METHOD AND SYSTEM FOR SUBSCRIPTION TELEVISION BILLING AND ACCESS
A subscription television system and method in which billing information regarding programs actually viewed by a subscriber of the system is accumulated (20) over nondedicated telephone lines. A scrambled television program signal containing a block of television program material (14), a program identification code (18) unique to the block of program material, and a program category code (18), is broadcast (16). The codes are preferably included in the vertical retrace interval of the video portion of the program signal and the transmitted program signal is selectively received at a subscriber station (12) and selectively unscrambled (24) to permit viewing of the block of program material being transmitted in response to subscriber action (30) indicating acceptance for viewing of the block of program material. The received program category code is compared (92) with a locally generated category code (90) to determine whether the program is acceptable for viewing. The program identification code is detected (64) and stored (68) for subsequent transmission in response to the subscriber action indicating acceptance for viewing of the received block of program material. The program identification code stored at the subscriber station is selectively accessed from a remote location (10) over telephone lines on other than a real time basis (e.g., a periodic basis) to thereby provide billing information at the remote location as to programs actually viewed by the subscriber. The subscriber can thus be billed monthly or on some desired periodic basis for programs actually viewed during the preceding period. The billing period can be varied (32, 70) from the remote location (10) to provide a means to control the number of programs which a subscriber can receive.