CA2092167A1 - Device for transmitting optical signals - Google Patents
Device for transmitting optical signalsInfo
- Publication number
- CA2092167A1 CA2092167A1 CA 2092167 CA2092167A CA2092167A1 CA 2092167 A1 CA2092167 A1 CA 2092167A1 CA 2092167 CA2092167 CA 2092167 CA 2092167 A CA2092167 A CA 2092167A CA 2092167 A1 CA2092167 A1 CA 2092167A1
- Authority
- CA
- Canada
- Prior art keywords
- inlet
- couplers
- distributor
- relay station
- coupler
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
- H04B10/071—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Optical Communication System (AREA)
- Testing Of Optical Devices Or Fibers (AREA)
Abstract
ABSTRACT
A device for transmitting optical signals is disclosed, in which glass fibers are placed between a relay station and several subscribers, in line with a passive distributor (V) equipped with a coupler. At least one glass fiber (1, 2) connects the distributor (V) to the relay station and each subscriber to the distributor (V). 'n' couplers (K) are located in cascade formation in the distributor (V), each of which has one inlet and at least two outlets, and are connected to each other in such a way that, starting with the glass fiber (1) coming from the relay station, another coupler (K) is connected in each stage of the cascade formation by its inlet to each outlet of a coupler (K). Couplers (K) that are equipped with a second inlet (M) are located in at least the last stage of the cascade formation in the direction of the subscribers for providing an optical time domain reflection measurement point without much backscatter.
A device for transmitting optical signals is disclosed, in which glass fibers are placed between a relay station and several subscribers, in line with a passive distributor (V) equipped with a coupler. At least one glass fiber (1, 2) connects the distributor (V) to the relay station and each subscriber to the distributor (V). 'n' couplers (K) are located in cascade formation in the distributor (V), each of which has one inlet and at least two outlets, and are connected to each other in such a way that, starting with the glass fiber (1) coming from the relay station, another coupler (K) is connected in each stage of the cascade formation by its inlet to each outlet of a coupler (K). Couplers (K) that are equipped with a second inlet (M) are located in at least the last stage of the cascade formation in the direction of the subscribers for providing an optical time domain reflection measurement point without much backscatter.
Description
~2~67 A DEVICE FOR TRANSMITTING OPTICAL SIGNALS
Technical Field The invention relates to a device for transmitting optical signals, in which glass fibers are placed between a relay station and several subscribers, in line with a passive distributor equipped with couplers, where at least one glass fiber connects the distributor to the relay station, and each subscriber to the distributor.
Back~round of the Invention Such a device can be used, for example, by a local telephone network to connect subscribers to the public telecommunication system. The glass fibers can provide the subscribers with all narrow and broad band services that are available today. In that instance, "subscribers" may be individual subscribers who have telephone and telefax devices in a residential building, for example. However, "subscribers" may also be a high-rise building or a hospital, for example, to which at least one glass fiber leads from the distributor. In such "subscribers", the signals transmitted by the glass fiber are internally distributed to a number of devices.
Furthermore, "subscribers" may be a collection point from which the signals can also be distributed by conventional technology.
OTDR (Optical Time Domain Reflection) devices are normally used to control the functionability of such a device; they evaluate the backscatter signal of a laser impulse that is supplied to the glass fiber, from which they obtain information about the application of attenuation to the glass fiber. The OTDR-device can also locate a defect in the glass fiber. The larger the number of glass fibers connected to the distributor and leading to the subscribers, the more problematic is the use of an OTDR-device. The backscatter signal is attenuated in accordance with the number of couplers being used, so that the dynamic range of the OTDR-device is exceedingly limited. Furthermore, the backscatter 2~2~7 signal represents a total signal of all transmission paths, so that a possible fiber break could not be attributed to a specific glass fiber.
Disclosure of Invention An object of the present invention is configuring the device described above, so that the measurement of an attenuation and the location of a defect with the OTDR-device produce useful results.
According to the present invention, 'n' couplers, each having one inlet and at least two outlets, are interconnected in cascade formation in the distributor, so that, starting with the glass fiber coming from the relay station, another coupler is connected by its inlet to each outlet of a coupler in each stage of the cascade formation, and couplers which are equipped with a second inlet, are installed at least in the last stage of the cascade formation in the direction of the subscribers.
The use of this device ensures simple attenuation measurement and the sure location of defects. There are no significant losses of the backscatter signal, because of the fact that the OTDR-device is only used in the last stage of the cascade formation. When the couplers in the last stage of the cascade formation only have two outlets, in the preferred configuration, the backscatter signal is only halved. In this device, the backscatter signal is the total signal of only a few, preferably two, transmission paths, so that a located defect can easily be attributed to the defective glass fiber. Testing the glass fiber that is connected to a coupler does not disturb the simultaneous operation in the other transmission paths. In each instance, the OTDR-device can be connected with particular ease, since the corresponding couplers are equipped with an easily accessible second inlet.
The couplers with a second inlet are used to advantage only in the last stage of the cascade 2~92~
formation, since only one connection of the OTDR-device in this area leads to meaningful and practical results.
However, the use of couplers with a second inlet in a different stage of the cascade formation is thereby not excluded.
Other advantageous configurations of the invention can be found described below.
The notations "inlet" and "outlet" for the couplers have been selected for the sake of simplicity. They correspond to this function during transmission of the signals from the relay station to the subscribers. In the other direction of the transmission, the outlets of the couplers would then be their inlets, and their inlet would then be their outlet.
These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of a best mode embodiment thereof, as illustrated in the accompanying drawing.
Brief Description of the Drawin~
Figure 1 is the device of the invention in schematic form.
Figure 2 is an enlarged view of a distributor that can be used in the arrangement according to the invention.
Figures 3 to 5 are views of different couplers that may be used according to the invention.
Best Mode for CarrYinq Out the Invention A glass fiber 1 leads from the relay station VST of a telecommunication network to a passive distributor V.
The distance between the relay station VST and the distributor V can be of any size, within the limitations of the system. In this way, the distributor V could even be located inside the relay station VST. In the configuration example shown, each of eight subscribers T
2~2~i7 are connected to the distributor V by a glass or optical fiber 2. The number of subscribers T that can be connected to the distributor V is also of any size, again within the limitations of the system. At least one glass fiber 2 is used for each subscriber T. For example, two glass fibers can be placed between the relay station VST
and the distributor V, which can be used alternatively if the distributor V has two inlets.
According to figure 2, several couplers K are connected to each other in three stages I, II, III in cascade formation in the distributor V. Each coupler K
is constructed, for example, as shown in figure 3. It has an inlet E and two outlets A1 and A2. Another coupler K is connected by its inlet to each outlet of an coupler K in the distributor V. The respective glass fibers of the couplers have been fusion spliced to each other, for example. However, they could also be connected by plugs.
In stage I of the cascade formation, a coupler K is connected to the glass fiber 1 coming from the relay station VST. Stage II of the cascade formation has two couplers K, which are connected by their inlets to both outlets of the coupler K of stage I. Since each coupler of stage II has two outlets, four couplers K are located in stage III, which are connected by their inlets to each outlet of the couplers K in stage II. The glass fibers 2 lead from the couplers K in stage III to the subscribers T. In a preferred configuration, the couplers K in stage III only have two outlets, so that only two glass fibers 2 can be connected to them. If the OTDR-device is connected to these couplers K, the attenuation measurement and the location of defects are particularly simplified in this manner.
More than three stages can be connected to each other in the distributor V by couplers K in cascade formation, if more than eight subscribers T must be connected to the relay station VST. However, it is also 2a~2~ 67 possible to use couplers with more than two outlets.
Therefore, the couplers K shown in figure 4 could be used, which have three outlets A1, A2 and A3. In that event, stage II of the distributor V would already have three couplers K, and stage III would have nine couplers K. Couplers with more than three outlets could also be used. It is equally possible to connect less than eight subscribers T to the distributor V.
In the represented configuration example, the couplers K in stage III have a second inlet M, as shown in figure 5. The second inlet M serves to connect an OTDR-device. It may be equipped with a plug for that purpose. Such a second inlet M can be reflection-optimized by grinding it at an angle. The second inlet M
may be extended with a so-called "pigtail" for connection of the OTDR-device, in a known manner.
Although the invention has been shown and described with respect to a best mode embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and additions in the form and detail thereof may be made therein without departing from the spirit and scope of the invention.
Technical Field The invention relates to a device for transmitting optical signals, in which glass fibers are placed between a relay station and several subscribers, in line with a passive distributor equipped with couplers, where at least one glass fiber connects the distributor to the relay station, and each subscriber to the distributor.
Back~round of the Invention Such a device can be used, for example, by a local telephone network to connect subscribers to the public telecommunication system. The glass fibers can provide the subscribers with all narrow and broad band services that are available today. In that instance, "subscribers" may be individual subscribers who have telephone and telefax devices in a residential building, for example. However, "subscribers" may also be a high-rise building or a hospital, for example, to which at least one glass fiber leads from the distributor. In such "subscribers", the signals transmitted by the glass fiber are internally distributed to a number of devices.
Furthermore, "subscribers" may be a collection point from which the signals can also be distributed by conventional technology.
OTDR (Optical Time Domain Reflection) devices are normally used to control the functionability of such a device; they evaluate the backscatter signal of a laser impulse that is supplied to the glass fiber, from which they obtain information about the application of attenuation to the glass fiber. The OTDR-device can also locate a defect in the glass fiber. The larger the number of glass fibers connected to the distributor and leading to the subscribers, the more problematic is the use of an OTDR-device. The backscatter signal is attenuated in accordance with the number of couplers being used, so that the dynamic range of the OTDR-device is exceedingly limited. Furthermore, the backscatter 2~2~7 signal represents a total signal of all transmission paths, so that a possible fiber break could not be attributed to a specific glass fiber.
Disclosure of Invention An object of the present invention is configuring the device described above, so that the measurement of an attenuation and the location of a defect with the OTDR-device produce useful results.
According to the present invention, 'n' couplers, each having one inlet and at least two outlets, are interconnected in cascade formation in the distributor, so that, starting with the glass fiber coming from the relay station, another coupler is connected by its inlet to each outlet of a coupler in each stage of the cascade formation, and couplers which are equipped with a second inlet, are installed at least in the last stage of the cascade formation in the direction of the subscribers.
The use of this device ensures simple attenuation measurement and the sure location of defects. There are no significant losses of the backscatter signal, because of the fact that the OTDR-device is only used in the last stage of the cascade formation. When the couplers in the last stage of the cascade formation only have two outlets, in the preferred configuration, the backscatter signal is only halved. In this device, the backscatter signal is the total signal of only a few, preferably two, transmission paths, so that a located defect can easily be attributed to the defective glass fiber. Testing the glass fiber that is connected to a coupler does not disturb the simultaneous operation in the other transmission paths. In each instance, the OTDR-device can be connected with particular ease, since the corresponding couplers are equipped with an easily accessible second inlet.
The couplers with a second inlet are used to advantage only in the last stage of the cascade 2~92~
formation, since only one connection of the OTDR-device in this area leads to meaningful and practical results.
However, the use of couplers with a second inlet in a different stage of the cascade formation is thereby not excluded.
Other advantageous configurations of the invention can be found described below.
The notations "inlet" and "outlet" for the couplers have been selected for the sake of simplicity. They correspond to this function during transmission of the signals from the relay station to the subscribers. In the other direction of the transmission, the outlets of the couplers would then be their inlets, and their inlet would then be their outlet.
These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of a best mode embodiment thereof, as illustrated in the accompanying drawing.
Brief Description of the Drawin~
Figure 1 is the device of the invention in schematic form.
Figure 2 is an enlarged view of a distributor that can be used in the arrangement according to the invention.
Figures 3 to 5 are views of different couplers that may be used according to the invention.
Best Mode for CarrYinq Out the Invention A glass fiber 1 leads from the relay station VST of a telecommunication network to a passive distributor V.
The distance between the relay station VST and the distributor V can be of any size, within the limitations of the system. In this way, the distributor V could even be located inside the relay station VST. In the configuration example shown, each of eight subscribers T
2~2~i7 are connected to the distributor V by a glass or optical fiber 2. The number of subscribers T that can be connected to the distributor V is also of any size, again within the limitations of the system. At least one glass fiber 2 is used for each subscriber T. For example, two glass fibers can be placed between the relay station VST
and the distributor V, which can be used alternatively if the distributor V has two inlets.
According to figure 2, several couplers K are connected to each other in three stages I, II, III in cascade formation in the distributor V. Each coupler K
is constructed, for example, as shown in figure 3. It has an inlet E and two outlets A1 and A2. Another coupler K is connected by its inlet to each outlet of an coupler K in the distributor V. The respective glass fibers of the couplers have been fusion spliced to each other, for example. However, they could also be connected by plugs.
In stage I of the cascade formation, a coupler K is connected to the glass fiber 1 coming from the relay station VST. Stage II of the cascade formation has two couplers K, which are connected by their inlets to both outlets of the coupler K of stage I. Since each coupler of stage II has two outlets, four couplers K are located in stage III, which are connected by their inlets to each outlet of the couplers K in stage II. The glass fibers 2 lead from the couplers K in stage III to the subscribers T. In a preferred configuration, the couplers K in stage III only have two outlets, so that only two glass fibers 2 can be connected to them. If the OTDR-device is connected to these couplers K, the attenuation measurement and the location of defects are particularly simplified in this manner.
More than three stages can be connected to each other in the distributor V by couplers K in cascade formation, if more than eight subscribers T must be connected to the relay station VST. However, it is also 2a~2~ 67 possible to use couplers with more than two outlets.
Therefore, the couplers K shown in figure 4 could be used, which have three outlets A1, A2 and A3. In that event, stage II of the distributor V would already have three couplers K, and stage III would have nine couplers K. Couplers with more than three outlets could also be used. It is equally possible to connect less than eight subscribers T to the distributor V.
In the represented configuration example, the couplers K in stage III have a second inlet M, as shown in figure 5. The second inlet M serves to connect an OTDR-device. It may be equipped with a plug for that purpose. Such a second inlet M can be reflection-optimized by grinding it at an angle. The second inlet M
may be extended with a so-called "pigtail" for connection of the OTDR-device, in a known manner.
Although the invention has been shown and described with respect to a best mode embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and additions in the form and detail thereof may be made therein without departing from the spirit and scope of the invention.
Claims (7)
1. A device for transmitting optical signals, in which glass fibers are placed between a relay station and several subscribers (T), in line with a passive distributor equipped with a coupler, where the distributor is connected to the relay station, and each subscriber to the distributor, by at least one glass fiber (1), wherein - 'n' couplers (K), each of which has one inlet (E) and at least two outlets (Al, A2), are connected to each other in cascade formation in the distributor (V) in such a way that, starting with the glass fiber (1) coming from the relay station (VST), each outlet of a coupler K
in each stage of the cascade formation is connected by its inlet to another coupler X, and - couplers (K), which are equipped with a second inlet (M), are located at least in the last stage of the cascade formation in the direction of subscribers (T).
in each stage of the cascade formation is connected by its inlet to another coupler X, and - couplers (K), which are equipped with a second inlet (M), are located at least in the last stage of the cascade formation in the direction of subscribers (T).
2. A device according to claim 1, wherein the last stage of the cascade formation only has couplers (K) with two outlets (Al, A2).
3. A device according to claim 1, wherein the second inlet (M) of couplers (K) is equipped with a plug.
4. A device according to claim 2, wherein the second inlet (M) of couplers (K) is equipped with a plug.
5. A device according to claim 1, wherein the second inlet (M) is reflection-optimized.
6. A device according to claim 2, wherein the second inlet (M) is reflection-optimized.
7. A device according to claim 3, wherein the second inlet (M) is reflection-optimized.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19924209357 DE4209357A1 (en) | 1992-03-23 | 1992-03-23 | Optical signal transmission system - uses branch couplers in last stage of distributor having additional inputs for connection of optical time domain reflection device |
| DEP4209357.0 | 1992-03-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2092167A1 true CA2092167A1 (en) | 1993-09-24 |
Family
ID=6454774
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2092167 Abandoned CA2092167A1 (en) | 1992-03-23 | 1993-03-22 | Device for transmitting optical signals |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPH0677905A (en) |
| CA (1) | CA2092167A1 (en) |
| DE (1) | DE4209357A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4343943A1 (en) * | 1993-12-22 | 1995-06-29 | Siemens Ag | Optical coupler module |
| JPH10156452A (en) * | 1996-11-28 | 1998-06-16 | Sango Co Ltd | Outer cylinder forming machine of silencer |
-
1992
- 1992-03-23 DE DE19924209357 patent/DE4209357A1/en not_active Withdrawn
-
1993
- 1993-03-19 JP JP5060459A patent/JPH0677905A/en not_active Withdrawn
- 1993-03-22 CA CA 2092167 patent/CA2092167A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0677905A (en) | 1994-03-18 |
| DE4209357A1 (en) | 1993-09-30 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |