In recent years, the market share of network cameras with POE interfaces is growing at a high speed. The 2008 Beijing Olympic Games and the 2010 Shanghai World Expo will be held, and the construction of “Safe City†will gradually deepen. The position of network cameras in the market will also increase. The higher it is. According to statistics, from 2005 to 2009, the network camera market has grown at a geometric level, and by June 2010, it has increased by dozens of times. At present, network cameras only account for about 3% of the camera market. Industry insiders estimate that the network camera market share is expected to reach 50% by 2015. If the share of network cameras increases, the proportion of PoE switches will increase. Within three years, China's PoE market will reach 300 million yuan. Kedi Communication is committed to popularizing the application of PoE products, and in the case of a rising environment, it has developed rapidly.
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The products using PoE standard on the network camera of the security industry are representative. It is gradually recognized by the market because of its convenient installation, simple configuration, simple network structure and good image quality. Therefore, it has the potential for rapid development and should cause cameras. The industry is highly concerned.
There are three common types of high-definition network camera PoE networking solutions: the PoE power supply networking solution, the PoE switch networking solution, and the ONU networking solution with POE function. The PoE switch solution is the current network monitoring mainstream networking solution. However, network transmission is limited by distance. Long-distance PoE switches are currently costly and have certain requirements on the environment and transmission media. In view of the security surveillance HD video networking requirements, the company introduced reverse PoE technology and designed a PoE repeater networking solution, namely a million HD full-network passive solution, which creates low cost, high efficiency, and more flexibility. HD monitoring networking solution.
Advantages in PoE networking applications
1. Flexibility, PoE only needs to install and support a cable, which is simple and saves space, and the device can be moved at will;
2, cost savings, video surveillance cameras, etc., need to be installed in places where it is difficult to deploy AC power, PoE makes it no longer need expensive power and the time it takes to install the power supply, saving cost and time;
3. The power supply is intelligent. The DC power supply is like data transmission. PoE can supervise and control the equipment by using Simple Network Management Protocol (SNMP).
4. Eliminate the hidden dangers of power supply security. The PoE power supply end device only supplies power to the equipment that needs to be powered. Only when the equipment that needs to be powered is connected, the Ethernet cable will have voltage, thus eliminating the risk of leakage on the line;
5, the advantages of centralized power supply, a single UPS can provide power for all related equipment in the event of power failure;
6, device compatibility advantages, users can automatically and safely mix the original equipment and PoE equipment on the network, these equipment can coexist with the existing Ethernet cable;
7. Make network devices easy to manage. When the remote device is connected to the network, it can be remotely controlled, reconfigured, or reset.
8. In a wireless LAN, PoE can simplify RF test tasks, and access points can be easily moved and accessed.
Monitor the advantages of PoE networking applications
The security industry PoE networking has the advantages of simplified wiring, energy saving, flexibility and convenience.
First, in addition to providing universal power support for connected devices, PoE networking reduces the total deployment cost of integrating power-on devices into a unified IP infrastructure. The POE module eliminates the need to install wall power connections for end devices, thereby reducing the cost of power outlets associated with supporting end devices.
Second, the need to install a wall power connection reduces the cost of the power outlet associated with supporting the terminal device.
Third, installing network connectivity devices in locations where local AC power is difficult to deploy provides greater flexibility. PoE network cameras have the function of supporting power identification circuits. When using UPS power supply, the advantages of energy saving are more obvious.
Fourth, when an intrusion occurs, it can prevent the surveillance camera from working due to short circuit. The PoE technology uninterruptible power supply system (UPS) is much safer. Once a large-scale power failure occurs, it can guarantee more. Long-term security protection. Interference between signals can be reduced during the routing process. In addition to cameras, the market for access control systems, radio frequency identification tracking (RFID), biometrics, fire detectors and other security devices is expanding thanks to PoE technology. Many access control device providers are now offering a variety of PoE-based identifiers, controllers, and quick-response locks.
PoE product technology analysis
PoE power supply technology
A complete PoE system includes a power supply device PSE and a power receiving device PD. The PSE device is a device that supplies power to the Ethernet client device and is also the administrator of the entire PoE Ethernet power supply process; the PD device is a PSE load that receives power, that is, a client device of the PoE system. PoE's two power supply methods: Mid-Span uses 4/5, 7/8 pairs to transmit DC power, that is, uses the unused pair of unused pairs in the Ethernet cable to transmit DC power, and the PSE of the corresponding endpoint. Supports PoE-enabled Ethernet switches; End-Span uses 1/2, 3/6 pairs to transmit DC power, that is, DC power is transmitted simultaneously on the core line used to transmit data, and its transmission uses Ethernet data signals. Different frequencies.
PoE relay technology
The PoE repeater introduces reverse PoE technology on the basis of the original PoE power supply switch, so that the original PoE switch not only has the power supply function, but also has the power function of the uplink port, so that the PoE repeater product can transmit the network again without external power supply. Data, which functions as a PoE signal extension extension transmission. The LS104P and LS102P-at products use high-power PoE technology for the uplink power receiving ports. The PoE power consumption is up to 60W, which fully satisfies the power requirements of four IEEE802.3af standard power ports and two IEEE802.3at standard power ports.
PoE million high-definition network passive network solution analysis
PoE repeater drag and drop network analysis
The PoE repeater is composed of three parts: a central computer room, a relay part, and a monitoring point. The central equipment room maintains the original equipment networking interface, only need to add PoE single-port power supply; the relay part is the core equipment part of the solution and the PoE repeater. In this scheme, one-to-one PoE repeater is used, and the PoE power supply is remote. 100 meters input, 100 meters from the PoE repeater to power the PoE camera; no external power supply for the monitoring point, PoE network HD camera. The solution is a traditional PoE repeater application solution, which solves the problem that the network transmission distance is insufficient and the transmission bandwidth of the long-distance PoE switch is insufficient.
PoE repeater one for two network analysis
The PoE repeater one-to-two network solution consists of three parts: the central computer room, the relay part, and the monitoring point. The central equipment room maintains the original equipment networking interface, only need to add PoE single-port power supply; the relay part is the core equipment part of the solution and the PoE repeater. In this solution, one-to-two PoE repeater is used, and the PoE power supply is remote. 100 meters input, 100 meters from the PoE repeater to power two PoE cameras; no need for external power supply for the monitoring point, PoE network HD camera. The solution breaks through the traditional PoE repeater application scheme, and not only solves the problem that the network transmission distance is insufficient, and the transmission bandwidth of the long-distance PoE switch is insufficient. At the same time, each application of a PoE repeater can save 100 meters of network cable transmission medium, further saving engineering costs.
PoE repeater one for four network analysis
The PoE repeater one-to-four network solution consists of three parts: the central computer room, the relay part, and the monitoring point. The central equipment room maintains the original equipment networking interface, only need to add PoE single-port power supply; the relay part is the core equipment part of the solution and the PoE repeater. In this solution, one to four PoE repeaters and PoE power supply remote are used. 100 meters input, 100 meters from the PoE repeater to power four PoE cameras; no external power supply for monitoring points, PoE network HD camera. The solution breaks through the traditional PoE repeater application scheme, and not only solves the problem that the network transmission distance is insufficient, and the transmission bandwidth of the long-distance PoE switch is insufficient. At the same time, each application of a PoE repeater can save 300 meters of network cable transmission media, further saving engineering costs.
Million HD monitoring network-wide passive solution value
1. Reasonable layout, simple structure, easy maintenance and maximum cost saving;
2. PoE relay is used, and the monitoring point is directly connected to the monitoring center within 200 meters. There is no need to lay the optical cable at a long distance, no need to add nodes, and the investment cost is low;
3, million high-definition has high bandwidth requirements, each channel provides more than 25M bandwidth margin, fully meet the bandwidth requirements of high-definition monitoring;
4, network power supply does not need to lay power, network is convenient, save engineering time;
5. Adopting one to two repeaters and one tow four repeaters, in addition to general cable saving, the network cable is further saved, and the networking cost is further reduced;
6. Passive networking, which is not bound by the power supply location, flexible networking, and can change the networking topology at will, and the later transformation is convenient;
7. The PoE repeater networking solution can combine the advantages of PoE power supply and PoE power supply switch to form a more flexible and passive network-wide passive solution.
Metal oxide semiconductor field effect (MOS) transistors can be divided into N-channel and P-channel. P-channel silicon MOS field-effect transistors have two P+ regions on the N-type silicon substrate, which are called source and The drain is not conductive between the two poles, and when a sufficient positive voltage (gate ground) is applied to the source, the surface of the N-type silicon under the gate exhibits a P-type inversion layer, which becomes a channel connecting the source and the drain. . Changing the gate voltage changes the density of the holes in the channel, thereby changing the resistance of the channel. Such a MOS Field Effect Transistor is called a P-channel enhancement type field effect transistor. If the surface of the N-type silicon substrate is free of gate voltage, the P-type inversion layer channel already exists, and the appropriate bias voltage can increase or decrease the resistance of the channel. Such a MOS field effect transistor is referred to as a P-channel depletion field effect transistor. They are collectively referred to as PMOS transistors.
P Channel Mosfet,P Channel Power Mosfet,Field Effect Transistor,Field Effect Transistor Symbol
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