Cordless telephone micro-cellular system

Abstract

A cordless telephone system is arranged for extending the operating range of a cordless telephone portable unit within such system. The cordless telephone system comprises a plurality of cordless telephone stations that plug into any available wall telephone jack and may share the intrapremises telephone wire-pair with one or more existing corded telephone stations without interference. Each cordless telephone station consists of a cordless telephone base unit and its associated cordless telephone portable unit. Although each of the portable units is associated with a particular base unit, all of the portable units are able to operate with any of the base units in the system. As a user of a portable unit with a call in progress roams about a premises, all base units monitor the quality of the radio frequency signal received from the portable unit. If the signal quality of a base unit actively communicating with the portable unit deteriorates to below an acceptable level, control apparatus in the system identifies another base unit and executes a hand-off of the communication link with the portable unit to this base unit that is then receiving the signal from the handset unit with an acceptable signal quality. Operational control for the base units is provided through a time division multiple access arrangement wherein a communications channel is imposed on the existing premises telephone wire-pair above the audio frequency band used for standard telephone service.