Cable television system with two-way telephone communication path

Abstract

A method and apparatus to enable billing of subscribers of pay-per-view television systems or the like on a non-real-time basis. A scrambled television signal is received at a subscriber terminal from a headend. The received signal is selectively descrambled in response to subscriber action indicating acceptance for viewing of a program contained in the signal. A record is maintained at the subscriber terminal of the billable programs accepted for viewing by the subscriber. The signal received from the headend is monitored by the subscriber terminal for a call-in command which instructs the subscriber terminal to forward the record of billable programs to the headend. A telephone communication path is established between the subscriber terminal and the headend in response to the call-in command. The record of billable programs is transmitted to the headend over the telephone communication path, and the subscriber is billed in accordance therewith. A plurality of transaction credits can be downloaded from the headend to the subscriber terminal, stored therein, and debited in response to the acceptance by a subscriber of a billable program for viewing. The descrambling of a program is prevented if there are not sufficient stored transaction credits available to pay for the program. A time-out count can be maintained in the subscriber terminal and reinitialized in response to a signal received from the headend. Descrambling of billable programs is prevented at the subscriber terminal if the time-out count expires.