Abstract: A telephone apparatus can receive information about a third party sent from a telephone exchange with a call waiting service when a call is issued from the third party during a conversation using the telephone apparatus. Upon issuance of the call from the third party during the conversation over the telephone apparatus, the exchange sends out an alert signal, in response to which the telephone apparatus sends back an acknowledge signal. The telephone apparatus also mutes a speech transmitter circuit in order to protect calling party information such as a telephone number sent from the exchange in succession from being destroyed by a speech signal. The calling party information sent from the exchange can be received without fail and can subsequently be displayed.

Abstract: A cordless telephone provided with a master unit and a slave unit which use a plurality of communication channels. In the case where information indicating a currently used channel or a usually used channel, which has been stored in the master unit, is lost due to, for instance, a power failure, the master unit comes to use an initially used channel, which is preset or determined by performing an operation on an identification code, and enters a standby state. At that time, the slave unit uses the usually used channel. However, when it is detected that the slave unit cannot communicate with the master unit, the slave unit calls the master unit by using the initially used channel. Then, the master and slave units come to perform, for example, an exchange of confirmation data by using the initially used channel. Next, the slave unit transmits to the master unit data indicating that the channel used by the master unit should be changed to the usually used channel.