In a simultaneous communication as in a POS system in which the same data including a multiplicity of data blocks is transmitted from a controller to a multiplicity of terminals all at once, the controller transmits all of the data blocks to the terminals without receiving any acknowledgement from each...http://www.google.fr/patents/US4896151?utm_source=gb-gplus-shareBrevet US4896151 - Simultaneous communication method and system
