Satellite system for vessel identification

• US 20050124291A1
• Filed: 11/26/2002
• Published: 06/09/2005
• Est. Priority Date: 11/26/2001
• Status: Active Grant

• Current Assignee: THISS Technologies Pte Ltd. (Touchpoint Group Holdings, Inc.)
• Original Assignee: THISS Technologies Pte Ltd. (Touchpoint Group Holdings, Inc.)
• Inventors: Meulman, Christopher Boyce, Hart, Nicholas Richard, Clifford, Peter James
• Granted Patent: US 7,483,672 B2
• Time in Patent Office: Days
• US Class Current: 455/12.100
• CPC Class Codes: G08G 3/02 Anti-collision systems
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system

Abstract

A system for communicating data among a plurality of ships is disclosed. The system comprises means for sending an inbound message from one of said plurality ships (501), via at least one geostationary satellite (503) and base station (505) to a control centre (507). Spatial information obtained from the control messages is consolidated by the control centre (507) to reduce traffic volume of outbound messages associated with inbound messages. Consolidated messages are then sent via base station (505) and at least one geostationary satellite (503), to a sub-set of said plurality of ships, wherein sub-set of ships are in at least one of the same (a) geographic region, and (b) adjacent region(s), as said one ship.

Claims

1. A method of communicating data among a plurality of mobile platforms via at least one geostationary satellite, said method comprising the steps of:

establishing a plurality of geographic regions dependent upon at least one of beam coverage areas of the at least one geostationary satellite and traffic loads associated with each said region;

sending an inbound message, from one of said plurality of mobile platforms, via said at least one geostationary satellite and a base station to a control centre, said inbound message including spatial information for said one mobile platform;

consolidating, by the control centre, of the inbound message, to thereby reduce a traffic volume of outbound messages associated with said inbound message; and

sending outbound messages dependent upon the consolidated inbound message, via the base station and the at least one geostationary satellite, to a sub-set of said plurality of mobile platforms, said sub-set of mobile platforms being in at least one of (a) the same geographic region, and (b) adjacent geographic region(s), as said one mobile platform.

2. A method according to claim 1, wherein after the sending of the inbound message, and prior to the sending of the outbound messages, the method comprises the further steps of:

determining a total traffic load for the plurality of mobile platforms as a function of spatial locations of the mobile platforms; and

establishing a plurality of geographic regions, each of which contains an associated sub-set of the plurality of mobile platforms, to thereby balance, between the plurality of geographic regions, the traffic load for each of the associated sub-sets of the plurality of the mobile platforms.

3. A method according to claim 2, wherein the inbound message and the outbound messages are sent over a single geostationary satellite using the C frequency band.

4. A method according to claim 2, wherein:

the inbound message is sent over a first geostationary satellite using the L band frequency for the mobile platforms-to-satellite up-link and the C band frequency for the satellite-to-base station down-link; and

the outbound message is sent over a second geostationary satellite using the C band frequency for the base station-to-satellite up-link and the C band frequency for the satellite-to-mobile platforms down-link.

5. A method according to claim 3, wherein the inbound message and the outbound messages are transmitted using spread-spectrum modulation.

6. A method according to claim 4, wherein the inbound message and the outbound messages are transmitted using FDM-TDMA modulation.

7. A method according to claim 1, wherein the consolidating step comprises one or more of:

taking account only of input messages relating to differential position information;

taking account only of input messages relating to moving mobile platforms;

taking account only of input messages relating to special mobile platforms; and

taking account only of input messages relating to mobile platforms in an emergency situation.

8. A method according to claim 5, wherein the modulation scheme is QPSK with a Turbo Convolutional Coding rate ¼

to rate ½

.

9. A system for communicating data among a plurality of mobile platforms, said system including at least one geostationary satellite, a base station and a control centre, the system further comprising:

means for establishing a plurality of geographic regions dependent upon at least one of beam coverage areas of the at least one geostationary satellite and traffic loads associated with each said region;

means for sending an inbound message, from one of said plurality of mobile platforms, via said at least one geostationary satellite and the base station to the control centre, said inbound message including spatial information for said one mobile platform;

means for consolidating, by the control centre, of the inbound message, to thereby reduce a traffic volume of outbound messages associated with said inbound message; and

means for sending outbound messages dependent upon the consolidated inbound message, via the base station and the at least one geostationary satellite, to a sub-set of said plurality of mobile platforms, said sub-set of mobile platforms being in at least one of (a) the same geographic region, and (b) adjacent geographic region(s), as said one mobile platform.

10. A mobile terminal adapted for use in a system for communicating data among a plurality of mobile platforms, said system including at least one geostationary satellite, a base station, said mobile terminal and a control centre, the mobile terminal comprising:

means for determining, for one of said plurality of mobile platforms on which the mobile terminal is located, spatial information for the mobile platform;

means for receiving information, from the control centre via the at least one geostationary satellite, regarding a plurality of geographic regions across which the mobile platforms are distributed, the geographic regions being dependent upon at least one of beam coverage areas of the at least one geostationary satellite and traffic loads associated with each said region;

means for determining, depending on said geographic region information, transmit parameters for sending an inbound message; and

means for sending the inbound message, using the transmit parameters, via said at least one geostationary satellite and the base station to the control centre, said inbound message including the spatial information.

11. A mobile terminal according to claim 10, the mobile terminal comprising a C-band terminal including an antenna having a nominal gain of 18 dBi, and adapted (a) to transmit a signal having a bit-rate between 300 and 2400 bps, and (b) to receive a signal having a bit-rate between 11 to 64 kps, wherein the transmitting and the receiving is performed in a half-duplex manner at RF.

12. A mobile terminal according to claim 10, the mobile terminal further comprising:

means for determining, for said one of said plurality of mobile platforms on which the mobile terminal is located, at least one of;

(a) a speed of the mobile platform; and

(b) a geographic region to which the mobile platform has been allocated by the control centre; and

wherein;

said means for sending the inbound message is further adapted to send the inbound message dependent upon said at least one of the speed of the mobile platform and the geographic region.

13. A control centre in a system for communicating data among a plurality of mobile platforms, said system including at least one geostationary satellite, a base station and said control centre, the control centre comprising:

means for establishing a plurality of geographic regions dependent upon at least one of beam coverage areas of the at least one geostationary satellite and traffic loads associated with each said region;

means for consolidating an inbound message from one of said plurality of mobile platforms to thereby reduce a traffic volume of outbound messages associated with said inbound message;

wherein the inbound message includes spatial information for said one of said plurality of mobile platforms, and

means for sending outbound messages dependent upon the consolidated inbound message, via the base station and the at least one geostationary satellite, to a sub-set of said plurality of mobile platforms, said sub-set of mobile platforms being in at least one of (a) the same geographic region, and (b) adjacent geographic region(s), as said one mobile platform.

14. A control centre according to claim 13, the control centre further comprising:

means for determining a total traffic load for the plurality of mobile platforms as a function of spatial locations of the mobile platforms; and

means for establishing a plurality of geographic regions, each of which contains an associated sub-set of the plurality of mobile platforms, to thereby balance, between the plurality of geographic regions, the traffic load for each of the associated sub-sets of the plurality of the mobile platforms.

15. A computer program product including a computer readable medium having recorded thereon a computer program for directing a processor to execute a method of communicating data among a plurality of mobile platforms via at least one geostationary satellite, said program comprising:

code for establishing a plurality of geographic regions dependent upon at least one of beam coverage areas of the at least one geostationary satellite and traffic loads associated with each said region;

code for sending an inbound message, from one of said plurality of mobile platforms, via at least one geostationary satellite and a base station to a control centre, said inbound message including spatial information for said one mobile platform;

code for consolidating, by the control centre, of the inbound message, to thereby reduce a traffic volume of outbound messages associated with said inbound message; and

code for sending outbound messages dependent upon the consolidated inbound message, via the base station and the at least one geostationary satellite, to a sub-set of said plurality of mobile platforms, said sub-set of mobile platforms being in at least one of (a) the same geographic region, and (b) adjacent geographic region(s), as said one mobile platform.

16. A computer program product according to claim 15, the program further comprising:

code for determining a total traffic load for the plurality of mobile platforms as a function of spatial locations of the mobile platforms; and

code for establishing a plurality of geographic regions, each of which contains an associated sub-set of the plurality of mobile platforms, to thereby balance, between the plurality of geographic regions, the traffic load for each of the associated sub-sets of the plurality of the mobile platforms.

17. A computer program for directing a processor to execute a method of communicating data among a plurality of mobile platforms via at least one geostationary satellite, said program comprising:

code for establishing a plurality of geographic regions dependent upon at least one of beam coverage areas of the at least one geostationary satellite and traffic loads associated with each said region;

code for sending an inbound message, from one of said plurality of mobile platforms, via at least one geostationary satellite and a base station to a control centre, said inbound message including spatial information for said one mobile platform;

code for consolidating, by the control centre, of the inbound message, to thereby reduce a traffic volume of outbound messages associated with said inbound message; and

code for sending outbound messages dependent upon the consolidated inbound message, via the base station and the at least one geostationary satellite, to a sub-set of said plurality of mobile platforms, said sub-set of mobile platforms being in at least one of (a) the same geographic region, and (b) adjacent geographic region(s), as said one mobile platform.

18. A computer program according to claim 17, the program further comprising:

code for determining a total traffic load for the plurality of mobile platforms as a function of spatial locations of the mobile platforms; and

code for establishing a plurality of geographic regions, each of which contains an associated sub-set of the plurality of mobile platforms, to thereby balance, between the plurality of geographic regions, the traffic load for each of the associated sub-sets of the plurality of the mobile platforms.