Extended range cordless telephone system

Abstract

An extended operating range is provided for a portable or handset unit operating within a cordless telephone system. The system employs multiple base units and multiple handset units, with only one of the multiple base units being activated at a time for communicating with a given handset unit. Each of the multiple handset units has an assigned or dedicated base unit with which only it may communicate. Other shared base units with which all the multiple handset units may communicate are also located in the system which supports multiple simultaneous users. An associated radio link control unit controls the activation and deactivation of the base units which are dispersed through a premises. This control unit also controls the connection of a voice path to the base unit actively communicating with a handset unit. As a user of a handset unit with a call in progress roams around the premises, this base unit monitors the quality of the signal received from the handset unit. If this signal quality deteriorates to below an acceptable level, the base unit notifies the radio link control unit which, in turn, initiates a polling procedure to identify and hand-off the communications to another base unit that is then receiving the signal from the handset unit with an acceptable signal quality. With no calls in progress, both base unit and handset unit transmitters are off thereby avoiding interference to other nearby cordless telephones. All receivers are active, however, in order to respond to incoming calls and service requests. Channel cycling and base unit polling procedures are advantageously employed to insure that incoming or outgoing calls are completed quickly, even though the location of a roaming handset unit may be unknown.