Patents by Inventor Kevin Callahan

Kevin Callahan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5504803
    Abstract: A personal communications system permits a wireless handset to access either a cellular mobile telephone system (CMTS) or a private wireless telephone system (WTS) which shares the CMTS frequency band by utilizing those CMTS channels which are idle in the area serviced by the WTS. The wireless handset automatically selects between the WTS and CMTS operating modes by maintaining a list of previously accessed WTS control channels and periodically scanning that list for a WTS available at the location of the handset. If a WTS control channel is not found in that list, then the handset periodically scans all possible WTS control channels for the purpose of registering on an available WTS. If no WTS is found, then the handset switches to CMTS mode. The scanning methodology permits the wireless handset to rapidly lock on to an available WTS which will provide service to the handset, so as to reduce the possibility of the wireless handset missing incoming paging signals.
    Type: Grant
    Filed: August 2, 1993
    Date of Patent: April 2, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Jun Yamada, Kevin Callahan, Charles A. Jacobs