Abstract: A telecommunications system having at least one base unit and a plurality of portable units is arranged to enable automatic re-registration of a portable unit with the system. The portable unit includes system and unit identity detectors and a registration sequence generator. The registration sequence generator is connected to a timer which monitors the elapse of time since a signal from a base unit of the system intended for the portable unit is received. The registration sequence generator generates a re-registration request in the event the monitored elapse of time is greater than a predetermined period and a signal from a base unit of the system is received which is not intended for the portable unit. With the system described portable units can automatically re-register with the system after being out of range of a base unit without the need for a separate beacon signal.

Abstract: A cordless telephone system is of the type including a plurality of telephone handsets communicating by two-way radio with a base unit connected to the public telephone network. In the larger premises, normally a plurality of spaced base units are employed, so that the handsets can communicate with the most favorably-positioned base unit wherever they are on the premises. In the present invention, however, larger premises are covered by just a single base unit, including within it all the necessary transceivers together with a plurality of transponders which are connected to the base unit and each other by means of an RF cable. The transponders each have aerials by which they can communicate by two-way radio with the handsets. The transponders downconvert the RF frequency of the radio link to a lower IF frequency which is passed to the transceivers via the cable. The transponders can be distributed about the premises as needed to provide complete radio coverage.