JP2009278359A - Satellite communication system, sng base station, and sng mobile station - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a BOD control of a data communication line without adding an modulating and demodulating apparatus for CSC control line to an SNG mobile station. <P>SOLUTION: In a satellite communication system, an SNG base station 1 and an SNG mobile station 2 are always connected by a PAMA line for audio communication. At a transmitter side, a CSC control signal from a DAMA control apparatus 11 provided in the SNG base station 1 is multiplexed with an audio signal by a multiplexer 15, and communication is carried out from an audio/CSC common modulator 14 to the SNG mobile station 2 via the PAMA line. At a reception side, a received signal is demultiplexed into the CSC control signal and the audio signal by a multiplexing/demultiplexing apparatus 27 to carry out BOD control which dynamically extends or reduces the used band by the CSC control signal. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is a satellite communication system in which an SNG (Satellite News Gathering) base station and an SNG in-vehicle station are always connected by a PAMA (Pre Assign Multiple Access) line for voice communication, and this satellite communication system is used. SNG base station and SNG in-vehicle station.

  A SNG (Satellite News Gathering) system for transmitting news material using satellite communication is used for news coverage of incidents and accidents. This SNG system encodes and modulates a video / audio signal taken from an incident / accident site at an SNG in-vehicle station, which is a news site, and launches it toward a communication satellite using a transmitter. It is a news material transmission system that receives, demodulates and decodes, and can transmit news material from anywhere where the communication satellite can be seen. In addition, voice communication for communicating between the SNG in-vehicle station and the SNG base station at the interview site is also performed using satellite communication.

In satellite communications, the frequency band that can be used is limited, so effective use of the frequency band is extremely important. As part of this effective use, in the SNG system, for data communication lines, the use bandwidth of the satellite line is not fixed, but the bandwidth that is available at the time of the line connection request is flexibly allocated. "Connection (Demand Assign Multiple Access: DAMA)" method is employed.
In addition, a “Pre Assign Multiple Access (PAMA)” system in which a frequency to be used is assigned in advance in part of a voice call line is also employed. In a general SNG system, these DAMA method and PAMA method are used in combination.

  Also, in information communication using communication satellites that have been increasing in recent years, by performing “BOD (Bandwidth On Demand) control” that dynamically expands / contracts the bandwidth to be used in accordance with the increase or decrease of the traffic volume, We plan effective use. In BOD control, it is necessary to make a communication speed change request to the DAMA master station while performing data communication. Therefore, in general, a common signal control channel (CSC) is provided separately from the data communication channel, A method of multiplexing a CSC (Common Signaling Channel: CSC) control signal on a data communication line is employed. The CSC control line is assigned a fixed frequency. (For example, see Patent Document 1)

JP 11-331056 A

Since the conventional satellite communication system is configured as described above, in order to realize the BOD control, a modulation / demodulation device for the CSC control line must be separately installed in the SNG base station and the SNG in-vehicle station. The interior of the in-vehicle station does not have enough space, and it is often difficult to add one modulation / demodulation device.
In addition, when the CSC control signal is multiplexed on the data communication line, it is not necessary to add a modulation / demodulation device. However, since the data communication line bandwidth is shared by the data and the CSC control signal, the data communication throughput is reduced. Problem arises.

  The present invention has been made in order to solve the above-described problems, and by utilizing a PAMA line generally used for voice communication between the SNG base station and the SNG in-vehicle station, the SNG in-vehicle station To provide a satellite communication system, an SNG base station, and an SNG in-vehicle station that realize BOD control of a data communication line without adding a modulation / demodulation device for a CSC control line to the network and without reducing the data communication throughput. It is intended.

  The satellite communication system according to the present invention is a satellite communication system in which a SNG base station and an SNG in-vehicle station are always connected by a PAMA line for voice communication, and a CSC from a DAMA controller provided in the SNG base station. The control signal is multiplexed with the audio signal and communicated to the SNG in-vehicle station via the PAMA line, thereby performing BOD control for dynamically expanding / contracting the use band.

  The SNG base station according to the present invention is a bandwidth management / control of multiple access on demand (DAMA) in an SNG base station of a satellite communication system that is always connected to a SNG in-vehicle station via a PAMA line for voice communication. A DAMA control device that performs the multiplexing, a multiplexing device that multiplexes the CSC control signal from the DAMA control device and the audio signal from the microphone, and a voice / CSC shared modulation device that modulates the signal multiplexed by the multiplexing device, And means for transmitting the signal modulated by the voice / CSC shared modulation apparatus to the SNG in-vehicle station through the PAMA line.

  The SNG in-vehicle station according to the present invention is an SNG in-vehicle station of a satellite communication system that is always connected to a SNG base station through a PAMA line for voice communication. A voice / CSC shared modulation / demodulation device that demodulates a CSC multiplexed signal, and a multiplexing / demultiplexing device that separates a signal demodulated by the voice / CSC shared modulation / demodulation device into a CSC control signal and a voice signal. BOD control for dynamically expanding / contracting the use band is performed by the separated CSC control signal.

  In the present invention, since the CSC control signal from the DAMA control device is multiplexed with the voice signal and communicated to the SNG in-vehicle station via the PAMA line, the modulation / demodulation device for the CSC control line is not added to the SNG in-vehicle station. In addition, it is possible to perform BOD control that dynamically expands / contracts the used bandwidth without reducing the throughput of data communication.

Embodiment 1 FIG.
Hereinafter, the satellite communication system in Embodiment 1 of this invention is demonstrated based on drawing. FIG. 1 is a block diagram showing a satellite communication system according to Embodiment 1 of the present invention, FIG. 2 is a diagram showing frequency band allocation in Embodiment 1 of the present invention, and FIG. 3 is a voice in Embodiment 1 of the present invention. FIG. 4 is a diagram showing a signal path, FIG. 4 is a diagram showing a CSC control signal path in Embodiment 1 of the present invention, and FIG. 5 is a diagram showing a data communication signal path in Embodiment 1 of the present invention.

In the configuration diagram of FIG. 1, the satellite communication system of the present invention comprises an SNG base station 1, an SNG onboard station 2, a server station 3, and a communication satellite 4 that connects these stations by satellite communication.
The SNG base station 1 is provided with a DAMA control device 11 that performs DAMA bandwidth management and control, and a microphone 12 and a speaker 13 for calling with the SNG in-vehicle station 2. As a transmission device, a voice / CSC shared modulation device 14 having a modulation function shared by both a voice communication line and a DAMA CSC control line is installed, and the outputs of the DAMA control device 11 and the microphone 12 are multiplexed. Connection is made via the device 15. The multiplexed signal modulated by the voice / CSC shared modulator 14 is transmitted to the SNG in-vehicle station 2 by a transmission means (not shown) using a PAMA line.

As the receiving device of the SNG base station 1, the same number of voice / CSC shared demodulators 16a and 16b having a demodulation function shared by both the voice communication line and the DAMA CSC control line are installed as many as the number of DAMA slave stations. The output is connected to the DAMA control device 11 and the speaker 13 via separation devices 17a and 17b for separating the CSC control signal and the audio signal, respectively.
The SNG base station 1 is connected to a video / audio processor 181 with a TV encoder 182 and a TV modulator 183 for TV wave transmission, and with a TV demodulator 184, TV decoder for TV wave reception. A device 185 is connected to the video / audio processing device 181.

  The SNG in-vehicle station 2 is provided with a microphone 21 and a speaker 22 for calling with the SNG base station 1 and an information terminal 23 such as a personal computer for data communication. As a transmitter / receiver, a voice / CSC shared modem 25 having a modulation function and a demodulation function shared by both a voice communication line and a DAMA CSC control line, and a data communication modem 25 used for a data communication line are installed. Has been. The data communication modem 25 is connected to the information terminal 23 via the data transmission adapter 26. The voice / CSC shared modulation / demodulation device 24 is connected to the microphone 21, the speaker 22 and the data transmission adapter 26 via a multiplexing / demultiplexing device 27 which multiplexes and separates the CSC control signal and the voice signal. Similarly to the SNG base station 1, a TV encoding device 282 and a TV modulation device 283 are connected to the video / audio processing device 281 for transmission of TV waves, and a TV demodulation device 284, TV for reception of TV waves. A decoding device 285 is connected to the video / audio processing device 281.

  The server station 3 basically has the same configuration as the SNG in-vehicle station 2, and a server device 33 is installed in place of the microphone 31 and the speaker 32 for calling and the information terminal 23 that performs data communication. As a transmission / reception device, there are installed a voice / CSC shared modem 34 having a modulation function and a demodulation function shared by both a voice communication line and a DAMA CSC control line, and a data communication modem 35 used for a data communication line. Has been. The data communication modem 35 is connected to the server device 33 via the data transmission adapter 36. The voice / CSC shared modem 34 is connected to the microphone 31, the speaker 32, and the data transmission adapter 36 via the multiplexer / demultiplexer 37.

  The communication satellite 4 connects satellite communication between the SNG base station 1 and the SNG in-vehicle station 2, between the SNG base station 1 and the SNG in-vehicle station 2, and between the SNG in-vehicle station 2 and the server station 3. It has been launched above 10km above the ground.

  FIG. 2 is a diagram showing an example of frequency band allocation in the SNG system. In FIG. 2, the usable frequency band is divided into a PAMA line (voice / CSC), a DAMA line (data), and a TV wave. The frequency for the PAMA line (voice / CSC) is composed of an SNG base station transmission line frequency, an SNG on-vehicle station transmission line frequency, and a server station transmission line frequency. The frequency of the PAMA line is always fixed, but the frequency for the DAMA line differs each time depending on the assignment from the DAMA master station and BOD control.

Next, the operation of the satellite communication system of FIG. 1 will be described. First, the operation during voice communication will be described.
FIG. 3 shows only the signal path of the voice communication line in the configuration diagram of FIG. Since the voice communication line is a PAMA line connection, the satellite line between the SNG in-vehicle station 2 and the server station 3 is connected by outputting a modulated wave from the voice / CSC shared modulator 14 of the SNG base station 1. The voice input from the microphone 12 of the SNG base station 1 is multiplexed with the CSC control signal output from the DAMA controller 11 by the multiplexer 15. Specifically, the PAMA line, which conventionally used only the communication of the voice signal (32 kbps), communicates by multiplexing the voice signal (16 kbps) and further the CSC control signal (16 kbps). The multiplexed signal is modulated by the voice / CSC shared modulator 14 and transmitted from the antenna to the communication satellite 4. The frequency to be transmitted is fixed, and the transmission signal of the SNG base station 1 can be received by all the SNG in-vehicle stations 2.

  In the SNG in-vehicle station 2, the signal transmitted from the SNG base station 1 is received by the antenna through the satellite line of the communication satellite 4, demodulated by the voice / CSC shared modem unit 24, and sent to the multiplexing / demultiplexing unit 27. The multiplexer / demultiplexer 27 separates the received signal into an audio signal and a CSC control signal, and the audio signal is sent to the speaker 22 and output from the speaker 22 as audio. On the other hand, the CSC control signal is sent to the data transmission adapter 26.

On the contrary, the voice input from the microphone 21 of the SNG in-vehicle station 2 is multiplexed with the CSC control signal output from the data transmission adapter 26 by the multiplexer / demultiplexer 27 and modulated by the voice / CSC shared modem 24. It is transmitted from the antenna to the satellite line toward the communication satellite 4. In order to avoid a double carrier by a plurality of SNG in-vehicle stations 2, a frequency to be transmitted is used for each SNG in-vehicle station.
In the SNG base station 1, the signal transmitted from the SNG in-vehicle station 2 is received by the antenna through the satellite line by the communication satellite 4, demodulated by the voice / CSC shared demodulator 16a, and sent to the separator 17a. The separation device 17a separates the received signal into an audio signal and a CSC control signal, sends the audio signal to the speaker 13, and is output from the speaker 13 as audio. On the other hand, the CSC control signal is sent to the DAMA controller 11.
The CSC control signal separated by the multiplexer / demultiplexer 27 and the CSC control signal separated by the separator 17a are used for line connection requests, BOD control described later, and the like.

Next, the operation at the time of data communication line connection will be described.
4 shows only the signal path of the CSC control line in the configuration diagram of FIG. Since the data communication line is DAMA connection, the DAMA controller 11 assigns frequencies. As an example, when data communication from the information terminal 23 of the SNG in-vehicle station 2 to the server device 33 of the server station 3 is started, the data transmission adapter 26 connects the DAMA control device 11 to the data communication line with the server station 3. For this purpose, the line connection request signal is output as a CSC control signal. The output CSC control signal of the line connection request signal is transmitted to the multiplexing / demultiplexing device 27 and multiplexed with the voice signal. The multiplexed signal is modulated by the voice / CSC shared modulation / demodulation device 24 and transmitted to the SNG base station 1 by a transmission means (not shown) through the PAMA line in the same manner as during voice communication.

  The SNG base station 1 receives the signal transmitted from the SNG in-vehicle station 2 by the antenna and demodulates it by the voice / CSC shared demodulator 16a. Further, the demodulated signal is separated into a voice signal and a CSC control signal by the separation device 17a, and the CSC control signal of the line connection request signal is transmitted to the DAMA control device 11. The DAMA control device 11 performs line connection control processing according to the CSC control signal of the line connection request signal, and generates a CSC control signal of the frequency allocation signal.

  The CSC control signal of the frequency allocation signal from the DAMA controller 11 is multiplexed with the voice signal by the multiplexer 15 and further modulated by the voice / CSC shared modulator 14, and is transmitted from the antenna by the transmission means in the same way as during voice communication. It is transmitted to the SNG in-vehicle station 2 and the server station 3 via the PAMA line. The SNG in-vehicle station 2 and the server station 3 demodulate the received multiplexed signal by the voice / CSC shared demodulator 24, 34, and further separate the voice signal and the CSC control signal of the frequency allocation signal by the multiplexer / demultiplexers 27, 37. To do. The separated CSC control signal of the frequency allocation signal is transmitted to the data transmission adapters 26 and 36, and the data transmission adapters 26 and 36 receiving the CSC control signal allocate frequency bands to the respective data communication modems 25 and 35. By performing the control, a data communication line is connected between the SNG in-vehicle station 2 and the server station 3. After the data communication line is thus connected, data communication is performed using the DAMA line. FIG. 5 shows a signal path of the data communication line with a bold line.

  In FIG. 5, data transmitted from the information terminal 23 of the SNG in-vehicle station 2 is sent to the data communication modem 25 via the data transmission adapter 26, and is modulated by the data communication modem 25. The signal modulated by the data communication modulation / demodulation device 25 is transmitted from the antenna to the server station 3 via the satellite line by the communication satellite 4 by the transmission means. The server station 3 receives the data signal with the antenna, and the data communication modem 35 demodulates the data signal from the SNG in-vehicle station 2. The data signal demodulated by the data communication modem 35 is sent to the server device 33 via the data transmission adapter 36. Data from the server device 33 of the server station 3 is sent to the information terminal 23 of the SNG in-vehicle station 2 through the reverse route.

Next, an operation at the time of BOD control for dynamically expanding / contracting the use band of the data communication line will be described.
As an example, a case will be described in which the amount of communication from the information terminal 23 of the SNG in-vehicle station 2 to the server device 33 of the server station 3 increases to increase the line speed. The data transmission adapter 26 of the SNG in-vehicle station 2 constantly monitors the amount of communication from the information terminal 23. When the amount of communication exceeds the upper limit value, a line speed increasing request signal is output to the DAMA controller 11 as a CSC control signal. To do. The output CSC control signal of the line speed increase request signal is transmitted to the DAMA controller 11 of the SNG base station 1 through the same route as the line connection request, and is processed by the DAMA controller 11.
The CSC control signal of the line speed increasing signal from the DAMA control device 11 is transmitted to the data transmission adapters 26 and 36 of the SNG in-vehicle station 2 and the server station 3 through the same path as the frequency allocation signal, and the data transmission adapter 26, When 36 controls the data communication modems 25 and 35, the speed of the data communication line between the SNG in-vehicle station 2 and the server station 3 is increased.

  As described above, the CSC control signal for performing the BOD control is transmitted / received using the PAMA line used for voice communication between the SNG base station 1 and the SNG in-vehicle station 2 which are provided as standard. Therefore, BOD control can be realized without adding a modulation / demodulation device for the CSC control line to the SNG in-vehicle station 2 and without reducing the throughput of IP data transmission.

It is a block diagram which shows the satellite communication system in Embodiment 1 of this invention. It is a figure which shows allocation of the frequency band in Embodiment 1 of this invention. It is a figure which shows the path | route of the audio | voice signal in Embodiment 1 of this invention. It is a figure which shows the path | route of the CSC control signal in Embodiment 1 of this invention. It is a figure which shows the path | route of the data communication signal in Embodiment 1 of this invention.

Explanation of symbols

1: SNG base station 11: DAMA controller 12: microphone 13: speaker 14: voice / CSC shared modulator 15: multiplexer 16a, 16b: voice / CSC shared demodulator 17a, 17b: separator 181: video / audio Processing device 182: TV encoding device 183: TV modulation device 184: TV demodulation device 185: TV decoding device 2: SNG in-vehicle station 21: Microphone 22: Speaker 23: Information terminal 24: Voice / CSC shared modem device 25: Data communication Modulation / demodulation device 26: data transmission adapter 27: multiplexing / demultiplexing device 281: video / audio processing device 282: TV encoding device 283: TV modulation device 284: TV demodulation device 285: TV decoding device 3: server station 31: microphone 32 : Speaker 33: Server device 34: Voice / CSC shared modem device 35: Data Modem for data communication 36: data transmission adapter 37: multiplexer / demultiplexer.

Claims (6)

  In a satellite communication system in which an SNG base station and an SNG in-vehicle station are always connected by a PAMA line for voice communication, a CSC control signal from a DAMA controller provided in the SNG base station is multiplexed with a voice signal. A satellite communication system configured to perform BOD control for dynamically expanding / contracting a use band by communicating with the SNG in-vehicle station via the PAMA line.   The SNG base station multiplexes the CSC control signal from the DAMA control device and the audio signal from the microphone, and transmits the signal multiplexed by the multiplexing means to the SNG in-vehicle station using the PAMA line. And the SNG in-vehicle station separates the signal received from the PAMA line into a CSC control signal and a voice signal, and transmits the CSC control signal separated by the separation means to the data transmission adapter. The satellite communication system according to claim 1, further comprising means for transferring each of the audio signals separated by the separation means to a speaker.   A DAMA control device that performs bandwidth management and control of multiple access on demand (DAMA) in a SNG base station of a satellite communication system in which a PANA circuit for voice communication is always connected to an SNG in-vehicle station, and this DAMA A multiplexing device that multiplexes a CSC control signal from a control device and a voice signal from a microphone, a voice / CSC shared modulation device that modulates a signal multiplexed by the multiplexing device, and a voice / CSC shared modulation device Means for transmitting a modulated signal to the SNG in-vehicle station through the PAMA line.   The SNG base station includes a voice / CSC shared demodulator that demodulates a signal transmitted from the SNG in-vehicle station, and a separator that separates a signal demodulated by the voice / CSC shared demodulator into a CSC control signal and a voice signal. The SNG base station according to claim 3, comprising:   In a SNG in-vehicle station of a satellite communication system that is always connected to an SNG base station via a PAMA line for voice communication, a voice / CSC multiplexed signal transmitted from the SNG base station through the PAMA line is demodulated. A voice / CSC shared modulation / demodulation device and a multiplexing / demultiplexing device for separating a signal demodulated by the voice / CSC shared modulation / demodulation device into a CSC control signal and a voice signal, and the CSC control signal separated by the multiplexing / demultiplexing device The SNG in-vehicle station that performs BOD control that dynamically expands and contracts the use band.   The multiplexing / demultiplexing means has multiplexing means for multiplexing the CSC control signal and the voice signal from the microphone, and the voice / CSC shared modem apparatus has modulation means for modulating the signal multiplexed by the multiplexing / demultiplexing means. The SNG in-vehicle station according to claim 5.

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