The hybrid fiber-coaxial CSI

When fiber-optic cable began to be deployed widely, the  cable companies started using  fiber to build  out  their infrastructure. But by that time,  much of the  coaxial cable infrastructure supporting localized connections had already been established. This is why a large share of today’s cable customers have  coaxial cable coming into their premises from the  nearby telephone pole.

The cable companies’ network is today known  as the  hybrid fiber-coaxial (HFC) CSI. It combines the  use of coaxial cable with fiber-optic cable. The HFC CSI may one day be all fiber-optic cable. In its present state, it provides not  only cable TV services but  also  cable modem, one of the  two popular methods of broadband Internet access. To run VoIP in your  home, you need broadband service. If you have cable modem service, you can usually add  VoIP transport services with little or no additional expense added to your  existing POTS telephone bill.

The HFC CSI began to evolve  in the  1980s as strictly a cable-television appli- cation. Companies in the  business of supplying closed-circuit cable television programming used satellite technology to capture both broadcast television signals from far-off places and  local TV signaling, and pipe  those TV signals through their cable-based infrastructure to consumers willing to pay for the  better quality and  channel selection.

Companies in the  cable TV business had  to bear the  cost of building out the  HFC infrastructure because there was nothing in place when  they  first got started. The cable carriers utilized many  of the  inground conduits and tele- phone poles already in use by the  OC and  DS CSI carriers. They  also built  buildings and  facilities for terminating cable services. When the consumer demand for broadband Internet access developed in the  early 1990s, the  HFC CSI was in a reasonably good  place to integrate Ethernet access — and  there-  fore VoIP — within the  home using  their existing cable television network. Today,  broadband Ethernet running over  the HFC carrier network has  more  than twenty million customers and  is growing  rapidly each month.