JP3000608B2 - Satellite communication system - Google Patents

Description

The present invention relates to a satellite communication system constituting a star network, and more particularly to a satellite communication system in which a master station and a plurality of slave stations are connected via a satellite. The present invention relates to a satellite communication system with improved data transfer to and from terminals belonging to a plurality of slave stations.

[Conventional technology]

Conventionally, in this type of satellite communication system, when a terminal belonging to a plurality of slave stations or a slave station requests the same data, the plurality of slave stations individually issue a data transmission request to the master station, and the master station transmits Since data was transmitted individually to each slave station, for example, 3
When there was a request for transmission of the same data from one of the small stations, the master station transmitted the same data three times, so that the efficiency of the entire system was poor.

[Problems to be solved by the invention]

In the conventional satellite communication method described above, even if the data is the same from the master station, the data is transmitted through the satellite line as many times as the number of the requested slave stations, so that the efficiency of using the number of satellite communication is reduced. is there.

[Means for solving the problem]

The satellite communication system of the present invention is a satellite communication system that configures a star network with a plurality of slave stations via a satellite and a master station holding original data.
An other station data discriminating circuit for discriminating whether the data sent from the master station is data of the own station or data of another station, a memory for storing the data in the case of data of another station, and connected to the slave station. A terminal interface circuit serving as an accepting unit for receiving a data request and a data transfer from / to a terminal, and performing data transmission via the terminal interface circuit when the terminal requests data in the memory.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of each slave station according to one embodiment of the present invention, FIG. 2 is a configuration diagram of a general satellite communication line, and FIG.
The figure is a sequence diagram of data transfer between a master station, a slave station, and a terminal according to the present embodiment. Now, the configuration of the satellite communication line on which the present embodiment is based will be described with reference to FIG. The master station 11 owning the original data forms a satellite communication line with the two slave stations VSAT1 and VSAT2 via the satellite 12, and the slave stations VSAT1 and VSAT2 are connected to the terminals 7A and 7B, respectively. Is supplied to the terminal. Next, as shown in FIG. 1, each of the slave stations VSAT1 and VSAT2
It has a transmission circuit 1 and a reception circuit 2 for communicating with the satellite 12. The transmission circuit 1 receives a data transmission request from the terminal 6, for example, and accepts the data at the terminal interface circuit 5, and sends a data transmission request to the master station 11 described later. Transmission circuit 1 if necessary
A data request is made to the via master station 11.

The other station data discriminating circuit 3 is a circuit for discriminating whether the output data of the receiving circuit is the data requested by the own station or not.
The memory 4 stores the data for another station in the memory 4. Next, a time sequence of data exchange between the master station 11, the slave stations VSAT1 and the terminals 7A and 7B will be described with reference to FIG. First, when there is a request for data 1 of VSAT1 from the terminal 7A, VSAT1 requests data 1 from the master station and has it transmitted. At this time, VSAT2 also receives data 1,
Since the data is not intended for the own station, it is stored in a memory. Next, similarly, when the terminal 7A requests the data 2 from the VSAT1, the data 2 is stored in the memory also in the VSAT2. That is, data 1 and data 2 are stored in the memory of VSAT2. At this time, when the terminal 7B requests the data 2 from the VSAT2, the data 2 is stored in the memory of the VSAT2.
Data can be transmitted to Next, when the terminal 7B requests the data 3, since there is no data 3 in the memory of the VSAT 2, the request 1 is actually transmitted to the master station.
Also, when broadcasting from the master station to multiple slave stations,
The other station data discriminating circuit 3 discriminates that the broadcast is to all stations, and can transfer the data to the terminal.

〔The invention's effect〕

As described above, the present invention provides a memory for storing the transmission data of the master station in each slave station, so that when a request for data stored in the memory is generated from the terminal, the slave station transmits the data. Since data can be transmitted to the terminal without receiving it, there is an effect that the throughput of the entire satellite communication system is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, FIG. 2 is a configuration diagram of a general satellite communication circuit, and FIG. 3 is a data sequence diagram of the present embodiment. 1 ... transmitting circuit, 2 ... receiving circuit, 3 ... other station data discriminating circuit, 4 ... memory, 5 ... terminal interface circuit, 6, 7A, 7B ... terminal, 11 ... master station, 12 ... … Satellite, VSAT
1, VSAT2 …… Slave station.

Claims (2)

(57) [Claims] In a satellite communication system in which a star network is formed with a plurality of slave stations via a master station holding original data and a satellite, the plurality of slave stations are transmitted from the master station. Another station data discriminating circuit for discriminating whether data is data of the own station or data of another station, a memory for storing the data in the case of data of another station, a data request from a terminal connected to the slave station, and A satellite communication system, comprising: a terminal interface circuit serving as a data transfer receiving unit, wherein data transmission via the terminal interface circuit is performed when the terminal requests data in the memory. 2. When the data communication from the master station is a broadcast communication, the other station data discriminating circuits of the plurality of slave stations indicate that the data is the own station and other station data indicating that the communication is the broadcast communication. The satellite communication system according to claim 1, wherein the determination is performed.