【作者】 吴华锋；

【导师】 孙文力；

【作者基本信息】 大连海事大学 ， 交通信息工程及控制， 2004， 硕士

【摘要】 AIS是一种船舶监测系统，并隶属于无线移动通信网络范畴，其网络性能是AIS的研究及应用中的一个关键问题。本论文就以源自交通部科教司的课题“基于STDMA技术的船载自动识别系统的基础研究”为背景，针对AIS的网络吞吐性能、监测容量及网络半径等问题，开展了广泛而深入的研究，并取得了一些成果。 本文首先简要介绍了船载自动识别系统的发展概况及其系统结构和原理，进而对AIS的通信原理即自组织时分多址(STDMA)通信原理进行了分析，并尝试性地建立起一套AIS的网络性能评价指标。然后基于这些原理和指标，以IMO、IEC及ITU等国际组织所建立的AIS相关的国际标准为依据，分别对AIS的网络吞吐性能、监测容量以及网络半径等重要性能进行了深入的分析和研究，并得出以下结论： 1)当AIS台站得到完全组织，且负载低于60.5％的情况下，其吞吐率几乎是100％。在不完全组织且负载不一定低于60.5％的情况下，则根据距离AIS台站的远近将其监测范围从近到远划分成三个区域，即保护区域、识别区域以及混淆区域。当负载较高时(高达500％)，在保护区域内仍然可获得很好吞吐性能，从而保证了近距离物标的可见。因此，AIS的吞吐性能是能够满足航海需求的。 2)一般情况下，在VTS管区水域内AIS的监测容量为814艘，在非VTS管区的航行水域内AIS的监测容量为246艘。因此，目前AIS的应用是能够满足当前各个水域中船舶数量的要求的。但在将来或是在交通非常繁忙的水域，则有必要再采取一些相应的措施。 3)AIS的网络半径主要受限于AIS中VHF频段的无线电波直线传播特性。因此，它主要跟AIS台站的天线高度有关，一般情况下认为船舶AIS台站的监测范围为25海里，VTS的AIS台站的监测范围为45海里。在两船对遇初期，该范围有可能会受到一定的削弱，但一般不会超过1海里。另外，当发生同步时源丢失的情况时，监测范围也会受到影响，但在同步时源丢失后的3个小时内仍能满足AIS的监测范围要求。因此，正常情况下，AIS的监测范围是能够满足航海需要的。更多还原

【Abstract】 AIS is a kind of ship surveillance system, belonging to the wireless mobile communication network category, and the network performance is a key problem in the research and application of AIS. Based on the project "Study on The Basic Theory AIS Based on STDMA Technology" organized by the Ministry of Communications of the P.R.C., a broad and deep research on the network throughput, monitoring capacity and monitoring radius is developed in this paper and some useful results are obtained.Firstly in this paper, the development course of AIS and its basic operation principles are introduced briefly, and also the communication principle of STDMA is analyzed. Then, based on these principles, regard AIS related international standards set up by IMO, IEC and ITU as basis, the network performance of AIS, such as throughput, monitoring capacity and monitoring radius were profoundLy studied. By the analysis and study of the network performance of AIS, several conclusions were drawn as follows:1) When got fully organized and the network load is lower than 60.5%, the throughput of AiS is almost 100%. While not fully organized and the network load may not lower than 60.5%, then according to the distance to AIS stations, the monitoring area of AIS is divided into 3 zones. From close-by to far-off, the 3 zones are: protected zone, discrimination zone and garbled zone. When load is relatively high, even 500%, very good performance of throughput can still be achieved in the protected zone, thus guaranteeing that the close quarter things can be caught. So, the performance of AIS’s network throughput can satisfy navigation demand.2) Under general situations, the monitoring capacity of AIS is 814 ships in the VTS waters and 246 ships in non-VTS waters. So, the application of AIS can satisfy request for the quantity of shipping in each waters at present. But in the future or in the waters with very heavy traffic it is necessary to adopt corresponding measures.3) The monitoring range of AIS is mainly limited to line-sight characteristic of the radiowave of VHF frequency. So, it is mainly related to the height of AIS’s antenna. Generally, the ship AIS’s monitoring range is 25 nautical miles and the VTS AIS’s monitoring range is 45 nautical miles. In the initial stage of ships’ meeting, this range may be impacted a certain one, but it would be less than 1 nautical mile. In addition, were the synchronization time source lost, the monitoring range might aIso be impacted. But within 3 hours after the loss of time source, it could still maintain its normal values. So, under the normal situation, the monitoring range of AIS can meet the demands of navigation.更多还原