CA2267825A1 - Portable testing device for telecommunications network - Google Patents
Portable testing device for telecommunications network Download PDFInfo
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- CA2267825A1 CA2267825A1 CA002267825A CA2267825A CA2267825A1 CA 2267825 A1 CA2267825 A1 CA 2267825A1 CA 002267825 A CA002267825 A CA 002267825A CA 2267825 A CA2267825 A CA 2267825A CA 2267825 A1 CA2267825 A1 CA 2267825A1
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- testing
- test
- loop
- communications
- interface device
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L43/00—Arrangements for monitoring or testing data switching networks
- H04L43/50—Testing arrangements
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/02—Details
- H04B3/46—Monitoring; Testing
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/14—Monitoring arrangements
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/24—Arrangements for testing
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
- H04M11/06—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
- H04M11/062—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors using different frequency bands for speech and other data
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/22—Arrangements for supervision, monitoring or testing
- H04M3/26—Arrangements for supervision, monitoring or testing with means for applying test signals or for measuring
- H04M3/28—Automatic routine testing ; Fault testing; Installation testing; Test methods, test equipment or test arrangements therefor
- H04M3/30—Automatic routine testing ; Fault testing; Installation testing; Test methods, test equipment or test arrangements therefor for subscriber's lines, for the local loop
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/22—Arrangements for supervision, monitoring or testing
- H04M3/26—Arrangements for supervision, monitoring or testing with means for applying test signals or for measuring
- H04M3/28—Automatic routine testing ; Fault testing; Installation testing; Test methods, test equipment or test arrangements therefor
- H04M3/32—Automatic routine testing ; Fault testing; Installation testing; Test methods, test equipment or test arrangements therefor for lines between exchanges
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M2203/00—Aspects of automatic or semi-automatic exchanges
- H04M2203/05—Aspects of automatic or semi-automatic exchanges related to OAM&P
- H04M2203/055—Aspects of automatic or semi-automatic exchanges related to OAM&P loopback testing
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/22—Arrangements for supervision, monitoring or testing
- H04M3/2209—Arrangements for supervision, monitoring or testing for lines also used for data transmission
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/22—Arrangements for supervision, monitoring or testing
- H04M3/26—Arrangements for supervision, monitoring or testing with means for applying test signals or for measuring
- H04M3/28—Automatic routine testing ; Fault testing; Installation testing; Test methods, test equipment or test arrangements therefor
- H04M3/30—Automatic routine testing ; Fault testing; Installation testing; Test methods, test equipment or test arrangements therefor for subscriber's lines, for the local loop
- H04M3/308—Craftsperson test terminals
Abstract
A portable testing interface device provides the functionality of conventional fixed test installations anywhere on a communications line. The portable testing interface device works with a conventional tester to provide test signals and to analyze the results of those signals from a selected communications loop on the communications laze. The present invention also facilitates simultaneous testing on two adjacent loops of the communications line.
Description
PORTABLE TESTING DEVICE FOR TELECOMMUNICATIONS
NETWORK
Technical Field s The present invention relates generally to testing portable testing devices for telephone and data lines. In particular, the present invention is directed to a portable interface device and a testing system for testing Tl digital links on twisted wire pairs in a telephone system, at any point on that system.
to Background Ay Telecommunication networks are constituted by twisted wire pairs which are used to convey analog voice signals. These same twisted wire pairs can also be used to cant' digital information usvng a number of different digital systems, having different organization and routing protocols, such as ISDN, T1, i5 T3, ATM and SONET.
The most common digital link used on twisted wire pairs telephone systems is T 1. The T 1 system enables the transmission of voice and data, as well as, video signals at the rate of 1.544 million bits per second. The key advantage of using a T 1 link is that multiple forms of communications (such as 2 o telephone, facsimile and computer data transfer;) can be placed on a single twisted wire pair. Consequently, the number of lines required for a particular number of users is reduced. Further, the speed .at which communications are routed and handled is greatly increased.
A T1 digital link is capable of handling .a wide variety of different communication modes over a limited number of lines due to the use of a variety of different multiplexing schemes. The most common method of digitalizing analog voice signals is a technique called pulse code modulation (PCM).
Essentially, PCM is sampling process that compresses voice conversations into a 64 KBS standard rate known as digital signal level DSQ3. Once digitized, voice and/or data signals from a number of different sources can be combined io by virtue of multiplexing, and transmitted over a single T1 link. Most commonly, this is done by means of time division multiplexing (TDM).
A common testing format for communication signals over T 1 is the DS 1 format, which is also used by digital end-users of the communications system.
This format is the result of pulse code modulation and time division i5 multiplexing, creating a single 1.544 MBS signal, which is based upon 8,000 samples per second. A full explanation of T1 protocol, including DS1, is found in Appendix I attached hereto, including Telecommunication Techniques Corporation technical note entitled TI Basics, published 1990 and incorporated herein by reference.
Digital signals attenuate as they progress along the T1 link. Such attenuation is usually the result of line noise caused by interference from other electrical forces. To compensate for these negative effects, devices designated as regenerative repeaters sample and recreate the original signal at periodic intervals along the communications link. Figure. 2 depicts the deployment of such a repeater 16 arranged on communication lines 10 (having two sides 14, 15) between two central offices 12,13 which carry out the standard switching and control functions associated with conventional telephone company switching stations. Repeaters such as device 1 Ei will be found at periodic io intervals along communication lines 10 in order to regenerate or renew the digital signals.
A wide variety of T1 system configurations and protocols are available.
One example is HDSL, described in the publication TI Basics, supra, as well as other parts of Appendix I. Figures 2 and 3 depict a number of elements that can i5 be found in a communication system employing T1 digital links. For example, a plurality of central offices or switching centers 12,13 are provided with interface equipment, 20. There is also customer installations 19 with associated customer equipment (CPE) including a loop extender 21. Further examples of the types of equipment, that can be found in use. with a TI digital link are 2 o depicted in the publication Tl Basics, supra., and the ADC
NETWORK
Technical Field s The present invention relates generally to testing portable testing devices for telephone and data lines. In particular, the present invention is directed to a portable interface device and a testing system for testing Tl digital links on twisted wire pairs in a telephone system, at any point on that system.
to Background Ay Telecommunication networks are constituted by twisted wire pairs which are used to convey analog voice signals. These same twisted wire pairs can also be used to cant' digital information usvng a number of different digital systems, having different organization and routing protocols, such as ISDN, T1, i5 T3, ATM and SONET.
The most common digital link used on twisted wire pairs telephone systems is T 1. The T 1 system enables the transmission of voice and data, as well as, video signals at the rate of 1.544 million bits per second. The key advantage of using a T 1 link is that multiple forms of communications (such as 2 o telephone, facsimile and computer data transfer;) can be placed on a single twisted wire pair. Consequently, the number of lines required for a particular number of users is reduced. Further, the speed .at which communications are routed and handled is greatly increased.
A T1 digital link is capable of handling .a wide variety of different communication modes over a limited number of lines due to the use of a variety of different multiplexing schemes. The most common method of digitalizing analog voice signals is a technique called pulse code modulation (PCM).
Essentially, PCM is sampling process that compresses voice conversations into a 64 KBS standard rate known as digital signal level DSQ3. Once digitized, voice and/or data signals from a number of different sources can be combined io by virtue of multiplexing, and transmitted over a single T1 link. Most commonly, this is done by means of time division multiplexing (TDM).
A common testing format for communication signals over T 1 is the DS 1 format, which is also used by digital end-users of the communications system.
This format is the result of pulse code modulation and time division i5 multiplexing, creating a single 1.544 MBS signal, which is based upon 8,000 samples per second. A full explanation of T1 protocol, including DS1, is found in Appendix I attached hereto, including Telecommunication Techniques Corporation technical note entitled TI Basics, published 1990 and incorporated herein by reference.
Digital signals attenuate as they progress along the T1 link. Such attenuation is usually the result of line noise caused by interference from other electrical forces. To compensate for these negative effects, devices designated as regenerative repeaters sample and recreate the original signal at periodic intervals along the communications link. Figure. 2 depicts the deployment of such a repeater 16 arranged on communication lines 10 (having two sides 14, 15) between two central offices 12,13 which carry out the standard switching and control functions associated with conventional telephone company switching stations. Repeaters such as device 1 Ei will be found at periodic io intervals along communication lines 10 in order to regenerate or renew the digital signals.
A wide variety of T1 system configurations and protocols are available.
One example is HDSL, described in the publication TI Basics, supra, as well as other parts of Appendix I. Figures 2 and 3 depict a number of elements that can i5 be found in a communication system employing T1 digital links. For example, a plurality of central offices or switching centers 12,13 are provided with interface equipment, 20. There is also customer installations 19 with associated customer equipment (CPE) including a loop extender 21. Further examples of the types of equipment, that can be found in use. with a TI digital link are 2 o depicted in the publication Tl Basics, supra., and the ADC
Telecommunications, Inc. publication ADCP-6i'-314, January 1996, incorporated herein by reference.
Equipment faults or other line problems can occur anywhere on the transmission lines 10 between the central offices 12,13 and the end users 19.
Precisely locating faults along a T1 line can be .a difficult and time consuming task, which requires line inspection and electro~uc testing of the line segments to isolate the problem.
The testing of a T 1 digital link can include checking for fault conditions along the communications lines 14, 15. Also included is the measurement of bit io errors, frame errors, CRC errors and bipolar violation (BPV). Out-of service testing allows the measurement of bit errors. Also, this type of testing is more precise than in service monitoring. Consequently, for purposes of this application, only out-of service testing is considered.
Out-of service testing requires that all hive traffic be removed from a i5 segment of Tl digital line before testing can begin. A test instrument is then used to transmit a specific data pattern to a receiving test instrument that recognizes the sequence of the pattern. Any deviations from the transmitted pattern are then counted as errors throughout the receiving instrument. Out-of service testing can be conducted on a point-to-point basis or by creating a loopback. Point-to-point testing is the technique most often in use but requires two test instruments.
Loopback testing is often used as a quick check of circuit performance, or when trying to isolate a fault. In this type of testing a single test instrument is used to send a loop-up code to a far end channel service unit or interface before data is actually transmitted. The loop-up crosses all transmitted data to be looped back toward the test instrument. By analyzing the received data for errors, the test instrument measures the performance of the link up to an including the far-end CSU. However, loopback: testing is limited so that it can i o only analyze the combined performance in both directions of the link.
Thus, it is often extremely difficult to determine whether the errors originating on the transmit 14 or the receive 15 sides of the T1 link at any one given time.
Nonetheless, loopback testing is in common usc~ since only a single instrument and technician need be used at any one time.
i5 The problem of testing is compounded in new insulations where the testing technician need to wait for the central oi~ce (CO) to be wired before testing the line to the customer. Further, using conventional loopback testing techniques, a number of points at which testing can be carried out are severely constrained. In conventional systems, loopbach testing is generally limited to central office locations or other similar installations since these are the only locations with sufficient facilities to carry out loopback testing.
A number of conventional techniques are used to carry out testing of a communications system on which T1 links can be used. However, these techniques are largely confined to fixed installations. For example, the function cards described in the publications listed in ApI>endix I are used to carry out a variety of different tests on associated communications lines. However, these cards and the testing apparatus associated therewith are confined to fixed installations such as central offices, repeating stations and the like.
io Consequently, the test functions facilitated by conventional testing devices are largely limited to telephone company installations.
There are no testing systems utilizing the function cards described by the publications of Appendix I that are the capability of moving to any point on the communications line in ordez to carry out tests at any selected point on the i5 communications line. Accordingly, the isolation of faults on communications lines is very difficult since segmenting the communications line into test loops most appropriate for finding the fault is severely constrained by the location of the facilities that contain the testing cards and associated devices. A more flexible system is required for quick, efficient isolation of faults on a o communication lines.
Equipment faults or other line problems can occur anywhere on the transmission lines 10 between the central offices 12,13 and the end users 19.
Precisely locating faults along a T1 line can be .a difficult and time consuming task, which requires line inspection and electro~uc testing of the line segments to isolate the problem.
The testing of a T 1 digital link can include checking for fault conditions along the communications lines 14, 15. Also included is the measurement of bit io errors, frame errors, CRC errors and bipolar violation (BPV). Out-of service testing allows the measurement of bit errors. Also, this type of testing is more precise than in service monitoring. Consequently, for purposes of this application, only out-of service testing is considered.
Out-of service testing requires that all hive traffic be removed from a i5 segment of Tl digital line before testing can begin. A test instrument is then used to transmit a specific data pattern to a receiving test instrument that recognizes the sequence of the pattern. Any deviations from the transmitted pattern are then counted as errors throughout the receiving instrument. Out-of service testing can be conducted on a point-to-point basis or by creating a loopback. Point-to-point testing is the technique most often in use but requires two test instruments.
Loopback testing is often used as a quick check of circuit performance, or when trying to isolate a fault. In this type of testing a single test instrument is used to send a loop-up code to a far end channel service unit or interface before data is actually transmitted. The loop-up crosses all transmitted data to be looped back toward the test instrument. By analyzing the received data for errors, the test instrument measures the performance of the link up to an including the far-end CSU. However, loopback: testing is limited so that it can i o only analyze the combined performance in both directions of the link.
Thus, it is often extremely difficult to determine whether the errors originating on the transmit 14 or the receive 15 sides of the T1 link at any one given time.
Nonetheless, loopback testing is in common usc~ since only a single instrument and technician need be used at any one time.
i5 The problem of testing is compounded in new insulations where the testing technician need to wait for the central oi~ce (CO) to be wired before testing the line to the customer. Further, using conventional loopback testing techniques, a number of points at which testing can be carried out are severely constrained. In conventional systems, loopbach testing is generally limited to central office locations or other similar installations since these are the only locations with sufficient facilities to carry out loopback testing.
A number of conventional techniques are used to carry out testing of a communications system on which T1 links can be used. However, these techniques are largely confined to fixed installations. For example, the function cards described in the publications listed in ApI>endix I are used to carry out a variety of different tests on associated communications lines. However, these cards and the testing apparatus associated therewith are confined to fixed installations such as central offices, repeating stations and the like.
io Consequently, the test functions facilitated by conventional testing devices are largely limited to telephone company installations.
There are no testing systems utilizing the function cards described by the publications of Appendix I that are the capability of moving to any point on the communications line in ordez to carry out tests at any selected point on the i5 communications line. Accordingly, the isolation of faults on communications lines is very difficult since segmenting the communications line into test loops most appropriate for finding the fault is severely constrained by the location of the facilities that contain the testing cards and associated devices. A more flexible system is required for quick, efficient isolation of faults on a o communication lines.
Summar3r of the Invention Accordingly it is an object of the present invention to provide a portable testing apparatus that can be applied on any point of a communications line to carry out loopback, out-of service testing.
It is another object of the present invention to provide out-of service testing device that can carry out loopback testing without relying upon the communications line to provide power.
It is a further object of the present invention to provide a system and method for carrying out-of service loopback testing onto two test loops io simultaneously.
It is an additional object of the present iinvention to provide a test system capable of accommodating a plurality o:f different signal formats for both the communications line under test and the testing apparatus.
It is still another object of the present irmention to provide a testing 15 system in which a standard test device can be used with standard interface cards.
It is again a further object of the present invention to simulate the operations of a telephone company central routing and control once or an interface to a customer installation for test purposes with a portable testing 2 o device.
These and other objects and goals of thf; present invention are facilitated by portable testing interface device for sending and receiving test signals over communications lines having a first and second side. The portable testing interface device is arranged to establish a testing loop at any point on the communications lines and includes a power system for obtaining power to send test signals through the testing loop. The portable testing interface also includes access devices for connecting to the first and second sides of the communications line to form the testing loop at any point on the communications line. Also included in the portable testing interface device is a i o conversion system for converting between communications line formats and test formats. An interface device within the portable testing interface device is used to operatively connect the conversion system and the access device to an independent testing device which is used for generating and evaluating test signals routed through the testing loop.
i5 Another embodiment of the present invention includes a method of testing at any point on a communications line at a communications loop with first and second sides. The method includes the steps of accessing any selected point on the communications line with a portable testing interface device to create a testing loop, and providing power to the testing loop from a source not 2 o dependent on the communications line. Then a test signal is generating in _8_ testing format, converting the communications line format and applied to the first side of the testing loop.
Another embodiment of the present invention includes a method of testing adjacent test loops at any point on a comunumications line. The method includes the steps of selecting an access point o:n the communications line and splitting the line into two segments, each constituting a separate test loop.
A
separate portable testing interface device having; a separate independent tester associated therewith is applied to each test loop. Each of the independent testers sends an appropriate set of test signals to the corresponding test loop.
io Responsive to each set of test signals, response signals are received from each test loop and sent to a corresponding independent tester for evaluation.
Brief Description of the Drawings Figure 1 is a block diagram depicting the components of one i5 embodiment of the present invention.
Figure 2 is a block diagram depicting components of a communications system supporting a T 1 digital link.
Figure 3 is a block diagram depicting additional elements of a communications system supporting a T 1 digital link.
_g_ Figure 4 is a block diagram depicting components in a second embodiment of the test device of the present invention.
Detailed Description of the Preferred Embodiments As previously discussed, Figures 2 and 3 depict components of a typical communications system used to support a T1 digital link. A more elaborate depiction of such systems and many more components therein is found in the publication TI Basics, supra. Figure 2 depicts .a communications system using twisted wire pairs 10 running between two central offices 20. The T1 digital io link supported by the system is aided by repeater 16 to boost or refresh the signal responsive to attenuation of the signal over long spans of the communication lines 10. The T1 digital link 10 is constituted by two full duplex, high-bit rate digital subscriber lines (HI)SL) 14, 15. The HDSL format is the one typically used between central office;. 12,13 in standard telephone i5 communication systems using twisted wire pairs. The central offices 12,13 include interface conversion modules 20 to convert incoming digital signals in DS1 format to the HDSL format. Typically, customer equipment 23 (in Figure 3) uses the DS 1 format while the HDSL format is used between central offices 12,13 . An installation using customer provided equipment (CPE) typically a o includes a loop extender 21 that interfaces with the HDSL loops, and it also -io-converts from HDSL to DS 1 for presentation to the CPE 23, typically a private branch exchange, telephones, facsimiles, computers and the like. Further elaboration on the interface between a customer installation 19 and an HDSL
link is found in the publication TI Basics, supra.
The present invention facilitates testing at any point of the system depicted by Figures 2 and 3. The portable testi~.zg interface of the present invention is sufficiently flexible so that the different test configurations determined by location and components (repeater, customer and the like) of a test loop within the communications system can. be provided. In order to test i o for faults on the communication line 10 or other problems inherent to T 1 digital links, a test signal loop is configured between a selected test point 100 and the system elements (such as a repeater 16, a central oi~ce 12,13, or customer installation 19) to form the test loop. The position of the test point 100 will determine in part the configuration required of the testing device, including the i 5 choice and configuration of the functional testing cards used for fixed telephone company installations and described in the ADC: Telecommunications, Inc.
publication found in Appendix I.
Figure 1 depicts the testing interface device 24 of the present invention.
This device is portable, including all necessary elements to serve as an interface 2 o between a test point 100, located anywhere on communications lines 10, and a -il-standard independent communications line digital tester (not shown), configured for DS 1 digital signals. An example of a standard independent communications line testing device is a T-Berd 209(a) T-carrier analyzer, manufactured by Telecommunication Techniques of Germantowr~, Maryland. This standard test device is commonly used in the telephone industry and is well understood by those skilled in the telephone art. It should be understood that any equivalent testing device can be used in lieu of the T-Berd 209(a). Further, while the T-Berd 209(a) uses a DS 1 digital format, both providing test signals and analyzing response signals in DS1 format, other test signal formats can be used with the io present invention. However, different formats will require different testing cards in the portable test interface device 24.
The standard independent test device (such as a T-Berd 209 (a)) is connected to the test interface device 24 by wav of eight pin modular data jack 30, as depicted in Figure 1. However, the standard independent test set can also be connected using two-1/4 phone jacks J3, J4 as depicted in Figure 4.
The portable testing interface 24 of the present invention, as depicted in Figure 1 has a 48 volt power supply 25 and a controller interface 26 such as that (21) as found in a standard central office 12, 13, 18 installment. Power output lines 28A and 28B extend between the controllc;r interface 26 and the power 2 o supply 25 with an on/off switch 29 on line 28A.. The power supply 25 provides the power necessary to operate the testing interface 24, as well as provide power for a test signal to be sent over the test loop as configured from test point 100. This is a feature not provided by test interface units in the conventional technology. Rather, the capability of providing power to a designated test loop is a function conventionally reserved to a central office installation 12,13,18.
The present invention can also be configured so~ as to use line power when available. The embodiment depicted in Figure 4 is arranged to be provided with power from the line 10 to provide test signals to the selected test loop.
However, the embodiment of Figure 4 can also be arranged to include the io power supply depicted in Figure 1 so that the portable testing interface of Figure 4 can operate independent of power from the communications line 10.
The central interface 26 is a plug-in type module having a number of chassis card connector wire wrap pins used in fragmented numerical sequence.
The operation and wiring of this device is set forth in the manufacturer's i5 installation manual from ADC Telecommunication, Inc., found in Appendix I
and identified as ADCD-61-062 first edition, issue no. 1, incorporated herein by reference.
A power line 28A' extends from the switch 29 to the controller interface 26 pin P19 (48Vdc return) with the power line ;?8B extending to controller 2o interface 26 pin P39 (48Vdc) thus supplying power to the controller interface 26. An eight pin modular data jack 30 is interconnected to the controller interface 26 via wire wrap pins P42 [DS1 TIP (:f~CV) (Ilk], pin P-43 [DS1 Ring (RCV) (in)], pin P-49 [DS1 TIP (XMT) (OUT)] and pin P-50 [DSI Ring (XMT) (OUT)]. In the alternative, 1/4 phone jacks can be used. Either the 48 volt supply is switched as shown, or the 1 l Ov A,C supply line can be switched.
A pair of standard 1/4 phone jacks 31 and 32 are used as test interconnections to the T 1 network and are interconnected to the controller interface 26 via respective pin pairs P-34 [HDSL Loop 1 TIP in/out] and pin P-35 [HDSL Loop 1 Ring in/out] for jack 32 that conforms to side - 1, 14 of the io T-1 line tested. Pin pairs P-26 [HDSL Loop 2 '.CIP in/out] and pin P-27 [HDSL
Loop 2 Ring in/out] for jack 31 conform to the side - 2, 15 of the T-1 line to be tested.
While the aforementioned arrangement is. a preferred method of wiring controller interface 26, other arrangements can ~be used within the concept of i5 the present invention. A,s described in the ADC; Telecommunication, Inc.
publication, a key function of controller interface 26 is to convert between format for the independent testing device (connected to jack 30) and HDSL
format for use on the communications line 10. lProbably the most feasible arrangement for testing telephone lines is the conversion between DS 1 and 2 o HDSL. However, if other formats are used on f;ither of the communication lines or the tester, they can be adopted by providing a controller interface similar to that of 26, but having the conversion capabilities for the desired format.
By utilizing the present invention a simple loopback line test can be made anywhere along T 1 network line 10 to pinpoint a line or equipment problem 5 and/or to verify the integrity of a newly installed line or new line access by equipment 23 at a customer installation 19. The actual test procedures need not be described for purposes of the present invention since they have been well developed within the industry and thus, are well' understood by those skilled in this art. With the testing interface of the present invention, a number of line io continuity tests can be performed verifying correct operation at all 24 sub-channels of a T1 line.
The portable testing interface device 24 of the Figure 1 embodiment, in some respects, operates to simulate the functions of a central office, having the ability to generate test signal loops when used vi connection with conventional i5 test equipment (not shown) such as T-Berd using DSl digital signals to monitor HDSL signals for line path performance and determine abnormalities therein.
This is done by carrying out a simple echo test using a first side 14 and a second side 15 of a T1 line 10 to create a test loop. It should be understood that other parts of a communications system can be at least partially simulated a o using the present invention and the selection of ;appropriate functional test cards as described in the ADC Telecommunications Inc. and the PairGain publications of Appendix I.
Another embodiment of the present invf;ntion is depicted in Figure 4.
This embodiment is provided without a power supply since in this particular configuration power is available from the line. However, it is expected that a power supply will be used with this embodiment when power is not available from a communications line 10. The present invention is configured to utilize power from the line when available, and to rely upon a power supply 35 (in Figure 1 ), which is independent of power from 'the communications line 10.
to . For convenience, the embodiment of Figure 4 utilizes 1/4 phone jacks J3, J4 for connection to the independent testing apparatus (not shown), as well as the connections Jl, J2 to the line spans 10 at test point 100. However, other types of connectors can be provided.
C 1 is a 56 pin, type 400 hard edge connector. This device provides interface for the remote line unit (described in the ADC and PairGain publications of Appendix I) which is responsible for connecting between tester format and communications line format. For example the remote line unit card will convert between DS 1 and HDSL for both test signals being sent to the communications line 10 and test signals being received from a communications line 10.
C2 is a 12 pin, type 239 card edge connector. This device provides interface to either a repeater card (described in the ADC and PairGain publications of Appendix I) or a "through" card. While both of the subject card connectors are preferably configured as shown nn Figure 4, other arrangements for the connectors can be used within the concept of the present invention.
In operation, DS1 data from the conventional test device, such as a T-Berd analyzer (not shown), enters the portable testing interface 24 through jack J3. The DSl data is carried to the remote lline unit card (not shown) which is plugged into card connector C1. The remote line unit is preferably the same io type as described in the ADC Telecommunications, Inc. publication previously incorporated herein by reference. The DS 1 data enters the remote line unit (not shown) via pins 50 and 130. The remote unit tr~en prepares test data for transmission to the line segment 10 under the test. Using the conversion between the appropriate formats, for example DS 1 to HDSL. The converted i5 data is conveyed from the remote unit card via pins 41 and 47 to pins Al 1 and A12 of card connector C2.
If a repeater or doubler is connected to .card connector C2, the test data is then regenerated for retransmission and is transmitted from the portable testing interface 24 via pins A8 and A9, as well as jack J2. If a repeater or 2 o doubter card is not used, a through card (not shown) completes the connection -i7-between cards C1 and C2. As a result, the test .data will pass with the communications lines 10 under test without regE;neration.
Data received from the communications line 10 under test enters the portable testing interface 24 via jack J1. From jack J1, the test data from the line 10 is conveyed to pins AS and A6 of card C2. From there, data passes through a repeater/doubler or a "through" card, and is conveyed through pins and 130 of card connector Cl. From card connector C1, the data is conveyed to through the remote line unit card (not shown), to be converted from the communications line format to the testing format. In the preferred embodiment io of the present invention the conversion at this point is from HDSL to DSI.
The converted test data is then transmitted through pins 47 and 55 to jack J4.
From there the data goes to the standard testing device where it is analyzed, and the relevant information provided to the technician ~nu~ning the test.
The wide range of modifications available with the present invention i5 allows a new testing technique to be used when employing two of the portable testing interface devices of the present invention (along with two separate independent conventional testing devices such as those manufactured by T-Berd). When testing in both directions of either side of a break in line 10, testing point 100 is preferably selected to be at .a repeater or doubter 16 on the 2 o communications line 10. The election of this location facilitates easy separation -is-of the communications lines 10 into two different segments, each of which is tested by a separate portable testing interface 24 and conventional independent tester. The testing operation is carried out by properly configuring the portable testing interface device 24 of the present invention to accommodate the device at the end of the selected test loop.
Flexibility of the present invention facilitates a wide variety of different test configurations. Such configurations allow relative testing interface device to be placed anywhere on the communication lines 10 of the communications system. A number of different function cards can be connected to controller s o interface 26 (of Figure 1 ) to facilitate the creation of testing loops on various parts of the communications lines 10.
The embodiment of Figure 4 with two connection cards (Cl, C2), facilitates even a greater variety of testing function cards such as that normally found in permanent installations and described in the publications of Appendix i5 I. One such test function card that can be used with the present invention is discussed in the PairGain Copper Optics Company publication entitled High Gain Remote Unit, Model HUE-443, incorporated herein by reference. A
number of different test function cards can be connected, either to central interface 26 (Figure 1 ) or either of connection cards C 1, C2 (Figure 4).
2 o Examples are found in the Pairgain Copper Optics Company publication entitled PairGain Technology High Gain Line UnitMo~del HLU 231; PairGain Technologies High Gain Mini Doublers; and, High Gain Remote Unit, all incorporated herein by reference.
The line units described in the PairGain publication (High Gain Line Unit Model HLU 251 ) is functionally the same as that described with respect to the central interface 26 of Figure 1 and can be used in the Figure 4 embodiment.
This card is used when testing in a test loop to a repeater or customer installation equipment 19, having a remote unit interface card (not shown) between the communications lines 10 and the customer installation 19. A
io further description of the interface is provided n~ the publication Tl Basics, supra. In erect, the use of the subject line unit card partially simulates a central office.
The high gain remote unit card in the Pa~irGain publication operates as a simulation of a customer installation interface which has been disconnected i5 from the line span under test. Likewise, the repeater card described in the PairGain publication is directed to a repeater which is necessary when the normal repeater circuits have been removed from the line span under test.
Other examples of similar cards with the same functionality can be found in the ADC Telecommunications, Inc. publication ADCP-61-314 previously 2 o incorporated by reference.
Simultaneous testing of two separate line spans is easily facilitated by the present invention, and is conducted by selecting an access point 100 on the communications line 10 at which to separate the; line 10 into two separate spans 200, 300. For example, selecting test point 100 in Figure 2 would divide communications line 10 into two spans, one (200) extending to the first central office 13 and the second span (300) extending to the repeater 16. While communications line 10 can be segmented at any point within the system in order to form the two test spans, in practical teams it is much easier to segment the communications line at an established access point such as repeater 16.
to Access points are not necessarily limited to doublers or repeaters but can be established at any point where the communications line 10 is easily separated or segmented into separate spans.
The easiest place to make the access point to form two spans would be at repeater 16. This operation is facilitated by removing a repeater card from the repeater installation and inserting a dedicated span splitter which provides cable connections to the two separate test interface devices 24 and their accompanying independent test devices (not shown) such as the T-Berd tester.
The communications line 10 between central offices 12 and 13 is divided into two separate spans 200, 300 for testing, at repeater 16. Since both test spans a o 200 and 300 terminate in a central office ( 13,12, respectively), power will be provided to the test arrangements on both sides from the line due to the presence of the central offices as the terminating points of the test loops.
Consequently, both arrangements can be accommodated by the embodiment of Figure 4 (without an independent power supply).
The card configurations of both portablf; test interface devices 24 will consist of a remote unit card as described in the PairGain publication (Model HRU 412) and the ADC Telecommunications publication ADCP-61-214. Since the test spans 200, 300 are shorter than that normally requiring a repeater 16, repeater cards are not required in either test interface device 29. Rather, the i o "through" cards as referred to with respect to flue Figure 4 embodiment can be connected to connector card C2. As usual, the functional test cards selected must be configured for the system and the specific type of device at the other end of the loop. However, this is a function well-known to those skilled in the art as explained in the PairGain and ADC Telecommunications publications i5 previously incorporated herein by reference.
Each of the portable testing interface devices 24 (along with the accompanying independent testers) can be used simultaneously to send appropriate stress patterns through the respective test loops 200, 300. The resulting signals will be monitored on each respective independent test set.
2 o Should an intermittent fault occur, it will have been isolated in one of the segmented spans. This testing process can be further repeated simply by fiuther segmenting any fault-prone portion of the communication line 10 until the exact location of the fault is determined.
The portable testing interface device 24 of the present invention is sufficiently flexible so that a different arrangement of the segmented communication line 10 can be accommodated for simultaneous testing of two adjacent spans, such as 200, 300. For example;, should central office 12 be replaced by customer installation such as 19 (in Figure 3), the portable testing interface device 24 that is being used on span 300 can be appropriately io reconfigured to accommodate this difference. Specifically, a line unit card such as the HL U 231, as described in the Pairgain publication previously incorporated herein by reference, can be substituted for the previously described high gain remote card or it's equivalent. In effect, this new test card simulates the presence of a central office. The test card would be used in the embodiment depicted in Figure 1 on segmented test loop 30CI. The independent power supply 25 would be a necessity since there would be no power provided from the central office 13. The portable testing interface device servicing span 200 can be configured as previously described in accordance with the Figure 4 embodiment of the present invention, using a through card connection 2 o rather than the repeater card connected to contact card C2 of Figure 4.
While this embodiment uses power provided by central oi~ce 13, it can also use an independent power supply to provide it's own power.
The portable testing interface device 24 of the present invention admits to additional modifications. For example, the power supply 26 can be equipped with an LED to indicate the presence of 48 volt DC output within a specific tolerance. A battery can also be added in lieu o~f the power supply or in addition thereto. The portable testing interface devices 24 can include equipment to provide additional test functions. These include voltage readouts, load-coil detections, loop and error code injections and the like. The present io invention can also include the capability of pro~riding span resistence simulation. Further, the present invention can b~e configured to provide the simulation of cable load on either side of a repeater. The inclusion of a permanent modem as part of the portable testing interface device provides additional test and control capability.
i5 Although a number of embodiments of the present invention have been shown by way of exaunple, the present invention should not be limited thereby.
Rather, the present invention should be construed to include any and all variations, permutations, modifications, embodiments and adaptations that would occur to one skilled in this art having been taught the invention by this a o application and the associated documents cited therein. For example, the present invention can be configured to include additional function testing cards other than those described in the documents citc;d herein so that additional system elements besides a central office, repeater and interface to a customer installation can be accommodated by the present invention. Accordingly, the present invention should be limited only by the following claims.
It is another object of the present invention to provide out-of service testing device that can carry out loopback testing without relying upon the communications line to provide power.
It is a further object of the present invention to provide a system and method for carrying out-of service loopback testing onto two test loops io simultaneously.
It is an additional object of the present iinvention to provide a test system capable of accommodating a plurality o:f different signal formats for both the communications line under test and the testing apparatus.
It is still another object of the present irmention to provide a testing 15 system in which a standard test device can be used with standard interface cards.
It is again a further object of the present invention to simulate the operations of a telephone company central routing and control once or an interface to a customer installation for test purposes with a portable testing 2 o device.
These and other objects and goals of thf; present invention are facilitated by portable testing interface device for sending and receiving test signals over communications lines having a first and second side. The portable testing interface device is arranged to establish a testing loop at any point on the communications lines and includes a power system for obtaining power to send test signals through the testing loop. The portable testing interface also includes access devices for connecting to the first and second sides of the communications line to form the testing loop at any point on the communications line. Also included in the portable testing interface device is a i o conversion system for converting between communications line formats and test formats. An interface device within the portable testing interface device is used to operatively connect the conversion system and the access device to an independent testing device which is used for generating and evaluating test signals routed through the testing loop.
i5 Another embodiment of the present invention includes a method of testing at any point on a communications line at a communications loop with first and second sides. The method includes the steps of accessing any selected point on the communications line with a portable testing interface device to create a testing loop, and providing power to the testing loop from a source not 2 o dependent on the communications line. Then a test signal is generating in _8_ testing format, converting the communications line format and applied to the first side of the testing loop.
Another embodiment of the present invention includes a method of testing adjacent test loops at any point on a comunumications line. The method includes the steps of selecting an access point o:n the communications line and splitting the line into two segments, each constituting a separate test loop.
A
separate portable testing interface device having; a separate independent tester associated therewith is applied to each test loop. Each of the independent testers sends an appropriate set of test signals to the corresponding test loop.
io Responsive to each set of test signals, response signals are received from each test loop and sent to a corresponding independent tester for evaluation.
Brief Description of the Drawings Figure 1 is a block diagram depicting the components of one i5 embodiment of the present invention.
Figure 2 is a block diagram depicting components of a communications system supporting a T 1 digital link.
Figure 3 is a block diagram depicting additional elements of a communications system supporting a T 1 digital link.
_g_ Figure 4 is a block diagram depicting components in a second embodiment of the test device of the present invention.
Detailed Description of the Preferred Embodiments As previously discussed, Figures 2 and 3 depict components of a typical communications system used to support a T1 digital link. A more elaborate depiction of such systems and many more components therein is found in the publication TI Basics, supra. Figure 2 depicts .a communications system using twisted wire pairs 10 running between two central offices 20. The T1 digital io link supported by the system is aided by repeater 16 to boost or refresh the signal responsive to attenuation of the signal over long spans of the communication lines 10. The T1 digital link 10 is constituted by two full duplex, high-bit rate digital subscriber lines (HI)SL) 14, 15. The HDSL format is the one typically used between central office;. 12,13 in standard telephone i5 communication systems using twisted wire pairs. The central offices 12,13 include interface conversion modules 20 to convert incoming digital signals in DS1 format to the HDSL format. Typically, customer equipment 23 (in Figure 3) uses the DS 1 format while the HDSL format is used between central offices 12,13 . An installation using customer provided equipment (CPE) typically a o includes a loop extender 21 that interfaces with the HDSL loops, and it also -io-converts from HDSL to DS 1 for presentation to the CPE 23, typically a private branch exchange, telephones, facsimiles, computers and the like. Further elaboration on the interface between a customer installation 19 and an HDSL
link is found in the publication TI Basics, supra.
The present invention facilitates testing at any point of the system depicted by Figures 2 and 3. The portable testi~.zg interface of the present invention is sufficiently flexible so that the different test configurations determined by location and components (repeater, customer and the like) of a test loop within the communications system can. be provided. In order to test i o for faults on the communication line 10 or other problems inherent to T 1 digital links, a test signal loop is configured between a selected test point 100 and the system elements (such as a repeater 16, a central oi~ce 12,13, or customer installation 19) to form the test loop. The position of the test point 100 will determine in part the configuration required of the testing device, including the i 5 choice and configuration of the functional testing cards used for fixed telephone company installations and described in the ADC: Telecommunications, Inc.
publication found in Appendix I.
Figure 1 depicts the testing interface device 24 of the present invention.
This device is portable, including all necessary elements to serve as an interface 2 o between a test point 100, located anywhere on communications lines 10, and a -il-standard independent communications line digital tester (not shown), configured for DS 1 digital signals. An example of a standard independent communications line testing device is a T-Berd 209(a) T-carrier analyzer, manufactured by Telecommunication Techniques of Germantowr~, Maryland. This standard test device is commonly used in the telephone industry and is well understood by those skilled in the telephone art. It should be understood that any equivalent testing device can be used in lieu of the T-Berd 209(a). Further, while the T-Berd 209(a) uses a DS 1 digital format, both providing test signals and analyzing response signals in DS1 format, other test signal formats can be used with the io present invention. However, different formats will require different testing cards in the portable test interface device 24.
The standard independent test device (such as a T-Berd 209 (a)) is connected to the test interface device 24 by wav of eight pin modular data jack 30, as depicted in Figure 1. However, the standard independent test set can also be connected using two-1/4 phone jacks J3, J4 as depicted in Figure 4.
The portable testing interface 24 of the present invention, as depicted in Figure 1 has a 48 volt power supply 25 and a controller interface 26 such as that (21) as found in a standard central office 12, 13, 18 installment. Power output lines 28A and 28B extend between the controllc;r interface 26 and the power 2 o supply 25 with an on/off switch 29 on line 28A.. The power supply 25 provides the power necessary to operate the testing interface 24, as well as provide power for a test signal to be sent over the test loop as configured from test point 100. This is a feature not provided by test interface units in the conventional technology. Rather, the capability of providing power to a designated test loop is a function conventionally reserved to a central office installation 12,13,18.
The present invention can also be configured so~ as to use line power when available. The embodiment depicted in Figure 4 is arranged to be provided with power from the line 10 to provide test signals to the selected test loop.
However, the embodiment of Figure 4 can also be arranged to include the io power supply depicted in Figure 1 so that the portable testing interface of Figure 4 can operate independent of power from the communications line 10.
The central interface 26 is a plug-in type module having a number of chassis card connector wire wrap pins used in fragmented numerical sequence.
The operation and wiring of this device is set forth in the manufacturer's i5 installation manual from ADC Telecommunication, Inc., found in Appendix I
and identified as ADCD-61-062 first edition, issue no. 1, incorporated herein by reference.
A power line 28A' extends from the switch 29 to the controller interface 26 pin P19 (48Vdc return) with the power line ;?8B extending to controller 2o interface 26 pin P39 (48Vdc) thus supplying power to the controller interface 26. An eight pin modular data jack 30 is interconnected to the controller interface 26 via wire wrap pins P42 [DS1 TIP (:f~CV) (Ilk], pin P-43 [DS1 Ring (RCV) (in)], pin P-49 [DS1 TIP (XMT) (OUT)] and pin P-50 [DSI Ring (XMT) (OUT)]. In the alternative, 1/4 phone jacks can be used. Either the 48 volt supply is switched as shown, or the 1 l Ov A,C supply line can be switched.
A pair of standard 1/4 phone jacks 31 and 32 are used as test interconnections to the T 1 network and are interconnected to the controller interface 26 via respective pin pairs P-34 [HDSL Loop 1 TIP in/out] and pin P-35 [HDSL Loop 1 Ring in/out] for jack 32 that conforms to side - 1, 14 of the io T-1 line tested. Pin pairs P-26 [HDSL Loop 2 '.CIP in/out] and pin P-27 [HDSL
Loop 2 Ring in/out] for jack 31 conform to the side - 2, 15 of the T-1 line to be tested.
While the aforementioned arrangement is. a preferred method of wiring controller interface 26, other arrangements can ~be used within the concept of i5 the present invention. A,s described in the ADC; Telecommunication, Inc.
publication, a key function of controller interface 26 is to convert between format for the independent testing device (connected to jack 30) and HDSL
format for use on the communications line 10. lProbably the most feasible arrangement for testing telephone lines is the conversion between DS 1 and 2 o HDSL. However, if other formats are used on f;ither of the communication lines or the tester, they can be adopted by providing a controller interface similar to that of 26, but having the conversion capabilities for the desired format.
By utilizing the present invention a simple loopback line test can be made anywhere along T 1 network line 10 to pinpoint a line or equipment problem 5 and/or to verify the integrity of a newly installed line or new line access by equipment 23 at a customer installation 19. The actual test procedures need not be described for purposes of the present invention since they have been well developed within the industry and thus, are well' understood by those skilled in this art. With the testing interface of the present invention, a number of line io continuity tests can be performed verifying correct operation at all 24 sub-channels of a T1 line.
The portable testing interface device 24 of the Figure 1 embodiment, in some respects, operates to simulate the functions of a central office, having the ability to generate test signal loops when used vi connection with conventional i5 test equipment (not shown) such as T-Berd using DSl digital signals to monitor HDSL signals for line path performance and determine abnormalities therein.
This is done by carrying out a simple echo test using a first side 14 and a second side 15 of a T1 line 10 to create a test loop. It should be understood that other parts of a communications system can be at least partially simulated a o using the present invention and the selection of ;appropriate functional test cards as described in the ADC Telecommunications Inc. and the PairGain publications of Appendix I.
Another embodiment of the present invf;ntion is depicted in Figure 4.
This embodiment is provided without a power supply since in this particular configuration power is available from the line. However, it is expected that a power supply will be used with this embodiment when power is not available from a communications line 10. The present invention is configured to utilize power from the line when available, and to rely upon a power supply 35 (in Figure 1 ), which is independent of power from 'the communications line 10.
to . For convenience, the embodiment of Figure 4 utilizes 1/4 phone jacks J3, J4 for connection to the independent testing apparatus (not shown), as well as the connections Jl, J2 to the line spans 10 at test point 100. However, other types of connectors can be provided.
C 1 is a 56 pin, type 400 hard edge connector. This device provides interface for the remote line unit (described in the ADC and PairGain publications of Appendix I) which is responsible for connecting between tester format and communications line format. For example the remote line unit card will convert between DS 1 and HDSL for both test signals being sent to the communications line 10 and test signals being received from a communications line 10.
C2 is a 12 pin, type 239 card edge connector. This device provides interface to either a repeater card (described in the ADC and PairGain publications of Appendix I) or a "through" card. While both of the subject card connectors are preferably configured as shown nn Figure 4, other arrangements for the connectors can be used within the concept of the present invention.
In operation, DS1 data from the conventional test device, such as a T-Berd analyzer (not shown), enters the portable testing interface 24 through jack J3. The DSl data is carried to the remote lline unit card (not shown) which is plugged into card connector C1. The remote line unit is preferably the same io type as described in the ADC Telecommunications, Inc. publication previously incorporated herein by reference. The DS 1 data enters the remote line unit (not shown) via pins 50 and 130. The remote unit tr~en prepares test data for transmission to the line segment 10 under the test. Using the conversion between the appropriate formats, for example DS 1 to HDSL. The converted i5 data is conveyed from the remote unit card via pins 41 and 47 to pins Al 1 and A12 of card connector C2.
If a repeater or doubler is connected to .card connector C2, the test data is then regenerated for retransmission and is transmitted from the portable testing interface 24 via pins A8 and A9, as well as jack J2. If a repeater or 2 o doubter card is not used, a through card (not shown) completes the connection -i7-between cards C1 and C2. As a result, the test .data will pass with the communications lines 10 under test without regE;neration.
Data received from the communications line 10 under test enters the portable testing interface 24 via jack J1. From jack J1, the test data from the line 10 is conveyed to pins AS and A6 of card C2. From there, data passes through a repeater/doubler or a "through" card, and is conveyed through pins and 130 of card connector Cl. From card connector C1, the data is conveyed to through the remote line unit card (not shown), to be converted from the communications line format to the testing format. In the preferred embodiment io of the present invention the conversion at this point is from HDSL to DSI.
The converted test data is then transmitted through pins 47 and 55 to jack J4.
From there the data goes to the standard testing device where it is analyzed, and the relevant information provided to the technician ~nu~ning the test.
The wide range of modifications available with the present invention i5 allows a new testing technique to be used when employing two of the portable testing interface devices of the present invention (along with two separate independent conventional testing devices such as those manufactured by T-Berd). When testing in both directions of either side of a break in line 10, testing point 100 is preferably selected to be at .a repeater or doubter 16 on the 2 o communications line 10. The election of this location facilitates easy separation -is-of the communications lines 10 into two different segments, each of which is tested by a separate portable testing interface 24 and conventional independent tester. The testing operation is carried out by properly configuring the portable testing interface device 24 of the present invention to accommodate the device at the end of the selected test loop.
Flexibility of the present invention facilitates a wide variety of different test configurations. Such configurations allow relative testing interface device to be placed anywhere on the communication lines 10 of the communications system. A number of different function cards can be connected to controller s o interface 26 (of Figure 1 ) to facilitate the creation of testing loops on various parts of the communications lines 10.
The embodiment of Figure 4 with two connection cards (Cl, C2), facilitates even a greater variety of testing function cards such as that normally found in permanent installations and described in the publications of Appendix i5 I. One such test function card that can be used with the present invention is discussed in the PairGain Copper Optics Company publication entitled High Gain Remote Unit, Model HUE-443, incorporated herein by reference. A
number of different test function cards can be connected, either to central interface 26 (Figure 1 ) or either of connection cards C 1, C2 (Figure 4).
2 o Examples are found in the Pairgain Copper Optics Company publication entitled PairGain Technology High Gain Line UnitMo~del HLU 231; PairGain Technologies High Gain Mini Doublers; and, High Gain Remote Unit, all incorporated herein by reference.
The line units described in the PairGain publication (High Gain Line Unit Model HLU 251 ) is functionally the same as that described with respect to the central interface 26 of Figure 1 and can be used in the Figure 4 embodiment.
This card is used when testing in a test loop to a repeater or customer installation equipment 19, having a remote unit interface card (not shown) between the communications lines 10 and the customer installation 19. A
io further description of the interface is provided n~ the publication Tl Basics, supra. In erect, the use of the subject line unit card partially simulates a central office.
The high gain remote unit card in the Pa~irGain publication operates as a simulation of a customer installation interface which has been disconnected i5 from the line span under test. Likewise, the repeater card described in the PairGain publication is directed to a repeater which is necessary when the normal repeater circuits have been removed from the line span under test.
Other examples of similar cards with the same functionality can be found in the ADC Telecommunications, Inc. publication ADCP-61-314 previously 2 o incorporated by reference.
Simultaneous testing of two separate line spans is easily facilitated by the present invention, and is conducted by selecting an access point 100 on the communications line 10 at which to separate the; line 10 into two separate spans 200, 300. For example, selecting test point 100 in Figure 2 would divide communications line 10 into two spans, one (200) extending to the first central office 13 and the second span (300) extending to the repeater 16. While communications line 10 can be segmented at any point within the system in order to form the two test spans, in practical teams it is much easier to segment the communications line at an established access point such as repeater 16.
to Access points are not necessarily limited to doublers or repeaters but can be established at any point where the communications line 10 is easily separated or segmented into separate spans.
The easiest place to make the access point to form two spans would be at repeater 16. This operation is facilitated by removing a repeater card from the repeater installation and inserting a dedicated span splitter which provides cable connections to the two separate test interface devices 24 and their accompanying independent test devices (not shown) such as the T-Berd tester.
The communications line 10 between central offices 12 and 13 is divided into two separate spans 200, 300 for testing, at repeater 16. Since both test spans a o 200 and 300 terminate in a central office ( 13,12, respectively), power will be provided to the test arrangements on both sides from the line due to the presence of the central offices as the terminating points of the test loops.
Consequently, both arrangements can be accommodated by the embodiment of Figure 4 (without an independent power supply).
The card configurations of both portablf; test interface devices 24 will consist of a remote unit card as described in the PairGain publication (Model HRU 412) and the ADC Telecommunications publication ADCP-61-214. Since the test spans 200, 300 are shorter than that normally requiring a repeater 16, repeater cards are not required in either test interface device 29. Rather, the i o "through" cards as referred to with respect to flue Figure 4 embodiment can be connected to connector card C2. As usual, the functional test cards selected must be configured for the system and the specific type of device at the other end of the loop. However, this is a function well-known to those skilled in the art as explained in the PairGain and ADC Telecommunications publications i5 previously incorporated herein by reference.
Each of the portable testing interface devices 24 (along with the accompanying independent testers) can be used simultaneously to send appropriate stress patterns through the respective test loops 200, 300. The resulting signals will be monitored on each respective independent test set.
2 o Should an intermittent fault occur, it will have been isolated in one of the segmented spans. This testing process can be further repeated simply by fiuther segmenting any fault-prone portion of the communication line 10 until the exact location of the fault is determined.
The portable testing interface device 24 of the present invention is sufficiently flexible so that a different arrangement of the segmented communication line 10 can be accommodated for simultaneous testing of two adjacent spans, such as 200, 300. For example;, should central office 12 be replaced by customer installation such as 19 (in Figure 3), the portable testing interface device 24 that is being used on span 300 can be appropriately io reconfigured to accommodate this difference. Specifically, a line unit card such as the HL U 231, as described in the Pairgain publication previously incorporated herein by reference, can be substituted for the previously described high gain remote card or it's equivalent. In effect, this new test card simulates the presence of a central office. The test card would be used in the embodiment depicted in Figure 1 on segmented test loop 30CI. The independent power supply 25 would be a necessity since there would be no power provided from the central office 13. The portable testing interface device servicing span 200 can be configured as previously described in accordance with the Figure 4 embodiment of the present invention, using a through card connection 2 o rather than the repeater card connected to contact card C2 of Figure 4.
While this embodiment uses power provided by central oi~ce 13, it can also use an independent power supply to provide it's own power.
The portable testing interface device 24 of the present invention admits to additional modifications. For example, the power supply 26 can be equipped with an LED to indicate the presence of 48 volt DC output within a specific tolerance. A battery can also be added in lieu o~f the power supply or in addition thereto. The portable testing interface devices 24 can include equipment to provide additional test functions. These include voltage readouts, load-coil detections, loop and error code injections and the like. The present io invention can also include the capability of pro~riding span resistence simulation. Further, the present invention can b~e configured to provide the simulation of cable load on either side of a repeater. The inclusion of a permanent modem as part of the portable testing interface device provides additional test and control capability.
i5 Although a number of embodiments of the present invention have been shown by way of exaunple, the present invention should not be limited thereby.
Rather, the present invention should be construed to include any and all variations, permutations, modifications, embodiments and adaptations that would occur to one skilled in this art having been taught the invention by this a o application and the associated documents cited therein. For example, the present invention can be configured to include additional function testing cards other than those described in the documents citc;d herein so that additional system elements besides a central office, repeater and interface to a customer installation can be accommodated by the present invention. Accordingly, the present invention should be limited only by the following claims.
Claims (20)
1. A portable testing interface device for sending and receiving test signals over a communications line having first and second sides, said interface device being arranged to establish a testing loop at any point on said communications lines, and comprising:
(a) power means for obtaining power to send said test signal through said testing loop;
(b) access means for connecting to said first and second sides of said communication line to form said testing loop at any point on said communications line;
(c) conversion means for converting between communications line formats and test formats; and, (d) interface means for operatively connecting said conversion means and said access means to independent testing means for generating and evaluating test signals routed through said testing loop.
(a) power means for obtaining power to send said test signal through said testing loop;
(b) access means for connecting to said first and second sides of said communication line to form said testing loop at any point on said communications line;
(c) conversion means for converting between communications line formats and test formats; and, (d) interface means for operatively connecting said conversion means and said access means to independent testing means for generating and evaluating test signals routed through said testing loop.
2. The portable testing interface device of claim 1, wherein said communication line is a twisted wire pair arranged for digital communication.
3. The portable testing interface device of claim 2 wherein said power means comprise a power source independent of said communications line.
4. The portable testing interface device of claim 3, wherein said communications loop is isolated from power from said communications line.
5. Portable testing interface device of claim 4, wherein power to said communications loop is provided by said portable testing interface device.
6. The portable testing interface device of claim 2, further comprising second interface means for operatively connecting means for repeating between said access means and said conversion means.
7. The portable testing interface device of claim 5, wherein said communications line format is HDSL and said test format is DS1.
8. The portable testing interface device of claim 7, wherein said test signal is configured for fault testing.
9. The portable testing interface device of claim 8, wherein said test signal is configured for digital data testing.
10. The portable testing interface device of claim 6, wherein said access means comprise two- 1/4 phone jacks.
11. The portable testing interface device of claim 10, further comprising an additional two-1/4 phone jacks arranged for connecting said independent testing means to said conversion means.
12. The portable testing interface of claim 9, wherein said access means comprise two 1/4 phone jacks.
13. The portable testing device of claim 12, wherein said conversion means comprise a single-chip HDSL CPU.
14. The portable testing device of claim 3, wherein said power source comprises a 48 volt power supply transformer.
15. The portable testing interface of claim 13, wherein said interface means comprise multiple wire wrap communications and inner connecting pins.
16. A method of testing at any point on a communications line including a communications loop have first and second sides, said method comprising the steps of (a) accessing any selected point on said communications line with a portable testing interface device to operate a testing loop;
(b) providing power to said testing loop from a source not dependent from said communications line;
(c) generating a test signal in testing format;
(d) converting said test signal to communications line format;
and, (e) applying said converted test signal to a first side of said testing loop.
(b) providing power to said testing loop from a source not dependent from said communications line;
(c) generating a test signal in testing format;
(d) converting said test signal to communications line format;
and, (e) applying said converted test signal to a first side of said testing loop.
17. The method of claim 15, further comprising the additional steps of:
(f) receiving a response to said test signal on said second side of said communication loop in communications line format;
(g) converting said response to testing format; and, (h) analyzing said converted response to derive conditions on said communications loop.
(f) receiving a response to said test signal on said second side of said communication loop in communications line format;
(g) converting said response to testing format; and, (h) analyzing said converted response to derive conditions on said communications loop.
18. The method of claim 16, wherein step (a) further comprises the sub-steps of moving said testing interface to one of a plurality of different points on said communications line to create a testing loop.
19. A method of testing two adjacent test loops at any point on a communications line, said method comprising the steps of:
(a) selecting an access point and splitting said communications line into two segments, each said segment comprising a separate test loop;
(b) applying a separate portable testing interface device to each of said test loops, and using a separate independent tester associated with each portable testing interface device, and sending an appropriate set of test signals to each corresponding test loop; and, (c) receiving two sets of response signals derived from corresponding sets of said test signals from each corresponding test loop, and evaluating each set of response signals at a corresponding independent tester.
(a) selecting an access point and splitting said communications line into two segments, each said segment comprising a separate test loop;
(b) applying a separate portable testing interface device to each of said test loops, and using a separate independent tester associated with each portable testing interface device, and sending an appropriate set of test signals to each corresponding test loop; and, (c) receiving two sets of response signals derived from corresponding sets of said test signals from each corresponding test loop, and evaluating each set of response signals at a corresponding independent tester.
20. The method of testing of claim 19 wherein, prior to splitting said communications line, comprising the steps of:identifying an end unit of each said test loop and configuring corresponding portable testing interface to function in a manner to accommodate a corresponding one of said end units.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/790,065 US5892756A (en) | 1997-01-28 | 1997-01-28 | Portable telecommunication network testing device |
| CA002267825A CA2267825A1 (en) | 1997-01-28 | 1999-04-01 | Portable testing device for telecommunications network |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/790,065 US5892756A (en) | 1997-01-28 | 1997-01-28 | Portable telecommunication network testing device |
| CA002267825A CA2267825A1 (en) | 1997-01-28 | 1999-04-01 | Portable testing device for telecommunications network |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2267825A1 true CA2267825A1 (en) | 2000-10-01 |
Family
ID=32094352
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002267825A Abandoned CA2267825A1 (en) | 1997-01-28 | 1999-04-01 | Portable testing device for telecommunications network |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US5892756A (en) |
| CA (1) | CA2267825A1 (en) |
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| Publication number | Publication date |
|---|---|
| US5892756A (en) | 1999-04-06 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |