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:
Feb. 01, 1994
Filed:
Apr. 17, 1991
Toshihiro Hara, Tokyo, JP;
Yukihiro Shimura, Tokyo, JP;
Shinji Kumataka, Tokyo, JP;
Kosuke Hashimoto, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In a cordless key telephone system for covering multiple service areas, access units are divided into groups corresponding respectively to the service areas, the access units of each group being located in the corresponding service area for broadcasting a recurrent sequence of address signals on a two-way radio control channel and carrying speech signals on an assigned two-way telephone channel. The access units of each group has a uniquely assigned control channel different in frequency from the control channel of the other group. Cordless stations are switchable to the control channel of a first group of the access units for detecting an address signal and subsequently switchable to the control channel of the access units of a second group if the address signal is not detected in a first sequence for detecting the addressed signal in a second sequence. A main controller is coupled to a switched telephone network for causing the access units to broadcast the address signals in response to an incoming call from the network and for establishing a connection between the network and one of the cordless stations.