The digital data communication

With the D-STAR tranceiver, it is possible to do digital data communication, in addition to digital speech communication. If you mention digital communication of the former amateur radio, amateur packet transmission of the 1200bps is typical. In the HF band where occupied bandwidth does not come off amateur packet transmission was used with the 300bps. In addition there is also a result where amateur packet transmission of the 9600bps is used as a portion of transfer type network.
With amateur packet transmission, through the tranceiver of analog modulation system and the peripheral device which calls the personal computer, the TNC, being something which by the fact that you connect, data communication is possible, it does, but, modulation and demodulation is done with the aural signal of the analog of the modem which the TNC has, () with restriction of occupied bandwidth of active radio wave, transmission speed in fact was the 9600bps stopping with system and such as AFSK and PSK the amateur radio.

With the D-STAR tranceiver data communication of the 128kbps becomes possible. Although it is inferior to the transmission speed of broadband network of the Mbps unit, it is designed in such a way that it can do data communication easily at speed of 100 times that former amateur packet transmission of the 1200bps. Furthermore, former amateur packet transmission meaning that transmission speed and protocol et cetera differ, there is no compatibility.

- Application for Internet applied possibility

In regard to the connection of the equipment, it is the point where the difference with the packet transmission by the former analog wireless radio the TNC does not need in connection with the personal computer, as in the figure the left the 10BASE-T (the ethernet terminal) with connects. Application for Internet such as browser and Mailer can use the data communication between the personal computer which connects the D-STAR tranceiver, that way. Also the animated picture due to the speech communication and the streaming software of the Voice-IP is possible, but, whether with the amateur radio excessively it is not comfortable in connection with circuit capacity, the \u3057\u308c\u307e\u305b\u3093.

The upper figure, is the outline figure of operation of the D-STAR tranceiver when digital data communication is used.
As for transmission of data type communication, through interface (block of Interface), you tie the data which is inputted from the 10BASE-T terminal, the similar GMSK to digital speech communication modulate with block of the Transmitter and expand and transmit. Concerning reception, the GMSK it recovers same as the aural signal, passes by interface and from the 10BASE-T terminal the data is outputted to the personal computer.
Constitution of the packet of digital data communication has become as in the following figure.

The radio header section is similar to digital speech communication. After of this radio header section consists of the ethernet packet. With Internet this I - it transmits the data with the protocol, sir net packet and the TCP/IP. The digital data communication of the D-STAR those where communication and affinity of Internet are high are this kind of reason.
With the data communication of the D-STAR, because the data sending and receiving it is done with the completely same data constitution as Internet, it meaning that it is possible to utilize the application for Internet easily, it does.

- As for the digital data how being transmitted?

The following figure has displayed the process which sends message with digital data type communication.

From user A of the left side message is sent to user B of the right side. The respective TCP, the header of the IP and Internet is attached to the message which was made in the wire section. This is processed with the personal computer which is been connected automatically. Attaching the radio header to this ethernet packet which comes out from the 10BASE-T, it sends out with the radio. On receiving end you decipher this radio header, remove the header and you transfer to the personal computer which is been connected, from the 10BASE-T as the ethernet packet. After the personal computer processing automatically, it means that message appears in the personal computer of user B.