wifi long-distance module communication maritime integrated wireless ad hoc network, since the 20th century, the communication system has experienced from cable to optical cable, wired to wireless, from analog to digital, from 1G to 5G, the development of land communication system software has been changing day by day Trend change. However, in the vast sea, the development of marine communication network is significantly behind the land communication network because of the complex and changeable marine environment and the difficulty of construction at sea. In recent years, with the increasing trend of maritime theme activities in my country and the rapid development of maritime economy, product development of a new generation of wifi long-distance module marine communication technology and system software has already become an important focus of attention in the academic circles. Whether it is seaports, wharves, coastal communication system software, coastal island communication systems, offshore ship formation, unmanned ship formation, sea-sky integration, and offshore platforms, there are more and more Internet networking requirements, and the required methods are also diverse. The requirements of long-distance, high-bandwidth, video, voice, data information, manipulation and other requirements are becoming more and more urgent.
The marine communication network mainly includes the maritime wireless communication system, the maritime satellite communication system and the shore-based mobile communication system based on the terrestrial cellular network. Because of the incompatibility of the communication system of this communication system, the different communication bandwidths, the blind spots at the coverage level, and the lack of efficient and unified management methods, marine communication networks are increasingly unable to consider the growing requirements for maritime themed activities in our country. , has become a major bottleneck restricting maritime development and exploring deep-seated development trends. Therefore, it is necessary to fully investigate the development trend of my country's maritime communication, understand the world's advanced maritime communication technology, explore a maritime channel model consistent with the maritime environment in my country, develop and design a maritime communication network architecture suitable for my country's national conditions, and build a A new type of maritime communication network with high speed, high reliability, full coverage, easy management method and low cost.
The widely used marine wireless communication system mainly includes wifi long-distance module marine wireless communication network, marine satellite communication network and shore-based mobile communication network, which together constitute a communication network architecture that basically realizes full coverage of the ocean. This system can ensure the daily communication of near sea, far sea, ship to coast and ship to ship; in the fields of marine transportation, oil and gas exploration and exploitation, marine environment monitoring, marine fishery, marine aquaculture and marine scientific research, it provides relatively reliable and accurate , Timely and secure communications infrastructure.
The coastal communication system can form a remote internal network system through ground optical fiber lines. Ships close to the coast can be interconnected with land base stations through the marine wireless ad hoc network communication system. When the ship is far away from the coastal basic wireless communication system, it can be combined with the ground center. The satellite communication system , the small ships around the mother ship can be connected with the mother ship through the self-organized network communication system built by the ocean, and the large ships can be connected with the coastal foundation or the island communication system or the high-altitude satellite communication system to form an effective marine communication network.
The so-called chain topology is not only through the direct transfer of nodes between adjacent nodes, but also through the communication between adjacent nodes. There are two main implementations:
The advantages of wifi long-distance module Mesh ad hoc network single frequency point and frequency group network jump communication are flexible settings, convenience, no center, and no trouble from the sequence of devices.
Relay transmission is also divided into two modes, one is an ordinary point-to-point bridging device, which needs to manually set the frequency points and sorting order (as shown in Figure 5), and each node needs to place a dual-frequency point communication device (which can be two device, or a device with two independent RF channels). Another way is to set up master and slave. After adjustment, the master station can issue commands to automatically arrange the networking.
The application of wireless networking is mainly a point-to-multipoint working method, which is mainly a central working method, and each point must be interconnected through a central node.
Each node in each of the wifi long-distance modules can be connected to each other, and each node can be connected to multiple nodes in the network, and at the same time, the phenomenon of a ring network can be avoided. The device itself can judge the direction of the data according to the network conditions.
Hybrid topology combines point-to-point (chain network), point-to-multipoint (star network), mesh network, tree topology, ring map, etc. Hybrid networking is often used in practical applications, which can maximize the advantages of various network structures and is more economical and reasonable.
4. Typical examples of marine communication applications
1. Ad hoc network communication application for marine emergency rescue.
2. Ad-hoc network communication application for maritime patrol.
3. The comprehensive communication support should be applied for boarding inspection at sea.
4. Self-organized network communication control system, unmanned target ship drill at sea.
5. Wireless ad hoc network communication guarantees the comprehensive application of ocean-going scientific research ships.
6. Application of unmanned ship formation networking.
7. Integrated application of wireless communication network by sea, land and air.
8. Marine buoy applications for fleet wireless communication networking.
9. The integrated wireless communication networking is applied to offshore platforms, buoys and satellites.
