implemented by means of portable electronic directories

Substation equipment, e.g. for use by subscribers > Devices for calling a subscriber > Devices whereby a plurality of signals may be stored simultaneously > with provision for storing more than one subscriber number at a time > using static electronic memories, e.g. chips > implemented by means of portable electronic directories

Substation equipment, e.g. for use by subscribers (subscriber services or facilities provided at exchanges H04M3/00; prepayment telephone coin boxes H04M17/00; current supply arrangements H04M19/08) > Devices for calling a subscriber (H04M1/66 takes precedence) > Devices whereby a plurality of signals may be stored simultaneously > with provision for storing more than one subscriber number at a time > using static electronic memories, e.g. chips > implemented by means of portable electronic directories