Abstract: A satellite communication system increases its efficiency by using adaptive pipeline polling as the control protocol. In this protocol, the earth stations are separated into active and inactive sets and a first number of slots (salary) is assigned to each active station. Additionally, periodically active stations are queried as to the length of their queues and assigned salary slots not needed by any active station are reallofted to stations with queues that exceed their assigned salary in proportion to the size of such excess. A contention period is included outside of the normal salary and bonus periods during which stations in the inactive are allowed to contend to be included in the active set.

Abstract: A teleconferencing video system uses two cameras at each station symmetrically positioned on opposite sides of the optical axis between the speaker and the monitor used to produce an image of the listener. The two cameras are used to provide from the two images observed by the cameras a virtual image corresponding to the image that would be viewed by a camera located on the first-mentioned optical axis. This system permits eye contact to be maintained between a speaker and a listener at different stations whereby the feeling of intimacy is enhanced.

Abstract: An asynchronous transfer mode switching system uses a parallel array of switching planes, distributors for distributing cells between the switching planes, and resequencers for collecting the cells after they have been switched. To balance the loads in the output buffers of the switching planes, each distributor includes two one-cell buffers and a load matrix. The load matrix stores the state of the output buffers in the switching planes, and this information is used to decide whether to send a cell arriving at the first of the one-cell buffers to its scheduled switching plane or to store the cell in the other of the one-cell buffers until either a switching plane with a lightly loaded output buffer for the cell's destination becomes available or another later arriving cell needs to be stored there.

Abstract: To control congestion in packet switching networks, control of the traffic sent by a given station to each of the downstream nodes to which it is directly connected is effected by control of the traffic that the upstream nodes to which it is directly connected are permitted to send to it. In this regard, a predictive model is used to predict the cross traffic, one round trip delay in advance that the given station can expect. The parameters for the predictive model are obtained by measurements in real time and by the use of moving averages. Using the predicted cross traffic, the amount of controlled traffic that the proximate downstream nodes can accommodate from the given node, and the correct state of the given node, the state of the given node one round trip delay into the future is predicted. This prediction is used to schedule the amount of traffic to be sent by each of its proximate upstream nodes.