序号 专利名 申请号 申请日 公开(公告)号 公开(公告)日 发明人
1 ISDN-to-ISDN communication via satellite microwave radio frequency communications link US119596 1993-09-10 US5412660A 1995-05-02 David T. Chen; Ronald A. Everoski; William C. Lam
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.
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