Communication terminal apparatus, communication satellite apparatus, satellite communication system, and non-transitory storage medium

Patent metadata

Field	Value
Publication number	US-2024214045-A1
Application number	US-202318390125-A
Country	US
Kind code	A1
Filing date	Dec 20, 2023
Priority date	Dec 27, 2022
Publication date	Jun 27, 2024
Grant date	—

Abstract

To provide a communication terminal apparatus, a communication satellite apparatus, and a satellite communication system, capable of facilitating rapid determination of the direction of a beam. A communication terminal apparatus ( 10 ) is a communication terminal apparatus configured to communicate with a communication satellite apparatus ( 20 ) by means of a radio beam, the apparatus including: an antenna ( 11 ) configured to receive a plurality of beacons (Fa 1 to Fa 3 ) from at least one communication satellite apparatus, and to transmit and receive a directional radio beam; and at least one processor executing a control process of determining a plurality of candidate directions of the radio beam to be transmitted, on the basis of information included in the plurality of beacons.

First claim

1 . A communication terminal apparatus configured to communicate with a communication satellite apparatus by means of a radio beam, the apparatus comprising:
an antenna configured to receive a plurality of beacons from at least one communication satellite apparatus, and to transmit and receive a directional radio beam; and at least one processor, the at least one processor executing a control process of determining a plurality of candidate directions of the radio beam to be transmitted from the antenna, on the basis of information included in the plurality of beacons.

2 . The communication terminal apparatus according to claim 1 , wherein, in the control process, the at least one processor:
assigns priorities to the plurality of candidate directions; selects a direction from among the plurality of candidate directions on the basis of the priorities; and transmits a radio beam including a connection request in the selected direction.

3 . The communication terminal apparatus according to claim 2 , wherein, in the control process, the at least one processor:
determines whether or not a response radio beam has been received in response to the connection request of the radio beam transmitted in the selected direction; and when it is determined that no response radio beam has been received, selects another direction from among the remaining candidate directions and transmits a radio beam including a connection request, whereas, when it is determined that the response radio beam has been received, continues communication by means of the radio beam.

4 . The communication terminal apparatus according to claim 3 , wherein
the information includes a movement speed of the at least one communication satellite apparatus, and in the control process, the at least one processor continues communication by means of the radio beam by adjusting a direction of the radio beam on the basis of the movement speed of the at least one communication satellite apparatus.

5 . The communication terminal apparatus according to claim 1 , wherein
the information includes a first coordinate of the at least one communication satellite apparatus, a first sent time of a first beacon from the first coordinate, a second coordinate of the at least one communication satellite apparatus, and a second sent time of a second beacon from the second coordinate, and in the control process, the at least one processor:
obtains a first receipt time of the first beacon, and a second receipt time of the second beacon;
derives a first distance between the first coordinate and the communication terminal apparatus, on the basis of the first sent time and the first receipt time;
derives a second distance between the second coordinate and the communication terminal apparatus, on the basis of the second sent time and the second receipt time; and
determines the plurality of candidate directions on the basis of the first and second coordinates and the first and second distances.

6 . The communication terminal apparatus according to claim 5 , wherein
the information includes a first transmitted signal strength of the first beacon and a second transmitted signal strength of the second beacon, and in the control process, the at least one processor:
obtains a first received signal strength of the first beacon, and a second received signal strength of the second beacon; and
corrects the first and second distances on the basis of the first and second transmitted signal strengths and the first and second received signal strengths.

7 . The communication terminal apparatus according to claim 5 , wherein
the information includes a first transmitted signal strength of the first beacon and a second transmitted signal strength of the second beacon, and in the control process, the at least one processor:
obtains a first received signal strength of the first beacon, and a second received signal strength of the second beacon; and
calibrates time of a timer on the basis of the first and second distances, the first and second transmitted signal strengths, and the first and second received signal strengths,
the calibrated timer being for use in obtaining the first receipt time and the second receipt time.

8 . The communication terminal apparatus according to claim 5 , wherein, in the control process, the at least one processor determines a first candidate direction corresponding to the first coordinate and a second candidate direction corresponding to the second coordinate.

9 . A communication satellite apparatus configured to communicate with the communication terminal apparatus according to claim 1 by means of a radio beam, the communication satellite apparatus comprising:
an antenna configured to receive a radio beam including a connection request from the communication terminal apparatus; and
at least one processor,
the at least one processor executing a control process in which a response radio beam is transmitted in response to the radio beam including the connection request.

10 . A satellite communication system comprising the communication terminal apparatus according to claim 1 and a communication satellite apparatus configured to communicate with the communication terminal apparatus,
the communication satellite apparatus being configured to communicate with the communication terminal apparatus by means of a radio beam,
the communication satellite apparatus comprising:
an antenna configured to receive a radio beam including a connection request from the communication terminal apparatus; and
at least one processor,

10 . the at least one processor executing a control process in which a response radio beam is transmitted in response to the radio beam including the connection request.

11 . The communication terminal apparatus according to claim 5 , wherein, in the control process, the at least one processor determines two candidate directions corresponding to a first communication satellite apparatus on the basis of the first and second coordinates and the first and second distances.

12 . The communication satellite apparatus according to claim 9 , wherein, in the control process, the at least one processor:
obtains a received signal strength of the radio beam including the connection request; determines whether or not to transmit the response radio beam on the basis of the received signal strength; and transmits the response radio beam when the response radio beam is determined to be transmitted.

13 . The communication satellite apparatus according to claim 9 , wherein, in the control process, the at least one processor determines that it is unable to connect with the communication terminal apparatus when a state in which no connection is established with the communication terminal apparatus continues for a predetermined duration of time after transmission of the response radio beam.

14 . The communication satellite apparatus according to claim 9 , wherein
the antenna transmits and receives an inter-satellite beacon from and to another communication satellite apparatus, and in the control process, the at least one processor:
obtains a coordinate and a movement speed of the another communication satellite apparatus, included in the inter-satellite beacon; and
causes a beacon including the coordinate and the movement speed of the another communication satellite apparatus to be transmitted to the communication terminal apparatus.

15 . The communication satellite apparatus according to claim 14 , wherein
the inter-satellite beacon includes a connection request to the another communication sat

Assignees

• Nec Corp

Inventors

• Sugyo Kazushi
• Watanabe Shingo
• Wakafuji Kenji
• Ono Masakazu

Classifications

• H04B7/0617 Primary

  for beam forming · CPC title