Cable Television Laboratories, Inc.

Auto-Trol Technology Corporation

Douglas M Young

Greg White

Garey L Hassler

Jon H Barber

Richard M Burkley

Matthew W Jackson

Ronald A Woodward

Erwin L Rehme

A multicast system is contemplated. The multicast system may be configured to facilitate changing between multicast steams by caching one multicast stream while tuned to another multicast stream in anticipation of tuning to the cached multicast stream. Attributes associated with available multicast streams may be communicated to assist accessing devices in deciding which one or more of the available multicast streams to cache.

Content multicasting

License management systems and methods allow licenses for a computer program to be available for use at each of a plurality of nodes of a network. If a valid license file at a local node contains an unexpired, available license, a license manager at the local node permits the computer program to be executed at the requesting local node. If no such license is available in a valid license file at such local node, the license manager searches the other nodes for a valid license file containing an unexpired, available license. In one embodiment, if an unexpired available license is located in a valid license file at a second (or 'remote') node, the license manager transfers such license to the local node, and assigns and encrypts a unique identification to such transferred license. The original record of the transferred license is modified by erasing it from the license file at the remote node so that the transferred license is no longer available there. In a second embodiment, the license manager modifies the license file to indicate use of the license at the local node without such transfer. The number of copies of the computer program that are authorized for execution simultaneously on the network is thus limited to the number of licenses that have been loaded into the license files on the network.

System for controlling the number of concurrent copies of a program in a

Growing community of inventors

Boulder, CO, United States of America

Douglas M Young