By Robert V .C. Dickinson, E-COM Laboratories Division
In the saga of addressable pay TV services the inevitable problem of increasing theft of service is now in full bloom. One of the most effective approaches toward limiting theft of service has been the development of pay TV control equipment which is mounted outside the subscribers residence where tampering is extremely difficult. Authorizations are transmitted to these off-premises units from the headend while communications from the home are implemented with a low cost keypad unit. The offpremises units are, in many cases, simply "pole mounted converters". These units consume a considerable amount of power, typically in the range of 15 to 35 watts per converter. Other off-premises premium TV security equipments include addressable jammers and/or taps which require less power per drop however this requirement is not insignificant. Some manufacturers are offering off-premises equipment powered from the cable distribution power supplies and others utilize power from the home via the drop cable. Powering of these off-premises devices in either case provokes a number of technical and economic considerations.