JP2001177461A - Communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a simple communication system with a medium scale by using a few ground base stations. SOLUTION: This invention provides the communication system where platforms resident in a stratosphere and user stations on ground are connected for communication. Each platform 1 collects signals received from user stations 4 in each coverage 2, transmits the collected signal to a stationary satellite 3, the stationary satellite 3 collects the signals from each platform transmits them to one ground base station 5 and the ground base station distributes the signals from the stationary satellite 3 to user stations connected to the base station.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system for performing communication by connecting a platform stopped in a stratosphere and a user station on the ground, and more particularly to a medium-sized simple communication system.

[0002]

2. Description of the Related Art Conventionally, there are the following documents relating to a communication system for performing communication by connecting a platform stopped in a stratosphere and a user station on the ground. Kingo Takasawa and Hirotaka Mori in “Document 1”: “Stratospheric Wireless Relay System”, IEICE, Vol. 73, No. 1, pp.69-71 (1990.1)
There is a proposal to expand the mobile communication service area as a wireless relay station by holding unmanned aircraft at 20 km. He is also working on research on energy sources for unmanned aerial vehicles. Reference 2, Yoshiyuki Fujino: “Microwave-Driven Airship and Prospects of Utilization Technology”, IEICE Journal, Vol. 80, No.
5, pp. In 457-460 (1997.5), there is an experimental report on an unmanned airship that took up microwave power transmission as an energy source for an unmanned aerial vehicle, which is a research subject in Reference 1. Reference 3,
“Communication System Using Stratospheric Airship”, Low Earth Orbit Satellite Communication System, IEICE, pp. 7 (1999.6.20)
As an introduction of a communication system using a stratospheric airship, what has been proposed at the present time is a fixed communication system similar to a terrestrial microwave line. A communication system consisting of multiple large airships parked at an altitude of about 20 km.
Each large airship and a fixed user station in its service area have an uplink and a downlink. Reference 4, Japanese Patent Laid-Open No. 10-30
In the publication 7179, a repeater is provided for each platform stopped in the stratosphere, and a ground base station is provided for each platform.

[0003]

Conventionally, there is a document related to this type of communication system, which is described above. In recent years, in particular, there has been a remarkable increase in the number of mobile user stations, while service areas of existing systems are unevenly distributed in and around cities. In addition, there is a need for a medium-sized simple communication system to supplement an existing communication system or as a social infrastructure, even as an alternative to a fixed communication line in a communication infrastructure undeveloped area, or as a strong communication system in the event of a disaster. To meet these needs, geostationary satellite communication systems have a drawback in the magnitude of radio wave propagation loss due to the physical distance between the geostationary satellite and the earth due to the advantage of space utilization. Looking at low-Earth-orbit satellite communication systems as non-geostationary satellite communication systems, continuous communication services require a large number of satellites, and medium-sized communication systems have difficulties in terms of their operation and equipment scale. There is.

[0004] The present invention has been made to solve the above-mentioned problems, and has as its object to obtain a simple, medium-scale communication system with as few terrestrial base stations as possible.

[0005]

In order to achieve the above object, a communication system according to claim 1 is a communication system that connects a platform stopped in a stratosphere and a user station on the ground to perform communication. Each platform bundles the signals received from the user stations within its coverage area and raises the signal to a geostationary satellite.The geostationary satellite bundles and transmits the signals from each platform to one ground base station, and the ground base station Characterized by having a configuration for distributing a signal from a geostationary satellite to user stations connected to the satellite.

[0006] A communication system according to claim 2 comprises:
A communication system that connects a platform stationed in the stratosphere and a user station on the ground to perform communication.One ground base station bundles signals from the user stations connected to the base station, raises the signal to a geostationary satellite, and transmits the signal to the geostationary satellite. The satellite distributes the signal to each platform, and each platform has a configuration for distributing the signal from the geostationary satellite to the user stations in the respective coverage.

Further, a communication system according to claim 3 comprises:
A user station performing high-speed transmission is partially accommodated in the coverage of the platform in the communication system according to claim 1, and communication between the user station performing high-speed transmission and the platform is performed by applying a pencil beam. It is characterized by having a configuration for performing.

The communication system according to claim 4 is
In the communication system according to claim 2, a user station performing high-speed transmission is partially accommodated within the coverage of the platform, and communication between the platform and the user station performing high-speed transmission is performed by applying a pencil beam. It is characterized by having a configuration for performing.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1. FIG. 1 is a schematic structural view showing Embodiments 1 and 2 of the present invention. Embodiment 1 of the present invention will be described with reference to FIG. In FIG. 1, reference numeral 1 denotes a stratospheric platform (a platform stopped in the stratosphere is referred to as a stratospheric platform, and when it is clear, it is simply referred to as a platform); 2 is a coverage of the stratospheric platform 1;
Is a geostationary satellite, 4 is a user station in the coverage 2 of the stratospheric platform 1, 5 is a terrestrial base station, and 8 is a communication network connected to the terrestrial base station 5.

Next, an operation example of the first embodiment will be described with reference to FIG. A communication system for performing communication by connecting a platform stopped in the stratosphere and a user station on the ground, wherein each platform 1 bundles a signal received from a user station 4 in each coverage 2 to form a geostationary satellite 3
The geostationary satellite 3 bundles and transmits signals from the platform to one terrestrial base station 5, and the terrestrial base station 5 distributes the signal from the geostationary satellite to user stations of the communication network 8 connected thereto. I do. The terrestrial base station 5 is provided with an exchange for distribution to user stations of a communication network 8 connected thereto. For example, if the communication network 8 is a public network or a dedicated line, a mobile user station within the coverage 2 of the platform 1 can access the user stations of these communication networks. Since the distance of the platform stopped in the stratosphere is about 20 km, the radio wave propagation loss is smaller than that of the geostationary satellite at an altitude of about 36000 km, and the terminal can be reduced in size and weight.

According to the first embodiment, each platform bundles the received signals from the user stations 4 in the respective coverages 2 and raises the signal to the geostationary satellite 3, and the geostationary satellite 3 is transmitted to one terrestrial base station 5. By bundling and transmitting signals from the platform, the number of ground base stations in the communication system can be reduced to one.

Embodiment 2 FIG. Embodiment 2 of the present invention will be described with reference to FIG. In the figure, 1 is a stratospheric platform, 2 is a coverage of the stratospheric platform 1, 3 is a geostationary satellite, 4 is a user station in the coverage 2 of the stratospheric platform 1, 5 is a terrestrial base station, and 8
Is a communication network connected to the ground base station 5.

Next, an operation example of the second embodiment will be described with reference to FIG. This is a communication system that performs communication by connecting a platform stopped in the stratosphere and a user station on the ground, and one ground base station 5 bundles signals from user stations of a communication network 8 connected to the ground base station 5 and The geostationary satellite 3 distributes this signal to each platform 1, and each platform 1 distributes the signal from the geostationary satellite 3 to the user stations 4 in the respective coverage 2. The geostationary satellite is provided with an exchange for distributing a signal from a ground base station to each platform.

According to the second embodiment, one terrestrial base station 5 bundles a signal from a user station of a communication network 8 connected thereto and sends the signal to the geostationary satellite 3. Since this signal is directly distributed to each other, there is no need for a line directly connecting each platform, which is simple.

Embodiment 3 FIG. 2 is a schematic configuration diagram showing Embodiments 3 and 4 of the present invention. In FIG. 2, 1
Is a stratospheric platform, 2 is a coverage of the stratospheric platform 1, 3 is a geostationary satellite, 4 is a user station in the coverage 2 of the stratospheric platform 1, 5 is a terrestrial base station, and 8 is a communication network connected to the terrestrial base station 5. . 6
Is a user station that performs high-speed transmission, and 7 is a pencil beam formed by the stratospheric platform to transmit signals to the user station that performs high-speed transmission.

Next, referring to FIG. 2, the third embodiment will be described.
An operation example will be described. This is a communication system that performs communication by connecting a platform parked in the stratosphere and a user station on the ground. In the third embodiment, a user station 6 that performs high-speed transmission is partially accommodated in each coverage of each platform. are doing. Each platform 1 forms a pencil beam 7 to enable communication to a high-speed user station 6 within a respective coverage 2. Each platform raises the signal received from the user station 6 performing high-speed transmission to a geostationary satellite, and the geostationary satellite 3 bundles and transmits the signal from the platform to one terrestrial base station 5, and the terrestrial base station 5 Distribute signals to connected user stations. An exchange for distributing signals to user stations connected to the ground base station 5 is installed in the ground base station 5. Here, the pencil beam 7 is formed by a phased array antenna.

According to the third embodiment, the first embodiment
The same effect as described above is obtained, and here, a user station for high-speed transmission is partially accommodated in the coverage of the platform, and communication between the high-speed user station and the platform is performed by applying a pencil beam. By doing
Processing corresponding to high-speed transmission becomes possible.

Embodiment 4 FIG. 2 is a schematic configuration diagram showing Embodiment 4 of the present invention. In FIG. 2, 1 is a stratospheric platform, 2 is a stratospheric platform 1
, 3 is a geostationary satellite, 4 is a user station in the coverage 2 of the stratospheric platform 1, 5 is a terrestrial base station, and 8 is a communication network connected to the terrestrial base station 5. Reference numeral 6 denotes a user station that performs high-speed transmission, and reference numeral 7 denotes a pencil beam formed by the stratospheric platform to transmit a signal to the user station 6 that performs high-speed transmission.

Next, referring to FIG. 2, the fourth embodiment will be described.
An operation example will be described. This is a communication system that performs communication by connecting a platform stopped in the stratosphere and a user station on the ground, and one ground base station 5 bundles signals from user stations of a communication network 8 connected to the ground base station 5 and The geostationary satellite 3 distributes this signal to each platform 1, and each platform 1 distributes the signal from the geostationary satellite 3 to the user stations 4 in the respective coverage 2. At this time, each platform 1 partially accommodates a user station 6 performing high-speed transmission in each coverage 2,
For communication between the platform 1 and the user station 6 that performs the high-speed transmission, a process corresponding to the high-speed transmission can be performed by applying a pencil beam.

According to the fourth embodiment, the second embodiment
The same effect as described above is obtained, and here, a high-speed user station that performs high-speed transmission is partially accommodated within the coverage of the platform, and communication between the high-speed user station and the platform is performed by applying a pencil beam. By doing so, processing corresponding to high-speed transmission becomes possible.

[0021]

As described above, according to the first aspect of the present invention, each platform bundles the signals received from the user stations in each coverage and sends the signals to the geostationary satellite.
The geosynchronous satellites can bundle the signals from the platform to one ground base station and transmit them, so that the number of ground base stations in the communication system can be reduced to one, and a medium-sized simple communication system can be obtained.

According to the second aspect of the present invention, one terrestrial base station bundles a signal from a user station connected thereto and sends the signal to a geostationary satellite, and the geostationary satellite distributes the signal to each platform. Furthermore, since each platform distributes signals from geostationary satellites to user stations in each coverage, there is no need for a line directly connecting each platform, and there are few ground base stations and a simple, medium-scale communication system. Obtainable.

According to the third aspect of the present invention, in addition to the effects of the communication system according to the first aspect, a user station that performs high-speed transmission is partially accommodated in the coverage of the stratospheric platform, and By performing communication by applying a pencil beam to communication with the user station performing the high-speed transmission, processing corresponding to the high-speed transmission can be performed.

According to the fourth aspect of the present invention, in addition to the effects of the communication system of the second aspect, a user station for high-speed transmission is partially accommodated in the coverage of the stratospheric platform, and By performing communication by applying a pencil beam to communication with the user station performing the high-speed transmission, processing corresponding to the high-speed transmission can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing Embodiments 1 and 2 of the present invention.

FIG. 2 is a schematic configuration diagram showing Embodiments 3 and 4 of the present invention.

[Explanation of symbols]

1 stratospheric platform (referred to as platform for short), 2 platform coverage, 3 geostationary satellites, 4 user stations within coverage, 5 ground base station, 6 user station for high-speed transmission, 7
Pencil beam, 8 A communication network connected to the ground base station 5.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Rumiko Yonezawa 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term in Mitsubishi Electric Corporation (reference) 5K067 AA42 BB02 EE02 EE07 EE10 EE16 GG01 5K072 AA19 BB22 BB25 DD02 DD13 DD16 DD17 DD20 EE02

Claims (4)

[Claims] 1. A communication system for performing communication by connecting a platform stopped in a stratosphere and a user station on the ground, wherein each platform bundles a signal received from a user station in each coverage and sends a signal to a geostationary satellite. , The geostationary satellite bundles and transmits signals from each platform to one terrestrial base station, and the terrestrial base station has a configuration to distribute signals from the geostationary satellite to user stations connected thereto. Communications system. 2. A communication system for performing communication by connecting a platform stopped in the stratosphere and a user station on the ground, wherein one ground base station bundles signals from the user stations connected to the base station to form a geostationary satellite. A communication system having a configuration for raising a signal, wherein the geosynchronous satellite distributes the signal to each platform, and wherein each platform distributes the signal from the geosynchronous satellite to user stations within a respective coverage. 3. A configuration in which a user station performing high-speed transmission is partially accommodated in the coverage of the platform, and communication between the user station performing high-speed transmission and the platform is performed by applying a pencil beam. 2. The communication system according to claim 1, comprising: 4. A configuration in which a user station performing high-speed transmission is partially accommodated in the coverage of the platform, and communication between the platform and the user station performing high-speed transmission is performed by applying a pencil beam. The communication system according to claim 2, comprising: