Time division exchange for carrying out a loop-back test
First Claim
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1. A time division exchange for serving plural lines, comprising:
- a network, coupled to the lines, for transmitting and receiving time division multiplexed signals;
a time division multiplexed trunk, coupled to said network, for providing, as an output time division multiplexed signal to another exchange, the time division multiplexed signal transmitted by said network, and for providing an input time division multiplexed signal to said network as the received time division multiplexed signal, said time division multiplexed trunk including means for interchanging predetermined time slots in one of the time division multiplexed signals when a loop-back test is to be performed; and
return means, coupled to said time division multiplexed trunk, for receiving the output time division multiplexed signal and for returning it to said time division multiplexed trunk, as the input time division multiplexed signal, during the loop-back test.
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Abstract
A time division exchange interchanges predetermined time slots of a time division multiplexed signal and returns it to a network during a loop-back test. A buffer memory in a time division multiplexed trunk is used to interchange the predetermined time slots. Alternatively, the buffer memory is provided in a return loop for use during the loop-back test. Therefore, it can be determined that the received signal is sent from another exchange and the loop-back test can be performed using ordinary exchanging processing procedures.
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Citations
17 Claims
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1. A time division exchange for serving plural lines, comprising:
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a network, coupled to the lines, for transmitting and receiving time division multiplexed signals; a time division multiplexed trunk, coupled to said network, for providing, as an output time division multiplexed signal to another exchange, the time division multiplexed signal transmitted by said network, and for providing an input time division multiplexed signal to said network as the received time division multiplexed signal, said time division multiplexed trunk including means for interchanging predetermined time slots in one of the time division multiplexed signals when a loop-back test is to be performed; and return means, coupled to said time division multiplexed trunk, for receiving the output time division multiplexed signal and for returning it to said time division multiplexed trunk, as the input time division multiplexed signal, during the loop-back test. - View Dependent Claims (2, 3, 4)
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5. A time division exchange for serving plural lines, comprising:
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a network, coupled to the lines, for transmitting and receiving time division multiplexed signals; a time division multiplexed trunk, coupled to said network, for providing, as an output time division multiplexed signal to another exchange, the time division multiplexed signal transmitted by said network, and for providing an input time division multiplexed signal; and return means, coupled to said time division multiplexed trunk, for interchanging predetermined time slots of the output time division multiplexed signal and for returning the input time division multiplexed signal having interchanged time slots to said time division multiplexed trunk during a loop-back test, said time division multiplexed trunk providing the input time division multiplexed signal having the interchanged time slots to said network as the received time division multiplexed signal. - View Dependent Claims (6, 7, 8)
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9. A time division exchange, connected to at least one other exchange, for serving plural lines, comprising:
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a network, coupled to the lines, for transmitting a first time division multiplexed signal and for receiving a second time division multiplexed signal; a time division multiplexed trunk, coupled to said network and to another exchange, for receiving the first time division multiplexed signal and for providing a third time division multiplexed signal as an output to the other exchange, said time division multiplexed trunk receiving a fourth time division multiplexed signal from the other exchange and for providing the second time division multiplexed signal to said network, said time division multiplexed trunk including means for interchanging predetermined time slots in one of the time division multiplexed signals when a loop-back test is to be performed; and return means, coupled to said time division multiplexed trunk, for receiving the third time division multiplexed signal and for returning the third time division multiplexed signal to said time division multiplexed trunk, as the fourth time division multiplexed signal, during the loop-back test. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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Specification