Patents by Inventor William C. Lam

William C. Lam 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).

  • ISDN-to-ISDN communication via satellite microwave radio frequency communications link
    Patent number: 5412660
    Abstract: An embodiment of the present invention includes a plurality of portable satellite terminals (PSTs) and a network control unit (NCU) in mutual communication by a communications satellite. Integrated services digital network (ISDN) basic rate interfaces (BRI) are provided at each PST and NCU such that commercially available equipment may be connected and link access procedure D-channel (LAPD) protocols are supported end-to-end. CCITT Recommendation V.42 link access procedure-modem (LAPM) with the selective frame reject option is used to carry whole LAPD frames within the information fields of LAPM frames over the satellite link. Protocol conversion units are employed at each PST and NCU to convert LAPD to LAPM and back again.
    Type: Grant
    Filed: September 10, 1993
    Date of Patent: May 2, 1995
    Assignee: Trimble Navigation Limited
    Inventors: David T. Chen, Ronald A. Everoski, William C. Lam