US3860769A
Expired / Lapsed
US
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Method and apparatus for testing the operation of a communication system
Assignee: AG Communication Systems Corp
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Filing: 1972-11-01
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Granted: 1975-01-14
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Expires: 1992-11-01
Abstract
Abstract A carrier loop comprises first and second carrier channels coupling signals in opposite directions and having at each end thereof a hybrid with one pair of opposing ports connected to the adjacent ends of associated channels. A balancing network is connected to a port of the other pair of opposing ports of one hybrid. A first relay adjacent the one hybrid has a pair of normally open contacts connected across the balancing network and has pairs of normally closed contacts connected in series with associated terminals of the other output port of the other pair of opposing ports of the one hybrid. A second relay adjacent the other hybrid has pairs of normally open contacts connecting a test signal source to associated terminals of one port of the other pair of opposing ports of the other hybrid, and has pairs of normally open contacts connecting an impedance network and a meter to one port of the one pair of ports of the other hybrid and to the associated end of the second channel, respectively, that is normally connected to this one port. The operation of the loop is tested by energizing the second relay to connect the test signal source and impedance network to associated ports of the other hybrid and the meter to the end of the second channel, and by transmitting a control signal over an associated test channel to energize the first relay to short-circuit the balancing network and open-circuit the output port of the one hybrid to produce 0 dB return loss in the latter. This causes the test signal that is coupled through the other hybrid to be transmitted on the first carrier channel and coupled through the one hybrid, onto the second carrier channel. The returned test signal on the second channel is applied to the meter to provide a measure of the operativeness of the carrier loop.
Inventors
- 👤 Jr Alvin L Pachynski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:52
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/46
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
74 words
In a method of testing the quality of transmission on a pair of unidirectional communication channels forming bidirectional transmission paths through a hybrid having a pair of ports connected to the pair of ends of associated channels, the improvement comprising the step of selectively varying the return loss of the hybrid to unbalance that hybrid for coupling an applied signal on one channel through the hybrid and onto the other channel for subsequent measurement.
Claim 2
Dependent Claim
74 words
In a method of testing the quality of transmission on a pair of unidirectional communication channels forming bidirectional transmission paths through a hybrid having a pair of ports connected to the pair of ends of associated channels, the improvement comprising the step of selectively varying the return loss of the hybrid to unbalance that hybrid for coupling an applied signal on one channel through the hybrid and onto the other channel for subsequent measurement.
Claim 3
Dependent Claim
24 words
The method according to claim 1 wherein said varying step comprises, the step of selectively producing substantially O dB return loss in the hybrid.
Claim 4
Independent Claim
126 words
The method of testing the quality of operation of bidirectional transmission paths including first and second unidirectional communication channels passing signals in opposite directions and having at each end thereof a hybrid with first and second opposing ports that are connected to associated ends of the first and second channels, respectively, for coupling signals thereto and therefrom; comprising the step of selectively decreasing the return loss in one of the hybrids that is in a balanced condition to unbalance that hybrid for coupling a prescribed amount of a signal that is applied on the first channel to the first port of the one hybrid, through the one hybrid, and from the second port thereof, and onto the second channel toward the other hybrid for subsequent measurement.
Claim 5
Independent Claim
126 words
The method of testing the quality of operation of bidirectional transmission paths including first and second unidirectional communication channels passing signals in opposite directions and having at each end thereof a hybrid with first and second opposing ports that are connected to associated ends of the first and second channels, respectively, for coupling signals thereto and therefrom; comprising the step of selectively decreasing the return loss in one of the hybrids that is in a balanced condition to unbalance that hybrid for coupling a prescribed amount of a signal that is applied on the first channel to the first port of the one hybrid, through the one hybrid, and from the second port thereof, and onto the second channel toward the other hybrid for subsequent measurement.
Claim 6
Dependent Claim
36 words
The method according to claim 3 wherein the one hybrid has a balancing network terminating a third port thereof and said decreasing step comprises the step of short-circuiting the balancing network for unbalancing the one hybrid.
Claim 7
Dependent Claim
46 words
The method according to claim 3 wherein the one hybrid has a balancing network terminating a third port thereof and said decreasing step comprises the step of open-circuiting the connection of the balancing network to the third port of the one hybrid for unbalancing the latter.
Claim 8
Dependent Claim
71 words
The method according to claim 3, wherein the other hybrid includes a third port and including the additional steps of coupling a test signal to the third port of the other hybrid and thus onto the first channel, and measuring at a point on the second channel adjacent the other hybrid the reTurn test signal that is coupled back through the opposing ports of the one hybrid to the other hybrid.
Claim 9
Dependent Claim
56 words
The method according to claim 6 including the additional steps of disconnecting the end of the second channel from the associated opposing second port of the other hybrid, terminating the associated opposing second port of the other hybrid in its characteristic impedance, and measuring the return test signal at the disconnected end of the second channel.
Claim 10
Independent Claim
198 words
The method of testing the operation of bidirectional transmission paths including first and second unidirectional communication channels passing signals in opposite directions and having at each end thereof a hybrid with one pair of opposing ports that are each connected to one end of a different channel for coupling signals thereto and therefrom, one of the hybrids having a balancing network terminating a third port thereof; comprising the steps of coupling a test signal to a third port of the other hybrid and thus onto the first channel, disconnecting the end of the second channel from the associated opposing one port of the other hybrid, terminating the associated opposing one port of the other hybrid in the impedance that the one port is designed to operate into, short circuiting the balancing network for selectively varying the return loss in the one hybrid for coupling a prescribed amount of the test signal on the first channel to one of the associated opposing ports of the one hybrid, through the one hybrid and its other opposing port, and onto the second channel toward the other hybrid, and, measuring the return test signal at the disconnected end of the second channel.
Claim 11
Independent Claim
198 words
The method of testing the operation of bidirectional transmission paths including first and second unidirectional communication channels passing signals in opposite directions and having at each end thereof a hybrid with one pair of opposing ports that are each connected to one end of a different channel for coupling signals thereto and therefrom, one of the hybrids having a balancing network terminating a third port thereof; comprising the steps of coupling a test signal to a third port of the other hybrid and thus onto the first channel, disconnecting the end of the second channel from the associated opposing one port of the other hybrid, terminating the associated opposing one port of the other hybrid in the impedance that the one port is designed to operate into, short circuiting the balancing network for selectively varying the return loss in the one hybrid for coupling a prescribed amount of the test signal on the first channel to one of the associated opposing ports of the one hybrid, through the one hybrid and its other opposing port, and onto the second channel toward the other hybrid, and, measuring the return test signal at the disconnected end of the second channel.
Claim 12
Dependent Claim
39 words
The method according to claim 8 wherein the one hybrid has a fourth port opposing the third port thereof, and including the additional step of simultaneously short-circuiting the balancing network and open-circuiting the fourth port of the one hybrid.
Claim 13
Dependent Claim
221 words
In a bidirectional communication system including first and second unidirectional communication channels having at adjacent one ends thereof a four-port hybrid with first and second ports of one pair of opposing ports thereof connected to the one ends of associated first and second channels, and having a network connected to the third port of the other pair of opposing third and fourth ports of the hybrid, the network having a prescribed impedance level balancing the network with a line circuit connected to the fourth port of the hybrid and causing the latter to have a value of return loss for blocking a signal on the first channel from being coupled through the hybrid and onto the second channel; apparatus for testing the quality of operation of the system comprising a source of test signals, means for coupling a test signal onto the first channel, means for selectively varying the value of the return loss of the one hybrid to unbalance the latter for coupling a prescribed measurable portion of the test signal on the first channel through the hybrid and onto the second channel, and, means for measuring the level of the coupled test signal on the second channel for obtaining an indication of the quality of operation of the hybrid and the first and second channels of the communication system.
Claim 14
Dependent Claim
221 words
In a bidirectional communication system including first and second unidirectional communication channels having at adjacent one ends thereof a four-port hybrid with first and second ports of one pair of opposing ports thereof connected to the one ends of associated first and second channels, and having a network connected to the third port of the other pair of opposing third and fourth ports of the hybrid, the network having a prescribed impedance level balancing the network with a line circuit connected to the fourth port of the hybrid and causing the latter to have a value of return loss for blocking a signal on the first channel from being coupled through the hybrid and onto the second channel; apparatus for testing the quality of operation of the system comprising a source of test signals, means for coupling a test signal onto the first channel, means for selectively varying the value of the return loss of the one hybrid to unbalance the latter for coupling a prescribed measurable portion of the test signal on the first channel through the hybrid and onto the second channel, and, means for measuring the level of the coupled test signal on the second channel for obtaining an indication of the quality of operation of the hybrid and the first and second channels of the communication system.
Claim 15
Dependent Claim
37 words
Apparatus according to claim 10 wherein said varying means is means for varying the degree of balance between the network and the line circuit that are connected to the third and fourth ports, respectively, of the hybrid.
Claim 16
Dependent Claim
40 words
Apparatus according to claim 11 wherein said coupling means couples a test signal to the fourth port of another hybrid having first and second opposing ports that are connected to associated other ends of the first and second communication channels.
Claim 17
Dependent Claim
30 words
Apparatus according to claim 12 wherein said measuring means measures the coupled test signal on the second channel at the end thereof adjacent the second port of the other hybrid.
Claim 18
Dependent Claim
228 words
In a bidirectional communication system including firSt and second unidirectional communication channels having at each end thereof a different four-port hybrid with first and second ports of one pair of opposing ports connected to the ends of associated first and second channels, and having a network connected to the third port of the other pair of opposing third and fourth ports of one hybrid, the network having a prescribed impedance level balancing the network with a line circuit connected to the fourth port of the one hybrid and causing the latter to have a value of return loss for blocking a signal on the first channel from being coupled through the one hybrid and onto the second channel; apparatus for testing the operation of the system comprising a source of test signals, means for coupling a test signal onto the first channel, means for selectively varying the value of the return loss of the one hybrid, and thus the degree of balance between the network and line circuit connected to the third and fourth ports, respectively, of the one hybrid, for coupling a prescribed measurable portion of the test signal on the first channel through the one hybrid and onto the second channel, said varying means comprising means for short-circuiting the balancing network, and means for measuring the level of the coupled test signal on the second channel.
Claim 19
Dependent Claim
228 words
In a bidirectional communication system including firSt and second unidirectional communication channels having at each end thereof a different four-port hybrid with first and second ports of one pair of opposing ports connected to the ends of associated first and second channels, and having a network connected to the third port of the other pair of opposing third and fourth ports of one hybrid, the network having a prescribed impedance level balancing the network with a line circuit connected to the fourth port of the one hybrid and causing the latter to have a value of return loss for blocking a signal on the first channel from being coupled through the one hybrid and onto the second channel; apparatus for testing the operation of the system comprising a source of test signals, means for coupling a test signal onto the first channel, means for selectively varying the value of the return loss of the one hybrid, and thus the degree of balance between the network and line circuit connected to the third and fourth ports, respectively, of the one hybrid, for coupling a prescribed measurable portion of the test signal on the first channel through the one hybrid and onto the second channel, said varying means comprising means for short-circuiting the balancing network, and means for measuring the level of the coupled test signal on the second channel.
Claim 20
Dependent Claim
246 words
In a bidirectional communication system including first and second unidirectional communication channels having at each end thereof a different four-port hybrid with first and second ports of one pair of opposing ports connected to the ends of associated first and second channels, and having a network connected to the third port of the other pair of opposing third and fourth ports of one hybrid, the network having a prescribed impedance level balancing the network with a line circuit connected to the fourth port of the one hybrid and causing the latter to have a value of return loss for blocking a signal on the first channel from being coupled through the one hybrid and onto the second channel; apparatus for testing the operation of the system comprising a source of test signals, means for coupling a test signal onto the first channel, means for selectively varying the value of the return loss of the one hybrid, and thus the degree of balance between the network and line circuit connected to the third and fourth ports, respectively, of the one hybrid, for coupling a prescribed measurable portion of the test signal on the first channel through the one hybrid and onto the second channel, said varying means comprising means for simultaneously short circuiting the balancing network and open-circuiting the connection of the fourth port of the one hybrid to the line circuit, and means for measuring the level of the coupled test signal on the second channel.
Claim 21
Dependent Claim
246 words
In a bidirectional communication system including first and second unidirectional communication channels having at each end thereof a different four-port hybrid with first and second ports of one pair of opposing ports connected to the ends of associated first and second channels, and having a network connected to the third port of the other pair of opposing third and fourth ports of one hybrid, the network having a prescribed impedance level balancing the network with a line circuit connected to the fourth port of the one hybrid and causing the latter to have a value of return loss for blocking a signal on the first channel from being coupled through the one hybrid and onto the second channel; apparatus for testing the operation of the system comprising a source of test signals, means for coupling a test signal onto the first channel, means for selectively varying the value of the return loss of the one hybrid, and thus the degree of balance between the network and line circuit connected to the third and fourth ports, respectively, of the one hybrid, for coupling a prescribed measurable portion of the test signal on the first channel through the one hybrid and onto the second channel, said varying means comprising means for simultaneously short circuiting the balancing network and open-circuiting the connection of the fourth port of the one hybrid to the line circuit, and means for measuring the level of the coupled test signal on the second channel.
Claim 22
Dependent Claim
251 words
In a bidirectional communication system including first and second unidirectional communication channels having at each end thereof a different four-port hybrid with first and second ports of one pair of opposing ports connected to the ends of associated first and second channels, and having a network connected to the third port of the other pair of opposing third and fourth ports of one hybrid, the network having a prescribed impedance level balancing the network with a line circuit connected to the fourth port of the one hybrid and causing the latter to have a value of return loss for blocking a signal on the first channel from being coupled through the one hybrid and onto the second channel; apparatus for testing the operation of the system comprising a source of test signals, means for coupling a test signal onto the first channel, means for selectively varying the value of the return loss of the one hybrid, and thus the degree of balance between the network and line circuit connected to the third and fourth ports, respectively, of the one hybrid, for coupling a prescribed measurable portion of the test signal on the first channel through the one hybrid and onto the second channel, said varying means comprising means for simultaneously open-circuiting the connection of the balancing network to the third port of the hybrid and connecting a short circuit across the fourth port of the hybrid, and means for measuring the level of the coupled test signal on the second channel.
Claim 23
Dependent Claim
251 words
In a bidirectional communication system including first and second unidirectional communication channels having at each end thereof a different four-port hybrid with first and second ports of one pair of opposing ports connected to the ends of associated first and second channels, and having a network connected to the third port of the other pair of opposing third and fourth ports of one hybrid, the network having a prescribed impedance level balancing the network with a line circuit connected to the fourth port of the one hybrid and causing the latter to have a value of return loss for blocking a signal on the first channel from being coupled through the one hybrid and onto the second channel; apparatus for testing the operation of the system comprising a source of test signals, means for coupling a test signal onto the first channel, means for selectively varying the value of the return loss of the one hybrid, and thus the degree of balance between the network and line circuit connected to the third and fourth ports, respectively, of the one hybrid, for coupling a prescribed measurable portion of the test signal on the first channel through the one hybrid and onto the second channel, said varying means comprising means for simultaneously open-circuiting the connection of the balancing network to the third port of the hybrid and connecting a short circuit across the fourth port of the hybrid, and means for measuring the level of the coupled test signal on the second channel.
Claim 24
Dependent Claim
82 words
Apparatus according to claim 14 wherein the varying means includes a selectively actuated control signal source, a first relay having a normally open first pair of contacts connected in parallel with the balancing network, and a third communication channel connected in series between said first relay and said control signal source, said first relay being responsive to a control signal for closing said first contacts for short-circuiting the balancing network and producing substantially O dB return loss of in the one hybrid.
Claim 25
Dependent Claim
121 words
Apparatus according to claim 17 including a second impedance network, a second relay having a normally open first pair of contacts, means connecting associated ones of said first contacts of said second relay to the second port of the other hybrid and the second impedance network, said second network having an impedance value for terminating the second port of the other hybrid in its characteristic impedance when said second relay is energized to close said first contacts thereof, and wherein said measuring means is responsive to the control signal for disconnecting the one end of the second channel from the second port of the other hybrid for measuring the coupled test signal at the one open end of the second channel.
Claim 26
Dependent Claim
56 words
Apparatus according to claim 18 wherein said second relay has second and third pairs of normally open contacts associated with the fourth port of the other hybrid and said test signal source for selectively connecting the latter to, and selectively disconnecting any line circuit from, the fourth port in response to energization of said second relay.
Claim 27
Dependent Claim
26 words
Apparatus according to claim 19 including other contacts of said first relay open-circuiting the fourth port of said one hybrid when said first relay is energized.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-01-13 | 1978-07-15 | 1979-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-13 | 1982-07-15 | 1983-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-13 | 1986-07-15 | 1987-01-14 | $7700.00 | Window Closed / Lapsed |