JPH04310025A - Satellite communication system - Google Patents

Abstract

PURPOSE:To connect an outgoing terminal equipment and an incoming terminal equipment via one satellite line by giving/receiving information relating to the use of the satellite line between exchanges and setting the satellite line again every time a line block by the satellite line is selected. CONSTITUTION:An incoming call terminal equipment 43 is a terminal equipment accommodated in a satellite line and connecting to a satellite line 102. An exchange 33 makes a request of a change in a setting block of a satellite line from a terminal station 56 closest to the terminal equipment 43 into a terminal station 51 closest to an outgoing terminal equipment 41 to a line controller 20. The controller 20 executes the processing to change the line 102 into the satellite line 103 and informs it to the exchange 33 when it is finished. The exchange 33 sends a setup signal to the terminal equipment 43 via a subscriber signal line 112. The terminal equipment 43 sends a reply signal thereto to the exchange 33 and the reply signal is informed to the terminal equipment 41 via a relay signal line 130, exchanges 32, 31 and a subscriber signal line 111. Thus, the terminal equipments 41, 43 start transmission and reception of terminal information via the satellite line 103 interconnecting directly them.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention is applied to communication networks that use satellite lines as subscriber lines or both subscriber lines and relay lines.

0002

[Prior Art] FIG. 6 is a block diagram showing a conventional satellite communication system in which satellite lines can be used for both subscriber lines and relay lines, and FIG. An example of a connection sequence is shown.

[0003] A subscriber information line through which terminal information is sent and received, and a subscriber signal line through which call control signals are sent and received are set up between the terminal and the exchange. A relay line for sending and receiving terminal information is set up between the exchanges.Satellite terminal equipment is connected to some of the terminals and the exchange that accommodates these terminals, and the satellite terminal is used as a subscriber information line. A line can be used.

[0004] To explain specifically using the example of FIG. 6, the terminal 41
and satellite terminal equipment 51, 52 in the exchange 31, respectively.
The terminal 41 is connected to the exchange 31 through a subscriber information line 101 and a subscriber signal line 111 using satellite lines. The terminal station 42 is connected to the exchange 31 via a subscriber information line 81 and a subscriber signal line 91 which are terrestrial lines. The terminal station 43 is connected to the exchange 33 via a subscriber information line 105 and a subscriber signal line 112 of the satellite line by satellite terminal devices 56 and 55. The terminal station 44 is connected to the exchange 33 via a subscriber information line 82 and a subscriber signal line 92 based on land lines.

[0005] The exchanges 31 and 33 manage the attributes of the terminals connected to each other, and terminals that accommodate satellite lines, such as terminal 41 in exchange 31 and terminal 4 in exchange 33,
Each time 3 communicates, the satellite line setting request process is executed.

[0006] Satellite line setting and release processing and satellite line management are centrally carried out by the satellite line control device 20. The satellite line control device 20 is connected via line control lines 61 to 63 to exchanges 31 and 33 to which satellite terminal devices are connected, and to an exchange 32 that executes connection processing for relay sections by satellite lines. Further, the satellite terminal devices 51 to 56 are connected through satellite line control lines 71 to 74.

[0007] In this satellite communication system, when a call is made from a terminal 41 accommodated in the satellite line or a call is received at the terminal 41, a subscriber information line 101 via the satellite line is set up between the satellite terminal equipment 51 and 52. , whereby terminal information is sent and received. In the case of the terminal 43, a subscriber information line 105 using a satellite line is similarly used. therefore,
When the terminals 41 and 43, which are satellite line accommodation terminals, communicate with each other, the subscriber information line 10 is connected to the satellite line.
1 and 105, terminal information is sent and received.

[0008]

[Problem to be Solved by the Invention] As described above, in the conventional satellite communication system, since the switching equipment does not have information other than the line section that it controls, it is difficult for the satellite You will have to go through the line at least twice. In addition, when communicating via a relay line using a satellite line like the satellite line 104 shown in FIG. 6, at least two
At least 3 times when satellite line accommodation terminals communicate with each other.
This will be done via a satellite link. If the satellite line is used multiple times, the propagation delay time of signals in the communication line between terminals increases, which has the drawback of degrading communication quality such as voice communication quality and information transmission efficiency in data communication. Furthermore, since the satellite line is set up for multiple sections for one call, there is a drawback that the utilization efficiency of the satellite line decreases.

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and provide a satellite communication system that connects a calling terminal and a receiving terminal via a single satellite line.

0010

[Means for Solving the Problems] The satellite communication system of the present invention is such that each of the plurality of exchanges in the network is connected to a satellite end station that is closest to the originating terminal or the terminating terminal in the circuit section of the satellite line. between the satellite terminal equipment closest to the originating terminal and the satellite terminal equipment closest to the terminating terminal, including means for notifying the next exchange of the identification information of the circuit connected to the satellite circuit, and each time a circuit section using the satellite circuit is selected. The present invention is characterized in that it is equipped with a means for changing the settings of the satellite line.

[0011] As a means of changing the settings of the satellite line,
Means for performing the satellite line setting process based on instructions from the exchange may be provided separately from the exchange, or may be provided in each of a plurality of exchanges so that the exchange accommodating the destination terminal performs the satellite line setting process.

0012

[Operation] When a satellite line accommodation terminal communicates, or when part of the relay line from the originating exchange to the destination exchange passes through the satellite line, the exchange information for identifying the line used by the satellite terminal equipment closest to the destination terminal, or information for identifying the line used by the satellite terminal equipment closest to the destination terminal among multiple sections of the satellite link; Alternatively, both of these pieces of information are notified to the next exchange, and a satellite line is set up to directly connect the satellite terminal equipment closest to the originating terminal and the satellite terminal equipment closest to the destination terminal.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing a satellite communication system according to a first embodiment of the present invention, and FIG. 2 is a line connection sequence diagram when a satellite communication relay line is used. Further, FIG. 3 is a diagram showing an example of the format of a call connection control signal transmitted and received between exchanges.

The terminal 41 is connected to the exchange 31 by a satellite line set up by satellite terminal devices 51 and 52, and the terminal 42 is connected to the exchange 31 by a terrestrial line. Also,
Terminal 43 is connected to exchange 33 by a satellite line set up by satellite terminal devices 55 and 56, and terminal 44 is connected to exchange 33 by a terrestrial line. The exchanges 31 and 33 manage the attributes of each connected terminal, and execute a satellite line setting request process every time a satellite line accommodation terminal communicates.

[0015] The terminal 41 accommodated by the satellite line makes a call,
An example of a connection process when a call arrives at a terminal 43 accommodated by a satellite line via a relay section by a satellite line will be explained. Note that the subscriber signal line 111 is set up before the terminal 41 makes a call and a call setup signal is sent to the exchange 31, and the subscriber signal line 111 is set up before the call setup signal is sent from the exchange 32 to the terminal 43 to notify the terminal 43 of the incoming call. It is assumed that the user signal line 112 is set.

When the terminal 41 makes a call, it transmits a call setting signal to the exchange 31 through the subscriber signal line 111. Based on the received call setup signal, the exchange 31 sends a request to the satellite line control device 20 to set up a satellite line with the required line speed between the satellite terminal devices 51 and 52 through the line control line 61.
Notify. Satellite line control device 20 transmits instructions for setting up subscriber information line 101 to satellite terminal devices 51 and 52 via satellite line control line 71 . When the satellite terminal devices 51 and 52 start transmission and reception on the designated satellite line, they notify the satellite line control device 20 of completion of the setting. The satellite line control device 20 includes satellite terminal devices 51 and 5.
2, the exchange 31 is notified that the line setting request has been completed. When the exchange 31 receives the completion signal from the satellite line control device 20,
A relay section using a satellite line is selected as a relay line going to the exchange 33 that accommodates the destination terminal, and the relay signal line 1 is transferred to the exchange 32 that executes connection processing for the relay section using the satellite line.
30, a call connection signal is sent.

As shown in FIG. 3, the contents notified from the exchange 31 to the exchange 32 include the line number of the selected relay information line, the subscriber number of the originating terminal, the subscriber number of the destination terminal, and the most Originating satellite terminal equipment number to identify the line used by the nearest satellite terminal equipment, originating satellite terminal equipment information line number, arriving satellite to identify the line used by the satellite terminal equipment closest to the destination terminal. The exchange 32, which has received the call setting signal including the terminal equipment number, the terminating satellite terminal equipment information line number, and the required information line speed, selects the exchange 33 as the connection destination of the trunk line based on the terminating terminal subscriber number. Furthermore, the line used by the satellite terminal equipment 51 indicated by the originating satellite terminal equipment number and the originating satellite terminal equipment information line number, and the exchange 33 which is the satellite terminal equipment closest to the destination terminal at the present time. The satellite line control device 2 is connected to the satellite line control device 2 through the line control line 62 so as to connect the line of the connected satellite terminal device 54 with the satellite line.
Send a connection request to 0. In order to change the setting of the subscriber information line 101 using the satellite line to the satellite line 102, the satellite line control device 20 transmits an instruction to release the subscriber information line 101 to the satellite terminal device 52, and sends an instruction to the satellite terminal device 54 to release the subscriber information line 101. , satellite line 102 via satellite line control lines 71 and 72
Send configuration instructions. The satellite end station device 52 notifies the satellite line control device 20 of a completion signal when it stops transmitting and receiving the designated satellite line, and when the satellite end station device 54 starts transmitting and receiving the designated satellite line. . When the satellite line control device 20 receives the completion signals from both the satellite terminal devices 52 and 54, it notifies the exchange 32 that the requested processing has been completed. Upon receiving the completion signal from the satellite line control device 20, the exchange 32 sends a call connection signal to the exchange 33. The originating satellite terminal equipment number and the originating satellite terminal information line number sent at this time are the numbers received by the exchange 32 from the exchange 31. The destination satellite terminal device number and the destination satellite terminal information line number are changed to the number of the line used by the satellite terminal device 54.

[0018] Upon receiving the call connection signal, the exchange 33 identifies whether or not the destination terminal is accommodated by a satellite line.
If the destination terminal is a land line accommodating terminal, normal incoming call connection processing is executed. If the destination terminal is a satellite line accommodation terminal and the route from the originating terminal has already passed through a satellite line section, the conventional incoming call connection process will select a new satellite line section. Become. In this embodiment, instead of selecting a new section for setting up a satellite line, the section for setting up a satellite line is changed. That is, the exchange 33 changes the section in which the satellite line is set up between the satellite terminal equipment closest to the originating terminal indicated in the received call connection signal and the satellite terminal equipment connected to the terminating terminal. To,
An instruction is given to the satellite line control device 20 via the line control line 63. In addition, if the destination terminal is a satellite line accommodation terminal and the route from the originating terminal is only a terrestrial line section, the exchange 3 which becomes the satellite terminal equipment closest to the originating terminal
The satellite line control device 20 is requested to set up a satellite line between the satellite terminal device 55 connected to the terminal 3 and the satellite terminal device connected to the destination terminal.

In the case of the example shown in FIG.
is a satellite line accommodating terminal, and is connected via the satellite line 102. Therefore, the setting section of the satellite line is changed to between the satellite terminal device 56, which is the satellite terminal device closest to the destination terminal, and the satellite terminal device 51, which is the satellite terminal device closest to the originating terminal indicated in the received call connection signal. The exchange 33 requests the satellite line control device 20 to do so. The satellite line control device 20 is connected to the exchange 3
Similar to the request from 2, the satellite line 102 is connected to the satellite line 103.
When the process is completed, a completion signal is sent to the exchange 33. Upon receiving this completion signal, the exchange 33 transmits the signal via the subscriber signal line 112.
A call setting signal notifying the incoming call is transmitted to the terminal 43. Terminal 43 transmits a response signal indicating a response to the call setup signal to exchange 33. This response signal is transmitted to the relay signal line 13.
0, the terminal 41 is notified via the exchanges 32 and 31 and the subscriber signal line 111. As a result, the terminal 41 and the terminal 43 start transmitting and receiving terminal information through the satellite line 103 that directly connects them.

[0020] In the case where only a terrestrial relay line is used between the exchange 31 and the exchange 33, the relay exchange performs processing similar to the relay connection processing for terrestrial play, and the call connection from the preceding exchange is From the signal, information to identify the line used by the satellite terminal equipment closest to the originating terminal, information to identify the line used by the satellite terminal equipment closest to the destination terminal, and information to identify the line used by the satellite terminal equipment closest to the destination terminal. The information identifying the line used by the nearest satellite terminal equipment is extracted and transferred to the next exchange.

FIG. 4 is a block diagram showing a satellite communication system according to a second embodiment of the present invention, and FIG. 5 is a line connection sequence diagram. This embodiment differs from the first embodiment in that the satellite line setting process is executed only in the exchange that accommodates the destination terminal. The same call connection signal as in the first embodiment is used as the call connection signal notified from the exchange to the next exchange. In this example,
Similar to the description of the first embodiment, a case will be described in which the terminal 41 makes a call and the call is received at the terminal 43 via a relay line using a satellite line.

When the terminal 41 makes a call, the exchange 31 selects the satellite terminal device closest to the originating terminal as the satellite terminal device 51 and the satellite terminal device closest to the destination terminal as the satellite terminal device 52.
A call setting signal is sent to the exchange 32. The exchange 32 selects the exchange 33 as the connection destination based on the subscriber number of the destination terminal,
The satellite terminal device closest to the originating terminal is the satellite terminal device 51 indicated by the call setup signal, and the satellite terminal device closest to the destination terminal is connected to the exchange 33 selected in the connection process at that time. It is assumed that the satellite terminal equipment 54 is the satellite terminal equipment 54 and sends a call setting signal to the exchange 33.

[0023] The exchange 33 identifies whether or not the terminating terminal is accommodated by a satellite line, and determines that the terminating terminal is accommodated by a satellite line and that a line section using a satellite line has been selected by the preceding exchange. In this case, the satellite line controller connects the satellite terminal equipment closest to the originating terminal indicated in the call connection signal received from the preceding exchange and the satellite terminal equipment connected to the terminating terminal. Request 20. In addition, if a line section using a satellite line has not been selected by the previous exchange, the satellite line control will issue a request to connect the satellite terminal equipment connected to itself and the satellite terminal equipment connected to the destination terminal. It is sent to the device 20. If the destination terminal is not accommodated by a satellite line, and a satellite line section has been selected by the previous exchange, the satellite terminal station closest to the originating terminal indicated in the received call connection signal. A request is made to the satellite line control device 20 to connect the device to the satellite terminal device closest to the destination terminal indicated in the call connection signal. If a line section using a satellite line has not been selected by the preceding exchange, conventional incoming call connection processing is executed.

In the case of the example shown in FIG. 4, terminal 43, which is the destination terminal, is a satellite line accommodating terminal and has already passed through the line section of the satellite line. Therefore, the exchange 33 requests the satellite line control device 20 to connect the satellite terminal device 51 indicated by the call contact signal to the satellite terminal device 56 connected to the terminal 43 which is the destination terminal. In response to a request from the exchange 33, the satellite line control device 20 sends instructions necessary for setting up the satellite line 103 to the satellite terminal device 51.
, 56. After the satellite line 103 is set up, the exchange 33 sends a call setting signal to the terminal 43, which is the destination terminal, and then, as in the case of the first embodiment, the terminal 41 and the terminal 43 are connected to each other via one satellite line. Transmission and reception of terminal information begins via the information line connected via 103.

[0025] Through the above processing, in a communication network that uses a satellite line for the subscriber information line or both the subscriber information line and the relay line, the satellite terminal equipment closest to the originating terminal and the satellite closest to the destination terminal are connected. It becomes possible to set up a satellite line to connect to the terminal equipment. In the above embodiments, a communication network including both a satellite line and a terrestrial line has been described as an example, but the present invention can be similarly implemented in a communication network having only a line section using a satellite line.

[0026]

[Effects of the Invention] As explained above, the satellite communication system of the present invention allows communication between the satellite terminal equipment closest to the originating terminal and the satellite terminal equipment closest to the terminating terminal without going through line sections of multiple satellite lines. You can set up a satellite line that connects directly to Therefore, it is possible to effectively utilize the satellite line, and it is also possible to prevent deterioration in communication quality due to passing through a plurality of satellite lines.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a satellite communication system according to a first embodiment of the present invention.

FIG. 2 is a line connection sequence diagram when a relay line is used as a satellite line.

FIG. 3 is a diagram showing a format example of a call connection control signal transmitted and received between exchanges.

FIG. 4 is a block configuration diagram showing a satellite communication system according to a second embodiment of the present invention.

FIG. 5 is a line connection sequence diagram.

FIG. 6 is a block diagram showing a conventional satellite communication system in which satellite lines can be used for both subscriber lines and relay lines.

FIG. 7 is a diagram showing an example of a line connection sequence when a terrestrial line is used via a relay line.

[Explanation of symbols]

10 Communication satellite 20 Satellite line control devices 31-33 Exchanges 41-44 Terminals 51-56 Satellite terminal equipment 61-63 Line control lines 71-74 Satellite line control lines 81, 82, 101, 105 Subscriber information line 91,
92, 111, 112 Subscriber signal lines 102-10
4 Satellite line 120 Relay information line 130 Relay signal line

Claims (1)

[Claims] [Claim 1] A plurality of exchanges are connected to each other via relay lines, and at least some of the exchanges are connected to satellite terminal equipment that is connected to terminals or other exchanges via satellite lines. In the satellite communication system, each of the plurality of exchanges notifies the next exchange of the identification information of the line used by the satellite terminal equipment closest to the originating terminal or the destination terminal in the line section of the satellite line. including a means for changing the setting of the satellite line between the satellite terminal equipment closest to the originating terminal and the satellite terminal equipment closest to the destination terminal each time a satellite link section is selected. Characteristic satellite communication method.