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Publication date
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Publication of BE658794ApublicationCriticalpatent/BE658794A/xx
H04M1/00—Substation equipment, e.g. for use by subscribers
H04M1/26—Devices for calling a subscriber
H04M1/515—Devices for calling a subscriber by generating or selecting signals other than trains of pulses of similar shape, or signals other than currents of one or more different frequencies, e.g. generation of dc signals of alternating polarity, coded pulses or impedance dialling
H—ELECTRICITY
H04—ELECTRIC COMMUNICATION TECHNIQUE
H04Q—SELECTING
H04Q3/00—Selecting arrangements
H—ELECTRICITY
H04—ELECTRIC COMMUNICATION TECHNIQUE
H04Q—SELECTING
H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems