The Internet

The Internet has always been based on a fiber optic backbone. It started as part of the telephone network which was then primarily voice but has become the largest communications network as data traffic has outgrown voice traffic. Now the telcos are moving their voice communications to Internet protocol (IP) for lower costs.

CATVMost CATV systems are using fiber backbones too. CATV companies use fiber because it give them greater reliability and the opportunity to offer new services, like phone service and Internet connections.

CATV used to have a terrible reputation for reliability, not really a problem with service but with network topology. CATV uses very high frequency analog signals, up to 1 GHz, which has high attenuation over coax cable. For a city-wide system, CATV needed many amplifiers (repeaters) to reach the users at the end of the system; 15 or more we common. Amplifiers failed often, meaning that subscriber downstream of the failed amp lost signal. Finding and fixing failed amps was difficult and time consuming, causing subscriber complaints.

December 3, 2011

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