Line testing method and apparatus therefor
DCFirst Claim
1. A method of assessing suitability of a wireline communication resource for supporting data transmissions at relatively high frequency between an infrastructure node and a subscriber terminal, the wireline communication resource inherently arranged to support voice band transmissions at relatively low frequency, the method comprising the steps of:
- at a test point, sending a test signal at the relatively high frequency to the subscriber terminal, the test signal having a predetermined level;
detecting an attenuated level of the test signal at the subscriber terminal;
communicating an indication of the attenuated level of the test signal to the test point; and
at the test point, assessing the suitability of the wireline communication resource for supporting data transmission at relatively high frequency based upon receipt of the indication of the attenuated level and the predetermined level.
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Accused Products
Abstract
To facilitate the use of relatively high frequency data transmission services over a wireline communication resource originally deployed to support low frequency voice band services, an assessment of the wireline communication resource (50-52) is based on attenuation of high frequency test signals, of known original level, that are generated (18) injected into the wireline communication resource from a test point (12). A detector (60) at a potential point of service, e.g. at a customers'"'"' premises (14), detects an attenuated level of the test signals and generates a control signal (70, 82), such as a drive current, indicative of the attenuation caused by the wireline communication resource (50-52). The control signal (70, 82) is then indirectly communicated back to the test point (12) in a coded form, and preferably within a voice band transmission. The coded form may be realized as modulation of a power supply provided to the customers'"'"' premises by the wireline communication resource, or could be achieved by up-link frequency mixing. In its most basic form, the control signal causes fluctuation on a visual level indicator at the customers'"'"' premises and therefore relies on a customer providing a verbal or toned response to the test point as to the level of the visual indicator. Effective attenuation at high frequencies can then be assessed based upon analysis of information coded into the voice band signal and its direct relationship with the original level of the injected high frequency signals.
35 Citations
35 Claims
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1. A method of assessing suitability of a wireline communication resource for supporting data transmissions at relatively high frequency between an infrastructure node and a subscriber terminal, the wireline communication resource inherently arranged to support voice band transmissions at relatively low frequency, the method comprising the steps of:
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at a test point, sending a test signal at the relatively high frequency to the subscriber terminal, the test signal having a predetermined level;
detecting an attenuated level of the test signal at the subscriber terminal;
communicating an indication of the attenuated level of the test signal to the test point; and
at the test point, assessing the suitability of the wireline communication resource for supporting data transmission at relatively high frequency based upon receipt of the indication of the attenuated level and the predetermined level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
the step of communicating the indication of the attenuated level to the test point further comprises the step of regulating a current of the wireline communication resource in response to the current generated to be representative of the attenuated level; and
the step of assessing further comprises the step of detecting variations in the current through the wireline communication resource to ascertain the level of attenuation.
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4. The method of assessing suitability of a wireline communication resource according to claim 3, wherein the subscriber terminal has an associated test circuit that draws current from the wireline communication resource and the method further comprising the steps of:
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generating tones in response to the current representative of the attenuated level; and
regulating a voltage supplied to a voltage regulator of the test circuit with said tones to vary the current drawn by the test circuit from the wireline communication resource.
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5. The method of assessing suitability of a wireline communication resource according to claim 2, the method further comprising the steps of:
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generating tones in response to the current representative of the attenuated level; and
modulating the tones onto the wireline communication resource for detection at the test point.
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6. The method of assessing suitability of a wireline communication resource according to claim 5, wherein the step of modulating comprises the step of sending the modulated tones in the voice band.
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7. The method of assessing suitability of a wireline communication resource according to claim 1, wherein the subscriber terminal has an associated test circuit comprising a non-linear circuit and a means for modulating and the method further comprises the step of:
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forming a voice band signal in the non-linear circuit in response to receiving the test signal; and
modulating the voice band signal onto the wireline communication resource for communication to the test point.
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8. The method of assessing suitability of a wireline communication resource according to claim 7, wherein the step of forming the voice band signal includes one of the steps of:
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receiving a plurality of high frequency test signals having a frequency separation within a voice band range and mixing the plurality of high frequency test signals to generate the voice band signal; and
receiving a high frequency test signal and generating the voice band signal from a harmonic of the high frequency test signal.
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9. The method of assessing suitability of a wireline communication resource according to claim 8, further comprising the step of generating a plurality of voice band signals in response to receiving the plurality of high frequency test signals.
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10. The method of assessing suitability of a wireline communication resource according to claim 7, wherein an amplitude of the voice band signal is directly proportional to the level of attenuation of the wireline communication resource at the relatively high frequency.
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11. The method of assessing suitability of a wireline communication resource according to claim 10, wherein the amplitude of the voice band signal is such as to be distinguishable from relatively low amplitude voice call transmissions.
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12. The method of assessing suitability of a wireline communication resource according to claim 1, wherein the wireline communication resource is a twisted pair.
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13. The method of assessing suitability of a wireline communication resource according to claim 2, further comprising the step of:
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generating a sensual indication of the attenuated level, the sensual indication provided in response to the current generated as being representative of the attenuated level; and
having a subscriber verbally report the sensual indication to the test point.
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14. A wireline test system for assessing an ability of a wireline communication resource to support data transmissions at relatively high frequencies between an infrastructure node and a subscriber terminal, the wireline communication resource inherently arranged to support voice band transmissions at relatively low frequency, the wireline test system comprising:
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a) a test desk arranged both to co-ordinate a transmission of relatively high frequency test signals of known level down the wireline communication resource and to assess a level of attenuation caused to the test signal in response to a report signal received subsequently thereby; and
b) subscriber associated test circuitry for coupling to the wireline communication resource, the subscriber associated test circuitry comprising;
a detector, responsive to the relatively high frequency test signals, for generating a signal representative of an attenuated level of the relatively high frequency test signals through the wireline communication resource; and
means for communicating an indication of the attenuated level of the test signal to the test desk. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23)
a tone generator arranged to generate tones in response to the current representative of the attenuated level, the tone generator further coupled to a voltage regulator and arranged to supply the tones thereto, whereby the tones vary the current drawn by the subscriber associated test circuitry from the wireline communication resource.
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18. The wireline test system of claim 15, wherein the subscriber associated test circuitry further comprises:
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a tone generator arranged to generate tones in response to the current representative of the attenuated level; and
a modulator responsive to the tones and coupled to modulate the tones onto the wireline communication resource for detection at the test desk.
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19. The wireline test system of claim 18, wherein the modulator generates tones in the voice band.
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20. The wireline test system of claim 14, wherein the subscriber associated test circuitry further comprises:
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a non-linear circuit coupled across the wireline communication resource and arranged to form a voice band signal in response to receiving the test signal; and
a modulator responsive to the voice band signal and coupled across the wireline communication resource, the modulator arranged to modulate the voice band signal onto the wireline communication resource for communication to the test point.
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21. The wireline test system of claim 20, wherein the subscriber associated test circuitry is responsive to a plurality of high frequency test signals having a frequency separation within a voice band range and wherein the non-linear circuit comprises a mixer for mixing th e plurality of high frequency test signals to generate the voice band signal.
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22. The wireline test system of claim 20, wherein the non-linear circuit generates the voice band signal from a harmonic of the high frequency test signal.
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23. The wireline test system of claim 21, further comprising a reactive short coupled from the wireline communication resource to the non-linear circuit, the reactive short having a high impedance for low amplitude signals and a low impedance for high amplitude signals.
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24. Subscriber associated test circuitry for coupling to a wireline communication resource inherently arranged to support voice band transmissions at relatively low frequency, the subscriber associated test circuitry further arranged to receive relatively high frequency test signals of known level transmitted to the subscriber associated test circuitry through wireline communication resource, the subscriber associated test circuitry comprising:
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a detector, responsive to the relatively high frequency test signals, for generating a signal representative of a level of the relatively high frequency test signals through the wireline communication resource; and
means for communicating an indication of the level of attenuation of the test signal to the test desk. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
a tone generator arranged to generate tones in response to the current representative of the attenuated level, the tone generator further coupled to a voltage regulator and arranged to supply the tones thereto, whereby the tones vary the current drawn by the subscriber associated test circuitry from the wireline communication resource.
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28. Subscriber associated test circuitry according to claim 25, further comprising:
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a tone generator arranged to generate tones in response to the current representative of the attenuated level; and
a modulator responsive to the tones and coupled to modulate the tones onto the wireline communication resource.
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29. Subscriber associated test circuitry according to claim 28, wherein the modulator generates tones in the voice band.
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30. Subscriber associated test circuitry according to claim 24, further comprising:
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a non-linear circuit for coupling across the wireline communication resource and arranged to form a voice band signal in response to receiving the test signal; and
a modulator responsive to the voice band signal and for coupling across the wireline communication resource, the modulator arranged to modulate the voice band signal onto the wireline communication resource for communication to the test point.
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31. Subscriber associated test circuitry according to claim 30, wherein the subscriber associated test circuitry is responsive to a plurality of high frequency test signals having a frequency separation within a voice band range and wherein the non-linear circuit comprises a mixer for mixing the plurality of high frequency test signals to generate the voice band signal.
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32. Subscriber associated test circuitry according to claim 30, wherein the non-linear circuit generates the voice band signal from a harmonic of the high frequency test signal.
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33. Subscriber associated test circuitry according to claim 31, further comprising a reactive short arranged to be coupled from the wireline communication resource to the non-linear circuit, the reactive short having a high impedance for low amplitude signals and a low impedance for high amplitude signals.
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34. Subscriber associated test circuitry according to claim 24, wherein the subscriber associated test circuitry is realised in a dongle.
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35. Subscriber associated test circuitry according to claim 24, wherein the wireline communication resource is a twisted pair.
Specification