Abstract: A programmable band-pass filter in a radio-frequency receiver. The band-pass filter has a bandwidth substantially covering a channel bandwidth. Once the appropriate channel in use is determined, the frequency band of the band-width filter is set to correspond to it.

Abstract: A base station (12) according to an implementation of the invention is adapted to identify a public power supply frequency, e.g., 50 Hz or 60 Hz. The base station (12) then adapts its frame and slot structures to the power supply frequency. The base station (12) transmits a synchronization word on a data channel, and also transmits a signal indicative of the power supply frequency. The mobile unit (14, 16) receives the data channel and the information indicative of the frequency. The mobile unit (14, 16) then adapts its frame and slot structure appropriately. After the link is established, and if periodic interference is detected, transmission occurs during the inactive period of the interference.

Abstract: A cordless digital telephone system which allows call screening is provided. Time division multiple access (TDMA) cordless phone systems provide a base unit which is able to provide connections for a plurality of mobile units, such as handsets. With time division, the mobile units are synchronized to different time slots. A broadcast mode is provided that causes the mobile units to be placed in a receive only mode and to synchronize to the same time slot where a broadcast message is sent. In this way, an incoming call can be recorded substantially simultaneously with being broadcast to any number of mobile units, any of which can elect to pick up the incoming call. Once so elected, the base station is reset to a standard mode thereby permitting an uninterrupted conversation between a caller and a user of the mobile unit as a callee.

Abstract: A cordless telephone system employing a base station (202) as slave and a plurality of handsets (204a, 204b) as masters is provided. The handsets (204a, 204b) periodically poll the base station. The base station (202) responds with acknowledge slots and also timing information whereby the handsets (204a, 204b) can adjust their poll timing so as avoid interfering with one another. If an active connection is set up between the base station (202) and a handset (204a), the other handset (204b) is not allowed to poll during the connection, effectively functioning as a system slave for the duration of the connection. Thus, the second handset (204b) stays synchronized to the first handset (204a) and listens until the connection is completed, whereupon it resumes normal functioning.