JP2000307498A - Dama line control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the line connection system which is enable to securely and speedily disconnect a telephone line at the end of a telephone call. SOLUTION: In the DAMA line connection system wherein multiple satellite terminals 2 and 3 communicate by using satellite communication, the respective satellite terminals 2 and 3 have an on-hook signal output means which outputs an on-hook signal to a communication line at the end of a call and a line disconnecting means which disconnects the communication line on receiving the on-hook signal from the communication line. Thus, the communication line is disconnected by using the communication line, so control information never collides in space unlike a case wherein the on-hook signal is transmitted through a control line and it does not take a long time to disconnect the line unlike a case wherein control is performed by an integrated station, so that the disconnection control can securely and speedily be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DAMA (demand assignmeme) in which a plurality of satellite terminals communicate using satellite communication.
The present invention relates to a DAMA line control system that enables a satellite terminal to reliably and quickly disconnect a communication line at the end of a call in a communication connection of an nt multiple access system.

[0002]

2. Description of the Related Art In any of the conventional DAMA systems, a communication line is disconnected at the end of a call using a control line, as described below.

Japanese Patent Application Laid-Open No. 5-206912 discloses that in a DAMA satellite communication system, when a call is terminated, a release request signal (call termination request signal) is transmitted from a satellite earth station (satellite terminal) via a control line. Due to satellite propagation problems, this release request signal (call termination request signal) is sent to the center station (control station).
Otherwise, the center station (control station) will determine that the call is continuing even though the call between the satellite earth stations (satellite terminals) has been terminated, and this problem. In order to prevent this, the center station (control station) periodically inquires about the state of communication between the satellite earth stations (satellite terminals). It is disclosed that an earth station (satellite terminal) is returned from a talk state to a no-talk state.

Japanese Patent Application Laid-Open No. Hei 5-206913 discloses that in a DAMA satellite communication system, a center station (control station) transmits a forced communication disconnection control signal to a talking satellite earth station (satellite terminal) via a control line. It is disclosed that when a satellite earth station (satellite terminal) receives a forced communication disconnection control signal via a control line, the satellite earth station controls release of the currently used communication line.

[0005] In the conventional DAMA line connection system, as shown in FIG.
A disconnection notification is transmitted to the control station using an SC (common signaling channel) line. After receiving and processing the disconnection notification, the control station transmits a disconnection instruction to the receiving-side satellite terminal using the control line (CSC line), and the receiving-side satellite terminal receives the disconnection instruction. The communication line was disconnected.

[0006]

However, the conventional line connection system has the following problems.

The first problem is that since the uplink of the control line (CSC line) is shared by a plurality of satellite terminals, there is a possibility of collision in space, and the control station can transmit information from the satellite terminal once. This means that you may not be able to receive it.

A second problem is that a busy tone cannot be quickly generated by a handset of a receiving-side satellite terminal due to control via a control station by a control line (CSC line).

It is an object of the present invention to provide a DAMA line control system which solves the above-mentioned problems and makes it possible to disconnect a communication line reliably and quickly at the end of a call.

Another object of the present invention is to solve the above-mentioned problems and to provide a method of disconnecting a telephone line which can disconnect the telephone line reliably and quickly at the end of the telephone call.

[0011]

According to the present invention, in a DAMA system in which a plurality of satellite terminals communicate using satellite communication, an end signal is provided on a communication line at the end of a call in each of the plurality of terminals. And a means for receiving the call termination signal from the communication line and disconnecting the communication line.

Further, according to the present invention, in a method for disconnecting a communication line in the DAMA system in which a plurality of satellite terminals communicate using satellite communication, one of the plurality of terminals includes:
Outputting a call termination signal on a communication line at the end of the call; and disconnecting the communication line by receiving another call termination signal from the communication line by another one of the plurality of terminals. Thus, a method for disconnecting a telephone line is obtained.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 shows a DAMA line control system according to the present invention. In the illustrated DAMA line control system, when the satellite terminal 2 and the satellite terminal 3 communicate, the line connection control is performed by the control line to connect the communication line.

In this state, according to the DAMA line control system of the present invention, when the slave station controller 7 receives a call end signal from the talk terminal 8 in the satellite terminal 2, the slave station controller 7
Transmits the end-of-call notification information to the slave station control device 7 of the satellite terminal 3 using the communication line for control, and enters a call end state. The slave station control device 7 of the satellite terminal 3 When the information is received, the call is terminated.

As described above, according to the present invention, since the line is disconnected using the communication line, the control information does not collide in space unlike the case where the end-of-call notification information is transmitted on the control line, and Moreover, disconnection control can be performed reliably and quickly without requiring time for disconnection as in the case of control by the control station.

In FIG. 1, a control station 1 includes a modem 4
And a master station control device 6.

FIG. 2 shows a satellite terminal used as each of the satellite terminals 2 and 3.

In the satellite terminal shown in FIG.
Is a terminal composed of a vocoder circuit and a handset circuit. The modulation / demodulation device 5 includes a CSC modulation / demodulation circuit used as a control line for connecting a communication line in the DAMA system, and a communication line modulation / demodulation circuit used as a communication line. Further, the slave station control device 7 includes a CPU for executing line connection control,
A communication LSI 2 for transmitting and receiving control information over the SC line;
It comprises a communication LSI 1 for transmitting an end signal on a communication line and receiving an end signal from a partner station, and a communication LSI 3 for setting a scrambling code in the modem 5.

First, at the start of a normal call, the call terminal 8
, The hook signal is output to the slave station control device 7 with the hook turned off, and then the other party's telephone number is output from the call terminal 8 to the slave station control device 7 by the dial signal. The slave station control device 7 that has received the hook signal off and the dial signal transmits a call request notification to the master station control device 6 of the control station 1 via the communication LSI 2.

When the transmission request is accepted, the master station controller 6 of the control station 1 starts the relay operation of the communication line, and a scramble code for using the DAMA line is transmitted from the control station 1 to the slave station controller 7. Sent to.

The slave station controller 7 having received the scramble code transmits the scramble code to the control circuit of the modem 5 via the communication LSI 3. The control circuit of the modem 5 which has received the scramble code sets the scramble code in the communication line modem and starts the modulation / demodulation operation. Next, the CPU of the slave station control device 7 sets CONT2
The signal is set to "H", the CONT1 signal is set to "L", and the SD signal, ST2 signal, RD signal, and RT signal of the communication terminal 8 are connected to the communication line modulation / demodulation circuit to enter the communication state. At the same time, the communication LSI 1 is set to the data communication state, and the RD signal is monitored and received from the communication line modem.

At the end of the call, the hook signal is output from the call terminal 8 to the slave station control device 7 when the hook signal is turned on. When the signal of the communication terminal 8 is set to “H” and the signal of the CONT1 is changed to “H”, the SD signal of the communication LSI 1 is connected to the modulation / demodulation circuit for the communication line. The call termination notification information is transmitted to the satellite terminal of the partner station. Further, by transmitting a disconnection notification to the master station control device 6 of the control station 1 using the CSC line, the control station 1 stops the communication line relay operation.

The satellite terminal 8 of the partner station detects the end of the call by receiving the end-of-call notification information from the communication LSI 1 of the slave station control device 7, and sets the CONT2 signal to "L" and the CONT1 signal to "H". To disconnect the signal from the call terminal 8 to end the call.

Although the configuration of the embodiment has been described above, since the modulation / demodulation device 5 and the communication terminal 8 in FIG. 2 are well known to those skilled in the art and are not directly related to the present invention, their detailed configurations are as follows. Omitted.

Next, the operation of the slave station control device 7 of FIG. 2 will be described with reference to a time chart shown in FIG.

In FIG. 3, "call terminal", "hook signal", "CONT1", "CONT2", "S
“D” and “RD” indicate parts or signals of the same name in the system diagram of FIG. “CSC line up” and “CSC line down” indicate transmission data and reception data on the CSC line in FIG.

First, when the handset is off-hook by the calling terminal 8 of the transmitting-side satellite terminal, the hook signal is turned off, and the signal is received by the CPU of the slave station control device 7 so that C
A connection request is transmitted to the control station 1 on the SC line uplink. The control station 1 performs an accepting process and, if the DAMA line is usable, receives an incoming call permission. The slave station control device 7 that has received the incoming call permission controls the CONT1 signal to “L” and the CONT2 signal to “H”, and transmits the transmission signal of the communication terminal 8 to the SD signal. At this time, the CPU of the slave station control device 7
The communication LSI 1 is controlled so that the RD signal can be received.

On the other hand, in the receiving-side satellite terminal 8, the slave station control device 7 receives the incoming request on the CSC line down, and
And the CONT1 signal is set to “L”,
The CONT 2 signal is controlled to “H”, and the RD signal received from the modem 5 is connected to the received signal of the communication terminal 8.
The ringing sound of the call terminal 8 causes the operator to go off-hook on the handset and start a call.

The time chart in FIG. 3 shows a case where the call is disconnected from the transmitting side satellite terminal 8, and when the operator goes on-hook, the hook signal is turned on. The slave station controller 7 sets the CONT1 signal to “H” and the CONT2 signal to “L” by turning on the hook signal, and sets the communication LSI 1
Is connected to the modem 5, and a disconnection notification is transmitted to the CSC line uplink. Next, the communication termination information is transmitted on the communication line using the communication LSI1.

The receiving-side satellite terminal 8 monitors the RD signal on the communication line by the communication LSI of the slave station control device 7, and determines that the communication has ended by receiving the end-of-call notification information. Outputs busy sound with sound control. At the same time, the CONT1 signal is controlled to "H" and the CONT2 signal is controlled to "L" to cut off the transmission / reception signal of the communication terminal. Further, a disconnection notification is transmitted to the control station on the CSC line uplink. The telephone call ends when the operator who hears the busy sound goes on-hook on the handset.

For comparison, the configuration of a satellite terminal in the conventional DAMA line connection system is shown in FIG.
FIG. 5 shows an operation time chart of the line connection method.

In the satellite terminal shown in FIG. 4, the communication terminal 8, the modem 5 and the radio device 10 have the same configuration as the satellite terminal of FIG. 2, but the slave station control device 7 'has the conventional configuration. is there.

In the conventional configuration, as shown in FIG. 5, the transmitting-side satellite terminal transmits a disconnection notification to the control station using the control line (CSC line), and the control station receives the disconnection notification. After processing, a control line (CS
As described above, the disconnection instruction is transmitted using the (C line), and the receiving-side satellite terminal disconnects the communication line by receiving the disconnection instruction.

[0035]

As described above, according to the present invention,
The following effects are obtained.

The first effect of the present invention is that the communication terminal uses the communication line to transmit the call termination notification information to the control station, so that the control line (CSC line) has been used in the DAMA system.
Therefore, it is possible to reliably transmit the end-of-call notification to the communication partner terminal without the possibility of collision occurring as in the case of using.

A second effect of the present invention is that since the communication terminal uses the communication line to transmit the call termination notification information to the control station, the control line (CSC line) has been used in the DAMA system.
As in the case of using, there is no processing delay at the control station and the call termination notification can be sent quickly to the communication partner terminal,
The busy sound at the end of the call is shortened, so that the call without discomfort can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a DAMA line control system according to the present invention.

FIG. 2 is a block diagram of a satellite terminal of the DAMA line control system of FIG. 1;

FIG. 3 is a time chart for explaining the operation of the DAMA line control system of FIG. 1;

FIG. 4 is a block diagram of a conventional DAMA line control satellite terminal.

FIG. 5 is a time chart for explaining the operation of the DAMA line control system shown in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control station 2 Satellite terminal 3 Satellite terminal 4 Modulator / demodulator 5 Modulator / demodulator 6 Master station controller 7 Slave station controller 8 Talk terminal 10 Wireless device

Claims (6)

[Claims] 1. In a DAMA system in which a plurality of satellite terminals communicate using satellite communication, an end signal output means for outputting an end signal to a communication line at the end of a call to each of the plurality of terminals, Means for receiving the end signal from the communication line and disconnecting the communication line. 2. In a DAMA system in which a plurality of satellite terminals communicate using satellite communication, an end signal output means for outputting an end signal on a communication line at the end of a call to each of the plurality of terminals, Means for receiving the end signal from the communication line and disconnecting the communication line, wherein the disconnection of the communication line is performed using the communication line. 3. In a DAMA system in which a plurality of satellite terminals communicate using satellite communication, an end signal output means for outputting an end signal to a communication line at the end of a call to each of the plurality of terminals, Means for receiving the end signal from the communication line and disconnecting the communication line, wherein the disconnection of the communication line is performed using the communication line without using a control line. DAMA line control system. 4. A method for disconnecting a communication line in a DAMA system in which a plurality of satellite terminals communicate using satellite communication, wherein one of the plurality of terminals outputs a call termination signal on the communication line when the call ends. And disconnecting the communication line by receiving another call termination signal from the communication line by another one of the plurality of terminals. 5. A method for disconnecting a communication line in a DAMA system in which a plurality of satellite terminals communicate using satellite communication, wherein one of the plurality of terminals outputs a call end signal on the communication line when the call ends. And disconnecting the communication line when the other one of the plurality of terminals receives the call termination signal from the communication line, and disconnects the communication line using the communication line. A method of disconnecting a telephone line. 6. A method of disconnecting a communication line in a DAMA system in which a plurality of satellite terminals communicate using satellite communication, wherein one of the plurality of terminals outputs a call end signal on a communication line when the call ends. And disconnecting the communication line by receiving another call termination signal from the communication line, and disconnecting the communication line using a control line. A method for disconnecting a telephone line using the communication line without using the communication line.