Enhanced Cable Modem Termination System (CMTS) functionality, including
programmable digital domain modulators and demodulators for dynamic
channel assignment, is incorporated into Fiber Nodes (FNs) or mini Fiber
Nodes (mFNs), yielding enhanced Fiber Nodes (eFNs). These eFns distribute
CMTS functionality deep into Hybrid-Fiber-Coax Networks (HFCN) rather
than centralizing the CMTS functions within a single location. Moving the
cable modem terminations closer to the subscribers shortens the analog RF
paths required to support cable modems. Communication of both subscriber
data and CMTS control data is performed over Ethernet-compatible packet
networks between the field-based CMTSs and an upstream facility (e.g.,
the Head End), which includes an Internet gateway. Packet data for
multiple subscriber cable modems is easily compressed and merged over
common network paths, reducing cabling plant complexity and increasing
bandwidth utilization. This approach dramatically reduces the
infrastructure cost per cable modem. Distributing CMTS functionality
among multiple eFNs also reduces demands on already stretched resources
at the Head End for space, power, and HVAC. For HFCN channels containing
signals with modulation or encoding schemes that are unknown or best
processed upstream, the invention also provides for tunneling their
spectrum over the same packet network as used for the cable modem data.
The channels to be tunneled are isolated using digital receivers,
translated to baseband, their data framed, merged with cable modem
subscriber data, and transmitted over the packet network. Upstream, the
framed channel data is parsed and the original channel spectrum
reconstructed to permit information recovery.