Low power system and method for DSL lines
View Patent ↗The transmit power level of a transceiver coupled to a digital subscriber line (DSL) line is reduced from a first transmit power level sufficient for the transceiver to continuously transmit data on the DSL line at a first bit rate to a second transmit power level below the first transmit power level sufficient for the transceiver to continuously transmit data on the DSL line at a second bit rate that is lower than the first bit rate. The reduction in transmit power is limited so that the change does not induce time-varying crosstalk sufficient to destabilize a nearby DSL line. While the transmit power level of the transceiver is reduced to the second transmit power level, the transceiver is suspended from transmitting data on the DSL line for repeated periods of time. Suspending the data transmission is controlled to avoid further time-varying crosstalk sufficient to destabilize the nearby DSL line.
1. A method for operating a transceiver coupled to a digital subscriber line (DSL) line, comprising:
reducing a transmit power level of the transceiver that uses a time-division duplex (TDD) system from a first transmit power level sufficient for the transceiver to transmit data on the DSL line at a first bit rate to a second transmit power level below the first transmit power level sufficient for the transceiver to transmit data on the DSL line at a second bit rate that is lower than the first bit rate and without generating time-varying crosstalk sufficient to harm a neighboring DSL line, wherein the second transmit power level varies with frequency and has a frequency-dependent Power Spectral Density.
2. The method of claim 1 , wherein the TDD system is a G.fast system.
3. The method of claim 1 , wherein the DSL line supports data transmission with Very high-speed/Very high-bit-rate DSL (VDSL), VDSL2, vectored VDSL2, or G.fast.
4. The method of claim 1 , wherein the transmit power of the TDD system is lowered within a VDSL frequency band.
5. The method of claim 2 , wherein the TDD system transmits in frequencies which overlap VDSL frequencies, such that the transmit power spectral density (PSD) of the G.fast system is lowered within a VDSL frequency band, to levels such that the G.fast crosstalk does not destabilize VDSL lines.
6. The method of claim 1 , wherein the TDD system uses one or more of: a flat power back-off (PBO) power spectral density (PSD), a PSD that only transmits on some frequencies, and a frequency-shaped PSD.
7. The method of claim 1 , wherein the TDD system does not transmit data in a frequency band that may be used by VDSL.
8. The method of claim 1 , wherein the TDD system operates asymmetrically, with different power spectral density (PSD) levels for upstream and downstream.
9. The method of claim 1 , wherein the TDD system uses different power spectral density (PSD) levels in upstream and downstream VDSL frequency bands.
10. The method of claim 1 , wherein compatibility with VDSL is enabled for the TDD system.
11. The method of claim 5 , wherein transmit PSD level within the VDSL bands is set to lower G.fast power usage.
12. An apparatus comprising:
a controller to operate a transceiver coupled to a digital subscriber line (DSL) line to:
reduce a transmit power level of the transceiver that uses a time-division duplex (TDD) system from a first transmit power level sufficient for the transceiver to transmit data on the DSL line at a first bit rate to a second transmit power level below the first transmit power level sufficient for the transceiver to transmit data on the DSL line at a second bit rate that is lower than the first bit rate and without generating time-varying crosstalk sufficient to harm a neighboring DSL line, wherein the second transmit power level varies with frequency and has a frequency-dependent Power Spectral Density.
13. The apparatus of claim 12 , wherein the transceiver is a G.fast transceiver.
14. The apparatus of claim 13 , wherein reducing the transmit power level of the transceiver from the first transmit power level to the second transmit power level comprises reducing the transmit power level of the G.fast transceiver within low frequency bands to enable operation of the DSL line in a cable or loop or binder comprising other DSL lines operating according to a Very high speed or Very high bit rate DSL (VDSL) standard.
15. The apparatus of claim 12 , wherein the controller is further configured to: increasing the transmit power level of the transceiver from the second transmit power level sufficient for the transceiver to transmit data on the DSL line at the second bit rate to the first transmit power level sufficient for the transceiver to transmit data on the DSL line at the first bit rate and without generating crosstalk sufficient to harm the neighboring DSL line.
16. The apparatus of claim 15 , wherein increasing the transmit power level of the transceiver from the second transmit power level to the first transmit power level comprises increasing the transmit power level from the first transmit power level to the second transmit power level in a series of steps incurred over a duration of time, in which for each step a maximum increase in the transmit power level is allowed such that transmitting data on the DSL line does not generate crosstalk sufficient to destabilize the neighboring DSL line.
17. A computer-readable non-transitory storage medium, comprising computer instructions, that when executed, cause a transceiver coupled to a digital subscriber line (DSL) line, to perform:
reducing a transmit power level of the transceiver that uses a time-division duplex (TDD) system from a first transmit power level sufficient for the transceiver to transmit data on the DSL at a first bit rate to a second transmit power level below the first transmit power level sufficient for the transceiver to transmit data on the DSL line at a second bit rate that is lower than the first bit rate and without generating time-varying crosstalk sufficient to harm a neighboring DSL line wherein the second transmit power level varies with frequency and has a frequency-dependent Power Spectral Density; or
increasing the transmit power level of the transceiver from the second transmit power level sufficient for the transceiver to transmit data on the DSL line at the second bit rate to the first transmit power level sufficient for the transceiver to transmit data on the DSL line at the first bit rate and without generating crosstalk sufficient to harm the neighboring DSL line.
18. The computer-readable non-transitory storage medium of claim 17 , wherein the TDD system is a G.fast system.
19. The computer-readable non-transitory storage medium of claim 18 , wherein the TDD system transmits in frequencies which overlap VDSL frequencies, such that the transmit power spectral density (PSD) of the G.fast system is lowered within a VDSL frequency band, to levels such that the G.fast crosstalk does not destabilize VDSL lines.
20. The computer-readable non-transitory storage medium of claim 19 , wherein transmit PSD level within the VDSL bands is set to enable compatibility with VDSL, to lower G.fast power usage, or both.