In many important places, it is quite necessary to install remote monitoring system in order to protect the safety of personnel and property on site. However, due to various reasons, there is no way to pull the network cable to access the Internet, such as remote mines, forest fire prevention, tunnel entrances, coastlines, border defense lines, large-scale buildings that have been built, there is no way to dig wiring, etc. these key places that need remote monitoring, but there is no Farah optical fiber or network cable, which was difficult to realize remote monitoring in the past. With the development of 4G communication technology and the large-area coverage of 4G network in recent years, the development of 4G image transmission technology of surveillance camera manufacturers makes it easy to realize smooth remote 4G monitoring, which can easily solve the problem that remote monitoring can be realized without network cable. Below, the author will talk about our experience in 4G image transmission technology in recent years:
1. In order to solve the problem of not being able to access the Internet and requiring remote monitoring, it is entirely possible to use 4G image transmission technology. Here, a key problem is that we should use industrial 4G network module to do the core communication of image transmission. What is the difference between industrial 4G communication module and civil 4G communication module? The 4G communication modules used on our mobile phones are civil level. Other usb4g adapters, mifi4g routers and power bank mobile 4G devices are civil level 4G modules. They have a common feature of miniaturization and lightweight. Because they are designed for household use, lighter and thinner is the consistent goal, This makes him more demanding on the environment. Because of his high integration, calorific value is a big problem. Generally, it doesn’t work much when the ambient temperature exceeds 45 degrees. Another point is that civil 4G modules will save many components in the protection circuit, so they are sensitive to current instability and have poor lightning protection performance; The industrial 4G module is designed for industrial applications. Its characteristics are: pursuing stability and durability, it can have a wider temperature application range and greater withstand voltage and lightning protection performance. Our outdoor monitoring system is to be exposed to the wind and sun in a harsh outdoor environment, so our first choice is the industrial 4G communication module.
2, to solve the problem of not being able to access the Internet and remote monitoring, the 4G operators who choose the sites for the engineering equipment are also very important. There are three main operators in China Chinese mainland: China Mobile, China Unicom and China Telecom. They are almost the same in the development of 4G Technology, no difference between the best and the inferior, but they are different in the 4G signal coverage of different places. This must be based on the actual measurement. The best way is to use 4G network mobile phones of different operators to measure the smoothness of video download at the monitoring points to be installed. Use the one that is smooth. Of course, if we also consider the problem of switching to 3G signal when 4G signal is unstable, the technology of China Unicom and China Telecom in 3G will be more mature.
3. In order to solve the problem of not being able to access the Internet and requiring remote monitoring, the traffic cost is also key when using 4G image transmission technology. The equipment is purchased and installed at one time. The cost of traffic is like that of mobile phone, which is consumed continuously. Therefore, we have these suggestions in this regard: 1. Use 4G surveillance camera with three code stream format. The so-called three code stream is: main code stream —– generally used for local video recording; Sub code stream —- for remote computer viewing; Mobile phone code stream —- for mobile phone remote viewing. When using mobile phone or PC monitoring at ordinary times, we generally recommend to adopt the principle of “see if you want”, that is, open the software and watch the video only when you want to watch, so as not to waste traffic. Moreover, when watching, you must select sub code stream to watch. If you find any abnormality, switch to the main code stream to watch, Because the traffic of the sub code stream is equivalent to 20% of the main code stream, while the mobile code stream will be smaller. 2. The selected 4G surveillance camera should have the storage function of front-end equipment (camera), and the storage format should be adaptive storage – HD storage only when it is moving, and sub code stream storage when it is static, which will save a lot of storage space. 64g card can also be stored for more than 10 days, so that we can use the camera to patrol regularly and at a fixed point. Once a problem is found, Call the video of the front-end camera to find out the cause. 3. It would be better if the 4G surveillance camera could capture images regularly and send them to the server. Capturing images is a good way to save evidence, easy to browse and save traffic. For example, Yutong’s yt-4gtf7130le4g image transmission surveillance camera has the function of capturing and sending FTP from 1 second to 9999 seconds. A 1080p Full HD picture is only about 400k. Capturing a picture in 5 minutes will not exceed 4G a month.
4. If there is no way to supply power where monitoring needs to be installed, using solar + wind power supply system and 4G monitoring camera is the best choice.
Responsible editor: CT