Simplex remote telemetry via a satellite system

• US 20040147220A1
• Filed: 01/29/2003
• Published: 07/29/2004
• Est. Priority Date: 01/29/2003
• Status: Active Grant

• Current Assignee: Globalstar Incorporated
• Original Assignee: Globalstar Incorporated
• Inventors: Monte, Paul A., Shah, Brinda T., Vaddiparty, Subrahmanyam V.
• Granted Patent: US 7,672,639 B2
• Time in Patent Office: Days
• US Class Current: 455/12.1
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

A satellite based communication system in a low-earth-orbit (LEO) has multiple beams and FDM channels within each beam for voice/data communication between user terminals and multiple gateways. The satellite based communication system has two links for duplex communication, i.e., a forward link between the gateway and the user terminals through the satellites and a return link between the user terminals and the gateway through the satellites. Low volume telemetry data from remotely located assets, such as liquid petroleum gas tanks, water tanks, oil storage tanks, rail cars is gathered, processed, and transferred to a customer over an Internet link. A remote telemetry unit with a sensor and a simplex transmitting unit transmits remote telemetry data. A gateway receives data and directs the data to a gateway applique for demodulating and decoding. Resulting messages are sent to the customer via a back office over an Internet connection.

Claims

1. A method for routing telemetry data, comprising:

receiving telemetry data in a simplex mode at a satellite having a bent-pipe configuration, wherein said telemetry data is combined with normal traffic in a compound signal;

transmitting said compound signal from said satellite to a gateway applique; and

extracting said telemetry data from said compound signal at said gateway applique.

2. The method according to claim 1, wherein said telemetry data is received from a remote telemetry unit.

3. The method according to claim 1, further comprising:

receiving said telemetry data repeatedly; and

disregarding duplicate telemetry data.

4. The method according to claim 1, further comprising:

transmitting said telemetry data from said gateway applique to a processor for routing to a customer.

5. The method according to claim 1, wherein said telemetry data is transmitted from a remote telemetry unit to said satellite, without obtaining permission from said satellite.

6. The method according to claim 1, wherein said satellite is a low-earth-orbit satellite.

7. The method according to claim 1, wherein said telemetry data is gathered from a sensor at a remote asset.

8. The method according to claim 1, wherein said normal traffic includes voice.

9. The method according to claim 1, wherein said satellite transmits said telemetry data in a first beam, and wherein said gateway applique deselects a second beam to reduce thermal noise or interference.

10. The method according to claim 1, wherein said gateway applique compensates for a Doppler shift of said compound signal.

11. A method for routing telemetry data, comprising:

transmitting said telemetry data via a telemetry unit in a simplex mode to a satellite over a low-earth-orbit communications system, wherein said telemetry data is superimposed over regular traffic on said low-earth-orbit communications system, thereby forming a compound signal.

12. The method according to claim 11, further comprising:

transmitting said telemetry data to a processor; and

transmitting said telemetry data from said processor to a customer.

13. The method according to claim 11, wherein said telemetry unit transmits said telemetry data over a low-speed data communication interface.

14. The method according to claim 11, wherein said telemetry data is formatted in a data structure comprising:

a message data field for storing information from a sensor at a remote asset; and

a sequence number field for reconstructing said information.

15. A system for routing telemetry data, comprising:

a gateway subsystem having an antenna to receive a compound signal from a satellite, wherein said compound signal comprises telemetry data superimposed on normal traffic; and

a gateway applique for receiving said compound signal, extracting said telemetry data, and transmitting said telemetry data to a network.

16. The system according to claim 15, further comprising a processor for receiving said telemetry data from said network, processing said telemetry data, and making said telemetry data available to a customer.

17. The system according to claim 15, wherein said satellite is a low-earth-orbit satellite with a bent-pipe configuration.

18. The system according to claim 15, wherein said gateway applique compensates for a Doppler shift of said compound signal.

19. The system according to claim 15, wherein said satellite transmits said compound signal on a first beam, and wherein said gateway applique deselects a second beam to reduce thermal noise or interference.

20. A compound signal, comprising:

normal traffic over a low-earth-orbit satellite communication system; and

telemetry data superimposed on said normal traffic.

21. The compound signal according to claim 20, wherein said telemetry data is superimposed over a predetermined channel of said low-earth-orbit satellite communication system.

22. The compound signal according to claim 20, wherein said telemetry data is superimposed over two or more channels of said low-earth-orbit satellite communication system to reduce interference with said normal traffic.

23. The compound signal according to claim 20, wherein said telemetry data has a low data rate.

24. The compound signal according to claim 20, wherein said telemetry data is in a radio frequency (RF) signal having a modulation and a protocol that are different from that of said normal traffic.

25. The compound signal according to claim 24, wherein said protocol is a simplex protocol.

26. A telemetry unit, comprising:

a transmitter that transmits telemetry data in a simplex mode to a satellite.

27. The telemetry unit according to claim 26, wherein said telemetry data is superimposed on normal traffic over a low-earth-orbit satellite communication system.