Abstract: The rapid popularization of ADSL technology has enabled the majority of Internet users to fully enjoy the convenience of surfing the high-speed trains on the Internet. However, most of the applications of ADSL are still browsing the web, transferring/downloading files, and sending and receiving e-mails. Traditional web applications such as online games, more updated applications are waiting for us to explore... This article refers to the address: http:// PQ 25 high frequency flyback transformer,ETD 34 high voltage transformer,240v to 12v SMPS transformer,EF15 LED transformer IHUA INDUSTRIES CO.,LTD. , https://www.ihua-magnetics.com
Keywords: ADSL network video system application
I. Overview
The rapid spread of ADSL technology has enabled the majority of Internet users to fully enjoy the convenience of surfing the high-speed trains on the Internet. However, most of the applications of ADSL are still browsing the web, transferring/downloading files, sending and receiving e-mails, and online games. With traditional web applications, more updated applications are waiting to be discovered. Here we introduce a network video application system based on ADSL transmission for multi-branch organizations, which is to use ADSL as a means of accessing the Internet to realize network transmission of video signals, thereby achieving low cost and simple operation. The construction of a cross-regional network video management system.
Project Summary: The construction scale of the project involves a monitoring area distributed in 59 branches in North China and East China to South China. The monitoring center and headquarters are located in Guangzhou, with 2 video monitoring points in each monitoring area. It is required to transmit the monitoring image collected by the monitoring point camera to the headquarters and the monitoring center through the network in real time. The monitoring center manager or the enterprise leader can remotely view the real-time live image of any monitoring point to perform remote remote operation of the camera. When needed, You can also query the video recording through this system.
The most important feature of the project is that the monitoring points are widely distributed and scattered. To realize such remote video surveillance and lease dedicated communication lines, it is obviously unrealistic for the average user. Fortunately, the Internet network makes the distance no longer Far away, the development and wide application of broadband access technology has made the last mile of the information superhighway not so narrow, which provides a good use for the video application of the “Anweishi Network Multimedia Management Platformâ€.
Second, the construction objectives and construction content
1. Construction goals
1) Multimedia: Synchronize and transmit the required video images and sound signals in real time; collect the alarm information of various sensors at the front end in real time, and give prompts when an alarm occurs; can be separately provided at the front end, monitoring center and client according to needs Or at the same time;
2) Networking: The transmission of multimedia information through LAN/WAN, this project is to access the Internet through ADSL; the video and audio signals on the monitoring site are collected and centralizedly managed in the total monitoring room, while the enterprise leader or authorized user can be in any place. Through the Internet, you can see real-time images of the monitoring site, remote monitoring devices, and video files at any time;
3) Integration: The monitoring system that has been built or to be built can be reasonably integrated to avoid unnecessary waste of resources;
4) Expansion: The system has simple and flexible system expansion and intelligent upgrade functions, which facilitates the continuous expansion of monitoring points;
5) Security: The monitoring signal has a security encryption function when performing network transmission to ensure the accuracy of the monitoring signal.
2. Construction content
The system consists of analog monitoring part (camera, pickup, etc.), network video part (NMVSTM network video server, etc.), network transmission part ADSL router, An GuardianTM network multimedia management platform (management service software, storage system) and client (minutes) Control) and other common components.
The actual situation of the branch office completes the collection of various information through the camera, pickup and sensor. The information such as the surveillance image is compressed and packaged by the NMVSTM network video server, and connected to the Internet via ADSL. This information is transmitted to the headquarters monitoring center or the leader through the Internet. desktop. As needed, the headquarters or leader can monitor or view the video files stored on their internal hard drive or flash memory card by visiting the NMVSTM network video server when needed.
a Camera selection and installation
A variable-magnification integrated camera and a 355-degree omnidirectional dome are installed at the monitoring points of each branch. Connect directly to the NMVSTM network video server for storage and transmission via video cable. The installation of the camera selects a wider viewing angle.
b Network video server selection and installation
The NMVSTM network video server has local storage capabilities, and users can choose either hard disk or flash card storage. At the same time, the network video server with the audio channel as one-way or two-way can be selected according to the requirements. The network video server can optionally be placed near the branch monitoring point.
c Network connection selection
ADSL provided by the network operator.
d connection 
Third, several video application modes based on ADSL access
Mode one
The client directly accesses the front-end video server. Each video server on the front-end is equipped with a fixed IP address of the public network, which is connected to the network by ADSL bridging. This mode is simple and stable, but it requires a certain fee for the fixed IP address of the public network. It is suitable for users with limited monitoring points, large spans, few monitoring personnel, and high requirements for system stability.
Mode two
The client directly accesses the front-end video server, and the front-end video server accesses the network through ADSL through PPPoE dialing. Since the IP address of the front-end video server changes after each dial-up, that is, its address is dynamic. To solve the problem of the front-end dynamic IP address, there are the following methods:
1) Set up DDNS (Dynamic Domain Name Server), and the client obtains the IP address of the front-end video server through DDNS.
The client can obtain the IP address of the front-end device by checking the E-Mail (requires device support) of the report's own IP sent by the front-end device.
Mode three
Client - multimedia management server mode. In this mode, the front-end video server first sends information such as video and audio to the multimedia management server on the network (having a fixed IP address of the public network), and the multimedia management server completes the relaying of multimedia information such as DDNS and video and audio. This model relies on the Security NetworkTM multimedia management platform and is suitable for building large-scale or ultra-large-scale network video applications.
Fourth, the application areas are large enterprises, chain enterprises, businesses and individuals with branches.
V. Conclusion
This article only briefly introduces a simple case based on ADSL-based network video applications. An GuardianTM network multimedia application system can be constructed through various transmission methods such as Ethernet, WLAN, CDMA, ADSL, DDN and optical fiber, and will not be described here.