GPS DATA ACCESS SYSTEM

摘要

An integrated receiver decoder (IRD), commonly called a set-top box, has a global positioning system (GPS) receiver. The GPS receiver checks to see if the IRD is at an authorized location and allows descrambling of video signals only if the location is authorized. A central access control system, remote from the customers/viewers, has a high quality GPS receiver and sends some GPS data in the transmission medium used to send video signals to the customers. The set-top box, referred to as a customer access control, establishes different geographic restrictions on different of various video or data signals. Location-specific signals require that the set-top box be at a single fixed location for descrambling. Geographic filtering of data signals is provided. Region-specific signals are accessible only if the set-top box is in a geographic region authorized for reception, there being several such regions. Large area signals are accessible anywhere within a large area including the regions. Region-exclusion signals are accessible only if the set-top box is outside of one or more regions where reception is no allowed.