By Emory McGinty, Scientific Atlanta
The cable industry has in place a highly efficient information delivery system to the home supporting video programming and text. Unknown to many people, the same cable system also delivers one-way data from the cable headend to data receivers in the home disguised as cable TV converters. Many addressable converter systems have been using one-way data over cable for years to address and control the services that are offered by the cable companies. The same technology can be used as a cost effective information delivery system to data subscribers having personal computers in their home.
This paper describes a one-way information delivery system using technology available today. Alternatives to modulation format, addressability and security are presented in detail. In order to help the cable operator better understand the impact of encryption on the cable system, many encryption methods are described along with their impact on the cable operator and cable subscriber. Finally, an addressable system with encryption is described which provides the best trade off between addressability, security and cost.