JPS6342446B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a demand assignment multiple access (DAMA) system in satellite communications.
In particular, it relates to management methods for satellite links and terrestrial links.

Conventionally, this type of DAMA system has a centralized control system in which satellite lines and terrestrial lines are managed collectively by a master station having a satellite line and station-specific terrestrial line management table 9 and a master station controller 8, as shown in Fig. 1. As shown in FIG. 2, there is a distributed control method in which the management of these is carried out on a station-by-station basis while coordinating between stations that have a satellite line and station-based terrestrial line management table 9. In the figure, 1, 2, 3 are ground exchanges for A to N stations, 4,
5 and 6 are A to N station DAMA devices, 7 is a satellite, 10
11 indicates a control line, and 11 indicates a speech line. However, in either method, the management of the satellite link and the terrestrial link were performed at the same time, which meant that there was a lack of flexibility in system changes. That is,
For example, when changing the number of terrestrial lines at station A, in the centralized control method it is generally necessary to change the station-by-station terrestrial line management table of the master station control device located at a different location from A station, and in the distributed control method, including station
In addition to the need to change the station-by-station terrestrial line management table of the DAMA equipment, it was also necessary to perform operations such as switching from the old table to the new table all at once.

The present invention provides two types of terrestrial line management: detailed management that manages each line, and general management that manages only the number of idle lines.
By using a hybrid control method, the slave station performs detailed management of only its own terrestrial line, and the master station performs general management of the satellite line and all slave station terrestrial lines. By making it possible to change the number of terrestrial lines by simply changing the detailed management table of the relevant station DAMA device, the above disadvantages are eliminated and flexibility is achieved when changing the number of terrestrial lines.
It provides the DAMA method.

Next, an embodiment of the present invention will be described with reference to FIG.

The embodiment of the DAMA system according to the present invention is composed of a master station and a plurality of slave stations, and the master station includes a control device 15 and a slave station land line summary management table 16,
Each slave station includes DAMA devices 4 to 6, exchanges 1 to 3, own station terrestrial line detailed management tables 12 to 14,
A control line 10 is interposed between the master station and each slave station.

To explain the operation step by step, taking as an example a case where a call occurs from station A to station B, when the A station DAMA device 4 receives a startup request from the exchange 1, it sends a startup completion notification to the exchange 1 and also automatically starts the process. The relevant line in the station land line detailed management table 12 is made busy, and the number of local station land lines is notified to the master station control device 15 as A station land line summary management information through the control line 10. The master station control device 15 updates the station-by-station terrestrial line summary management table 16 based on this information. When the A-station DAMA device 4 receives the partner station number from the exchange 1, it continues to receive the number up to a predetermined number of digits, and at the same time requests the master station control device 15 to connect to the partner station via the control line 10. The master station control device 15 refers to the satellite line and the terrestrial line summary management table 12 of the B station, and if there is a sky, the A
A satellite line designation and connection permission are sent to the station DAMA device 4, and a satellite line designation and connection request are sent to the B station DAMA device 5 through the control line 10.

The A-station and B-station DAMA devices 4 and 5 establish a connection, update their own station's terrestrial line detailed management tables 12 and 13, and each notify their own station's terrestrial line summary management information to the master station controller 15 through the control line 10. . Thereafter, the number with lower digits than the station number is sent from the A-station DAMA device 4 through the telephone line 11 to the B-station DAMA device 5 to the exchange 2, and by the operation of the exchange 2, it is connected to a predetermined terminal of the B-station. When a call is terminated, the call termination process and the restoration process of various tables are similarly performed through the telephone line 11 and the control line 10.

As is clear from the above explanation, according to this method,
DAMA control is performed at the master station based only on the satellite line and station-specific terrestrial line summary management table, and the station-specific terrestrial line summary management table is constantly updated by notifications from the relevant slave station. Therefore, when changing the number of land lines of a slave station, it is possible to do so by simply changing the land line detailed management table of the slave station.

As explained above, the present invention divides ground station line management into detailed management and summary management in the DAMA system for satellite communication, and provides the slave stations with detailed management functions for their own terrestrial lines. By dividing the functions to provide a line summary management function and a satellite line management function, it is possible to change the number of slave station terrestrial lines by simply changing the detailed management table of the station DAMA device, and change the number of terrestrial lines. This provides a flexible method for

[Brief explanation of the drawing]

1 and 2 are block diagrams of a conventional DAMA system using centralized control and distributed control, and FIG. 3 is a block diagram of a hybrid DAMA system according to the present invention. 1...A station terrestrial exchange, 2...B station terrestrial exchange, 3...N station terrestrial exchange, 4...A station DAMA
Device, 5...B station DAMA device, 6...N station
DAMA device, 7... Satellite, 8, 15... Master station control device, 9... Satellite line and station-specific terrestrial line management table, 10... Control line, 11... Call line, 12-14... Own station terrestrial line management table,
16... Satellite line and station-by-station terrestrial line summary management table.

Claims (1)

[Claims] 1 Manage own station's terrestrial lines on a line-by-line basis, notify the master station of the number of own air-to-air terrestrial lines, detect the occurrence of a call, and make a connection request to the master station, as well as respond to a connection request from the master station. It has multiple slave stations that connect their own air and ground lines to the designated satellite lines based on the above, and also manages the satellite lines, and manages the number of air and ground lines of all slave stations for each station based on notifications from each slave station. At the same time, based on a connection request from the calling slave station, if the satellite line and the terrestrial line of the called slave station are free, there is a master station that makes a connection request to the called slave station, and this master station and each of the slave stations The DAMA method is characterized by having a control line between them to send and receive various notifications and requests.