Multipoint teleconferences-investigations into uses, with different variations

The cost of providing a multipoint conference system can be very expensive as compared with the old telephone conference. To minimise these costs, investigations on comparative systems were carried out at the Berlin Heinrich-Hertz Institute. The five conference variations were: (1) sound only, enhanced by 'pseudo-stereo' to help identify the source origin (used in all variants); (2) still picture (TV quality), including split-screen production from all partner stations; (3) single moving picture-'broadcast', i.e. from one station at a time, but selectable for the whole station group; (4) single moving picture 'autonomous', i.e. from any station, regardless of choice at another station; and (5) multiple moving pictures-split screen, allowing simultaneous viewing of all participating stations. Each investigating place contained a 14 in. colour monitor, separate cameras for persons and for documents with user-controlled zoom, a microphone of kidney-shaped response, a pair of stereo loudspeakers, a service keyboard and a telefax machine.