JP5210746B2 - Satellite communication earth station system and satellite communication method - Google Patents

Description

  The present invention relates to a portable satellite communication earth station system and a satellite communication method.

The portable satellite communication earth station system is used as means for constructing a communication line from a disaster site using a satellite communication line when a disaster or the like occurs. Such a portable satellite communication earth station system is generally a communication system using a terminal called VSAT (Very Small Aperture Terminal).
In the conventional portable satellite communication earth station system, it was difficult to use it normally because it was a dedicated device for configuring the portable satellite communication earth station.

In addition to the portable satellite communication earth station, a satellite communication earth station used as a fixed station is used. A satellite communication earth station used as a fixed station is generally composed of an IDU (In-Door Unit), an ODU (Out-Door Unit), and an antenna installed in the building, and the required length between the IDU and the ODU.・ Connected with a connection cable having type and characteristics.
When a building with a fixed satellite communication earth station cannot be used due to an earthquake disaster in recent years, the facilities of the fixed satellite communication earth station can be used together because the building cannot be used. The problem of disappearing occurred.
However, since the conventional fixed satellite communication earth station is optimized for fixed installation and use, the installation location cannot be changed easily like the portable satellite communication earth station.
JP-A-5-122115

By the way, a portable satellite communication earth station is required to be easily established by connecting the IDU and ODU of the portable satellite communication earth station transported to the destination with a dedicated connection cable.
However, a fixed satellite communication earth station generally has a structure that is not suitable for use as a portable type, and the components of the fixed type satellite communication earth station are assembled at a place other than the normal installation location. Opening a satellite communications earth station has not been easy.
In addition, portable satellite communication earth stations, like fixed satellite communication earth stations, install aerials on the roof of a building and install in-home equipment in a communication machine room. Could not adapt to place and connect via cable.

Patent Document 1 discloses a technique in a satellite communication receiving station that detects an attenuation amount by a cable and changes output power to the cable based on the detected attenuation amount. According to this technology, it is necessary to mount a circuit for automatically setting the amplification degree according to the attenuation amount in both the IDU and the ODU, and the circuit scale of the IDU and the ODU increases. In addition, since the amplification level is automatically set, the signal that is actually output can be used as a reception system, but it can be applied to a transmission system in which the transmission output of radio waves is managed. It is difficult to determine whether the level is set correctly. Furthermore, it leads to an increase in power consumption with an increase in circuit scale, which becomes a problem when performing portable operation.
If the signal level between the IDU and ODU is set in advance and the cable with the same specifications as the cable used for the fixed type is selected as the portable connection cable, the weight of the cable becomes heavy and portable. There is a problem that the configuration is not suitable.
Thus, there is a problem that the problem cannot be solved even by combining conventional techniques.

  The present invention has been made to solve the above problems, and its object is to provide a portable satellite communication earth station system and satellite communication that can be applied to two or more connection forms having different cable lengths for connecting an in-home device and an outdoor device. It is to provide a method.

In order to solve the above problems, the present invention provides a satellite communication earth station system including a satellite communication earth station apparatus that is a transmitting / receiving station that communicates with a communication satellite, the satellite communication earth station apparatus comprising: a first apparatus; form the first device and set, and a second device opposite the first device, the first device can communicate via the first cable, via the second cable An amplifying device communicable with a second device , wherein the satellite communication earth station device amplifies the signal according to an attenuation amount of a signal communicated between the first device and the second device. The first device and the second device are connected by the first cable without adjusting any of the first device and the second device. when the, and can output radio waves of a desired transmit power, the first cable The first device and the second device to a length capable of maintaining communication performance stipulated in the satellite earth station device when connected via the first cable, the first cable The one end is connected to the first device, the other end is detachably connected to the amplifying device, and the amplifying device is compensated according to the loss characteristic of the second cable. the amount is adjustable, said and said compensation amount according to the second cable is adjusted in the compensation amount to the equivalent of the loss characteristics of the second cable, the other end of said first cable during operation said A signal that is connected to one end of the second cable, compensates the loss characteristic of the second cable according to the adjusted compensation amount, and is output from the first device or the second device. The second device is configured to relay and amplify When the signal is relay-amplified by the width device, the other end of the second cable is connected to communicate with the first device. When the signal is not relay-amplified by the amplifier, the amplifier device The other end of the removed first cable is connected, and the pair of the first device and the second device facing each other is a pair of the in-home device and the outdoor device facing each other in the satellite communication earth station device. This is a satellite communication earth station system.

In the present invention, the outdoor device outputs an abnormality detection signal indicating the abnormal state when the outdoor device detects an abnormal state in the generation of the transmission wave, and the indoor device outputs the abnormality detection signal. In response, a control signal for stopping transmission in the outdoor device is output,
The amplification device includes: a transmission signal amplification unit that amplifies a signal from the in-home device; a reception signal amplification unit that amplifies a signal from the outdoor device; the transmission signal amplification unit; the reception signal amplification unit; or the outdoor device A power supply unit that supplies power to the vehicle, and relays the abnormality detection signal output from the outdoor device during the operation to the indoor device, and relays the control signal output from the indoor device to the outdoor device And a monitoring control unit .

Further, the present invention is a satellite communication method in a satellite communication earth station system including a satellite communication earth station apparatus that is a transmission / reception station that communicates with a communication satellite , wherein the satellite communication earth station apparatus includes the first apparatus, The second device that forms a pair with the first device and faces the first device can communicate with the first device via the first cable, and the second device via the second cable. And an amplifying device capable of communicating with the second device, wherein the satellite communication earth station device outputs the signal according to an attenuation amount of a signal communicated between the first device and the second device. The first device and the second device are connected by the first cable without adjusting the amplification degree to be amplified by any of the first device and the second device. If it is a step that enables output radio waves of a desired transmit power, before The first cable, the length that can maintain the first device and the communication performance of the second device as defined in the satellite earth station device when connected via the first cable, the has is defined length of the first cable has one end connected to the first device, the steps of the other end is detachably connected to the amplifier, the amplifying device, the second The compensation amount according to the loss characteristic of the cable is adjustable, and the compensation amount according to the second cable is adjusted to a compensation amount that equalizes the loss characteristic of the second cable . are connected to the other end of the cable and one end of the second cable, to compensate for the loss characteristics of the second cable in accordance with the adjusted amount of compensation, the first device or the second Repeatedly amplifies signal output from device 2 A step of communicating with the first device via the second cable when the second device relays and amplifies the signal by the amplifying device; and the second device is the amplifying device. And a step of communicating with the first device by connecting the other end of the first cable removed from the amplifying device when the signal is not relay-amplified by the satellite. It is a communication method.

According to the present invention, in the satellite communication earth station system, the first device can be connected to the amplifying device via the first cable, and the amplifying device is connected to the second device via the second cable. In the satellite communication earth station system that can be connected, the first cable has a predetermined length, one end is connected to the first device, and the other end is detachably connected to the amplifying device. The amplifying device is connected to the other end of the first cable and one end of the second cable, respectively, during operation, compensates for the loss characteristic of the second cable, and is output from the first device or the second device. Relay amplification of the signal. The second device communicates with the first device by connecting the other end of the second cable when the amplifier device relays and amplifies the signal, and when the amplifier device does not relay and amplify the signal. The other end of the first cable removed from the amplifying device is connected. The pair of the first device and the second device facing each other is a pair of the in-home device and the outdoor device facing each other in the satellite communication earth station device.
Thereby, even in the operation that cannot be connected only by the first cable, the satellite communication earth station system can be configured by using the second cable together. In addition, it is possible to compensate for the attenuation and the change in frequency characteristics that occur in the signal transmitted and received by the second cable by the amplifying apparatus. By combining the characteristics of the second cable and the characteristics of the amplifying device in advance, the influence of the second cable can be reduced. Therefore, as a method for establishing a portable satellite communication earth station, not only can a portable station be established by connecting a cable in the same way as a conventional portable satellite communication earth station, but it can be relayed in normal times. It can be used as a fixed station via an amplification device. That is, it is possible to easily establish a portable satellite communication earth station by opening a satellite communication earth station as a fixed station at normal times and taking out devices used in the fixed station.

According to the present invention, in the above invention, the amplification device includes a transmission signal amplification unit that amplifies the signal from the in-home device, a reception signal amplification unit that amplifies the signal from the outdoor device, a transmission signal amplification unit, and a reception And a power supply unit that supplies power to the signal amplification unit or the outdoor device, and the transmission signal amplification unit and the reception signal amplification unit include at least one of them.
Thus, the transmission signal amplification unit and the reception signal amplification unit can be integrated or separated. In addition, since the power supply can be stabilized by the power supply unit, characteristic deterioration due to power supply noise can be prevented. Necessary amplification and compensation can be appropriately performed, and various installation conditions can be dealt with.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram illustrating a satellite communication earth station system 100 and a terminal device 300 connected to the satellite communication earth station system 100 according to the present embodiment.

The satellite communication earth station system 100 includes an IDU (In-Door Unit) 10, an ODU (Out-Door Unit) 20, and a cable 40.
The IDU 10 in the satellite communication earth station system 100 is a device that includes a modem unit (hereinafter referred to as “modem part”) and connects various terminals to the satellite communication earth station system 100. The IDU 10 multiplexes information from the connected terminal device 300, modulates the information into a signal that can be transmitted to the satellite, and transmits the signal. The terminal device 300 connected to the IDU 10 includes an analog telephone 310, a facsimile (FAX) 320, a data terminal (personal computer) 330, and the like. An analog signal input from the analog telephone 310, the facsimile 320, or the like is converted into a digital signal by an input / output processing unit provided in the IDU 10, and multiplexed with the digital signal input from the data terminal 330. Modulated. The modulated signal modulated by the modem unit is frequency-converted into an IF (Inter-frequency) signal by an IF (Inter-frequency) unit. This IF signal is a signal output to the connection cable 40 connected to the IDU 10. In the IDU 10, the signal input from the connection cable 40 is converted into a modulated signal demodulated by the modem unit by the IF unit. The modulated signal is demodulated by the modem unit and input to the input / output processing unit. The input signal is separated by the input / output processing unit, is output to the data terminal 330 as a digital signal, is further converted to an analog signal, and is output to the analog telephone 310 or the facsimile 320. When the IDU 10 detects that an abnormality detection signal indicating an abnormal state detected by the connected ODU 20 is input, the IDU 10 transmits a control signal instructing the ODU 20 to stop radio wave transmission.

  The ODU 20 performs frequency conversion from an IF signal (1 GHz (gigahertz) band) input from a connected cable to a satellite frequency (14 GHz (gigahertz) band). The ODU 20 amplifies the frequency-converted signal, and transmits a radio wave via an equipped antenna. The ODU 20 converts the radio wave received by the antenna into an electrical signal and outputs it to a connected cable. The ODU 20 performs frequency conversion using an internal PLL (Phase-locked loop) circuit. The ODU 20 detects an abnormal state (unlocked) of the local oscillation frequency (local) signal output from the PLL circuit, and outputs an abnormal detection signal (unlocked abnormal signal). Further, when it is detected that a control signal instructing to stop the transmission of radio waves input from the IDU 10 is input, the transmission of radio waves is stopped. The control signal transmitted from the IDU 10 to the ODU 20 and the abnormality detection signal transmitted from the ODU 20 to the IDU 10 are superimposed on the coaxial cable included in the cable 40 or a signal cable other than the coaxial cable included in the cable 40 is used. It is communicated by using.

Connection in the satellite communication earth station system 100 will be described.
The terminal device 300 is connected to the IDU 10 by respective cables, and the connected terminal device 300 communicates via a satellite communication line. A cable 40 is connected to the IDU 10, and a signal communicated bidirectionally by a satellite communication line is transmitted. The ODU 20 is connected to the other end of the cable 40, and the ODU 20 converts a signal input from the IDU 10 into a radio signal, and transmits the radio signal to the satellite via the antenna line included in the ODU 20. Further, the ODU 20 receives a signal transmitted from the satellite, converts it into an electric signal, and inputs it to the IDU 10 via the cable 40. IDU10 transmits the input signal to the terminal device 300 connected with each cable.

FIG. 2 is a schematic block diagram showing the configuration shown in FIG. Hereinafter, the same components as those in FIG. 1 are denoted by the same reference numerals, and different components will be described.
In this figure, a form in which the IDU 10 and the ODU 20 are connected by a cable 40 is shown. The connection of the terminal device 300 with the analog telephone 310, the facsimile 320, and the data terminal 330 is omitted.

A configuration when used with a fixed station will be described with reference to the drawings.
FIG. 3 is a configuration diagram showing a configuration when used as a fixed station. FIG. 4 is a schematic block diagram showing a configuration when used as a fixed station.
The satellite communication earth station system 200 shown in these drawings further includes an EQA 30 and a cable 50 in addition to the satellite communication earth station system 100 shown in FIGS.
The satellite communication earth station system 200 includes an IDU (In-Door Unit) 10, an ODU (Out-Door Unit) 20, an EQA (amplifier) 30, a cable 40, and a cable 50. The same components as those in the satellite communication earth station system 100 are denoted by the same reference numerals as those in FIG. 1, and the EQA 30 having a different configuration will be described below.

  The EQA 30 in the satellite communication earth station system 200 is a compensation amplifier that compensates for the characteristics of the cable 50. The EQA 30 compensates for signal attenuation that does not depend on the frequency characteristics, and attenuation due to frequency-dependent loss in which the loss amount increases in a higher frequency band depending on the frequency characteristics of the cable 50. The signal output to the radio link to the satellite is amplified before being input to the cable 50. On the other hand, the signal received from the satellite is converted by the ODU 20, input to the EQA 30 via the cable 50, amplified by the EQA 30, and input to the IDU 10 via the cable 40.

FIG. 5 is a block diagram showing the EQA 30 in the satellite communication earth station system 200. The EQA 30 in the satellite communication earth station system 200 includes a TXEQ 31, an RXEQ 32, a monitoring control unit 33, and a power supply unit 34.
In the EQA 30, TXEQ 31 is a line characteristic equivalent circuit that amplifies and compensates for the characteristic of the cable 50 in advance. The signal input from the connected cable 40 is amplified and output to the cable 50. RXEQ 32 is a line characteristic equivalent circuit that receives, amplifies, and compensates for a signal degraded by the characteristics of the cable 50. The signal input from the connected cable 50 is amplified and output to the cable 40. The monitoring control unit 33 receives an abnormality detection signal (unlocked abnormality signal) for notifying the abnormal state detected by the ODU 20 from the ODU 20, and relays the notification of the abnormal state to the IDU 10. Further, when the monitoring control unit 33 detects a control signal for stopping radio wave transmission from the IDU 10, it sends a control signal for instructing the ODU 20 to stop radio wave transmission. The power supply unit 34 is supplied with power from the IDU 10 via the cable 40 connected to the IDU 10. Alternatively, a prepared power source is connected to the power input terminal of the IDU 10 to share power. The power supply unit 34 converts the input power and supplies it to the ODU 20 via the TXEQ 31, RXEQ 32, the monitoring control unit 33, and the cable 50 that constitute the EQA 30.

The cable 40 is connected to the IDU 10 to which the terminal device 300 is connected in the satellite communication earth station system 200. An EQA 30 is connected to the other end of the cable 40, and an IF signal input from the IDU 10 is amplified and output. The ODU 20 is connected to the EQA 30 via the cable 50, and a signal equivalently amplified by the EQA 30 is attenuated by a loss due to the characteristics of the cable 50 and input to the ODU 20.
Further, the EQA 30 is connected to the ODU 20 via the cable 50, and the IF signal output from the ODU 20 is attenuated by the loss due to the characteristics of the cable 50 and is input to the EQA 30. The EQA 30 equivalently amplifies the input signal and outputs it as an IF signal. The IDA 10 is connected to the EQA 30 via the cable 40, and the output IF signal is input to the IDU 10. The IDU 10 transmits the input IF signal to the connected terminal device 300.
The EQA 30 superimposes the control signal transmitted from the IDU 10 to the ODU 20 via the EQA 30 and the abnormality detection signal transmitted from the ODU 20 to the IDU 10 via the EQA 30 on the coaxial cable included in the cable 40 and the cable 50. Or by using a signal cable other than the coaxial cable included in the cable 40 and the cable 50.

  The satellite communication earth station system 200 is configured to be used as a fixed station. For example, a case where the ODU 20 is provided on the roof of a building and the IDU 10 and the EQA 30 are provided in a communication machine room or the like can be used as a model. In this model, the cable 40 connecting the IDU 10 and the EQA 30 can be connected with the standard cable specification of the cable 40. On the other hand, the cable 50 that connects the EQA 30 and the ODU 20 is determined based on the layout of the device in the building and the condition of the cable route. Further, if the device is relocated, the cable length is changed. For this reason, the cable compensation characteristic of the cable 50 of the EQA 30 can be adjusted by setting. That is, the signal amplification factor for compensating for the loss caused by the cable 50 and the adjustment such as the smoothing of the frequency characteristic can be adjusted by changing the setting or changing the setting value.

  As described above, the characteristics of the cable 50 cannot be standardized and cannot be handled by the portable satellite communication earth station system in which the IDU and ODU characteristics are fixed. By using the EQA 30 shown in the present embodiment, it is possible to operate as if the IDU 10 and the ODU 20 are connected by equalizing the characteristics of the cable 50. That is, by applying the IDU 10 and ODU 20 and the cable 40 used in the satellite communication earth station system 200 to the form of the satellite communication earth station system 100 in which the IDU 10 and ODU 20 are directly connected by the cable 40, the satellite communication earth station system is used. 100 can be configured. That is, this satellite communication earth station system 100 is the same as the conventional portable satellite communication earth station system, and can be easily switched between a fixed station operation and a portable station operation. A system 200 can be provided.

  The present invention is not limited to the above embodiments, and can be modified without departing from the spirit of the present invention. There are no particular limitations on the number of configurations and connection forms in the satellite communication systems 100 and 200 of the present invention.

Moreover, although EQA30 demonstrated as connecting with IDU10 using the communication cable 40 of the satellite communication earth station system 100 which performs portable operation, EQA30 is good also as connecting with ODU20 using the communication cable 40. . At that time, the cable between the IDU 10 and the EQA 30 becomes the cable 50, and the EQA 30 is equivalent to the cable 50. Moreover, although EQA30 demonstrated as what has both TXEQ31 and RXEQ32, it is good also as providing at least any one. Moreover, it is good also as arrange | positioning combining EQA30-1 provided with TXEQ31, and EQA30-2 provided with RXEQ32. The EQA30-1 with TXEQ31 is placed on the IDU10 side, the EQA30-2 with RXEQ32 is placed on the ODU20 side, EQA30-1 and EQA30-2 perform the equivalent amplification process first, and the signal is attenuated by the cable characteristics It can also be made.
It is also possible to employ a configuration in which a plurality of EQAs 30 are connected in multiple stages.
Further, the monitoring control unit 33 may detect an abnormal state of each signal input from the cable 40 and the cable 50 and output an alarm signal. When it is determined that the detected state is an abnormal state, the monitoring control unit 33 may transmit a control signal instructing the ODU 20 to stop transmitting radio waves.

  Further, even in operation at a fixed station that cannot be connected only by the cable 40, the use of the cable 50 together can ease restrictions on the installation of the apparatus. Further, the EQA 30 can compensate for attenuation and a change in frequency characteristics that occur in a signal transmitted and received by the cable 50. By combining the characteristics of the cable 50 and the characteristics of the EQA 30 in advance, the influence of the cable 50 can be reduced. Therefore, the opening method as the portable satellite communication earth station system 100 can not only open the portable station by connecting the same cable as the conventional opening method of the portable satellite communication earth station, but can be fixed in normal times. The satellite communication earth station system 200 used as a station can be configured. In other words, a satellite communication earth station 200 of the satellite communication earth station system 200 that is used as a fixed station at normal times is opened, and some devices (IDU 10, ODU 20 and cable 40) used in the satellite communication earth station system 200 are taken out and portable. The satellite communication earth station of the satellite communication earth station system 100 can be easily established.

  The TXEQ 31 and the RXEQ 32 can be integrally configured as described above. Alternatively, TXEQ 31 and RXEQ 32 can be configured separately. In addition, since the power supply can be stabilized by the power supply unit 34, characteristic deterioration due to power supply noise can be prevented. The EQA 30 can appropriately perform necessary amplification and compensation, and can cope with various installation conditions.

  The in-home device in the present invention corresponds to the IDU 10. Moreover, the outdoor apparatus in this invention is corresponded to ODU20. The first cable in the present invention corresponds to the cable 40. The satellite communication earth station system in the present invention corresponds to the satellite communication earth station system 100 and the satellite communication earth station system 200. The second cable in the present invention corresponds to the cable 50. In addition, the amplification device according to the present invention corresponds to EQA 30, EQA 30-1, and EQA 30-2. Further, the transmission signal amplifying unit for amplifying the signal from the in-home device according to the present invention corresponds to the TXEQ 31. In addition, the reception signal amplification unit that amplifies the signal from the outdoor device according to the present invention corresponds to RXEQ32. The power supply unit in the present invention corresponds to the power supply unit 34. The monitoring control unit in the present invention corresponds to the monitoring control unit 33.

It is a block diagram (the 1) which shows the satellite communication earth station system by this embodiment. It is a block diagram (the 1) which shows the satellite communication earth station system in the embodiment. It is a block diagram (the 2) which shows the satellite communication earth station system by this embodiment. It is a block diagram (the 2) which shows the satellite communication earth station system in the embodiment. It is a block diagram which shows EQA30 (amplifier) in the same embodiment.

Explanation of symbols

200 Satellite Communication Earth Station System 10 IDU
20 ODU
30 EQA
40, 50 Cable 300 Terminal device 310 Analog phone 320 Facsimile 330 Data terminal

Claims (3)

A satellite communication earth station system including a satellite communication earth station device which is a transmitting / receiving station communicating with a communication satellite ,
The satellite communication earth station device
A first device;
A second device forming a pair with the first device and facing the first device;
The first device is capable of communicating via the first cable, amplifier and is capable of communicating with the second device via a second cable
With
The satellite communication earth station device
Any one of the first device and the second device has an amplification factor for amplifying the signal in accordance with an attenuation amount of a signal communicated between the first device and the second device. Without adjustment, and when the first device and the second device are connected by the first cable, it is possible to output a radio wave of a desired transmission power,
The first cable has a length capable of maintaining the communication performance determined for the satellite communication earth station device when the first device and the second device are connected via the first cable. The length of the first cable is determined, one end is connected to the first device, the other end is detachably connected to the amplification device,
The amplification device includes:
The compensation amount according to the loss characteristic of the second cable is adjustable, and the compensation amount according to the second cable is adjusted to a compensation amount that equalizes the loss characteristic of the second cable, are respectively connected to the one end of the said other end of the first cable second cable during operation, to compensate for the loss characteristics of the second cable in accordance with the adjusted amount of compensation, the first Relay amplification of the signal output from the device or the second device,
The second device includes:
When the signal is relay-amplified by the amplification device, the other end of the second cable is connected to communicate with the first device, and when the signal is not relay-amplified by the amplification device, the amplification device The other end of the first cable removed from is connected,
The pair of the first device and the second device facing each other is a pair of the in-home device and the outdoor device facing each other in the satellite communication earth station device. The outdoor device is
When detecting an abnormal state in the generation of the transmission wave, an abnormality detection signal indicating the abnormal state is output,
The indoor device is
In response to the abnormality detection signal, output a control signal to stop transmission in the outdoor device,
The amplification device includes:
A transmission signal amplifier for amplifying a signal from the in-home device;
A reception signal amplifier for amplifying a signal from the outdoor device;
A power supply unit for supplying power to the transmission signal amplification unit, the reception signal amplification unit or the outdoor device;
The abnormality detection signal output from the outdoor device during the operation is relayed to the indoor device, and the monitoring control unit relays the control signal output from the indoor device to the outdoor device. The satellite communication earth station system according to claim 1. A satellite communication method in a satellite communication earth station system including a satellite communication earth station device which is a transmission / reception station communicating with a communication satellite ,
The satellite communication earth station device is paired with a first device and the first device, the second device facing the first device, and the first device receiving the first cable. And an amplifying device capable of communicating with the second device via a second cable,
The satellite communication earth station device has an amplification factor for amplifying the signal in accordance with an attenuation amount of a signal communicated between the first device and the second device. It is possible to output a radio wave having a desired transmission power when the first device and the second device are connected by the first cable without adjusting any of the devices. Process,
The first cable has a length capable of maintaining the communication performance determined for the satellite communication earth station device when the first device and the second device are connected via the first cable. The length of the first cable is determined, one end is connected to the first device, and the other end is detachably connected to the amplifying device;
The amplifying apparatus can adjust a compensation amount according to the loss characteristic of the second cable, and the compensation amount according to the second cable is a compensation amount that equalizes the loss characteristic of the second cable. The process to be adjusted;
The amplifying device, is connected to the other end of said first cable during operation one end of the second cable, and in response to said adjusted compensation amount to compensate for the loss characteristics of the second cable a step of repeating and amplifying a signal outputted from said first device or said second device,
When the second device relays and amplifies the signal by the amplifying device, communicating with the first device via the second cable; and
Communicating with the first device by connecting the other end of the first cable removed from the amplification device when the second device does not relay and amplify the signal by the amplification device; ,
A satellite communication method comprising:

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