Network Manual: outdoor WLAN layout details

Wireless network technology is already full of our daily lives, whether outdoors or indoors, so we need to consider more factors. Here we will introduce you to several layout methods.

Outdoor WLAN considerations

A wireless bridge can seamlessly connect a remote network to create a unified LAN. In a simple network, the bridge connects to a hub or switch of the LAN and is connected through cables and antennas; if the LAN network contains multiple subnets, the wireless bridge must first connect to the router.

There are many factors to consider when setting up an outdoor WLAN: the buildings to be connected must have a clear line of sight. Therefore, obstacles such as tall trees and buildings will directly affect the transmission of radio waves. When the bandwidth is reduced, the distance between buildings can be increased for long-distance transmission. At present, the distance between wireless transmission can reach a maximum of 80 kilometers in the case of accessibility, but in the application, the actual distance may be far less than 80 kilometers. Therefore, in the mountainous area, or when there is an obstacle, the distance should not be too long. If you really need it, you can set up a relay station in the middle to bypass the obstacle. During WLAN close-range transmission, in order to obtain the maximum bandwidth, you can connect the wireless bridge to a router that supports redundant channels, so that three wireless bridges can be integrated together, in addition, the antenna height is basically unaffected. Most WLAN devices require line-of-sight (LOS) transmission, so it is important to set the antenna height. If the antenna height is not enough, the method of increasing power amplification or antenna gain will produce very limited results. In the wireless coverage area, plan and select a channel that will not interfere with other wireless communications. If a building is connected through a WLAN, the antenna can be installed on the roof, and small antennas can be used to keep the electric waves concentrated to avoid interference from other enterprises. Although the wireless network uses the frequency hopping technology, it is difficult to detect the frequency carrier (that is, the security performance is good), but to prevent it, You can also set the network ID at the access point, in this way, the access point can be synchronized and connected to the network only when the two sides set the same ID number wirelessly. In addition, encryption in transmitted data is a further measure to improve security.

Field example

Wireless LAN has the following structures: point-to-point, point-to-point, multi-point-to-point, and hybrid. Various structures have different application scenarios. Users should choose carefully based on the actual situation.

Outdoor WLAN1. point-to-point

This type is usually used between fixed locations connected to the network, and is a common method of wireless connection. The network built using this connection method has the advantages of long transmission distance and high transmission rate, it is less affected by the external environment.

Outdoor WLAN2. point-to-point type

This type is usually used when there is a central point and Multiple Remote points. Its biggest advantage is its low network construction cost and simple maintenance. Secondly, due to the use of omnidirectional antennas in the center, equipment debugging is relatively easy. The disadvantage of this network is that the omnidirectional antenna is used, and the omnidirectional spread of the beam greatly degrades the power and the network transmission rate is low. The network reliability cannot be guaranteed for remote points over a long distance. In addition, because multiple remote stations share one device, network latency increases, resulting in a lower transmission rate. If the central device is damaged, the entire network stops working. Second, all remote stations and central stations use the same frequency. When a remote station is disturbed, other stations must change the same frequency, if multiple remote sites are affected, changing the frequency is more troublesome and cannot take into account each other.

Outdoor WLAN3. multi-point-to-point Model

This type is actually a combination of multiple point-to-point pairs. It is often used in networks with Multiple Remote points in a central point. Each remote point has its own device. A network composed of this method uses the point-to-point method for each point. Therefore, if a device in the center is damaged, only one point is affected and the entire network is not affected. When creating a large network, if each point uses the point-to-point method, the network cost is increased. In addition, the point-to-point method uses a targeted antenna in both directions, which makes it difficult to install and debug the device. However, considering the stability and reliability of the network after it is built, it is recommended to use point-to-point networking.

Outdoor WLAN4. Hybrid

This type of network is suitable for long-distance points, close-distance points, and blocked points of buildings or mountains. When constructing this network, the above several types of network methods are used comprehensively, point-to-point is used for long-distance points. Point-to-point is used for multiple points at close distance, and blocked points are retransmitted.