Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Publication of BE515845ApublicationCriticalpatent/BE515845A/xx
H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
H04L1/00—Arrangements for detecting or preventing errors in the information received
H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
H04L1/14—Arrangements for detecting or preventing errors in the information received by using return channel in which the signals are sent back to the transmitter to be checked ; echo systems