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 BE464918ApublicationCriticalpatent/BE464918A/xx
H04Q1/00—Details of selecting apparatus or arrangements
H04Q1/18—Electrical details
H—ELECTRICITY
H04—ELECTRIC COMMUNICATION TECHNIQUE
H04M—TELEPHONIC COMMUNICATION
H04M15/00—Arrangements for metering, time-control or time indication ; Metering, charging or billing arrangements for voice wireline or wireless communications, e.g. VoIP
H04M15/08—Metering calls to called party, i.e. B-party charged for the communication
H—ELECTRICITY
H04—ELECTRIC COMMUNICATION TECHNIQUE
H04Q—SELECTING
H04Q1/00—Details of selecting apparatus or arrangements
H04Q1/18—Electrical details
H04Q1/30—Signalling arrangements; Manipulation of signalling currents
H04Q1/38—Signalling arrangements; Manipulation of signalling currents using combinations of direct currents of different amplitudes or polarities over line conductors or combination of line conductors