This standard defines the characteristics and normative specifications for the network interface
between a cable television plant and commercially available consumer equipment that is used to
access multi-channel television programming. The interface is also compatible with existing settop
terminal equipment owned by cable operators and with terminal equipment developed via the
OpenCable™ specification process (see www.opencable.com). In this standard the Cable
Network Interface is defined as the interface between the cable drop and the input terminals of
the first device located on the subscriber's premises regardless of whether that device is owned
by the subscriber or the cable operator. A coaxial-based broadband access network is assumed.
This may take the form of either an all-coax or hybrid-fiber/coax (HFC) network. The generic
term "cable network" is used here to cover all cases. Cable networks typically use a sharedmedium,
tree-and-branch architecture with analog and/or digital transmission. The key
functional characteristics assumed in this document are the following:
- Two-way transmission.
- The maximum optical/electrical spacing between the cable headend and the most distant
deployed terminal equipment is 100 miles, although typical maximum separation may be
10-15 miles.
- A maximum differential optical/electrical spacing between the cable headend and the closest
and most distant deployed terminal equipment is 100 miles, although this would typically be
limited to 15 miles.
The cable network provides services utilizing 6-MHz in-band channel(s), out-of-band forward
data channel(s), and out-of-band reverse data channel(s). The 6-MHz in-band channels are used
to transport digital services as well as analog services. These services may be either in the clear
or scrambled.
A typical channel plan for a cable network places analog services (NTSC AM-VSB channels) in
the 54 to 450/550 MHz range; and digital services (QAM MPEG-2 multiplex channels) in the
450/550 to 864 MHz range (Note 1). These channels shall all comply with the EIA/CEA-542-A
channel-tuning plan. However, the frequency location may change over time such that analog
and digital channels may be located anywhere in the downstream operating range.
| ANSI : | ANSI Approved |
| File Size : | 1
file
, 130 KB |
| Number of Pages : | 32 |
| Published : | 01/01/2004 |
