System for controlling communications between a terminal and satellite and method therefore

• US 6,430,394 B1
• Filed: 06/17/1999
• Issued: 08/06/2002
• Est. Priority Date: 06/17/1999
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Global Telecommunications LLC (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Boyden, Albert K.
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): SMITH, SHEILA B
• Application Number:
  US09/336,378
• Time in Patent Office: 1,146 Days
• Field of Search: 455/522, 455/13.4, 455/12.1, 455/13.1, 455/427, 455/63, 455/67.3, 370/318, 370/316
• US Class Current: 455/13.4
• CPC Class Codes: H04B 7/18528 Satellite systems for providing two-way communications service to a network of fixed stations, i.e. fixed satellite service or very small aperture terminal [VSAT] system
• CPC Class Codes: H04B 7/18543 for adaptation of transmission parameters, e.g. power control for detecting or preventing errors in the information received H04L1/00
• CPC Class Codes: H04W 52/20 using error rate

Abstract

A system for determining uplink transmission quality of timing probe signals sent from a terminal to a satellite the satellite having a system to provide an indicator signal to the terminal as to whether a timing probe signal sent from the terminal has been received thereby. Timing probe signals are sent to the satellite, which determines if they are received. If not received, the satellite informs the terminal. The terminal thereafter increases transmission power until the satellite informs the terminal of receipt. The terminal thereafter adjusts the transmission power downward until the satellite no longer detects the signal. The process is repeated so that terminal power transmission is kept at a minimum.

Claims

1. A system for determining the uplink transmission quality of timing probe signals sent from a terminal to a satellite, the system comprising:

the satellite including first means mounted within said satellite to provide an indicator signal to the terminal as to whether a timing probe signal sent from the terminal has been received thereby; and

the terminal comprising

a transmission power control for transmitting timing probe signals to the satellite at variable power settings;

second means for preparing timing signals for transmission to the satellite by said transmission power control at a specific power setting;

receiver means for receiving said timing probe indicator signal from the satellite;

processor means for determining if said indicator signal has been received; and

third means for adjusting the transmission power level of said transmission power control incrementally downward if said signal is received and incrementally upward if said indicator signal is not received.

2. The system as set forth in claim 1 further comprising

the terminal comprising:

said transmission power control also for transmitting data packets to the satellite; and

said third means also for adjusting the transmission power level at which said data packets are transmitted by said transmission power control incrementally downward if said indicator signal is received and incrementally upward if said indicator signal is not received.

3. The system as set forth in claim 2 comprising:

the satellite adapted to receive uplink data packets transmitted from the terminal at either light or heavy encoding rates upon receipt of a switching signal;

a network controller for providing said switching signal to the satellite; and

the terminal including fourth means to request said network controller to switch the satellite to said heavy encoding, if said transmission power control for transmitting data packets to the satellite at variable power settings can not further increase its power output on command from said third means.

4. The system as set forth in claim 3 wherein the terminal including sixth means to request said network controller to switch the satellite to said light encoding if said transmission power control for transmitting data packets to the satellite for at variable power settings can not further decrease its power out on command from said means to adjust the power adjust the transmission power level of said transmission power control.

5. A communication system comprising:

a satellite having first means to receive timing probe signal and to provide an indicator signal indicating that the timing probe signal was not received;

a terminal comprising;

a transmission power control for transmitting timing probe signals to said satellite at variable power settings;

second means for preparing timing signals for transmission to said satellite by said transmission power control at a specific power setting;

receiver means for receiving indicator signal from said satellite;

processor means for determining if said indicator signal has been received; and

third means for adjusting the transmission power level of said transmission power control incrementally downward if said indicator signal is received and incrementally upward if said indicator signal is not received.

6. The system as set fourth in claim 5 comprising:

said satellite adapted to receive uplink data packets transmitted from said terminal at either light or heavy encoding rates upon receipt of a switching signal;

a network controller for providing said switching signal to said satellite; and

said terminal including fourth means to request said network controller to switch said satellite to said heavy encoding, if said transmission power control for transmitting data packets to said satellite at variable power settings can not further increase its power out on command from said third means.

7. The system as set forth in claim 6 comprising:

said satellite adapted to receive uplink data packets transmitted from said terminal at either light or heavy encoding rates upon receipt of a switching signal;

a network controller for providing said switching signal to said satellite; and

said terminal including fifth means to request said network controller to switch the satellite to said heavy encoding, if said transmission power control for transmitting data packets to said satellite for at variable power settings can not further increase its power out on command from said third means.

8. The system as set forth in claim 7 wherein said terminal including sixth means to request said network controller to switch said satellite to said light encoding if said transmission power control for transmitting data packets to said satellite for at variable power settings can not further decrease its power out on command from said third means.

9. A method of adjusting the transmission quality of a timing signal sent from a terminal to a satellite, the method comprising the steps of:

preparing timing probe signals;

periodically transmitting a specific timing probe signal to the satellite with the timing probe signal at a specified power level;

determining whether the satellite has received the specific timing probe at the specific power level;

generating a signal by the satellite and sending the satellite generated signal to the terminal from the satellite indicative of whether the satellite has received the specific timing probe signall; and

incrementally increasing the power output of the terminal used to transmit the specific timing probe, if the previously sent specific timing probe is not received, and incrementally deceasing the power level used to transmit the specific timing probe, if the previously sent specific timing probe is received by the satellite.

11. The method as set forth in claim 9 wherein the satellite has the capacity to switch transmissions from light to heavy encoding rates at the command of a network control center and when said terminal can not further increase power;

the additional steps of;

requesting the network control center to switch the satellite to receive uplink signals transmitted by the terminal from light encoding rates to heavy encoding rates;

switching the satellite from a light encoding rate to heavy encoding rates; and

transmitting uplink signals from said terminal to the satellite at heavy encoding rates.

10. A method of adjusting the transmission quality of data packets sent form a terminal to a satellite, the method comprising the steps of:

preparing timing probe signals;

periodically transmitting a specific timing probe signal to the satellite with the timing probe signal at a specified power level;

determining whether the satellite has received the specific timing probe at the specific power level;

generating a signal by the satellite and sending the satellite generated signal to the terminal from the satellite indicative of whether the satellite has received the specific timing probe;

incrementally increasing the power output of the terminal during transmission of the specific timing probes, if the previously sent the specific timing probe is not received, and incrementally decreasing the power level used to transmit the specific timing probe, if the previously sent specific timing probe is received by the satellite; and

incrementally increasing or decreasing the power output of the terminal during the transmittal of data packets in proportion to the incremental increase or decrease, respectively, in the power output of the terminal during transmission of the specific timing probes.