Patent ID: 7664142

Claim:
A subchannel digital data communication apparatus comprising: a transmitter means for: receiving subchannel data which includes control and management data corresponding to at least one high speed digital data signal, and modulating the subchannel data onto a host signal which propagates via a media configured to carry high speed digital data signals generated by a high speed data transmitter, wherein modulating includes modulating, via frequency-shift keying, said subchannel data onto a subchannel carrier having a frequency in a portion of the spectrum of said high speed digital data signal where excessive interference from frequency components of said high speed digital data signal will not be substantially experienced; a receiver means, coupled to said media, for recovering recovered subchannel data from a host signal received by the receiver means; and wherein said transmitter means employs frequency shift keying to alter the frequency of said subchannel carrier between a mark frequency and a space frequency; and wherein said receiver means includes a digital filter: having a passband centered on said subchannel carrier frequency, and having a bandwidth wide enough to simultaneously encompass most of the frequency components of said mark and space frequencies but few of the frequency components of said high speed digital data signal.