Abstract: A simultaneous voice-call system for a cordless telephone where communication between a base unit and a plurality of portable units is established through the use of a radio communication channel. The base unit includes a transmitter/receiver which establishes a communication channel between base unit and plurality of portable units. The transmitter/receiver has a control channel and a plurality of talk channels. A portable-unit-identifying number memory stores portable-unit-identifying numbers preassigned to the plurality of portable units. A first simultaneous call controller responsive to a simultaneous call command from a user to establish a talk-channel between the plurality of portable units by transmitting through the control channel portable-unit-identifying numbers stored in the portable-unit-identifying number memory, a vacant-talk-channel number, and a simultaneous call code to the plurality of portable units.

Abstract: A portable-to-portable talk system for cordless telephone. The transmitter-receiver of base unit has a control channel and a plurality of talk channels. The transmitter-receiver transmits the channel number of a vacant talk channel to a first portable unit and to a second portable unit over the control channel upon reception of a connection request from the first portable unit over the control channel. The transmitter-receiver is then switched from the control channel to the vacant talk channel after having transmitted the channel number of vacant talk channel over the control channel. Then, the receiver output of the transmitter-receiver is connected to the transmitter input. The transmitter-receiver of the portable unit has the control channel and the plurality of talk channels and transmits the connection request to the base unit over the control channel.