Application and advantages of Wireless LAN in Video Surveillance

From: Source: Network Interface

Wireless Local-Area Network (WLAN) provides Ethernet or token Network functions without using traditional cables. Generally, the transmission media in computer networks rely mainly on copper or optical cables to form a wired LAN. However, in some cases, wired networks are restricted by wiring: a large number of cabling and line change projects; lines are prone to damage; nodes in the network cannot be moved. Especially when connecting distant nodes, it is difficult, expensive, and time-consuming to build dedicated communication lines. This creates a serious bottleneck for the rapidly expanding demand for networking.

With the rapid development of video monitoring, wired network alone cannot fully meet the needs, and is not the most economical way. Therefore, wireless network monitoring is gradually favored by integrators as a special way of using wireless networks. More and more monitoring systems use wireless methods to establish connections between monitored points and monitoring centers.

1. Advantages of wireless network video monitoring

Compared with traditional monitoring solutions, wireless network monitoring has the following advantages.

(1) Easy installation

Generally, in network construction, network cabling construction projects have the longest construction period and the greatest impact on the surrounding environment. During the construction of a wired network, it is often necessary to break through the walls and drive the cables. The biggest advantage of a wireless LAN is to avoid or reduce the workload of network wiring. Generally, you only need to install one or more AP (access point) devices, you can create a local area network covering the entire building or area.

(2) flexible networking

In a wired network, the placement of network devices is limited by the location of network information points. After the wireless LAN is built, the network can be connected to any location in the signal coverage area of the wireless network.

(3) low maintenance costs

The lack of flexibility in wired networks requires network planners to consider future development needs as much as possible, which often leads to a large number of Preset low-utilization information points. Once the development of the network exceeds the design plan, it will take a lot of money to perform network transformation, while the wireless LAN can avoid or reduce the occurrence of such a situation.

(4) good scalability

A wireless LAN can be configured in multiple ways and can be flexibly selected as needed. In this way, the wireless LAN can be competent for a small LAN with only a few users to a large network with thousands of users, and can provide functions that cannot be provided by wired networks such as "roaming.

2. Application Scope of wireless network video monitoring

WLAN video monitoring can be widely used in a wide range of security monitoring, traffic monitoring, industrial monitoring, Home monitoring, and many other fields, in general:

(1) wireless network monitoring of ATMs, bank clerks, supermarkets, factories, etc;

(2) nursing homes, kindergartens, and schools provide remote wireless monitoring services;

(3) unattended systems for power stations and mobile base stations;

(4) wireless monitoring systems for oil, drilling, and exploration;

(5) smart buildings and Smart Community wireless management systems;

(6) Pipeline Monitoring and wireless supervision of warehouses;

(7) 24-hour monitoring of road traffic;

(8) wireless remote monitoring of forest, water source, and river resources;

(9) Monitoring and Management of outdoor equipment;

(10) Traffic Monitoring System for bridges, tunnels, and intersections.

3. Outdoor networking

Wireless LAN has the following structures: point-to-point, point-to-point, and hybrid.

(1) point-to-point

Point-to-point models are commonly used in wireless networking and are fixed between two locations for networking. The advantage of this network is that the transmission distance is long, the transmission rate is high, and it is less affected by the external environment, as shown in Mode 1.

(2) point-to-point

Point-to-multiple is often used when there is a central point and Multiple Remote points. Its biggest advantage is its low networking cost and simple maintenance. Secondly, due to the use of omnidirectional antennas in the center, equipment debugging is relatively easy. The disadvantage of the 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.

(3) Hybrid

This type is suitable for building networks with long distance points, close points, and buildings or mountains blocking points. When establishing such a network, the above network methods are used comprehensively. Point-to-point methods are used for long-distance points, and point-to-point methods are used for multiple points at close distance, blocked points are retransmitted.

4. engineering instance

On the basis of unified planning and management, the "wireless network video surveillance system" project adopts fixed-location camera, A variety of video capturing devices (Network gun camera, digital network ball camera, network video server, infrared night vision camera, etc.) are used ), in different geographic locations and perspectives, such as transportation environments, mountain environments, and high-rise environments, high-quality image shooting is performed for important scenarios and main parts of different areas of the Community, the captured images are transmitted to the monitoring center through radio waves.

Specifically, the wireless networking mode is point-to-point: the clubhouse-monitoring center (2.4 GHz ). Equipment Selection: AP equipment is generally used WA1208E-GP, can ensure normal operation in harsh environments, waterproof lightning protection function, and high data stability transmission; at the same time, the use of 2.4GHz vertical polarization oriented antenna, ensures strong signal strength and ensures smooth image data transmission.