JPS6343429A - Satellite communication system - Google Patents

Abstract

PURPOSE:To prevent excessive line congestion and delay in transmission through a CSC line by storing once an unurgent data of a small capacity and sending the data together when a DAMA line is opened by other matter. CONSTITUTION:An earth station is provided with a memory for stations A, B, C,...and accommodates many terminal equipments such as fax telephone and electronic mail. The information with small capacity and not requiring urgency among the information of the terminal equipments is stored in a memory once corresponding to a transmission opposite station. When any of terminal equipments accommodated in the earth station sends information with large capacity or urgency, a DAMA slave station equipment requests the line assignment and when the line is opened, the information with large capacity or urgency is sent and the content of the memory corresponding to an opposite station is sent at the same time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a satellite communication system that performs line switching using the DAMA system.

(Prior Art) In recent years, satellite communications have come into widespread use for various reasons such as system flexibility and broadcast capability. In this satellite communication system, the DAbIA method has recently been attracting attention and being introduced because of its high line utilization efficiency. Among these DAMA systems, the centralized DA:VtA system is often used because of the stability and reliability of line settings. By the way, in this centralized control DAMA system, for example, when a first ground station (slave station) attempts to communicate with a second ground station (slave station), the first ground station first uses the C8C line. , a line allocation request is issued to the master station to allocate a line between the first station and the second station. In accordance with the line allocation request, the master station allocates a line between the first and second earth stations and instructs the first and second earth stations to communicate using the line. Here, ml and the second station communicate using the allocated line, and after communication is completed, notify the master station that the line will be disconnected, and after receiving confirmation of line disconnection from the master station, complete all communication procedures. do. FIG. 3 schematically shows this. In this way, communication can be performed with extremely high line utilization efficiency. However, what is noteworthy about this method is the propagation escalation that occurs in satellite communications. In other words, in satellite communications, especially in geostationary satellite communications, there are zero
．． It takes 25 seconds. This also applies to the C10 line.
Mr. m, therefore, in order to be allocated a line, at least 0.
Requires 5 seconds. Also, 0.5 sec is required to terminate the line, and a total of 1 sec is required for line control.

Incidentally, the information transmitted via the satellite communication network includes not only instantaneous and large-capacity audio and images, but also small-capacity information such as e-mail and computer communication. By the way, when attempting to transmit such a small amount of information using the DAMA method, the line control time required to set up the line used for communication is far greater than the time required for communication. arise. In other words, extremely complicated procedures such as line allocation requests, line assignments, and line disconnections are required even for the transmission of extremely small amounts of information, and as a result, especially when there is a large amount of small amount of data, there is significant line utilization. Efficiency may decrease or congestion may occur.

(Problems to be Solved by the Invention) In this way, in the conventional technology, when transmitting a large amount of non-immediate small capacity data, the efficiency of line utilization is improved by making a line allocation request every time such small capacity data is generated. The average delay time of the CSC line increased when a C8C line was used.

Therefore, the present invention provides a satellite communication system that eliminates all the problems of the conventional technology, prevents a decrease in line usage efficiency, and reduces the average delay time when using a C8C line. The purpose is to

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a memory for temporarily storing small-capacity, non-immediate data to be transmitted through a satellite line in a memory corresponding to a partner ground station, and a memory for temporarily storing small-capacity, non-immediate data to be transmitted through a satellite line. When the line is opened for transmission, it is constituted by means for transmitting together the contents of the memory corresponding to the ground station on the other end of the line using the line.

(Function) In this invention, even if line setting using the DAMA method takes more time than data transmission, the capacity is small and
Accumulate non-immediate data once and use it for other purposes = DAM
When the A line is opened, they will transmit together. Therefore, excessive line congestion and transmission delay on the CSC line are reduced.

(Example) FIG. 1 shows an example of the present invention. Ground stations are A, B, and C.
...Equipped with open memory and accommodates many terminals such as fax, telephone, and e-mail. At any one of these terminals, small-capacity, non-immediate information is temporarily stored in a memory corresponding to the transmission partner station. When any of the terminals accommodated in this ground station transmits large capacity or immediate information, the DAMA slave station device requests line assignment, and when the line is opened, the large capacity or immediate information is transmitted. At the same time, the contents of the memory (small capacity, non-immediate information) corresponding to the other station are also transmitted at the same time. Voice is a typical example of this instant communication. In the voice communication line, the line where the voice information actually monopolizes the line - N is at most 5
It is about 0 to 60%.

During this time, it is easy to send out the information in the memory at the same time, and it also leads to an improvement in the line exclusiveness rate of the information. In addition, it is also possible to multiplex and transmit large-capacity files when transmitting them.

FIG. 2 shows an embodiment of the present invention in chronological order. That is, small volume non-immediate data issued from station B or station A 11.12.13...16,21゜22, .
. . 26 are temporarily stored in the A-side memo IJ of the B-station and the B1-interval memory of the A-station, respectively. Then, when a large capacity or instantaneous information transmission request 31 is issued from the terminal, station B issues a line allocation request 51 to the master station and receives line assignment. The contents of the corresponding memory are transmitted, and the line is then disconnected.

The present invention has many other embodiments, additional features, and the like. For example, if the data in the memory of each station exceeds a certain amount, it is effective to request line allocation before the memory flows out and transmit only the data stored in the memory.

In addition, in order to prevent the time accumulated in the memory from exceeding a certain period of time, if a line is not allocated for a certain period of time and some data is accumulated in the memory, a line allocation request is made. It is also possible to transmit data stored in memory. Furthermore, when the usage rate of the satellite communication network itself is low, the data in the memory may be transmitted.

〔Effect of the invention〕

According to the present invention, due to the transmission of data that can be transmitted in a much shorter time than the time required for line allocation, there are frequent requests for line allocation, a consequent decrease in line utilization efficiency, and an increase in CSC line delay time. It is possible to avoid this.

[Brief explanation of the drawing]

1 and 2 are diagrams for explaining the present invention in detail, and FIG. 3 is a diagram for explaining the conventional DAMA system. Agent Patent Attorney Noriyuki Ken Yudo Takehana Kikuo rv＊'Th Figure 1 Figure 2

Claims (4)

[Claims] (1) Communicate with other ground stations via a satellite line set up by the DAMA method, and correspond to individual ground stations that can communicate with a ground station that accommodates one or more terminals. The device is equipped with a memory for temporarily storing non-immediate, small-capacity data issued from the terminal of the ground station to be transmitted to the other ground station in the memory corresponding to the other ground station, and transmits the data between the ground station and the other ground station. , satellite communication characterized in that when a line is opened to transmit or receive data other than the non-immediate small capacity data, data stored in a memory corresponding to the destination ground station is also transmitted through the line. method. (2) The satellite communication system according to claim 1, wherein a line allocation request is issued to a partner ground station corresponding to the memory when a certain amount of data is accumulated in the memory. (3) If a line is not opened with the partner ground station corresponding to the memory within a certain period of time after data is stored in the memory, issue a line allocation request with the partner ground station. A satellite communication system according to claim 1, characterized in that: (4) When the line utilization rate is low, the DAMA master station line allocation device issues and transmits a command to transmit the data stored in the memory provided in the ground station to the partner ground station corresponding to the memory. The satellite communication system according to claim 1, characterized in that a line is also allocated.