Communication protocol for mobile earth terminal communication device used in mobile satellite communication system

In a mobile satellite system including a satellite communication switching office (SCSO) having a satellite antenna for receiving/transmitting a satellite message via a satellite from/to a mobile communication system (MCS), a central controller receiving/transmitting the satellite message from/to the satellite communication switching office issued from the MCS via the satellite to another party, a method of performing a call setup procedure in the mobile satellite system from a call initiated by a destination served by a public switched telephone network (PSTN) to the MCS, said method comprising the steps of:

• (a) receiving by the SCSO a call from the destination served by the PSTN;
• (b) transmitting by the SCSO to the central controller a channel request using interstation signaling, the channel request including a destination number;
• (c) determining by the central controller an identity of the MCS responsive to the destination number, and transmitting a call announcement via a time division multiplex (TDM) channel;
• (d) acknowledging by the MCS the call announcement via the time division multiple access (TDMA) channel to the central controller;
• (e) transmitting frequency assignments to the MCS via the TDM channel and to the SCSO via an interstation signaling channel, the frequency assignment including the call type, and the destination phone number, and an access security check field used to verify the MCS's identity;
• (f) receiving by the MCS the frequency assignment, and transmitting a scrambling vector message to the SCSO via the single channel per carrier (SCPC) communication channel;
• (g) verifying by the SCSO the identity of the MCS responsive to the scrambling vector;
• (h) upon successful verification in said verifying step (g), transmitting by the SCSO a ring command to the MCS;
• (i) receiving by the MCS of the ring command, generating a ringing signal to a MCS user, and transmitting a ring command acknowledgement to the SCSO;
• (j) receiving by the SCSO the ring command acknowledgement from the MCS;
• (k) once the call setup is complete and the MET user has acknowledged the ringing signal by going off-hook, transmitting by the MCS voice frames to the SCSO and disabling voice activation in the MCS for at least 3 super frames;
• (l) upon detection of the MCS switching to a voice mode, switching by the SCSO to the voice mode, and re-enabling voice activation by the MCS;
• and
• (m) establishing voice communication between the PSTN and the MCS.

In a mobile satellite system including a satellite communication switching office (SCSO) having a satellite antenna for receiving/transmitting a satellite message via a satellite from/to a mobile communication system (MCS), a central controller receiving/transmitting the satellite message from/to the satellite communication switching office issued from the MCS via the satellite to another party, a method of performing a call setup procedure in the mobile satellite system from a call initiated by the MCS to a destination served by a public switched telephone network (PSTN), said method comprising the steps of:

• (a) initiating the call by the MCS;
• (b) the MCS formatting and transmitting an access request message including call type and destination number;
• (c) receiving by the central controller the access request message, and transmitting frequency assignments to the MCS and to the SCSO, the frequency assignment including the call type, and the destination phone number, and a security field used to verify the MCS's identity;
• (d) receiving by the MCS the frequency assignment, and transmitting an identification message to the SCSO;
• (e) verifying by the SCSO the identity of the MCS responsive to the identification message;
• (f) upon successful verification in said verifying step (e), switching by the SCSO and the MCS from call setup mode to voice mode;
• (g) transmitting by the SCSO a disable signal to the MCS to disable voice activation in the MCS for a predetermined time period after which voice activation is re-enabled in the MCS, and transmitting a destination number to the PSTN;
• and
• (h) establishing voice communication between the PSTN and the MCS.

In a mobile satellite system including a satellite communication switching office (SCSO) having a satellite antenna for receiving/transmitting a satellite message via a satellite from/to a mobile communication system (MCS), a central controller receiving/transmitting the satellite message from/to the satellite communication switching office issued from the MCS via the satellite to another party, a method of performing a call setup procedure in the mobile satellite system from a call initiated by a destination served by a public switched telephone network (PSTN) to the MCS, said method comprising the steps of:

• (a) receiving by the SCSO a call from the destination served by the PSTN;
• (b) transmitting by the SCSO to the central controller a channel request including a destination number;
• (c) determining by the central controller an identity of the MCS responsive to the destination number, and transmitting a call announcement;
• (d) acknowledging by the MCS the call announcement to the central controller;
• (e) transmitting frequency assignments to the MCS and to the SCSO, the frequency assignment including the call type, and the destination phone number, and a security field used to verify the MCS's identity;
• (f) receiving by the MCS the frequency assignment, and transmitting an identification message to the SCSO;
• (g) verifying by the SCSO the identity of the MCS responsive to the identification message;
• (h) upon successful verification in said verifying step (g), transmitting by the SCSO a ring command to the MCS;
• (i) receiving by the MCS of the ring command, generating a ringing signal to a MCS user, and transmitting a ring command acknowledgement to the SCSO;
• (j) receiving by the SCSO the ring command acknowledgement from the MCS;
• (k) once the call setup is complete and the MCS user has acknowledged the ringing signal by going off-hook, transmitting by the MCS a disable signal to the SCSO and disabling voice activation in the MCS for a predetermined period of time;
• (l) upon detection of the MCS switching to a voice mode, switching by the SCSO to the voice mode, and re-enabling voice activation by the MCS;
• and
• (m) establishing voice communication between the PSTN and the MCS.

A method of performing a call setup procedure in a mobile satellite system from a call initiated by a mobile communication system (MCS) to a destination, said method comprising the steps of:

• (a) initiating the call by the MCS, the MCS formatting and transmitting an access request message;
• (b) receiving by a central controller in the mobile satellite system the access request message, and transmitting frequency assignments to the MCS and to a satellite communication switching office (SCSO) in the mobile satellite system;
• (c) verifying by the SCSO the identity of the MCS, and upon successful verification, switching by the SCSO and the MCS from call setup mode to voice mode;
• (d) transmitting by the SCSO voice frames to the MCS to disable voice activation in the MCS for at least 3 super frames after which voice activation is re-enabled in the MCS;
• and
• (e) establishing voice communication between the MCS and the destination.

A method of communication in a mobile satellite system from a call initiated by a mobile communication system (MCS) to a destination, said method comprising the steps of:

• (a) receiving by a central controller in the mobile satellite system an access request message from the MCS, and transmitting frequency assignments to the MCS and to a satellite communication switching office (SCSO) in the mobile satellite system;
• (b) switching by the SCSO and the MCS from call setup mode to voice mode;
• (c) transmitting by the SCSO voice frames to the MCS to disable voice activation in the MCS for at least 3 super frames after which voice activation is re-enabled in the MCS;
• and
• (d) establishing voice communication between the MCS and the destination.

A method of communication in a mobile satellite system from a call initiated by a mobile communication system (MCS) to a destination, said method comprising the steps of:

• (a) receiving by a central controller in the mobile satellite system an access request message from the MCS, and transmitting frequency assignments to the MCS and to a satellite communication switching office (SCSO) in the mobile satellite system;
• (b) transmitting by the SCSO disable information to the MCS in a voice mode to disable voice activation in the MCS for a predetermined period of time after which voice activation is re-enabled in the MCS;
• and
• (c) establishing voice communication between the MCS and the destination.