CA1208815A - Test equipment for manually testing an optical glassfibre subscriber line which is operated with bidirectional wavelength multiplex - Google Patents
Test equipment for manually testing an optical glassfibre subscriber line which is operated with bidirectional wavelength multiplexInfo
- Publication number
- CA1208815A CA1208815A CA000440992A CA440992A CA1208815A CA 1208815 A CA1208815 A CA 1208815A CA 000440992 A CA000440992 A CA 000440992A CA 440992 A CA440992 A CA 440992A CA 1208815 A CA1208815 A CA 1208815A
- Authority
- CA
- Canada
- Prior art keywords
- converter
- transmitter
- high frequency
- subscriber line
- signal
- 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.)
- Expired
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
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J14/00—Optical multiplex systems
- H04J14/02—Wavelength-division multiplex systems
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Optical Communication System (AREA)
Abstract
ABSTRACT
Test equipment for manually testing an optical glassfibre subscriber line which is operated with bi-directional wavelength multiplexing, has, in series, a high frequency transmitter comprising a parallel/series converter, an electro-optical converter comprising a laser transmitter and opto-electrical converter and a high frequency receiver comprising a serial/parallel converter. A keyboard with an interlock permitting actuation of the transmitter only during service-free periods enables the transmitter and permits transmission of a period synchronization signal at one end of the line. At the opposite end of the line, the synchron-ization signal is detected after conversion thereof by the opto-electrical converter and, in response thereto, a logic signal is transmitted in a rearward direction in a channel of a multi-channel system.
Test equipment for manually testing an optical glassfibre subscriber line which is operated with bi-directional wavelength multiplexing, has, in series, a high frequency transmitter comprising a parallel/series converter, an electro-optical converter comprising a laser transmitter and opto-electrical converter and a high frequency receiver comprising a serial/parallel converter. A keyboard with an interlock permitting actuation of the transmitter only during service-free periods enables the transmitter and permits transmission of a period synchronization signal at one end of the line. At the opposite end of the line, the synchron-ization signal is detected after conversion thereof by the opto-electrical converter and, in response thereto, a logic signal is transmitted in a rearward direction in a channel of a multi-channel system.
Description
2~8~1S
The present invention relates to test equipment for manually testing an optical glassfibre subscriber line.
The employment of wavelength multiplex operated glassfibre communication lines in the region of subscriber stations requires increasingly complicated measuring- and checking technology to detect the precise function of each communication line.
Therefore, maintenance staff should be able to obtain go-no go information with simple means for monitor~ing the operational readiness of the optical trans-mission lines and the wavelengths to be transmitted over the lines.
It is accordingly an object of the present invention to provide an equipment which, with simple means, enables monitoring of the operability of communication lines corresponding to each of the transmitted wavelengths on an optical subscriber circuit which is operated by wavelength multiplexing.
The present invention provides test equipment for manually testing an optical glassfibre subscriber line which is operated with bidirectional wavelength multiplexing, the subscriber line being provided in series with: a high frequency transmitter comprising a parallel/series converter;
an electro-optical converter comprising a laser transmitter;
an opto-electrical converter and a high frequency receiver comprising a serial/parallel converter, wherein the equip-ment further comprising key means, including interlocking means for permitting actuation of the laser transmitter only during service-free periods, for enabling the laser ~$
- 2 - ~Z~8~1S
transmitter and permitting the transmission of a period synchronizàtion signal at one end of the subscriber line;
the high frequency transmitter comprising means for providing the synchronization signal; means at the opposite end of the subscriber line for detecting the synchronization signal after conversion thereof by the opto-electrical converter and, in response, thereto, generating a logic signal and transmitting the logic signal in a rearward direction in a channel of a multi-channel system.
~ Testing the functioning of each individual transmission line, allocated to respective optical wave-length, is carried out during the duration of depression of a corresponding key (at the transmitter station) and is finished upon the release of the key.
Preferably, the interlocking means test equip-ment as claimed in Claim 1, wherein the interlocking means comprise means responsive to a threshold current of the laser transmitter for enabling the operation of the laser transmitter.
The equipment may include LED test equipment as claimed in Claim 1, further comprising ~ED means for indicat-ing the emission of a TEST signal and the existence of the logic signal.
An embodiment of the invention is described by way of example below with reference to the accompanying drawings in which:-Figure 1 shows a switching device for a laser transmitter, _ 3 _ 1 2~ 5 Eigure 2 shows devices at a remote location of a transmission path for connecting DSE-signals into a multi-channel system, Figure 3 shows the complete equipments at the starting point and the end point of the transmission path.
In Figure 1 logic signals obtained in depend-ence of the operational state of a laser transmitter 1 and more particularly in dependence on the threshold current of the laser, and by the actuation of a keyboard 2 are combined 10: by an RS-flipflop (not shown). As a result of the combina-tion, a "TEST" logic signal is produced. The circuit for generating the "TEST" logic signal includes an "OR"-output so that the simulation of the function of the keyboard 2 by other sources is also possible.
The function of the keyboard 2 is overridden as long as the laser transmitter 1 is in operation, i.e. the threshold current is flowing.
The initiation of the manuel subscriber line test is displayed at the laser transmitter to be tested by a LED (not shown).
As shown in Figure l a cable is used to trans-mit data signals D and bit time signals BT on lines 4 and 5 between a high frequency transmitter 7 and a corresponding electro-optical converter, i.e. the laser transmitter 1, as is well known in the art. A line 6 is used for transmitting back the "TEST" logic signal and carries out the following two functions, with self-holding of the high frequency trans-mitter 7 during the keyboard operation:
_ 4 _ ~2~8815 a) switching on the high frequency transmitter 7 through an input e~a, b) generation of a continuous synchronization signal, which is initiated by an input DS. The output of data signals is blocked as long as the continuous synchroni-zation signal is generated. Transmission of the continuous synchronization signal means that the whole time-multiplex-frame which is generated in the high frequency transmitter 7 is occupied by a synchronizing word at each time point.
~ Figure 2 shows by way of example an embodiment of a circuit for wavelengths ~1 and ~4.
At the remote end of the transmission line for the wavelength ~1 the continuous synchronization signals for the wavelength ~1 are detected. Additionally a converter 10 carries out an opto-electrical conversion. From the out-put signal of the converter 10 the seriall~ transmitted data D and the accompanying bit timing signal BT, which is generated by means of a phase-locked loop-circuit (not shown) are supplied to a serial-parallel-converter, which comprises a high frequency receiver 11 together with means for corres-ponding time frame- and continuous synchronization identi-fication. As a result of the identification of the con-tinuous synchronization signal, a "DSE" logic signal is generated.
The output of the circuit generating the "DSE"
logic signal is provided with an OR gate so that "DSE"-signals from a plurality of transmission lines, operated at different wavelengths (e.g. ~2'~3)' can be summarized at a junction point 8.
_ 5 ~ 815 The "DSE" logic signal is supplied to a stand-by circuit 9 which is allocated to the line for wavelength ~4. Upon application of the "DSE"-signal the high frequency transmitter 7 is switched on by output e/a of the stand-by circuit 9. In this state the high frequency transmitter 7 generates a time-multiplex-frame beginning with a synchroniz-ing block. A PCM multi-channel system (in this embodiment a PCM system with 30 channels (PCM 30)) is connected by the stand-by circuit 9 through a multiplex device 13 in this time-multiplex-frame. For the time duration o~ the test the stand-by circuit 9 supplies the "DSE"-signal to an 8 kbit/s-channel of the PCM-30 system which is reserved for the "DSE"
-transmission. The serially data stream D supplied by the high frequency transmitter 7, which includes the "DSE"-signal, is passed together with the bit timing signal BT to the electro-optical converter 1, i.e. the laser transmitter.
The test ("forward test") can also be initiated directly at the electro-optical converter 1 in the above described -nn~r by the key 2, which is allocated to the laser transmitter 1. If the test is initiated by the key 2, the time frame which is transmitted on the transmission line with the wavelength ~4 is filled uninterruptedly with synchronizing words.
As it is shown in Figure 3 the backwardly trans-mitted data are received by an electro-optical converter lOa and further processed in serial/parallel-converter 11. If a tr~n~m;tted data includes the "DSE"-signal in a 8 kbit/s-channel of a PCM-30-system the "DSE"-signal is detected by multiplex devices 13 and 14 and displayed by a LED 3a. If - 6 - 12~88~5 otherwise the received information consists of synchronizing words the "DSE"-signal is directly detected in the serial/
parallel-converter ll and also can be displayed by a LED.
Figure 3 shows further that the "DSE"-signal also can be fed in an 8 kbit/s-channel of a PC~-30-system which is transmitted thereupon by the electro-optical con-verter l (laser transmitter) with the wavelength ~l For this purpose the stand-by circuit 9, the multiplexer 13 ~format converter 13) and the high frequency transmitter HF-S 7 iare employed as described with reference to Figure 2.
The invention offers the possibility for a simple test of the functions of the essential parts of a transmission line.
Thereby the transmission of data consisting of synchronization words is effected at the transmitting station by a keyboard and an interlocking device which en-ables the laser transmitter only during a time which is free of services. At the remote location of the transmission line this data is detected and outputted as the "DSE" logic 2~ signal and eventually is displayed by a LED.
By means of the stand-by circuit 9 the "DSE"
~signal can be transmitted back to the location at which the test is initiated by a further wavelength in a reserved channel of the multi-channel system.
The present invention relates to test equipment for manually testing an optical glassfibre subscriber line.
The employment of wavelength multiplex operated glassfibre communication lines in the region of subscriber stations requires increasingly complicated measuring- and checking technology to detect the precise function of each communication line.
Therefore, maintenance staff should be able to obtain go-no go information with simple means for monitor~ing the operational readiness of the optical trans-mission lines and the wavelengths to be transmitted over the lines.
It is accordingly an object of the present invention to provide an equipment which, with simple means, enables monitoring of the operability of communication lines corresponding to each of the transmitted wavelengths on an optical subscriber circuit which is operated by wavelength multiplexing.
The present invention provides test equipment for manually testing an optical glassfibre subscriber line which is operated with bidirectional wavelength multiplexing, the subscriber line being provided in series with: a high frequency transmitter comprising a parallel/series converter;
an electro-optical converter comprising a laser transmitter;
an opto-electrical converter and a high frequency receiver comprising a serial/parallel converter, wherein the equip-ment further comprising key means, including interlocking means for permitting actuation of the laser transmitter only during service-free periods, for enabling the laser ~$
- 2 - ~Z~8~1S
transmitter and permitting the transmission of a period synchronizàtion signal at one end of the subscriber line;
the high frequency transmitter comprising means for providing the synchronization signal; means at the opposite end of the subscriber line for detecting the synchronization signal after conversion thereof by the opto-electrical converter and, in response, thereto, generating a logic signal and transmitting the logic signal in a rearward direction in a channel of a multi-channel system.
~ Testing the functioning of each individual transmission line, allocated to respective optical wave-length, is carried out during the duration of depression of a corresponding key (at the transmitter station) and is finished upon the release of the key.
Preferably, the interlocking means test equip-ment as claimed in Claim 1, wherein the interlocking means comprise means responsive to a threshold current of the laser transmitter for enabling the operation of the laser transmitter.
The equipment may include LED test equipment as claimed in Claim 1, further comprising ~ED means for indicat-ing the emission of a TEST signal and the existence of the logic signal.
An embodiment of the invention is described by way of example below with reference to the accompanying drawings in which:-Figure 1 shows a switching device for a laser transmitter, _ 3 _ 1 2~ 5 Eigure 2 shows devices at a remote location of a transmission path for connecting DSE-signals into a multi-channel system, Figure 3 shows the complete equipments at the starting point and the end point of the transmission path.
In Figure 1 logic signals obtained in depend-ence of the operational state of a laser transmitter 1 and more particularly in dependence on the threshold current of the laser, and by the actuation of a keyboard 2 are combined 10: by an RS-flipflop (not shown). As a result of the combina-tion, a "TEST" logic signal is produced. The circuit for generating the "TEST" logic signal includes an "OR"-output so that the simulation of the function of the keyboard 2 by other sources is also possible.
The function of the keyboard 2 is overridden as long as the laser transmitter 1 is in operation, i.e. the threshold current is flowing.
The initiation of the manuel subscriber line test is displayed at the laser transmitter to be tested by a LED (not shown).
As shown in Figure l a cable is used to trans-mit data signals D and bit time signals BT on lines 4 and 5 between a high frequency transmitter 7 and a corresponding electro-optical converter, i.e. the laser transmitter 1, as is well known in the art. A line 6 is used for transmitting back the "TEST" logic signal and carries out the following two functions, with self-holding of the high frequency trans-mitter 7 during the keyboard operation:
_ 4 _ ~2~8815 a) switching on the high frequency transmitter 7 through an input e~a, b) generation of a continuous synchronization signal, which is initiated by an input DS. The output of data signals is blocked as long as the continuous synchroni-zation signal is generated. Transmission of the continuous synchronization signal means that the whole time-multiplex-frame which is generated in the high frequency transmitter 7 is occupied by a synchronizing word at each time point.
~ Figure 2 shows by way of example an embodiment of a circuit for wavelengths ~1 and ~4.
At the remote end of the transmission line for the wavelength ~1 the continuous synchronization signals for the wavelength ~1 are detected. Additionally a converter 10 carries out an opto-electrical conversion. From the out-put signal of the converter 10 the seriall~ transmitted data D and the accompanying bit timing signal BT, which is generated by means of a phase-locked loop-circuit (not shown) are supplied to a serial-parallel-converter, which comprises a high frequency receiver 11 together with means for corres-ponding time frame- and continuous synchronization identi-fication. As a result of the identification of the con-tinuous synchronization signal, a "DSE" logic signal is generated.
The output of the circuit generating the "DSE"
logic signal is provided with an OR gate so that "DSE"-signals from a plurality of transmission lines, operated at different wavelengths (e.g. ~2'~3)' can be summarized at a junction point 8.
_ 5 ~ 815 The "DSE" logic signal is supplied to a stand-by circuit 9 which is allocated to the line for wavelength ~4. Upon application of the "DSE"-signal the high frequency transmitter 7 is switched on by output e/a of the stand-by circuit 9. In this state the high frequency transmitter 7 generates a time-multiplex-frame beginning with a synchroniz-ing block. A PCM multi-channel system (in this embodiment a PCM system with 30 channels (PCM 30)) is connected by the stand-by circuit 9 through a multiplex device 13 in this time-multiplex-frame. For the time duration o~ the test the stand-by circuit 9 supplies the "DSE"-signal to an 8 kbit/s-channel of the PCM-30 system which is reserved for the "DSE"
-transmission. The serially data stream D supplied by the high frequency transmitter 7, which includes the "DSE"-signal, is passed together with the bit timing signal BT to the electro-optical converter 1, i.e. the laser transmitter.
The test ("forward test") can also be initiated directly at the electro-optical converter 1 in the above described -nn~r by the key 2, which is allocated to the laser transmitter 1. If the test is initiated by the key 2, the time frame which is transmitted on the transmission line with the wavelength ~4 is filled uninterruptedly with synchronizing words.
As it is shown in Figure 3 the backwardly trans-mitted data are received by an electro-optical converter lOa and further processed in serial/parallel-converter 11. If a tr~n~m;tted data includes the "DSE"-signal in a 8 kbit/s-channel of a PCM-30-system the "DSE"-signal is detected by multiplex devices 13 and 14 and displayed by a LED 3a. If - 6 - 12~88~5 otherwise the received information consists of synchronizing words the "DSE"-signal is directly detected in the serial/
parallel-converter ll and also can be displayed by a LED.
Figure 3 shows further that the "DSE"-signal also can be fed in an 8 kbit/s-channel of a PC~-30-system which is transmitted thereupon by the electro-optical con-verter l (laser transmitter) with the wavelength ~l For this purpose the stand-by circuit 9, the multiplexer 13 ~format converter 13) and the high frequency transmitter HF-S 7 iare employed as described with reference to Figure 2.
The invention offers the possibility for a simple test of the functions of the essential parts of a transmission line.
Thereby the transmission of data consisting of synchronization words is effected at the transmitting station by a keyboard and an interlocking device which en-ables the laser transmitter only during a time which is free of services. At the remote location of the transmission line this data is detected and outputted as the "DSE" logic 2~ signal and eventually is displayed by a LED.
By means of the stand-by circuit 9 the "DSE"
~signal can be transmitted back to the location at which the test is initiated by a further wavelength in a reserved channel of the multi-channel system.
Claims (4)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Test equipment for manually testing an optical glassfibre subscriber line which is operated with bi-directional wavelength multiplexing, said subscriber line being provided in series with:
a high frequency transmitter comprising a parallel/series converter;
an electro-optical converter comprising a laser transmitter;
an opto-electrical converter and a high frequency receiver comprising a serial/
parallel converter, wherein said equipment further comprising key means, including interlocking means for permitting actuation of said laser transmitter only during service-free periods, for enabling said laser transmitter and permitting the transmission of a period synchronization signal at one end of said subscriber line;
said high frequency transmitter comprising means for providing said synchronization signal;
means at the opposite end of said subscriber line for detecting said synchronization signal after conver-sion thereof by said opto-electrical converter and, in response thereto, generating a logic signal and transmitting said logic signal in a rearward direction in a channel of a multi-channel system.
a high frequency transmitter comprising a parallel/series converter;
an electro-optical converter comprising a laser transmitter;
an opto-electrical converter and a high frequency receiver comprising a serial/
parallel converter, wherein said equipment further comprising key means, including interlocking means for permitting actuation of said laser transmitter only during service-free periods, for enabling said laser transmitter and permitting the transmission of a period synchronization signal at one end of said subscriber line;
said high frequency transmitter comprising means for providing said synchronization signal;
means at the opposite end of said subscriber line for detecting said synchronization signal after conver-sion thereof by said opto-electrical converter and, in response thereto, generating a logic signal and transmitting said logic signal in a rearward direction in a channel of a multi-channel system.
2. Test equipment as claimed in Claim 1, wherein said interlocking means comprise means responsive to a threshold current of said laser transmitter for enabling the operation of said laser transmitter.
3. Test equipment as claimed in Claim 1, further comprising LED means for indicating the emission of a TEST
signal and the existence of said logic signal.
signal and the existence of said logic signal.
4. Test equipment as claimed in Claim 1, 2 or 3, wherein said high frequency receiver includes means for period synchronizing word identification.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3242175.3 | 1982-11-13 | ||
| DE3242175 | 1982-11-13 | ||
| DE19833335674 DE3335674A1 (en) | 1982-11-13 | 1983-09-30 | DEVICE FOR MANUAL DISTANCE TESTING OF AN OPTICAL SUBSCRIBER CONNECTING LINE MADE OF GLASS FIBER WITH BIDIRECTIONAL WAVELENGTH MULTIPLEX |
| DEP3335674.2 | 1983-09-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1208815A true CA1208815A (en) | 1986-07-29 |
Family
ID=25805787
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000440992A Expired CA1208815A (en) | 1982-11-13 | 1983-11-10 | Test equipment for manually testing an optical glassfibre subscriber line which is operated with bidirectional wavelength multiplex |
Country Status (6)
| Country | Link |
|---|---|
| CA (1) | CA1208815A (en) |
| DE (1) | DE3335674A1 (en) |
| FR (1) | FR2536228B1 (en) |
| GB (1) | GB2131247B (en) |
| IN (1) | IN159452B (en) |
| SE (1) | SE8306221L (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6201620B1 (en) | 1997-03-26 | 2001-03-13 | Alcatel | Test method for a network element of an optical communication system and network element therefor with test module |
| CN109426240A (en) * | 2017-09-05 | 2019-03-05 | 大唐联仪科技有限公司 | A kind of test method and device |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE456190B (en) * | 1983-10-14 | 1988-09-12 | Ericsson Telefon Ab L M | PROCEDURE THAT IN A FIBER OPTICAL TRANSMISSION SYSTEM META THE DISPERSION OF THE TRANSMITTING OPTICAL FIBER |
| DE3434775A1 (en) * | 1984-09-21 | 1986-04-03 | Siemens AG, 1000 Berlin und 8000 München | Method for two-way data transmission |
| GB8906937D0 (en) * | 1989-03-28 | 1989-05-10 | Plessey Telecomm | Testing optical fibre links |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2716788A1 (en) * | 1977-04-15 | 1978-10-19 | Spinner Georg | Optical data system using test signal - transmits test signal between transmitter and receiver to monitor state of light guide |
| JPS593051B2 (en) * | 1978-01-09 | 1984-01-21 | ケイディディ株式会社 | Fault monitoring method for optical relay transmission lines |
| US4278850A (en) * | 1978-04-11 | 1981-07-14 | Kokusai Denshin Denwa Co., Ltd. | Monitoring system for optical transmission line repeaters |
| DE2829076A1 (en) * | 1978-07-01 | 1980-01-10 | Tekade Felten & Guilleaume | TEST ARRANGEMENT FOR DATA TRANSMISSION ROUTES |
| JPS596538B2 (en) * | 1979-02-08 | 1984-02-13 | ケイディディ株式会社 | Optical repeater monitoring method |
-
1983
- 1983-09-30 DE DE19833335674 patent/DE3335674A1/en active Granted
- 1983-10-25 IN IN1310/CAL/83A patent/IN159452B/en unknown
- 1983-11-10 CA CA000440992A patent/CA1208815A/en not_active Expired
- 1983-11-10 FR FR8317945A patent/FR2536228B1/en not_active Expired
- 1983-11-11 SE SE8306221A patent/SE8306221L/en not_active Application Discontinuation
- 1983-11-14 GB GB8330332A patent/GB2131247B/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6201620B1 (en) | 1997-03-26 | 2001-03-13 | Alcatel | Test method for a network element of an optical communication system and network element therefor with test module |
| CN109426240A (en) * | 2017-09-05 | 2019-03-05 | 大唐联仪科技有限公司 | A kind of test method and device |
| CN109426240B (en) * | 2017-09-05 | 2020-10-27 | 大唐联仪科技有限公司 | Test method and device |
Also Published As
| Publication number | Publication date |
|---|---|
| SE8306221D0 (en) | 1983-11-11 |
| DE3335674A1 (en) | 1984-05-24 |
| DE3335674C2 (en) | 1987-10-22 |
| FR2536228A1 (en) | 1984-05-18 |
| FR2536228B1 (en) | 1986-05-23 |
| IN159452B (en) | 1987-05-23 |
| GB8330332D0 (en) | 1983-12-21 |
| GB2131247A (en) | 1984-06-13 |
| GB2131247B (en) | 1986-06-11 |
| SE8306221L (en) | 1984-05-14 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |