JPH05300061A - Mobile object communication/positioning system - Google Patents

Abstract

PURPOSE:To apply positioning information obtained at a satellite for the communication of a mobile terminal equipment by using a satellite line utilizing the satellite as the assistance for the communication between the mobile terminal equipment and a base station. CONSTITUTION:An antenna 11 provided in a base station 10 and an antenna 2 provided in an automobile 1 being a mobile terminal equipment are connected by a radio wave. A satellite antenna 3 is selected from the antenna 2 of the automobile 1 depending on the state of a radio wave due to the automobile 1 located behind a mountain or a building or the like when viewed from the base station 10 and the antenna 3 is used to connect at first a figure 8-shaped satellite 8 and a radio line. The 8-shaped satellite 8 is connected to a parabolic antenna 12 of the base station 10 by the radio line and the automobile 1 and the base station 10 are connected via the figure 8-shaped satellite 8. A satellite control station 9 controls plural figure 8-shaped satellites 8 above the earth while drawing an figure 8-shaped on-ground orbit around the equator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication / positioning system for mobiles such as ships and automobiles, and more particularly to a mobile communication / positioning system that complements the ground system network and applies the positioning service to mobile communication services. Positioning system.

[0002]

2. Description of the Related Art In recent years, with the development of the information industry, mobile communication terminals such as mobile phones and car phones have become widespread. Such a communication terminal is connected to a base station via a wireless line, and the base station is connected to the other party's telephone via a wired public general line. In this state, communication between the communication terminal and the other party's telephone or the like becomes possible. In a communication system using this mobile communication terminal, in order to be able to connect the mobile terminal and the base station with a wireless line, a plurality of base stations having a certain wireless coverage area cover the entire specific area, The mobile terminal and the base station can be connected to each other via a wireless line, so that they can talk to each other. However, even within the radio coverage of each base station, the radio wave propagation state sometimes changes due to the shadow of buildings, the shadow of mountains, and the like, and a state where the wireless line cannot be connected sometimes appears. In such a case, you cannot call. Therefore, conventionally, a mobile communication system using a geostationary satellite has been proposed.

This system communicates with a base station via a communication line using a geostationary satellite when the mobile terminal moves away from the base station and is out of a radio coverage area where communication with the base station is possible. Is. However, when mobile communication is performed using such geostationary satellites, the elevation angle of geostationary hygiene seen from the ground is 40 ° to 5 because Japan is at a high latitude.
There is a drawback that when the geostationary satellite is shaded by a building or a mountain, it becomes impossible to communicate between the mobile terminal and the geostationary satellite.

When the mobile terminal and the base station are connected without using a geostationary satellite, the location can be specified by managing which base station the mobile terminal is communicating with. Special numbers such as "No." and "119" can be used. However, if communication is performed using geostationary satellites, it is impossible to use special numbers because the entire country of Japan is handled in a unified manner, for example, by one satellite. In other words, since the satellite does not know the positioning information (location information) of the person who owns the mobile terminal, the police station or fire station receiving this notification cannot identify the location even if there is a 110 or 119 notification. It is not possible to contact the nearest police station or fire station.

[0005]

As described above, in the conventional mobile communication system, since the communication service is complemented by using the geostationary satellite, the elevation angle is low and the radio waves are blocked by the shadows of buildings and mountains. It had the drawback of not being able to communicate. Further, in the past, mobile terminals such as mobile phones and car phones did not have a function of obtaining positioning information using satellites, so there was a problem that the above special number could not be reported from a place where the location could not be specified. there were.

Further, since the location of a mobile terminal cannot be specified, it is determined which mobile terminal should be assigned to this base station, even if many mobile terminals are concentrated on a particular base station. Since it was impossible, there was a problem that the congestion state could not be resolved.

The present invention has been made in order to solve such a conventional problem, and an object thereof is to enable communication even in the shadow of a building or a mountain, and
It is an object to provide positioning information of a mobile terminal to a user and to provide a mobile communication / positioning system that can apply this positioning information to communication.

[0008]

In order to achieve the above object, the present invention provides a mobile communication and positioning system in which communication between a mobile terminal and a base station is performed through a satellite line using a satellite. Is characterized by being composed of a plurality of ground-synchronous satellites that draw an 8-shaped ground locus around the equator.

Further, the base station obtains positioning information of the mobile terminal based on the time from when the mobile terminal emits a radio wave to when the radio wave reaches the base station via a satellite, and the positioning information is obtained. It is provided to the mobile terminal.

Furthermore, mobile communication for communicating between a mobile terminal and a base station with the aid of a satellite communication line using satellites.
In the positioning system, the mobile terminal calculates the positioning information based on the time taken until the radio wave emitted from the mobile terminal is received by the mobile terminal via the satellite, and the positioning information calculation means. Whether to communicate between the mobile terminal and the base station via the satellite line based on the positioning information obtained from the means or to communicate between the mobile terminal and the base station without the satellite line. And a switching means for switching.

[0011]

With the above-described structure, the user of the mobile terminal can always see the figure-8 satellite (ground synchronization satellite) at a high elevation angle of 70 ° or more. Therefore, it becomes possible to provide a communication service in which communication via satellite is possible and communication is not always possible.

It is also possible to measure the arrival time of a radio wave when communicating via an 8-figure satellite at a mobile terminal or a base station and obtain the distance between the 8-figure satellite and the mobile terminal based on this. it can. Then, if the distances between a plurality of 8-shaped satellites and the mobile terminal are obtained, the position of the mobile terminal can be specified and the positioning information can be obtained. Then, this positioning information can be applied to the navigation system of the automobile and the congestion process and special number process of the base station.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing an embodiment of a mobile communication / positioning system to which the present invention is applied.

FIG. 1 shows a car telephone as an example of the mobile terminal. The figure-8 satellite 8 orbits around the earth so as to draw a figure-8 ground locus around the equator, and a plurality of figure-8 satellites 8 are provided. That is, a plurality of 8-shaped satellites 8 pass through this 8-shaped locus. By adjusting the orbital intervals of each of the figure-8 satellites 8, one or more figure-8 satellites 8 will always be visible over Japan. The figure-8 satellite 8 is called from the ground locus as described above, and is generally called a ground synchronization satellite.

First, in the base station 10, the antenna 11 provided in the base station 10 and the antenna 2 provided in the automobile 1 are wirelessly connected to each other so that an automobile (not shown) provided in the automobile 1 is provided. A telephone can be communicated with an ordinary telephone through an ordinary line connected to the base station 10. Although there is only one base station 10 in the figure, a plurality of base stations are installed in a certain area so that the radio wave coverage of each base station covers a certain area. There is. The one base station 10 is shown as a representative here. However, since the base station 10 and the car telephone are connected by a wireless line, even if the base station 10
Even if the automobile 1 is in the radio wave reachable range of the base station 10
Depending on the radio wave condition, the wireless line may be disconnected depending on the condition of the radio wave such as the car 1 seen from the shadow of a mountain or a building. At this time, the communication is switched to the figure-8 satellite 8 as described later. That is, the antenna 2 of the automobile 1 is switched to the antenna 3 and the antenna 3 is used to connect the figure-8 satellite 8 and the wireless circuit. Further, the figure-8 satellite 8 connects the parabola antenna 12 provided in the base station 10 with a wireless line. In this way, the automobile 1 and the base station 10 are in a state of being connected to each other by the wireless line via the figure-8 satellite 8. As a result, good communication can be performed without making communication impossible under any radio wave condition. The satellite control station 9 does not control the plurality of figure-eight satellites 8 in communication connection. For example, the integrated control means a plurality of 8
Since the satellites in the shape of "8" above Japan are limited and change every moment, the control mainly switches to the "8" satellite in the sky above Japan each time. Next, FIG.
The operation of communication between the mobile terminal and the base station will be described using the internal block diagram of the mobile terminal shown in FIG. 3 and the internal block diagram of the base station shown in FIG.

FIG. 3 (a) shows the case where the base station side is provided with means for obtaining positioning information, and FIG. 3 (b).
Shows the case where the base station side is provided with the electric field strength measuring means. Further, FIG. 7C is a diagram showing a case where the base station side is provided with a means for obtaining positioning information and an electric field strength measuring means. First, a case where communication is performed will be described with reference to FIGS. 2 and 3A. It is assumed that the automobile 1 and the base station 10 are communicating now. That is, the data processing unit 6 of the automobile 1 is connected to an automobile telephone (not shown), and this automobile telephone is connected to a public general line. To be more specific, a car phone call
The data processing unit 6 performs data processing, and this data is transmitted by the transmission / reception unit 5. Then, the signal transmitted by the transmission / reception unit 5 is transmitted from the antenna 2 via the switching unit 4 and received by the antenna 11 of the base station 10. The signal received by the antenna 11 is received by the transmission / reception unit 25 via the switching unit 24 and transmitted from the transmission / reception unit 25 to the public general line.
On the other hand, the call signal from the public general line is, on the contrary, the base station 1
It is received by the transmitting / receiving unit 25 of 0 and transmitted from the antenna 11 via the switching unit 24. The transmitted signal is for car 1
It is received by the transmission / reception unit 5 via the antenna 2 and the switching unit 4. The signal received by the transmitter / receiver 5 is sent to the data processor 6
Is input to the mobile phone, processed as data, and then output as voice to the car phone. In this way, the control unit 7 of the automobile 1 outputs a control signal to the switching unit 4 to switch the antenna 2 to the satellite antenna 3 at regular time intervals during a call that is generally performed. Then, the data processing unit 6 causes the transmitting / receiving unit 5 to output the specific data, and the transmitting / receiving unit 5 transmits the specific data from the satellite antenna 3 via the switching unit 4. This specific data is received by the satellite antenna 12 of the base station 10 via the figure 8 satellite 8 shown in FIG. At this time, in the base station 10, the switching unit 24 switches the antenna 11 to the satellite antenna 12 in advance. The specific data received by the transmission / reception unit 25 via the satellite antenna 12 and the switching unit 24 is the positioning information calculation unit 2
1, the positioning information is calculated, and the calculation result is
It is input to the determination unit 22. If the positioning information calculation is performed for, for example, four figure-8 satellites, it becomes possible to geometrically specify the existing position of the vehicle 1 based on the distance between the vehicle 1 and each satellite, and to know the positioning information. You can Therefore, by having the determination unit 22 determine based on this positioning information, the number of mobile terminals handled by this base station can be known on the base station side, and regarding the mobile terminals that cannot be handled due to the congestion state of this base station, the control unit 23 Controls the transmitting / receiving unit 25 to transmit a signal for specifying the mobile terminal from the satellite antenna 12 via the switching unit 24. This signal is received by the transmitting / receiving unit 5 via the satellite antenna 3 of the automobile 1 and the switching unit 4, and the data processing unit 6 processes the data. As a result, the car telephone in the car 1 talks either through the other base station or through the figure-8 satellite. The method of controlling the call using the positioning information has been described above. Next, the method of controlling the call using the information on the electric field strength will be described below with reference to FIG. The operation of the call between the automobile 1 side and the base station 10 shown in FIG. 24 is the same as that described in FIG. Similarly to FIG. 3A, the signal from the transmitting / receiving unit 25 of the base station 10 is input to the electric field strength measuring unit 26, and the electric field strength is measured. The measured electric field strength value is input to the determination unit 22. The strength of the radio wave of each mobile terminal can be known from the input electric field strength value, and if the electric field strength value is weak, the judgment unit 22 judges that the mobile terminal is about to come out of the radio wave coverage of this base station. Then, a control signal is sent to the mobile terminal side, and control is performed using the antenna 3 so as to talk via the figure-8 satellite. Finally, what is shown in FIG. 3 (c) is a combination of FIG. 3 (a) and FIG. 3 (b). Either the positioning information or the electric field strength value may be used, or only one of the information may be used. Among these information, the positioning information is useful as the information of the navigation system of the car. Further, it has been described that the transmission and reception of the radio wave for obtaining the information are performed at regular intervals between the base station and the mobile terminal, but they may be performed when necessary. As described above, according to the present invention, the communication between the base station and the mobile terminal can be complemented and smooth communication can be performed by making good use of the electric field strength value and the positioning information.

The figure-8 satellite 8 will be described in more detail. As shown in FIG. 4, it is launched on a ground-synchronous orbit 15 inclined by 45 ° with respect to the equator 14 of the earth 13. And the ground locus of this figure-8 satellite is as shown in FIG.
The orbit 16 is drawn in the shape of a figure of 8 from the latitude 45 ° north to the latitude 45 ° south with a 24-hour cycle centering on the equator. At this time, the user who uses the mobile phone has at least one 8
The U-shaped satellite 8 can be seen from the ground at a high angle of elevation of 70 ° to 75 °. And, since the figure 8 satellite 8 can be seen from the ground at an elevation angle of 70 ° or more, it is about 7 hours.
By launching four 8-figure satellites by shifting the longitude by 90 ° and shifting by a quarter cycle, 7 × 4 = 28 hours, which can cover 24 hours a day. In addition, the orbits of these four figure-8 satellites are shown on the world map as shown in Figure 1
4a to 14d, and Japan is 4 even if the earth rotates.
Understand that one of the satellites is approaching. As a result, a stable communication service that does not make communication impossible without being blocked by buildings or mountains between the satellite and the mobile phone becomes possible.

The car telephone which receives the service is
As shown in FIG. 1, it has a satellite antenna 3 used for communication with a figure-8 satellite 8 and an antenna 2 used for communication with a base station 10, and each antenna 2 and 3 is switched. Selected by section 4. The selection method at this time is performed based on the electric field strength of the radio wave transmitted from the base station 10 as described above. That is, when the electric field strength is larger than the predetermined threshold value, the car telephone and the base station 10 can communicate well, so that direct communication is performed during this period, and when the electric field strength is below the threshold value, Car phone and base station 1
When it is determined that 0 cannot communicate well, communication is performed via the figure-8 satellite 8 controlled by the satellite control station 9.

This makes it possible to complement the conventionally used mobile communication system. Further, since the conventional post processing of the switching unit 4 shown in FIG. 1 can be used as it is, there is no need to make a large design change.

In addition, the number of lines that can be communicated with each 8-figure satellite is determined, and if this number of lines is exceeded, further communication cannot be performed. Therefore, on the base station side, based on the positioning information of each car phone, the one with the farest distance between the base station and the car phone is preferentially communicated, and the one near is directly communicated with the base station without using the satellite. Switch to do.
This enables smooth and smooth communication.

Also, since the positioning information of each car telephone can be known, even if there is a special number report such as "110" or "119", the nearest police or fire station can be immediately known and contacted.

Further, when the number of lines in a specific area increases due to a disaster or the like, communication using satellites is permitted only in this area, and communication with the base station is directly made in other areas. It can also be dealt with in an emergency.

Further, in this embodiment, since the figure-8 satellite 8 is used, the elevation angle of the satellite is high and the antenna pattern can be made simple. That is, the conventional geostationary satellite antenna needs to have a radiation pattern as shown in FIG. 8, but in this embodiment, since the elevation angle is high, the radiation pattern as shown in FIG. 7 may be used. This facilitates the design and manufacture of the antenna and allows the use of low profile antennas such as patch antennas.

Further, as shown in FIG. 5, since the figure-8 satellite reaches Asia and Australia, it is possible to communicate not only in Japan but also in Asia and Australia. Trajectories 16a, 16b, 16c, 16d in FIG.
If the satellites use the surrounding orbits having, the mobile communication / positioning system of the present invention can be implemented in other regions as well. In the present embodiment, a car phone is shown as an example of the mobile terminal, but the mobile terminal is not limited to these, and it is needless to say that it can be applied to communication of a mobile phone or a ship.

[0025]

As described above, according to the present invention, a satellite line that uses a satellite is used to assist communication between a mobile terminal and a base station.
Since it is performed using a ground-synchronous satellite that draws a V-shaped ground orbit, the elevation angle when looking at the satellite from the ground will be high, so reliable communication can be performed without being affected by buildings or mountains. become.

Further, since the positioning information of each mobile terminal can be obtained from the communication via the satellite, special number processing can be smoothly performed when it has been a problem than before, and this positioning information can be used for mobile communication. The effect is that it can be applied to congestion control.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a mobile communication / positioning system to which the present invention is applied.

FIG. 2 is an internal block diagram of a mobile terminal of the present invention.

FIG. 3 is an internal block diagram of a base station of the present invention.

FIG. 4 is an explanatory diagram showing the orbit of a figure-8 satellite of the present invention.

FIG. 5 is an explanatory diagram showing a ground orbit of a figure-8 satellite of the present invention.

FIG. 6 is an explanatory diagram showing a ground orbit of four figure-8 satellites of the present invention.

FIG. 7 is an explanatory diagram showing a radiation pattern of an antenna when the figure-8 satellite of the present invention is used.

FIG. 8 is an explanatory diagram showing an antenna radiation pattern when a conventional geostationary satellite is used.

[Explanation of symbols]

2 ... Antenna 3 ... Satellite antenna 4, 24 ... Switching unit 5, 25 ... Transceiver unit 8 ... Figure 8 satellite 9
... Satellite Bureau 10 ... Base Station 13 ... Earth 14 ... Equator 15 ... Ground Orbit 16 ... Orbit
21 ... Positioning information calculation unit 22 ... Judgment unit 23 ... Control unit 26 ... Electric field strength measurement unit

Claims (6)

[Claims] 1. A mobile communication / positioning system in which communication between a mobile terminal and a base station is performed with the aid of a satellite communication line using a satellite, wherein the satellite has an 8-shaped ground trajectory centered on the equator. A mobile communication / positioning system characterized by comprising a plurality of ground-synchronizing satellites to be drawn. 2. A mobile communication / positioning system for performing communication between a mobile terminal and a base station with the aid of a satellite communication line using a satellite, wherein the base station transmits radio waves from the mobile terminal via the satellite. Via the satellite line based on the positioning information obtained from the positioning information calculation means, which calculates the positioning information of the mobile terminal based on the time taken by the base station to be received by the base station. And a control means for switching between performing communication between the mobile terminal and the base station or performing communication between the mobile terminal and the base station without going through the satellite line. Communication / positioning system. 3. A mobile communication / positioning system for performing communication between a mobile terminal and a base station with the aid of a satellite communication line using a satellite, wherein the base station transmits radio waves from the mobile terminal via the satellite. And a positioning information calculation unit that obtains positioning information of the mobile terminal based on the time taken to be received by the base station, the mobile terminal based on the positioning information obtained from the positioning information calculation unit. And a switching means for switching between performing communication between the mobile terminal and the base station via the satellite line or performing communication between the mobile terminal and the base station without passing through the satellite line. Mobile communication / positioning system. 4. A mobile communication / positioning system for performing communication between a mobile terminal and a base station with the aid of a satellite communication line using a satellite, wherein the mobile terminal transmits radio waves from the mobile terminal via the satellite. Positioning information calculating means for obtaining positioning information based on the time taken to be received (up to the mobile terminal), and the movement via the satellite line based on the positioning information obtained from this positioning information calculating means. A mobile communication / positioning system characterized by comprising switching means for switching between communication between the terminal and the base station or communication between the mobile terminal and the base station without going through the satellite line. .. 5. A mobile communication / positioning system for performing communication between a mobile terminal and a base station with the aid of a satellite communication line using a satellite, wherein the base station transmits radio waves from the mobile terminal via the satellite. And a radio wave of the base station based on the positioning information obtained from the positioning information calculating means, the positioning information calculating means obtaining the positioning information of the mobile terminal on the basis of the time taken by the base station. Judgment means for judging whether or not the mobile terminal exists in the coverage area, and if this judgment means judges that the mobile terminal does not exist in the radio coverage area of the base station, the mobile terminal and the base station Communication is performed via the satellite, and when the determination means determines that the mobile terminal exists within the radio wave coverage of the base station, the communication between the mobile terminal and the base station does not go through the satellite. A mobile communication / positioning system characterized by comprising control means for controlling to perform. 6. A mobile communication / positioning system for communicating between a mobile terminal and a base station with the aid of a satellite channel using a satellite, wherein the base station measures the electric field strength of the radio wave emitted from the mobile terminal. Electric field strength measuring means, positioning information calculating means for determining positioning information of the mobile terminal based on time taken until the radio wave emitted from the mobile terminal is received by the base station via the satellite, Whether to communicate between the mobile terminal and the base station via the satellite line based on the positioning information and the electric field strength, or to communicate between the mobile terminal and the base station without the satellite line. A mobile communication / positioning system, comprising: