed signal from the downstream optical fiber 9, and separating the multiplexed signal into data band signals for a plurality of subscriber circuits 57. It comprises a circuit 55.
[0045]
In the xDSL optical access system configured as described above, a voice band signal from the telephone exchange 39 or the ISDN exchange 41 is multiplexed by the concentrator / distributor 37 and supplied to the optical splitter 35. Further, a data band signal such as image data from the Internet service provider 45 is supplied to the optical splitter 35 via the router 43. The optical splitter 35 multiplexes the voice band signal from the concentrator / distributor 37 and the data band signal from the router 43 and sends the multiplexed signal to the downstream optical fiber 9.
[0046]
The subscriber terminal accommodating device 5 receives the multiplexed signal from the downstream optical fiber 9 by the optical splitter 31, separates the audio band signal and the data band signal, and separates the audio band signal by the concentrator / distributor 25 for each subscriber terminal. The data band signal is converted to the xDSL system by the xDSL aggregation modem 27 and separated for each subscriber terminal and supplied to each splitter 23. Each splitter 23 multiplexes the voice band signal from the concentrator / distributor 25 and the data band signal from the xDSL aggregation modem 27 and sends the multiplexed signal to the copper wire 3.
[0047]
Each subscriber terminal 1 receives the multiplexed signal from the copper wire 3 by the splitter 17, separates the voice band signal and the data band signal, supplies the voice band signal to the telephone terminal 13, and converts the data band signal into the xDSL. The data is supplied from the terminating device 21 to the data terminal 15 via the switch 19.
[0048]
Further, the voice band signal from the telephone terminal 13 of each subscriber terminal 1 is supplied to the splitter 17, and the data band signal from the data terminal 15 is supplied to the xDSL terminator 21 through the switch 19, where the xDSL system is used. The data is converted and supplied to the splitter 17. The splitter 17 multiplexes the voice band signal from the telephone terminal 13 and the data band signal from the data terminal 15 and sends out the multiplexed signal to the copper wire 3.
[0049]
In the subscriber terminal accommodation device 5, the multiplexed signal from the copper wire 3 is received by the corresponding splitter 23, separated into an audio band signal and a data band signal, and the audio band signal is supplied to the concentrator / distributor 25. The line concentrator 25 multiplexes the audio band signal from each subscriber terminal 1 and supplies it to the optical splitter 29. The data band signal separated by the splitter 23 is combined and multiplexed with the data band signal from each subscriber terminal 1 in the xDSL aggregation modem 27 and supplied to the optical splitter 29. The optical splitter 29 multiplexes the voice band signal from the concentrator / distributor 25 and the data band signal from the xDSL aggregation modem 27 and sends the multiplexed signal to the upstream optical fiber 7.
[0050]
In the communication carrier apparatus 11, the multiplexed signal from the upstream optical fiber 7 is received by the optical splitter 33 and separated into an audio band signal and a data band signal. The voice band signal is supplied to the telephone exchange 39 or the ISDN exchange 41 via the concentrator / distributor 37, and the data band signal is transmitted to the Internet service provider 45 via the router 43.
[0051]
As described above, the xDSL-based optical access system of the present embodiment can be easily applied to a system having an optical fiber in a transmission line, which has been difficult to apply conventionally. High-speed communication services can be provided.
[0052]
Conventionally, since the characteristic that the xDSL system can be realized only on the copper wire, its promotion has been a hindrance to FTTH, and if the opticalization (FTTH) is promoted, the xDSL system cannot be used. Although it was not possible to promote both of the optical systems, as can be seen from the above-described embodiment, the xDSL system can be easily introduced into an access system in which an optical transmission path is interposed, and the FTTH , It is possible to provide a subscriber with a high-speed communication service using xDSL.
[0053]
【The invention's effect】
As described above, according to the present invention, a multiplexed signal transmitted from an exchange via an optical fiber is separated into a voice band signal and a data band signal by an optical splitter, and the data band signal is converted into an xDSL system by xDSL conversion means. Since the data band signal and the voice band signal converted to the xDSL system are multiplexed by a splitter and transmitted to each subscriber terminal via a copper wire, it has been difficult to introduce xDSL in the past. Introduces the xDSL system without affecting the existing system by using the existing optical fiber provided between the exchange side and the subscriber terminal accommodating device for the optical transmission line interposed in the middle. And a high-speed data communication service can be realized efficiently and economically.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of an xDSL optical access system according to an embodiment of the present invention.
FIG. 2 is a diagram showing an optical splitter connected to a downstream optical fiber used in the xDSL optical access system shown in FIG. 1 and a detailed configuration of the optical splitter.
FIG. 3 is a diagram showing a configuration of an xDSL aggregation modem used for a subscriber terminal accommodation device of the xDSL optical access system shown in FIG. 1;
FIG. 4 is a diagram showing a basic configuration of an xDSL application system.
FIG. 5 is a diagram showing the configuration of an xDSL application system similar to the xDSL application system shown in FIG. 4 in more detail.
FIG. 6 is a diagram illustrating a carrier frequency in an ADSL system, which is one of typical xDSL systems.
FIG. 7 is a diagram showing a configuration of an optical transmission system in a case where an optical cable made of an optical fiber is used for connection between a subscriber terminal and a communication carrier device.
FIG. 8 is a diagram illustrating a configuration of a CR / RT type optical transmission system.
FIG. 9 is a diagram illustrating a configuration of a π-type optical transmission system.
FIG. 10 is a diagram showing a configuration of an optical transmission system of the SBM / ASM system.
[Explanation of symbols]
1 subscriber terminal
3 Copper wire
5 Subscriber terminal accommodation device
7 Upstream optical fiber
9 Downlink optical fiber
11 Telecommunications carrier equipment
13 telephone terminals
15 Data terminal
17,23 splitter
21 xDSL termination equipment
25, 37 Line concentrator
27 xDSL aggregation modem
29-35 Optical splitter

Claims (2)

In a system connected to a subscriber terminal accommodating device via an optical fiber from the exchange side and connected to a plurality of subscriber terminals via a copper wire from the subscriber terminal accommodating device,
The subscriber terminal accommodation device,
With separating logically multiplexed signal transmitted from the exchange side through a physically single optical fiber multiplexed into 2 lines in voiceband signal and a data band signal, and an audio band signal to the exchange side an optical splitter for transmitting the optical fiber and a data band signals are multiplexed, and xDSL conversion means for converting the separated data band signal in this light splitter xDSL scheme, converted data band signal to the xDSL system and voice A plurality of splitters for multiplexing a band signal for each subscriber terminal and transmitting the multiplexed multiplex signal for transmission to each subscriber terminal via a copper wire. system. In a system connected to a subscriber terminal accommodating device via an optical fiber from an exchange provided in a communication carrier device, and connected to a plurality of subscriber terminals via a copper wire from the subscriber terminal accommodating device,
The carrier device,
A concentrator for concentrating the voice band signal from the switch, and distributing the signal to the switch; and an external data including a voice band signal from the switch concentrated by the concentrator and an Internet service provider other than the switch. An optical splitter for logically multiplexing a data band signal from the device and physically transmitting the data band signal to one optical fiber, the subscriber terminal accommodating device,
An optical splitter that separates the multiplexed signal from the optical fiber into a voice band signal and a data band signal, multiplexes the voice band signal and the data band signal to the optical fiber, and sends the multiplexed signal to the optical fiber; Correspondingly provided, the multiplexed signal from the subscriber terminal is separated into a voice band signal and a data band signal, and the voice band signal and the data band signal to the subscriber terminal are multiplexed and transmitted to the copper wire. A plurality of splitters, and a concentrator that distributes the audio band signal separated by the optical splitter to the plurality of splitters, multiplexes the audio band signals from the plurality of splitters, and sends the multiplexed audio band signal to the optical splitter, A data band signal from an optical splitter is separated for a plurality of subscriber terminals, converted into an xDSL system, and supplied to the plurality of splitters. Both the plurality of data band signals from the plurality of splitters multiplexes, and a xDSL set modem supplied to the optical splitter,
The subscriber terminal,
It is connected to the copper wire, receives a multiplexed signal from the splitter of the subscriber terminal accommodating device, separates it into a voice band signal and a data band signal, supplies the voice band signal to the telephone terminal, and A splitter for multiplexing a band signal and a data band signal converted into an xDSL format from a data terminal and transmitting the multiplexed multiplexed signal to the copper wire; and a data band signal from the splitter connected to the splitter. And an xDSL terminator for converting the data band signal from the data terminal into an xDSL system and supplying the converted data to the splitter.

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