The Information Footprint: A Satellite-Based Information on Demand Teleservice

An INFORMATION ON DEMAND (IOD) Teleservice developed at the German National Research Center for Information Technology (GMD) provides remote access to multimedia information consisting of audio, video, and text. It uses a bidirectional narrowband message link between the end user and the service provider, and a unidirectional broadband data link from the service provider to the end user. Hyperstructure of the multimedia database, clear information presentation (on SUN workstations and on PCs) and high speed communication with long round-trip-delays were the major problems to be solved. Since the IoD teleservice uses a satellite connection (among others), it turned out to be necessary to implement an access protocol optimized for the access of real-time multimedia data across a long-delay high-bandwidth link, a LONG FAT PIPE [2] ; we called it the MEDIASERVICE PROTOCOL (MSP). This paper introduces the Information on Demand Teleservice and describes a first implementation.