基于位置的船舶机会网路由研究

发布时间：2019-05-29 17:18

【摘要】：我国是世界上重要的海洋大国,大陆海岸线长达18000多千米,广阔无垠的海洋中蕴含着丰富的资源,21世纪是海洋世纪,实现海洋信息化是时代的要求,海洋互联网是实现海洋管理信息化的基础,因此积极发展海洋互联网技术有着重要而深远的意义。目前,海洋上的网络通信远不如陆地发达,在缺乏基础设施,自然环境恶劣的情况下,除卫星通信外,在海上要接入互联网络往往比较困难,海洋上的船舶之间依靠相遇机会,可能完成通信。机会网络往往不依赖于基础设施,不存在贯穿始终的端到端连接,通过节点移动带来的相遇机会进行数据转发。本文针对海洋环境特点,将机会网络应用于海洋互联网,结合船舶的运动特征,展开对船舶机会网络及其路由的研究。由于海洋面积大,船舶(通讯节点)分布稀且不均匀,造成船与船相遇通信的概率相对较低,并且没有专门的船舶机会网路由,传统协议性能不高。基于以上问题,根据船舶航行速度较慢,障碍物少,有固定的航道,船舶位置可预测等相关特征,结合海洋上船舶机会网络的特点,设计出一种基于位置信息的船舶机会网路由协议,提高了海洋上船舶之间通信的可能性和组网后的网络性能。本文的工作主要包括以下几个方面:(1)对机会网络进行了介绍,分析了船舶机会网络的特点,指出了现有的机会网络路由的不足之处;(2)对机会网络的连通性评价指标进行了分析,构建了一整套系统的连通性度量方案,通过计算路由探测包的收发比来分析整个网络的性能,在仿真平台上进行了验证;(3)根据海洋环境特点和船舶移动特性,利用卫星定位获取船舶位置信息,AIS获取航向方向及速度,结合拉格朗日多项式插值算法预测下一个时间点的船舶位置,提出了一种船舶位置预测的方案;(4)分析了经典机会路由协议的缺点,对Spray and wait协议进行了改进,引入船舶的位置信息,结合上述的位置预测算法,设计出新的路由协议,提高了路由收敛速度,在一定程度上提高了网络性能;(5)依据真实的航道,建立网络模型,进行仿真,对实验数据进行具体的分析和说明。实验结果表明,与现有的经典机会路由协议相比,本文所提出的算法在数据包传输成功率方面有明显提高,路由收敛时间减少,路由开销降低;另一方面,在海洋场景下,以探测包的收发比为度量,参照原来的协议,改进后的P-SAW协议在连通性方面有较大的改善。
[Abstract]:China is an important marine power in the world, the coastline of the mainland is more than 18000 kilometers long, and the vast ocean contains rich resources. The 21st century is the marine century, and the realization of marine informatization is the requirement of the times. Marine Internet is the basis of realizing ocean management informatization, so it is of great and far-reaching significance to actively develop marine Internet technology. At present, the network communication on the sea is far less developed than that on land. In the absence of infrastructure and the harsh natural environment, in addition to satellite communication, it is often difficult to access the Internet at sea, and ships on the sea rely on the opportunity to meet. Communication may be completed. Opportunity network often does not rely on infrastructure, there is no end-to-end connection throughout the process, and data forwarding is carried out through the encounter opportunity brought by node movement. In this paper, the opportunity network is applied to the marine Internet according to the characteristics of the marine environment, and the research on the ship opportunity network and its routing is carried out according to the motion characteristics of the ship. Because of the large ocean area and the sparse and uneven distribution of the ship (communication node), the probability of communication between the ship and the ship is relatively low, and there is no special ship opportunity network routing, and the performance of the traditional protocol is not high. Based on the above problems, according to the characteristics of slow navigation speed, few obstacles, fixed waterway, predictable ship position and so on, combined with the characteristics of marine ship opportunity network, A ship opportunity network routing protocol based on location information is designed, which improves the possibility of communication between ships on the sea and the network performance after networking. The work of this paper mainly includes the following aspects: (1) the opportunity network is introduced, the characteristics of ship opportunity network are analyzed, and the shortcomings of the existing opportunity network routing are pointed out. (2) the connectivity evaluation index of opportunity network is analyzed, and a set of system connectivity measurement scheme is constructed. the performance of the whole network is analyzed by calculating the transceiver ratio of routing detection packets, and verified on the simulation platform. (3) according to the characteristics of marine environment and ship movement, the ship position information is obtained by satellite positioning, the heading direction and speed are obtained by AIS, and the ship position at the next time point is predicted by Lagrangian polynomial interpolation algorithm. A scheme of ship position prediction is proposed. (4) the shortcomings of the classical opportunity routing protocol are analyzed, the Spray and wait protocol is improved, the position information of the ship is introduced, and a new routing protocol is designed according to the above location prediction algorithm, which improves the convergence speed of the route. To a certain extent, the network performance is improved. (5) according to the real waterway, the network model is established, the simulation is carried out, and the experimental data are analyzed and explained concretely. The experimental results show that compared with the existing classical opportunity routing protocols, the proposed algorithm improves the success rate of packet transmission, reduces the routing convergence time and reduces the routing overhead. On the other hand, in the ocean scene, the improved P-SAW protocol has a great improvement in connectivity by taking the receiving and sending ratio of the detection packet as a measure and referring to the original protocol.
【学位授予单位】：上海师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.5

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