The Research Of Key Technology For MIP-AIS Based On Public Communication System

Since human began sailing, has been faced with the security/safety problems. With the electronic information technology developing, the technology of maritime security also has been changing. Those technology or systems play an important role, such as radio voice communication, radar/ARPA, GNSS, satellite communication, the automatic identification system (AIS), GMDSS, and so on. In there, AIS is a new maritime security system, which just arises in this century. However, since it has been applying, AIS was to play a crucial role in the collision prevention and maritime security. But, AIS based SOTDMA technology and VHF frequency has two key defects: one is limited system capacity, and the other is that 9.6kbps communication bandwidth of AIS based VHF frequency is too narrow. Those problems cause AIS system can't meet the ship more and more information transmission requirements in the coastal and inland waterway. Especially, can't satisfy the e-Navigation strategy development needs. Therefore, this paper put forward an automatic identification technology based on the public network GPRS/CDMA/3G mobile IP technology. which can be effectively make up for the deficiency of the general AIS system. And, it is especially important for the ship automatic identification in the coastal and inland waterway. So, this thesis mainly completes the following tasks.(1) The research of MIP-AIS (Mobile IP Automatic Identification System) model based public network GPRS/CDMA/3G mobile IP communication system. In this paper, we firstly propose the model of public network MIP-AIS. And then, design S-C (Ship-Center), S-CA(Ship-Center Assisting) and S-S (Ship-Ship) three identification modes. Using this technology, a ship can automatically identify others in its identification range at the public network MIP-AIS system. This thesis also defines the business functions of public network MIP-AIS, and analyses the features of S-C, S-CA and S-S identification modes. Theoretical analysis shows that the implementation of S-C mode is simplest, but, it requires more communication bandwidth and causes higher work load for ship identification center. The S-C mode isn't adequate for enormous ship terminals on line at the same time, however, the cooperation of S-CA and S-S mode can solve the problem. (2) The research of Center Assisting Automatic Identification Search Algorithm (CAAISA), based on Interim SIN Automatic Identification Search Algorithm (ISAISA) and Self Organization Automatic Identification Search Algorithm (SOAISA). With these algorithms cooperating, one ship in the public network MIP-AIS can quickly identify and obtain other ships in its identification range at any stage. According to the three algorithms, we designed the key function, execute flow and the applicative ship distributed architecture, In addition, theoretically analyse the efficient of those algorithms. The study indicated that these three algorithms are appropriate for different stage at public network MIP-AIS. When cooperating, they can effectively improve the efficiency of ship identification center.(3) Information transmission technology in the public network MIP-AIS. Firstly, we design the information transmission protocol of public network MIP-AIS and the MINI mobile IP protocol in the terminal device, accordingly to the ISO/OSI architecture. And, design three work stages of ship terminal device, which are the first on line stage, re-identification off line stage, and work stage at movement. In this paper, provides the work flow status and information transmission messages of each stage. Moreover, studies the terminal device technical architecture of public network MIP-AIS, discusses the stage transition flow and optimization method of MINI mobile IP protocol stack. The MINI mobile IP protocol is much fit for the low-end terminals of public network MIP-AIS, ensures the real-time of information transmission, improves the cost performance of ship terminals.(4) Business dispatching algorithm based on the PID theory. Effective muti-business dis-patching is a problem in the public network MIP-AIS ship identification center. In the thesis, multi-business dispatching algorithm is put forward, which is based on the PID theory. This algorithm integrates the complexities of business types and the proficiency of business processing terminals. In practical, the algorithm can effectively balances the workload of business processing terminals of ship identification center in the public network MIP-AIS, and improves the business processing efficiency.(5) Developing the ship identification service software and the ship terminal of public network MIP-AIS. Practice has proved that the public network MIP-AIS can effectively make up the deficiency of the general AIS, and realize the automatic identification between ships.