#夏日生活打卡季#
preface
Hello everyone, cloud intelligence knowledge sharing, in the monitoring system engineering installation practice, we need to develop monitoring design solutions according to different environments and different customer requirements, only a complete and suitable monitoring scheme can ensure the stability, economy and efficiency of the monitoring system. Today, let's talk about several transmission methods for the installation of several network monitoring systems.
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The first way: the traditional way, which is composed of IP camera + power supply + network cable
When the integrated wiring, the power cable and network cable should be laid at the same time, and the power supply can also be taken from the nearest 220V AC power, so as to save the power cable, and its pros and cons will not be discussed here. Power is provided to each network camera. Then there is a network cable to transmit network data to the network DVR NVR.
The second way: POE power supply mode, there is a network camera + POE switch
In this way, a power cord is saved than the previous way, and a network camera only needs a network cable as a medium for transmitting signals, and the power cord is no longer used. The network cable can be used with unshielded super five category twisted pair cable, and the transmission distance is 100 meters without any problems.
The connection method is as follows:
The third type: in the case of long distance, network camera + optical fiber + transceiver, can transmit farther!
As we said earlier, the normal transmission of network cable is within 100 meters, so if it exceeds 100 meters, we generally consider using optical fiber transmission, which not only has a long transmission distance (can transmit 20 kilometers) but also has a stable effect. We all know that when optical fiber transmits data, the data signal is converted into optical signal transmission, and then the optical signal is converted into a data signal, so that we use optical fiber transceiver to complete the work.
As shown in the figure:
The fourth: wireless transmission mode, camera + wireless bridge.
In the specific monitoring system implementation environment, if the wiring is difficult to encounter natural barriers or insurmountable obstacles, we can use wireless transmission, so that the wireless bridge is used. For example, in the community that has been hardened the road, elevators, factories that have been built, open areas that are far away, the field and so on, these environments are suitable for wireless transmission. A wireless bridge that converts network signals into radio waves for point-to-point transmission. Use in pairs. Due to point-to-point directional transmission, long-distance wireless transmission can be realized, from a few hundred meters to tens of kilometers. Precautions for the construction of wireless bridges: there can be no obstruction between the transmitter and the receiver, and there can be no obstacles. In this way, the signal transmission will be stable.
The fifth: long-distance transmission, network camera + optical fiber private network + transceiver
The monitoring and transmission network system mainly uses the operator's optical fiber resources to achieve the purpose of transmission, provides basic guarantee for the applications of the central management platform, and can better serve all kinds of users. The problem is that the cost is too high, and generally only public service projects use this kind of networking, such as the Skynet project.
The network structure is shown in the following figure:
Data center core
The core switch is the main device of the core layer, which is the brain of the entire network, and the configuration performance of the core switch is high. At present, core switches generally have dual power supplies and dual engines, so core switches generally do not use the dual-core switch deployment mode, but they have high requirements for backplane bandwidth and processing power with core switches.
Front-end video resource access
The front-end network uses an independent IP address network segment to complete the interconnection of multiple monitoring devices on the front-end. Front-end video resources are connected to the monitoring center or data room through the IP transmission network for aggregation. At present, two common methods are used for front-end network access, which are usually point-to-point optical fiber access and point-to-point PON access. The access layer provides support for the network access of NVR storage devices to ensure a safe and reliable network environment for NVR storage devices.