A "Broadcast Combining" Application

The figure illustrates a database retrieval application in which frequently asked questions and periodic data updates are broadcast on the downlink and filtered in the end terminals. The results of less frequent queries are scheduled for a slot on the broadcast channel with lower priority. If an individual user has a high priority request-and is willing to pay for that priority-his or her request can move to the head of the queue. In the figure, the uplink path through the local area network, the local Internet gateway, the Internet, and the DBS gateway, has been simplified.