Talking about the video conference system based on telephone and monitoring network

1 Introduction
Traditional conferences are organized by the organizers to organize all participants to conduct face-to-face discussions and research in conference rooms. However, due to time and space constraints, it is often difficult for all participants to attend at the same time. For Hebei Iron and Steel Corporation (hereinafter referred to as Chenggang Company), the production links are tight, and the organization scheduling and information communication requirements between the departments of procurement, production, and sales are more and more efficient, negotiating important matters and production coordination and communication. The conference is very frequent and the traditional conference organization model is far from meeting the needs of the rapid development of the company.

Therefore, it is imperative to build a set of interactive conference systems that are not limited by time and space to meet the company's daily management and handling of various affairs. The interactive teleconferencing system breaks the limitations of the traditional centralized conferences in terms of time and space. Participants can directly attend conferences through fixed telephones, mobile phones or conference terminals. Therefore, based on the technical advantages and network characteristics in communications and video surveillance, with the help of video surveillance networks, Chenggang has built a conference system based on teleconferencing and video surveillance.

Using a combination of teleconferencing and video surveillance networks, the invisibility of teleconferences is supplemented by video surveillance. The limitations of videoconferencing are supplemented by teleconferencing systems. This set of solutions will seamlessly connect the video surveillance network and the teleconference to a unified control and run independently. When a video conference encounters a network, device, or other failure, the conference call system can ensure that the audio part of the conference can be held normally without interrupting the conference, but there is no image. Where there is no video terminal, participants who need to attend the conference can join the conference through ordinary telephones, mobile phones, and other communication tools to listen to or participate in the conference discussion.

2 System Overview
The conference system based on telephone and video surveillance network consists of a voice module and a video module. The system platform controls voice and video. The voice module is carried through the traditional telephone network. The video module is carried through a two-way video surveillance network. The system controls the voice and video through the channel control and voice recognition technologies. The system structure is shown in Figure 1.

The system voice module is connected to the switch through a 2Mbit/s link by a digital trunk card. The system assigns a number to the access number and supports the No.7 signaling protocol. This set of systems takes into account the characteristics of connection delay and system functions, and uses No. 7 signaling as the communication protocol between the switch and the system platform.

The system first presets the conference group. When the meeting conditions are met, the conference is started. At the same time, the group call and group call technologies are used to make a call connection for the users in the group; the nodes connected by the user are controlled through the softswitch technology, and the node will be controlled at the call node. Users in the conference group are simultaneously connected on one bus;

Through the mixer on the control channel, multiple channels of outgoing calls can be freely talked, interactive conferences can be realized, and related auxiliary functions, such as channel control and phone state recognition, can be used to call and delete users. Line redial. Terminal equipment accessed by the conference system is flexible and can be fixed telephones, mobile phones, and professional conference terminals.

The system video module is connected to the video matrix server through the serial port, and uses the serial port technology to control the matrix. Real-time monitoring of the conference scene with high-definition cameras, and transmission of real-time images to the system optical matrix platform through the network, using optical double-division multiplexing technology to realize the synchronous transmission of the main conference site and the subsite video through the two-way video optical transceiver, and in the system database Make the appropriate settings.

A voice detection module is set at the conference member of the conference member. When detecting that there is voice on the channel, the system searches for corresponding information from the database, and converts the information into control commands to the matrix and camera, so as to realize switching of the display screens of the respective conference sites. , camera angle, focal length and other parameters of the adjustment.

3 system features

(1) The teleconference part and the video part of the video teleconference system can operate independently and do not interfere with each other. Voice teleconferences and network video conferences can be held separately.

(2) The system can provide flexible management and control to participants, including stitch removal, speaking, bans, continuous calls, video switching, etc., as well as unique signal recognition capabilities. Even if any party hangs up, the system will Automatic identification of stitches does not affect the other party's progress.

(3) Voice part uses high-quality digital trunk card to connect to the switch, support and No. 7 signaling, no matter what kind of terminal, how many people attend, can keep voice clear; built-in echo suppression and unique signal tone Eliminate functions; flexible configuration, easy expansion and upgrade, and adopt IIS structure, support remote network access; with IVR voice guidance function.

(4) The video part utilizes optical division multiplexing technology and adopts a single-core optical cable to achieve bidirectional optical network transmission design, which improves the security and stability of system operation. This kind of network structure has low construction cost and is easy to expand and maintain.

(5) The system is in a hot backup state. Once the video surveillance network or the video surveillance equipment fails, manual switching is not required to ensure the accurate transmission of voice and truly seamless connection is achieved.

4 system application effect

Since the system was put into use at the beginning of 2009, it has been operating stably, with clear speech and high image resolution. It has basically achieved simultaneous control of voice and video images, meeting the company's requirements for meeting system timeliness and presence. In 2009, the system successfully organized more than 1,000 meetings for the company.

Through the docking of the two systems, the advantages complement each other, making the video teleconferencing system more meaningful, fully embodying the system's security, reliability, convenience and flexibility, effectively reducing meeting costs, improving work efficiency, and improving enterprise management. Enhance the execution of the company and enhance the company's competitiveness.

5 Conclusion

With the development of the era and continuous advancement of technology, video teleconferencing systems will play an increasingly important role in various industries. Only by building a videoconferencing system with stable performance, full-featured and unique features can it truly The advantages. The successful use of the video teleconference system based on telephone and video surveillance networks in Chenggang has broken the company's traditional conference mode and brought great convenience to the company's production, command and dispatch, and business decision-making. Video teleconferencing system will inevitably create huge economic and social benefits for enterprises.