ISDN-to-ISDN communication via satellite microwave radio frequency communications link

A communications system for extending International Telegraph and Telephone Consultive Committee, CCITT, integrated services digital network, ISDN, connectivity over a communications satellite link, the system comprising:

• first conversion means codected between a first ISDN basic rate interface, ISDN/BRI, and a first satellite communications interface for translating a link access procedure-ISDN/D-channel, ISDN/LAPD, protocol at said first ISDN/BRI to and from a CCITT Recommendation V.42-link access procedure-modem, V.42/LAPM, protocol at said first satellite communications interface;
• second conversion means connected between a second ISDN basic rate interface, ISDN/BRI, and a second satellite communications interface for translating a V.42/LAPM protocol at a satellite communications interface to and from an ISDN/LAPD protocol at an ISDN/BRI interface;
• and
• satellite communication means connected between said first and second satellite communication interfaces for carrying said V.42/LAPM protocol transparently between the first and second conversion means and for establishing an ISDN-to-ISDN connection of said ISDN/LAPD end-to-end across the system in the presence of noise and delays associated with such satellite communication.

A communications system, comprising:

• protocol conversion means connected between a first and a second communications port and for translating an integrated service digital network basic rate interface, ISDN/BRI, signal at
• said first communications port to and from a link access protocol/modem, LAPM CCITT Recommendation Q.921/Q.931 signal at said communications second port;
• and
• satellite communication means connected to said second communications port for coupling said LAPM CCITT Recommendation Q.921/Q.931 signal between said second port and a second port of a second one of said communications system via a communications satellite for ISDN-to-ISDN communication.

A communications system, comprising:

• first protocol conversion means connected between a first and a second communications port and for interfacing a first International Telegraph and Telephone Consultive Committee (CCITT) integrated service digital network basic rate interface, ISDN/BRI, signal at first communications port to and from a first CCITT Recommendation V.42-link access procedure-modem, V.42/LAPM, CCITT Recommendation Q.921/Q.931 signal at a second port;
• and
• first satellite communication means connected to said second communications port and for coupling said first LAPM-type CCITT Recommendation Q.921/Q.931 signal at said second communications port to a communications satellite in earth orbit;
• second protocol conversion means connected between a third and a fourth communications port and for translating a second ISDN/BRI signal at said third communications port with a second LAPM CCITT Recommendation Q.921/Q.931 signal at said fourth port;
• and
• second satellite communication means connected to said third communications port for coupling said second LAPM-type CCITT Recommendation Q.921/Q.931 signal at said fourth port to said communications satellite for establishing ISDN-to-ISDN communication via said communications satellite.