U.S. Philips Corporation

Hubert Grucza

Peter Hirth

Werner Frerichs

A method and apparatus for providing dialling intervals in dialling sequences indirectly dialled by a register in which such sequences are stored, such intervals being in accordance with the dialling intervals produced by a user during direct dialling of such sequences. Direct dialled subscriber numbers which include a dialling interval after at least one digit therein, such as for line access, are stored in a reference memory along with such interval. Upon an indirect dialling of such sequence from a redial or abbreviated dialling register, a microprocessor in the telephone set compares such sequence digit by digit with sequences stored in the reference memory, and if there is a match inserts in the dialled sequence the dialling interval in the matching stored sequence. By counting the number of such agreements for each stored sequence of dialling digits, the sequence having the lowest count value can be erased from the reference memory and replaced by a new dialed sequence having a dialling interval, thereby reducing the necessary storage capacity of the reference memory. A dialling interval in a stored sequence is altered in accordance with the interval inserted by a user each time such sequence is directly dialled, thereby adapting to the dialling behavior of the user.

Method of and circuit arrangement for inserting dialling intervals

A subscriber telephone set which comprises a multifrequency dialing tone oscillator, a microprocessor connected thereto for controlling selection of the tones produced thereby, and an acoustic signal element for producing a ringing sound corresponding to ringing tones applied thereto. The microprocessor prevents incorrect triggering of the acoustic signal element by noise voltages on the subscriber line by verifying that the amplitude of the ringing current received on the line exceeds a predetermined level, and also that the ringing current frequency corresponds to the frequency of a resetting signal internally generated within the microprocessor. Upon such verification, the microprocessor controls the dialing tone oscillator to generate a ringing tone which is applied to the acoustic signal element to cause it to generate a ringing sound, the dialing tone oscillator thereby also serving as a ringing tone generator for activating the acoustic signal element.

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Nurnberg, Germany

Hubert Grucza