The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 26, 1995
Filed:
Jan. 27, 1994
Toshihiro Hara, Tokyo, JP;
Shinji Kumataka, Tokyo, JP;
Kosuke Hashimoto, Tokyo, JP;
Ichiro Tamura, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
In a cordless key telephone system for servicing separate service zones (3.sub.1, 3.sub.2), a cordless station (5) establishes a two-way radio channel with an access unit (4) of the service zone in which it is located, and constantly monitors the field intensity of the established channel and transmits a zone switching signal when the field intensity is below a specified level as an indication that the cordless station is leaving a first zone (3.sub.1) and entering a second zone (3.sub.2). A main controller (2) establishes a switched connection between exchange lines (6) and the access units (4). In response to the zone switching signal from a given cordless station via the access unit of the first zone, the main controller holds an exchange line (6.sub.i) that is connected to the access unit (4.sub.j) of the first zone through a first switched connection, and establishes a second switched connection between the exchange line (6.sub.i) and the access unit (4.sub.j) of the second zone, instead of the first switched connection. A vocal announcement is applied to the exchange line indicating to a communicating party that the cordless station is switching zones.