Patent ID: 7720101

Claim:
A cable modem, comprising: wideband circuitry configured to receive radio frequency (RF) band data arriving downstream from a cable modem termination system (CMTS) external to the cable modem over multiple different downstream channels at the same time, the wideband circuitry demodulating signals in the different downstream channels and then formatting the demodulated signals into individual packets or frames for sending out over an Internet Protocol (IP) network interface; a narrowband circuit configured to operate in a narrowband mode; and a control bus coupling the narrowband circuit and the wideband circuitry and configured to allow the narrowband circuit to control the wideband circuitry via the control bus in order to selectively extract Data Over Cable Service Interface Specification (DOCSIS) data in a preconverted, modulated format from one of the multiple downstream channels such that the narrowband circuit receives the data after the data has been preprocessed by a conversion operation in the wideband circuitry and while the data is in a modulated format suitable for demodulation by the narrowband circuit; wherein the wideband circuitry includes a first Quadrature Amplitude Modulation (QAM) demodulator and the narrowband circuit comprises a second different QAM demodulator; and wherein the control bus passes the selectively extracted DOCSIS data from the wideband circuitry prior to such data being processed by the first QAM demodulator such that the selectively extracted DOCSIS data bypasses the first QAM demodulator of the wideband circuitry and is directed to the second different QAM demodulator of the narrowband circuit for demodulation.