By establishing a digital network covering the city's main roads and junctions, the traffic junctions video monitoring system, equipped with the image wireless surveillance cameras and software, traffic intersection vehicle operating conditions can be transmitted in real time to the dispatch center to monitor road vehicle operating conditions. At the same time, the public security traffic management departments according to the actual situation of road traffic flow control, the arrangements for the vehicle to the smooth flow of road sections, reduce congestion, to ensure a smooth flow of road traffic, intelligent urban traffic management to solve the urban traffic congestion phenomenon very important. Urban traffic intersection control points and traffic control centers are generally far apart, and their distribution is more dispersed, using traditional network cabling cost is very high, long construction period, and the scalability and flexibility of poor, once the need to increase or reduce the monitoring points, will bring a new construction cycle. Wireless network monitoring points and the traffic control center connected and set up quickly, quickly established a wireless network link in the shortest possible time, using a wireless bridge can support as far as 50 km above the bridge. In order to guarantee the stability of the transmission of video compression file must have enough network bandwidth, different video compression files on network bandwidth requirements vary, all the more important in order to achieve better video quality and network bandwidth. The wireless network standard protocol the IEEE802.11a definition of network bandwidth to 54Mbps, the effective data transfer bandwidth of 22Mbps, wireless links to achieve high network bandwidth of 54Mbps. Wireless video surveillance system has the following advantages and features: easy installation and construction, and use the wireless network to avoid or reduce the workload of the network cabling, without undermining the original environmental facilities, with a short construction period, high cost; achieve rapid coverage The biggest advantage of the Wi-Fi system is able to achieve rapid coverage using point-to-multipoint wireless communication, generally only need to install one or more wireless central station equipment, you can establish a broadband wireless access network system to cover the entire area of the city; high flexibility, the city traffic intersection has a wide distribution, geographical dispersion characteristics, lack of flexibility, a wired network must consider the needs of future development as much as possible, which must be the default lower utilization information, and After the completion of the wireless network, wireless signal coverage any one location in the region set up a wireless terminal station, network access can be achieved, and a high degree of flexibility; scalability, management without the need to increase the business point area network transformation, only need to increase or decrease the monitoring point wireless ip camera equipment. Wireless video surveillance system intersection by the video information collection point wireless transmission system, the traffic control center is composed of three parts. According to the specific circumstances of each city, the monitor ip camera installed at traffic junctions (color or black and white, fixed or PTZ, fixed focus or zoom network camera) and software systems. One or several monitor ip camera can be installed in each traffic intersection the peripheral each equipped with a head, shield and PTZ controller. Each video collection point each match a video codec, monitor ip camera used to capture the video signal of the real-time traffic conditions of the city roads, the main monitoring distance traffic junctions within a certain range of the vehicle, PTZ can be controlled by the computer control center surveillance cameras, the user can horizontally 360 degrees, 90 degrees vertical and a zoom control; video codec is responsible for the monitor ip camera of the analog video signal into a digital signal, while compression, while also transmit control signals, video codecs Built-in 10/100M LAN, through the network cable is connected to the wireless monitoring equipment, compression coding processing monitoring information compiled through the wireless network traffic monitoring and management center, the monitoring center can see under the jurisdiction of the roads and junctions condition monitoring can view video images in real time, remote control PTZ through LAN or Internet remote monitoring center. To fully guaranteed bandwidth for each monitoring point, using MPEG4 encoding standards, bandwidth, and can achieve high-quality image transmission and storage, and transmission distance, and applies to the vast area of the city monitoring. By using point-to-multipoint wireless broadband access equipment to establish a wireless broadband network covering the city intersection. Installed at the center point of a wireless bridge Sunet5800 (Central Station), remote monitoring point is installed Sunet5800-RU (remote sites). Central station installed on the commanding heights of the city, such as the top of a tall building, tower top, high-Peak, to try to ensure that the signal received over each segment point launch. A central point and connect a number of distributed access points, sharing the center point total channel bandwidth of each distribution access point shared shared total bandwidth needs to be allocated based on real-time access users. The system uses the 802.11a protocol standards, the total system bandwidth of 54Mbps, the effective bandwidth of 22Mbps Each of these stations connected wireless remote monitoring point for 3-5, effective access bandwidth of each distribution access points generally 4Mbps. The equipment of Sunet5800 remote site and the central station provides a 10/100BaseT Ethernet interface, the monitoring center switches, video decoder and video cameras directly on twisted-pair Ethernet 10/100BaseT interface connection to Sunet5800 equipment. Monitoring center by the video codec decoder matrix video wall, monitoring server, DVR, you can complete the the intersection scene image receiving and display video storage, retrieval, playback, backup, recovery. Codec video codec is transmitted via a wireless network to the front-end monitoring point monitor ip camera captured video signal processing, spread to the monitoring and management center the LAN video surveillance server, spread through the internal LAN via a switch to individual departments or personnel client. User by multi-channel video wall in the center to watch the scene multiple monitoring point of the image matrix video wall displayed a picture of the 9/16 monitor ip camera can be displayed simultaneously. Wireless monitoring center issued for PTZ camera control instructions transmitted via wireless devices to the monitoring point control equipment to control the field at any point can be at the center of the monitor PTZ PTZ, lens aperture, focal length, zoom; The head on the upper, lower, left, right, automatic or auxiliary remote control the power supply, the switch of the monitor ip camera. The site returns the video image into a digital signal is stored on the DVR, convenient data storage, update, query, backup for traffic violations and other law enforcement work to provide the basis.
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