Method and system for power management in a frequency division multiplexed network
View Patent ↗A network device may receive a signal from a headend, wherein a bandwidth of the received signal spans from a low frequency to a high frequency and encompasses a plurality of sub-bands. The network device may determine, based on communication with the headend, whether one of more of the sub-bands residing above a threshold frequency are available for carrying downstream data from the headend to the circuitry. The network device may digitize the signal using an ADC operating at a sampling frequency. The sampling frequency may be configured based on a result of the determining. When the sub-band(s) are available for carrying downstream data from the headend to the network device, the sampling frequency may be set to a relatively high frequency. When the sub-band(s) are not available for carrying downstream data from the headend to the network device, the sampling frequency may be set to a relatively low frequency.
1. A system comprising:
an analog-to-digital converter operable to digitize a signal received from a headend;
a digital processing circuit operable to:
determine, based on signals received from said headend, which one or more of a plurality of sub-bands are available for carrying data from said headend to said cable modem; and
control a sampling frequency of said analog-to-digital converter such that:
when one or more of said plurality of sub-bands that are above a particular threshold frequency are available for carrying data from said headend to said cable modem, said sampling frequency is set to a frequency that is twice a highest frequency of said one or more of said plurality of sub-bands that are above said particular threshold; and
when said one or more of said plurality of sub-bands that are above a particular threshold are not available for carrying data from said headend to said cable modem, said sampling frequency is set to a frequency that is at least twice said particular threshold frequency.
2. The system of claim 1 , comprising a filter operable to filter said signals received from said headend prior to said digitization of said signals by said analog-to-digital converter.
3. The system of claim 2 , wherein a frequency response of said filter is configurable during runtime of said system.
4. The system of claim 2 , wherein:
when one or more of said plurality of sub-bands that are above a particular threshold frequency are available for carrying data from said headend to said cable modem, a cut-off frequency of said filter is set to a frequency that is twice a highest frequency of said one or more of said plurality of sub-bands that are above said particular threshold; and
when said one or more of said plurality of sub-bands that are above a particular threshold are not available for carrying data from said headend to said cable modem, said cut-off frequency of said filter is set to a frequency that is at least twice said particular threshold frequency.
5. The system of claim 1 , wherein said data consists of management messages.
6. The system of claim 5 , wherein said management message comprise one or more of: a DOCSIS SYNC message, a DOCSIS UCD message, and a DOCSIS MAP message.
7. The system of claim 1 , wherein said digital processing circuit is operable to negotiate said particular threshold frequency with said headend.
8. The system of claim 1 , wherein said digital processing circuit is operable to determine said particular threshold frequency based on communications from said headend.
9. A system comprising:
an analog-to-digital converter operable to digitize a signal received from a headend;
a digital processing circuit operable to:
determine, based on signals received from said headend, which one or more of a plurality of sub-bands are available for carrying management messages from said headend to said cable modem, wherein for a first network configuration said management messages are restricted to one of more of said plurality of sub-bands below a particular threshold frequency, and for a second network configuration one or more of said plurality of sub-bands above said particular threshold frequency are available for carrying said management messages, and
control a sampling frequency of said analog-to-digital converter such that:
for said first network configuration, said sampling frequency is set to a frequency that is at least twice said particular threshold frequency; and
for said second network configuration, said sampling frequency is set to a frequency that is at least twice a highest frequency of said plurality of sub-bands.
10. The system of claim 9 , comprising a filter operable to filter said signals received from said headend prior to said digitization of said signals by said analog-to-digital converter.
11. The system of claim 9 , wherein a frequency response of said filter is configurable during runtime of said system.
12. The system of claim 9 , wherein:
for said first network configuration, a cut-off frequency of said filter is set to a frequency that is at least twice said particular threshold frequency; and
for said first network configuration, said cut-off frequency of said filter is set to a frequency that is at least twice a highest frequency of said plurality of sub-bands.
13. The system of claim 5 , wherein said management messages comprise one or more of: a DOCSIS SYNC message, a DOCSIS UCD message, and a DOCSIS MAP message.
14. The system of claim 9 , wherein said digital processing circuit is operable to negotiate said particular threshold frequency with said headend.
15. The system of claim 9 , wherein said digital processing circuit is operable to determine said particular threshold frequency based on communications from said headend.