05172413 is referenced by 714 patents and cites 18 patents.

Disclosed is an improved system for the delivery of entertainment and educational programming from a plurality of electronic libraries to a plurality of users. Users actuate a hand operated control device to: review a listing of available programming; enable the delivery of a program from a library; or control the delivery of forwarding and rewinding through the programming, and authorizing the purchase of advertised consumer goods by entering in personal identification numbers. The network of libraries and the paths for delivering the programming stored therein is arranged for optimum transmission efficiency and maximum access capacity. The key idea in optimizing transmission efficiency and access capacity is to recognize that programming can be grouped into different classes, and that not all classes of programs should be stored in all libraries. High demand entertainment programming should be stored and delivered from a central source whereas low demand educational or cultural programming should be stored and delivered from a local neighborhood library where there is a special interest in such programming. The system is intrinsically secure and encryption is not required. Programs are not delivered to any physical address other than that of the ordering user. Apparatus is employed to discourage the unauthorized copying of delivered programming. The system also permits the delivery of conventional cable television signals on a competitive basis. Apparatus is employed that maximizes access capacity and minimizes investment cost.

Title
Secure hierarchial video delivery system and method
Application Number
7/632122
Publication Number
5172413
Application Date
December 20, 1990
Publication Date
December 15, 1992
Inventor
Terry L Leier
Regina
CA
Alton O Stretton
Regina
CA
Graham C Bradley
Regina
CA
Agent
Davis Bujold & Streck
Assignee
SaskTel
CA
IPC
H04N 7/16
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