Wireless Bridge Dry Goods Collection: A book takes you from first knowledge to knowledge

The bridge uses air as a medium to propagate signals, and the bridge at one end converts the signals in the network into wireless electromagnetic signals and directs them into the air. The bridge at the other end acts just the opposite. It receives the wireless electromagnetic wave signal in the air and converts it into a wired signal.
This can solve many difficult problems in cable deployment: highways, rivers, mountain barriers, or road hardening. In today's increasingly high construction costs and accelerating engineering progress, reducing engineering construction and accelerating construction progress has become a problem that must be taken seriously. Wireless transmission allows you to do more work with fewer people and directly enhance the company's competitiveness.
Four transmission modes of the wireless bridge

Point-to-point transmission mode
This is the simplest transmission mode, which is what we often call PTP, which is transmitted by a single device and then received by a single device. One-to-one transmission and reception is simple and straightforward. It is often used for transmission distances, or the distribution of monitoring points is extensive, and point-to-multipoint transmission cannot be achieved.
Point-to-multipoint transmission mode
In the development based on the point-to-point transmission mode, it often appears as a receiving end to multiple transmitting ends, which is often used in situations where the transmission distance is relatively close, the monitoring points are large, and the distribution is dense.
Relay transmission mode
Since the transmitting end and the receiving end block the microwave signal due to an obstacle that cannot be avoided, a relay device is added in the middle to allow the microwave signal to be smoothly transmitted to the receiving end through the relay device.
Reflection transmission mode
Microwave transmission and transmission is carried out by means of objects other than the transmission equipment. For example, the transmitting end and the receiving end cannot be seen, but there is a large building or a smooth rock wall in the middle, so that the device can be adjusted. From the perspective of wireless communication through buildings or mountain reflection microwave signals.
The difference between wireless bridge 2.4G and 5.8G
Different transfer rate
Due to the different standards they use, they are divided into different transmission rates. For example, 2.4G is divided into 802.11b or 802.11G or 802.11GN, and the bandwidth of this wireless LAN is up to 11Mbps, but we say that 5.8G is divided into two. Standard 802.11a or 802.11an, and is specified for data rates up to 54Mbps.
Can I connect to a WIFI hotspot?
The 2.4G band wireless bridge can be used as a WIFI hotspot. It can be connected to the INTERNET directly after receiving it from our computer or some WIFI devices, and the 5.8G band cannot be connected like this.
Disturbed condition, penetration capability, signal strength and transmission distance
1, 5.8g signal compared with 2.4g, the same frequency band interference is not so much, but the penetration ability is not as strong as 2.4g, easy to be absorbed by metal or other obstacles, better handling of signal reception and transmission.
2. The 2.4G wireless bridge has a stronger diffraction ability than 5.8G. For example, if you install a WIFI device at home, you can receive your signal next door or a little further away, so install it at home. When you are using the device, you should set a login password directly so that others can receive your signal, but you can't log in without a password.
3, due to the use of 2.4G frequency band WIFI, microwave oven, Bluetooth, many home wireless routers use this frequency band, so 2.4G is easy to cause channel interference problems, and 5.8G frequency band is not easy to cause interference!
4. 5.8G equipment has a longer transmission distance than 2.4G equipment, and the rain attenuation is smaller and the stability is better.
Installation and commissioning of the wireless bridge in the elevator
Here we will talk specifically about the use of wireless bridges in the most common elevator monitoring. Since 2015, the wireless bridge has been popular in elevator monitoring and application scenarios. It has simple installation, long service life and convenient management. It is a natural match with elevator monitoring. The direct selection of 5G bridge transmission is becoming more and more mainstream.
How to install the wireless bridge in the elevator?
(Example of Fengrunda Elevator Bridge S400):
1. First install a network HD camera in the elevator. The signal from the camera is led to the top or bottom of the car with a network cable.
2. Install an S400 on the top or bottom of the elevator to transmit the signal. Install an S400 on the top or bottom of the elevator shaft as the receiving end to receive the signal transmitted from the front end and ensure that there is no connection between the receiving end and the transmitting end. The PoE port of the PoE power module is connected to the PoE port of the bridge.
3. Connect the network cable from the camera to the transmitter bridge. The receiver then uses the network cable to route the signal to the network hub of the monitoring center.
How to configure debugging after installation?
1. Set the IP address of the computer to the same network segment as the wireless bridge.
2. Modify the network name (bridge). The names of the wireless bridges on the transmitting end and the receiving end must be the same.
3. Check the status of the wireless bridge, such as the signal of the connected device, the receiving/sending rate, and so on. The larger the signal, the better, and the higher the receive/send rate, the better.
How to avoid interference when multiple elevators?
1. There are four elevators in the same building. If the two are opposite, the frequency (channel) can be set alternately.
2. There are multiple elevators on the same side, and the complementary intersecting 1, 6, and 11 channels can be selected and interleaved.
How many cameras can I bring with a wireless bridge?
Regarding the number of pairs of wireless bridges and surveillance cameras, we have to consider three factors: the bandwidth occupied by the camera, the transmission distance, and the transmission bandwidth of the wireless bridge.
Camera bandwidth
The following is the calculation formula between the number of cameras and the transmission bandwidth of the wireless bridge:
Number of cameras = wireless bridge bandwidth / camera bit rate
Explain the bandwidth of the bridge inside, to consider the real-time transmission bandwidth of a bridge, the actual transmission bandwidth of the 1000M bridge may be only about 100M, that is, only about 20 million pixels of the camera.

Wireless bridge transmission distance and bandwidth
How to choose a wireless bridge?
Industrial grade stability
In order to ensure the stability of signal transmission, the protection performance of the bridge is especially important. Fengrunda Bridge is designed according to industry standards. After comprehensive three-temperature detection, lightning protection detection, wide temperature reliability test and wide voltage test, reliability is guaranteed. Excellent waterproof and dustproof performance allows normal operation in harsh weather conditions such as humid southern and northern winter. The configuration software watchdog system process is guarded for 24 hours, and the fault is automatically restored. In the security monitoring application scenario, the video is prioritized, and the priority transmission of the video image is ensured that the card is not stuck or lost, and the smoothness of the monitoring picture is ensured.
Super long transmission distance
For wireless bridges, the most important thing is to be able to transmit over long distances and to ensure signal stability. Therefore, the bridge used in the scheme adopts Qual Qualcomm scheme and TDMA technology, and the independent PA cooperates with the directional antenna to ensure stable transmission over long distances. Both 2.4G and 5G RF can give you a good data transmission experience. High-power directional antenna, 14dbi high gain, point-to-point transmission ultra-high throughput, can guarantee high-quality long-distance transmission in security scenarios. At the same time, considering the device expansion in the large security scenario, the solution can be arbitrarily added to the bridge according to the scenario requirements, which can realize point-to-multipoint transmission, and the scene flexibility is stronger and the scalability is better.
Easy to install, easy to manage
The Fengrunda Bridge is factory-free, and the default pair of bridges is automatically bridged, eliminating the need for cumbersome connection configurations. And the unique one-button master-slave switch setting, quickly realize one-to-many connection of the bridge, the setting is simpler and more user-friendly.
In large security scenarios, there are a large number of devices and they are widely deployed. Especially when the wireless bridge is outdoors, it is more difficult to manage. However, the bridge in the Fengrunda security scenario adopts the +AI cloud management solution, which can uniformly view the status of all devices and upgrade the configuration. Once the device is abnormal, the fault can be solved in the first time, which greatly simplifies device management.

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