JPH02159834A - Line controller for satellite communication network - Google Patents

Abstract

PURPOSE:To improve the utilizing efficiency of a satellite communication network and to enhance the convenience of use for the user by providing a line management station to an earth station being a master station and making the reservation of communication available when no idle line exists and no communication is available. CONSTITUTION:When a line assignment request signal is sent from a terminal controller 13 in a caller earth station to a central controller 12 of a master station 2, the controller 12 checks the line operating state of a relay line 5 and when no idle line exists, a line assignment disable signal is sent to the caller earth station. Then as required, the caller station sends a reservation request signal to the controller 12 and the controller 12 sends a reservation confirming signal to the caller station and a reservation confirmation message from the caller station is informed to the caller. When any idle line is caused in lines among satellite lines, the caller and the called party, the controller 12 calls a subscriber and communication is applied in response to the call. Thus, the controller 12 as the line management station is provided and when idle lines few and the communication is disabled, the reservation of the communication is attained to improve the utilizing efficiency of the satellite communication network and the convenience of use are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a satellite communication system to which a line connection request allocation method is applied.

(Prior art) In a satellite communication system, as a method for allocating satellite lines when multiple connection is made between multiple local stations, there is a fixed allocation (briasyment) method in which a line 9 is fixedly allocated to each earth station. , a certain number of lines are pooled in common to each earth station, and each time a call occurs, a pair of sending and receiving lines in the common pool is allocated between the earth stations, and when the communication ends, the allocation is canceled. There is a line connection request assignment (mand assignment) method that returns lines to the pool.

Among these, the line connection request allocation method is a method that allows a limited number of lines to be used effectively by a large number of earth stations. There are two types of line connection request allocation systems: a centralized control system in which one earth station serves as a master station and the master station controls all satellite lines; and a distributed control system in which each earth station controls its own satellite lines.

Among these, satellite communication systems that use a centralized control line connection request allocation method are composed of one master station and several slave stations, and each earth station is connected to a terminal device via an exchange. . The master station is provided with a central control unit that manages the satellite line of the communication network, and controls each slave station via the communication satellite using a common control line for transmitting and receiving control signals.

FIG. 4 shows a communication sequence when telephone communication is performed using the conventional centralized control line connection request allocation method. When the caller attempts to make a call and sets it to 0FF-) (00, the exchange activates and returns a dial tone to the caller.The caller sends out the satellite line designation number, activates the earth station, and then The station identification number and called subscriber number are sent.The earth station receives this and sends a line allocation request signal to the central control unit of the parent station to request line allocation.The central control unit sends a line allocation request signal to the central control unit of the master station.The central control unit connects the satellite line and the called party relay. Checks the line status, and if the line is free, starts the call, and if the line is full, sends a signal that the line cannot be allocated to the calling earth station, sends a busy tone to the caller, and terminates the call. In response, the caller makes an 0N-HOOK, and the exchange sends a disconnection signal to the earth station, which in turn sends it to the central control unit.The central control unit sends a restoration confirmation signal to the earth station. Additionally, a clearing signal is sent to the exchange.

In this way, if the satellite line or trunk line is full, the central control unit informs the caller that communication is not possible. For this reason, the caller had to end the call and then make the call again after a while when it seemed possible to communicate. However, in this case, the caller did not check whether the satellite line was available, so there were cases where the caller could not connect to the line again.

(Problems to be Solved by the Invention) As described above, in the conventional communication circuit control system, the caller cannot know the usage status of the satellite line, so if the satellite line is blocked, the caller cannot The communication request must be made again later.

Furthermore, at the time of communication later, the caller has not confirmed that the satellite line or the relay line on the other side is free, so it may not be possible to reconnect the line, which is very inconvenient for the user. .

SUMMARY OF THE INVENTION An object of the present invention is to provide a line control system that eliminates these problems, improves the utilization efficiency of a satellite communication network, and enables user-friendly satellite communication.

[Structure of the invention]

In a satellite communication network line control method in which a line management station monitors the line status and controls the communication line of each earth station, the line management station controls the satellite line of the earth station in response to the communication request of each earth station. If there is no free space in the satellite line to be allocated, a line management station is provided that calls the earth station that issued the communication request and connects the satellite line when the satellite line becomes free. This is a line control device for a satellite communication network.

(Function) In the present invention, a central control unit serving as a line management station manages and allocates satellite lines. If the satellite line and relay line are full, the central control unit monitors the line and
Since both the calling party and the called party are called to connect the line when a call occurs, there is no need for the calling party to call again if communication is impossible due to the satellite line being blocked.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, communication is performed between two earth stations among the central control type line connection assignment method 2 and slave stations 3 and 4. A number of exchanges 6 are connected to these master stations 2 and slave stations 3 and 4 via trunk lines 5, respectively, and terminal equipments are connected to each exchange 6 via subscriber lines 7. 8 are connected. Here, the master station 2 includes an antenna section 9, a transmitting/receiving device 10,
A terminal device 11 and a central control device 12 that manages the satellite line.
It is made up of. Similarly, the slave station 3.4 includes an antenna section 9, a transmitting/receiving device IO1 terminal device 11, and a terminal control device 13.
It consists of Here, the central control device 12 of the master station 2
allocates and releases lines according to requests from slave stations 3.4,
The operating status of each earth station is monitored, and the terminal control devices 13 of the slave stations 3 and 4 control each slave station in response to control signals sent from the central controller 12 via the communication satellite. It controls the satellite line and relay line 5 of 3.4.

Next, the operation will be explained. When a subscriber makes a call from the terminal device 8, the exchange 6 starts up and operates the earth station.

At the earth station, a terminal control device 13 equipped with earth station internal pressure uses a common signal line (CSC) to transmit control signals such as line allocation.
A line connection allocation request is made to the central control unit 12 provided in the master station 2 via the communication satellite 1 using the . Central control device 1
In step 2, when a line connection allocation request is received, the satellite line is allocated if the satellite line and the relay line 5 on the calling side and the called side are vacant. Once the line is allocated, the terminal control device of the earth station on the called side calls the called side terminal device.

When the called terminal device [13] responds, communication is performed by transmitting voice, data, etc. via the assigned satellite line.

Here, regarding the line allocation procedure for this communication system,
This will be explained using FIGS. 2 and 3.

Note that control signals are exchanged between the master station 2 and the slave stations 3.4 using a common signal line (CSC) when performing line assignment. FIG. 2 shows a communication sequence when telephone communication is performed using this communication system.

When the calling party attempts to make a call and selects 0FF-HOOK, the exchange 6 notifies the calling party via a dial tone that it is ready to receive a selection signal. Next, the subscriber sends out the satellite line designation number to activate the originating earth station.
Furthermore, the station identification number and called subscriber number are sent out. In response, the terminal control device 13 in the originating earth station sends a line allocation request signal to the central control device 12 of the master station 2 via the common signal line. The central control unit 12 checks the line usage status of the satellite line and the trunk line 5 connected to the receiving earth station, and if the line is vacant, the line is allocated and a call is made. In addition, if there is no free line, a line allocation unavailable signal is sent to the originating earth station, and the originating earth station sends a busy tone to inform the caller that communication is impossible.

At this time, the calling party sends a reservation request number and calling subscriber number to the calling earth station, if necessary, and the calling earth station sends a reservation request signal to the central controller 12. Central control device 1
In step 2, in response, a reservation confirmation signal is sent to the originating earth station, and the originating earth station notifies the caller of a reservation confirmation message. After confirming this, the caller turns the receiver on 0N-
HOOK is sent to the originating earth station, and in response, a call termination signal is sent to the exchange 6 to terminate the call.

Next, FIG. 3 shows a communication sequence after a reservation request is made and the satellite line and the relay line 7 on the transmitting side and the receiving side become vacant and communication becomes possible. When the satellite line and the trunk line 7 become vacant, the central control unit 12 sends a line designation signal and a subscriber number to call the originating and terminating earth stations, thereby calling the subscriber. In response to this call, the terminal that made the 0FF-HOO'K first hears the ringing tone of the other party's terminal, and the call is started by the 0FF-HOOK of the other party's terminal.

Note that when communication is started, the central controller 12 is notified by response signals from the earth stations on the calling and receiving sides.

What has been described above is only one embodiment of the present invention, and the present invention is not limited thereto. Although a conversation between the terminal devices 8 connected to the slave station 3.4 is described here, it goes without saying that the same can be done between the terminal devices 8 connected to the master station 2. In this case, the central control unit 12 performs line control of the terminal device 8 connected to the master station 2. Further, in this embodiment, the central control device 12 is installed within the master station 2, but the central control device 12 may be provided independently from the master station 2.

Furthermore, the terminal device 8 is not limited to a telephone, and can be used for various communication means such as image communication and data communication. As described above, various modifications can be made without departing from the gist of the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, when there is no free line and communication is not possible, communication can be reserved.
When the satellite line becomes vacant, both the calling and receiving parties can be called and communicated. Therefore, it is possible to improve the service to the users, increase the usage rate of the line, and use the satellite communication network more efficiently.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an outline of a satellite communication system using a centralized control line connection allocation method, Fig. 2 is a communication sequence when using the line control method of the present invention, and Fig. 3 is when communication becomes possible. FIG. 4 shows a communication sequence of a conventional satellite communication system. 1... Communication satellite, 2... Parent earth station, 3.
4...Slave earth station, 5...Relay line, 6.
... Switchboard, 7... Subscriber line, 8... Terminal device,
9... Antenna section, 10... Transmitter/receiver,
11... Terminal device, 12... Central control device, 1
3...Terminal control device. Agent Patent Attorney Noriyuki Chika

Claims (1)

[Claims] In a satellite communication network line control system in which a line management station monitors the communication line status between earth stations that communicate via a communication satellite and controls the communication line of each earth station, the line management station controls each earth station. The satellite line of the earth station is allocated in response to the communication request of the station, and if there is no free space on the satellite line to be allocated, the earth station that issued the communication request is called when the satellite line becomes free. A line control device for a satellite communication network, comprising a line management station for connecting satellite lines.