4.2 Mobile Communication

It is essential to apply the suitable data communication system to realize the seamless management for both ships and trucks. Therefore we developed the data communication software by using of TCP-IP protocol on the basis of packet communication technology. Between the ships and the ship management company, the satellite packet communication system which is in service from April 2000 by NTT DoCoMo, is applied, and between trucks and the vehicle management company, the mobile packet communication system, DOPA by NTT DoCoMo is applied.

The principal particular of the satellite packet communication service and the mobile packet communication service are shown in Table 1.

　

Table 1 Details of the satellite and mobile packet communication service

　

The data communication by using the current marine satellite telephone has to repeatedly connect and disconnect in order to exchange the information every time. However, the packet data communication can communicate continuously without line disconnecting. And current telephone is charged according to the consumed time during the line connection, but the packet telephone is charged by the mount of transmitted packets (128bite=1packet). Economical data communication can be realized with packet communication even if the communication line is connected all the time.

By using of packet communication, the system can transmit the necessary data such as operation order, cargo loading order, any information from the company's office to ships and trucks, and transmit the confirmation of the received information, report, etc. from ships and trucks to the company's office.

　

4.3 Information supply service

The WEB server supplies information about ships and trucks, such as their position or status through the Internet for specified users who have the identification code. At the branch office of the carrier or the transportation management company, the users can get the necessary information such as mobile's position on the electronic map all the time by using of Internet and HTML viewer.

And the WEB server has the security function that can manage and control user's accesses through Internet so it can prevent unauthorized accesses by unexpected users.

　

Fig.5 shows the sample display of the information service with homepage style.

　

Fig. 5 Sample display of information service with homepage style

　

4.4 Voice Input/Output

To operate the mobile system, voice input/output function is available which frees the user to operate the system at any time without causing danger to him or others because of being distracted by sailing or driving. The system can output important information by voice message, so usually it is not necessary for the operator to watch the monitor. Moreover, voice-input can control as scroll or zoom up/down of digital map, so the operation of the system become easier.

To construct this function, we used off-the-shelf software of speech recognition and voice synthesis.

　

5. FIELD TEST AND ITS RESULT

　

We carried out the field test through the real management work for about two months through the cooperation of some of the ships and vehicles management companies. During this period, this system was tested to evaluate its on availability and practicality. Four (4) ships and trucks are tested. Fig.6 shows the outline of test equipment onboard the ship. Fig.7 shows the outline of test equipment on trailer truck.

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