Abstract: A cordless telephone system includes a base station having a base clock indicative of the time of day, and a handset having a handset clock indicative of the time of day. The handset is synchronized to the base station. When power is lost in the handset or the base station, the unit with power detects loss of synchronization therebetween. Upon restoration of the power, the continually powered unit provides the power restored unit with clock recovery information for updating the clock of the power restored unit. The clock recovery information is generated in the continually powered unit by counting elapsed time when the loss of synchronization is detected.

Abstract: A telephony device includes a wireless handset having a memory and a processor; and a base station having a connection to a telephone line and a transceiver for communicating with the wireless handset. The processor encrypts data to form encrypted data prior to storage in the handset memory, and stores the encrypted data in the handset memory. Further, the processor reads the encrypted data from the handset memory and decrypts the encrypted data for further use.

Abstract: A method and apparatus for changing the language of the menus in a telephony device formed by a base station and a plurality of handsets. The handset sends a change-language order to the base station. The base station acknowledges receipt of the order and the handset which has formulated the order then modifies it change of language. The base station can also send such orders to other handset which are connected to the base station.

Abstract: An invention is disclosed having a base station and a plurality of handsets connected to this base station by various radio channels. For saving on accumulators which supply power to these handsets, these handsets are put in a standby mode for as long periods as possible: notably the periods of scanning for idle channels become very much interspaced with time.

Abstract: A telephony device includes a base station and a wireless handset. The base station has a responder with a memory. A processor of base station processes digital speech signals having a first code on signal lines connecting the input and output of the base station. The same processor also controls a converter which is located between the memory and the signal lines. Prior to storing in the memory, the converter codes the digital speech signals into a second code for storage in the memory, where the second code is the same code of the digital signals exchanged between the base station and the handset. Further, prior to reading from the memory, the converter decodes the digital speech signals of the second code stored in the memory into the first code.

Abstract: A telephony device is disclosed having a base station connectable to a switched network. At least two mobile units are connectable to the switched network through the base station to receive incoming calls in a normal mode. The first mobile unit is operable in a monitor mode, where ringing thereof is prevented when incoming calls are received in the monitor mode. A microphone of the monitoring unit has a higher gain in the monitor mode than in the normal mode. In the monitor mode, transmission of sound signals to monitoring unit is suppressed.