JPH01190134A - Satellite communication system - Google Patents

Abstract

PURPOSE:To attain inexpensive transmission of communication information not requiring real time by mounting a communication information storage means, a destination identification means and a position detection means to a circulating satellite, controlling them by a program and applying transmission/ reception. CONSTITUTION:n-Set of zones are set on ground and when a satellite 10 comes on the zone, an earth station 20 sends a facsimile signal. Upon the receipt of a signal, the satellite 10 stores the signal in a communication information storage section 14 mounted in the inside. A destination code is added to the facsimile equipment and a destination detection section 17 identifies the destination corresponding to the information of the stored signal by the destination corresponding to the information. Then the position detection section 15 makes the read timing correspondent to the position on grown by the information stored in the storage section 14 according to the identified destination and a program control section 16 reads the information and sends the result from a transmission/reception section 13. Thus, the communication information not requiring the real time is sent inexpensively.

Description

[Detailed description of the invention] [Industrial application field] INDUSTRIAL APPLICATION This invention is utilized for the satellite communication system using an artificial satellite.

In particular, a receiver is mounted on an artificial satellite that orbits the earth while changing its position relative to the earth's surface, and receives transmission signals transmitted from an earth station, and a receiver that directs the output information of this receiver to a limited part of the earth's surface. The present invention relates to a satellite communication system including a transmitting device for transmitting data.

The present invention can be used for communications other than conversational communications, ie, data communications in which signals are transmitted in the negative direction, facsimile communications, selective call (pager) communications, and others.

[Conventional technology]

Using geostationary satellites whose position relative to the earth's surface is fixed,
Satellite communication systems are widely used, in which a transmitted signal from an earth station is received, and this signal is relayed and transmitted to other earth stations. However, since geostationary satellites must be set in circular orbits at a certain distance directly above the equator, the number of geostationary satellites that can be placed is limited.

On the other hand, in the method of relaying signals using orbiting satellites whose position relative to the earth's surface changes, there are loose restrictions on the number of satellites that can be deployed, but both the earth station and the satellite station Attempting to carry out efficient communications within a narrow space requires complicated tracking equipment, and there are times when communications become unavailable as the satellite orbits.

Using an orbiting satellite, when the satellite approaches a transmitting station on the ground, it transmits information to that satellite, stores that information in the satellite, and when the satellite approaches the receiving station with which it is communicating. Sometimes, a method is used as a small-scale communication method in which stored information is read out according to access from the receiving station and transmitted to the receiving station.

[Problem that the invention seeks to solve]

This method is advantageous for transmitting information that does not necessarily require real-time, but conventional methods
The information that can be stored on satellites is extremely limited.
Furthermore, it is not convenient for use in general information transmission, as it requires access from the receiving station. In other words, although this method has been used for research satellites, military satellites, etc., there is no method for using this type of satellite for public communications.

On the other hand, new storage devices have been developed in recent years, and devices that are lightweight and small enough to be mounted on satellites, and that can store extremely large amounts of data, have become available.

The present invention was made against this background, and it is an object of the present invention to provide a system for transmitting information that does not require real-time information at low cost, using orbiting satellites that have relatively few restrictions on installation.

[Means for solving problems]

The present invention provides storage means for temporarily accumulating output information of a receiving device that receives signals from an earth station and providing the readout output to the transmitting device, and identifying the destination of the signal corresponding to the information of the signal received by the receiving device. and a means for controlling the readout timing of each piece of information stored in the storage means according to the destination identified by the means so as to correspond to the position on the earth's surface where the radio waves transmitted by the transmitter reach. It is characterized by being mounted on a satellite.

A destination code can be added to the earth station's transmission signal to identify the destination in an information-based manner.

The destination code can be based on a zone number that is set in advance by dividing the service area into zones.

The number of read timings can be once for each piece of information each time the satellite orbits the earth's surface, or can be read multiple times.

The device that receives the transmitted radio waves from the satellite may be a mobile station on the earth or a fixed station.

〔Example〕

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention. The orbiting satellite 10 is equipped with an antenna 12 and a transmitting/receiving section 13 as a receiving device that receives a transmission signal from an earth station and a transmitting device that transmits output information of this receiving device to a limited part of the earth's surface. There is.

This satellite 10 includes a communication information storage section 1 as a storage means for temporarily accumulating received output information and transmitting the readout output.
4, a destination detection section 17 as a means for identifying the destination of the received signal according to the information thereof;

A position detection unit 15 is provided as a means for controlling the readout timing of each piece of information stored in the communication information storage unit 14 according to the classified destination in accordance with the position on the ground surface, and these are controlled by a program control circuit 16. It has a controlled configuration.

On the other hand, the earth station 20 includes a communication control unit 21 connected to a communication network within the zone, a communication information storage unit 22 that temporarily stores communication information to be transmitted inputted from the communication control unit 21,
a destination adding section 24 that adds a destination code to the signal read from the communication information storage section 22; and a transmitting/receiving section that transmits the communication signal to which the destination code is added to the satellite 10 and receives the signal from the satellite 10. 25 and an antenna 26. Each of these devices is controlled by a program control circuit 23.

In FIG. 1, a telephone 31, an exchange 32, and an inter-office line 33 are shown as a communication network.

FIG. 2 is a system configuration diagram of an embodiment of the present invention. This figure shows that as the orbiting satellite 10 moves relative to the earth's surface over time, the communication range from the satellite 10 moves from zone l to zone 2 to zone 3, etc. It shows the progress of the situation. The communicable range of the satellite 10 moves in the latitude and longitude directions of the earth, depending on the situation in which it orbits the earth.

- As an example, if we consider a satellite whose orbit takes about 2 hours to complete one revolution around the center of the earth, and whose orbit is at an angle of 60 degrees with respect to the equator, the surface of the earth that the satellite passes directly above Due to the earth's rotation, the position of the earth moves by 30 degrees in latitude each time it goes around, and it returns to its original position on the earth's surface in about 12 hours. In other words, by setting n zones on the earth's surface, 1
The satellite 10 will pass through one zone twice a day.

In the example of FIG. 2, when the satellite 10 is above zone l,
A facsimile signal is transmitted from an earth station 20-1 installed in zone 1 to satellite 10. Assume that a destination code is added to this facsimile signal, and the destination code is, for example, zone 2 and zone 3. When the satellite 10 receives this facsimile signal, it is stored in the communication information storage unit 14 provided inside the satellite 10, and as time passes, when the satellite 10 reaches a position where it can communicate with zone 2, this communication information is stored. The facsimile signal stored in the storage unit 14 is read out and transmitted to the earth station 20-2 in zone 2. When the satellite 10 reaches a position where it can communicate with zone 3, this facsimile signal is read out again and transmitted to the earth station 20-3 in zone 3. At this time, there is no need for the earth station 20-2 or 20-3 to access the satellite 10, and the satellite 10 will identify this and send it automatically.

The earth station 20-1 in zone 1 has information to be transmitted from a terminal connected to the communication network transmitted to the earth station 20-1 in advance and stored therein, and the satellite 10 orbits within the communication range of zone 1. wait for that. Furthermore, the earth stations 20-2 and 20-3 that have received the signal from the satellite 10 further identify the destination and distribute the facsimile signal to the terminal using the communication network connected to the earth station.

For example, the destination code is in the form of a telephone number with a country code, and the destination adding section 24 is equipped with a table that identifies the upper digits and converts them into codes for each zone, and the transmitted signal includes a code for each zone. Add the code as the destination code. satellite 10
The position detecting section 15 detects the position of the satellite 10 with respect to the earth's surface based on the time, and the destination detecting section 17 reads out the information stored in the communication information storage section 14 at the timing corresponding to the transmission zone and transmits it from the transmitting/receiving section 13. .

The above example is an example where the earth station 20 is a fixed station, but
Earth station 20 can be a mobile station.

FIG. 3 is a system configuration diagram showing an example in which the present invention is applied to a selective call reception system. In this example, selective call information is provided from telephone 31 in zone 1 to earth station 20-1 via exchange 32. This information allows you to specify the zone where the called party is most likely to be located, and the number of the specified zone is added as a destination code to receive the selective call that the called party carries. It is transmitted to the satellite 10 along with the calling number of the aircraft 35.

In the satellite 10, this information is stored in the communication information storage section 14.

Assuming that the called party is currently in zone n, the satellite 10 moves its position over time, and when it reaches the communication range of zone n, it transmits the called number to the earth's surface. . When the selective call receiver 35 receives this signal and identifies that the call is to itself, it generates a ring tone.

When the zone in which the called party may exist spans multiple zones, it is possible to specify transmission for the multiple zones. That is, by adding destination codes for multiple zones, the same calling number can be transmitted in multiple zones.

Such a system allows selective calls to be made in a wide range beyond national borders.

Although the above example uses one satellite, it is also possible to provide a plurality of orbiting satellites within the same system so that the satellites pass through one zone one after another over time. This reduces communication waiting time and improves throughput.

In addition to the above example, the present invention can be implemented in various types of communication that do not need to be conversational communication.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to obtain a method for inexpensively transmitting communication information that does not require real-time communication using an orbiting satellite.

Orbiting satellites have relatively few restrictions on installation, are easy to use, and are economical because orbit adjustment is simple.

Efficient operation becomes possible by dividing the service area into zones and using the zone number set in advance as the destination code.

In addition, by setting the number of read timings to be multiple times, it is possible to transmit broadcast communication, and the possibility of establishing communication when the other station is a mobile station is increased ( can do.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention. FIG. 2 is a system configuration diagram of an embodiment of the present invention (when the earth station is a fixed station). FIG. 3 is a system configuration diagram of an embodiment of the present invention (when the earth station is a mobile station). 10... Orbiting satellite, 12... Antenna, 13...
Transmitting/receiving section, 14... Communication information storage section, 15... Position detecting section, 16... Control circuit, 17... Destination detecting section,
20...Earth station, 21...Communication control unit, 22...
Communication information storage section, 24... Destination adding section, 25... Transmitting/receiving section, 26... Antenna. Patent applicant Nippon Telegraph and Telephone Corporation, d Representative patent attorney Nao Takashi Ide°1 Example device Fig. 1

Claims (1)

[Claims] 1. A receiving device that receives a transmission signal from an earth station and a transmitting device that transmits output information of this receiving device to a limited part of the earth's surface while changing their position with respect to the earth's surface. In a satellite communication system mounted on an artificial satellite orbiting the earth, this artificial satellite has a storage means for temporarily storing the output information of the above-mentioned receiving device and providing the readout output to the above-mentioned transmitting device, and a storage means for temporarily storing the output information of the above-mentioned receiving device and providing the readout output to the above-mentioned transmitting device, means for identifying the destination corresponding to the information of the signal, and a readout timing for each piece of information stored in the storage means according to the destination identified by the means, to a position on the earth's surface where the transmitted radio wave from the transmitting device reaches. A satellite communication system characterized by being equipped with means for corresponding control. 2. The satellite communication system according to claim 1, wherein a destination code for identifying the destination is added to the transmitted signal from the earth station in accordance with the information. 3. The satellite communication system according to claim 2, wherein the destination code includes a zone number set by dividing the service area into zones in advance. 4. The satellite communication system according to claim 1, wherein the number of read timings is one or more times for one piece of information each time the satellite orbits the earth's surface.