System Overview

As a densely populated gathering area, the safety of train stations is particularly important due to their special functional use; At the same time, in order to meet the needs of modern management, ensure the safety of personnel, numerous property facilities, and important materials in the region, and to timely and effectively control and handle sudden and group incidents, these are the issues that need to be considered in this construction. Therefore, establishing an effective security system is an important foundation for intelligent security prevention. Video surveillance system is an important component of security system transformation and a manifestation of intelligent management, which greatly improves the level of modern management and is an important part of building a harmonious society.

The design of the video surveillance system for this construction is based on digital network architecture and applies multimedia control management technology based on computer networks. The control, storage, transmission, and query of surveillance video images are integrated into the unified management of the computer network. The two complement and complement each other, jointly building a practical, efficient, and fast security monitoring system. Provide advanced technological means for security monitoring systems to ensure the safety of the entire area. Establish a comprehensive and powerful technical prevention system using technical defense measures to meet customers' security monitoring requirements. At the same time, cooperate with security personnel management to achieve the unity and coordination of civil defense and technical defense, in order to achieve the goal of safe and efficient management.

　　System Design

　　1. System Overview

The main function of the train station video surveillance system is to assist the security system in monitoring the live situation inside and outside the entire area. It enables management personnel to observe the situation of all important locations inside and outside the control room, providing monitoring means for the operation of various equipment and personnel activities, and is the most important part of the entire regional security system. The front-end of the system adopts high-definition network cameras, which are transmitted to the security center through the network. The central part controls and displays images through a management platform and high-definition digital matrix.

　　2. Requirement analysis

According to the communication and professional design experience, the high reliability, progressiveness, flexibility, expandability, manageability and high performance price ratio of the system are fully considered, and according to the actual situation and future development trend, in combination with product performance characteristics, professional technical design experience and other factors, the high-definition network system architecture is recommended for the Owner's reference and selection in this construction.

　　3. System topology diagram

Design Notes:

The entire video surveillance system uses a digital IP architecture;

The front-end camera is equipped with a 2-megapixel high-definition network camera, and corresponding infrared high-definition network ball cameras, high-definition network gun cameras, etc. are used according to different environmental locations;

The front-end network camera collects signals, encodes and compresses them into digital IP signals, and transmits them to the security center through the network. The video signals are encoded using H.264 and stored in a disk array, achieving centralized management and digital recording of front-end monitoring points by the center;

◆ The center is equipped with a comprehensive management platform and high-definition digital matrix. The high-definition digital matrix supports mixed signal input: video signals from different interfaces such as HDMI/DVI/VGA/AV/SDI/IP can be simultaneously connected, and output to the large screen for functions such as splicing, roaming, stacking, and transparency adjustment;

◆ Center configuration platform server, build a comprehensive video management platform, and effectively manage devices, clients, access permissions, etc.:

The alarm signals of each alarm subsystem are input to the central alarm interface box, which is linked with the high-definition digital matrix to output corresponding alarm videos;

Network switches can be equipped with 100Mbps or 1G switches according to actual needs to achieve redundant exchange of network data transmission.

　　4. System composition

This system mainly consists of front-end cameras, transmission links, and central control/display parts. The cameras at each monitoring point send video image signals to the monitoring center through the network, and store them through the IP-SAN network. Computers can query monitoring video recording and other data through the client; On the other hand, multiple monitoring images are displayed in real-time in front of the on duty personnel through the display unit set up in the control center.

1) Front end video capture system

The front-end video capture system is designed to observe and collect information. The front-end monitoring equipment can adopt high-definition network cameras based on the standard H.264 algorithm according to the actual needs of users. The compressed resolution of high-definition network cameras reaches 1980X1280. Due to the standard 16:9 widescreen display ratio of high-definition network cameras, they have a larger visual range than traditional analog videos. Moreover, due to their higher effective pixels and resolution, the resulting video images are clearer than traditional analog cameras.

2) Video transmission system

The transmission private network for videos is to ensure smooth video flow, similar to the "blood vessels" of the human body, which need to be ensured not to be blocked. The main equipment includes access switches, fiber optic transceivers, aggregation switches, core switches, backbone transmission optical cables, and video access using Category 5e (Category 6) unshielded twisted pair cables. The construction of a dedicated video transmission network needs to consider bandwidth, packet forwarding rate, backplane bandwidth, multicast, and QoS technologies. If the video transmission network requires external network access, security and antivirus measures need to be taken, and a firewall needs to be added in the private network system. Build a digital video dedicated network according to customer requirements, carrying video images and other data.

In terms of the relative relationship between video quality and access bandwidth for monitoring, an upstream bandwidth of 384Kbps can transmit clear and smooth CIF resolution images, an upstream bandwidth of 512Kbps can transmit clear and smooth 2CIF resolution images, and an upstream bandwidth of 1.5Mbps can transmit clear and smooth D1 resolution images. The video bandwidth for this high-definition 1080P transmission is approximately 8Mbps. Select different switches for exchange and transmission based on the actual number and bandwidth of cameras.

3) Central management control system

The monitoring center is the core of the entire system, connecting various monitoring resources and managing, storing, calling, and displaying them accordingly. Its main purpose is to improve security prevention and provide a centralized application venue for decision-making, command and dispatch, and evidence collection by leaders at all levels. The central control design of this system consists of three parts:

⑴ Control section

The control part of the system is mainly composed of platform management software and high-definition digital matrix. The comprehensive management platform is the core of the entire network video surveillance, mainly responsible for authentication and management of front-end access devices and client user access, media scheduling and video forwarding, central storage and network management, and other application interface services. High definition digital matrix is a specialized device used for switching between high-definition/standard definition, digital/analog, and other video controls on the wall. It controls image processing and display functions such as video segmentation, scaling, stacking, and splicing.

Platform management configuration platform server, building a digital video management platform, software modules including:

◆ System management server software: Implement configuration, equipment inspection, and real-time access control management for remote digital video devices, including organization, personnel, equipment, tasks, alarms, logs, etc;

Monitoring center main control software: The client main control software of the monitoring center under the C/S architecture can access all on-site devices under the authentication of the system management server;

Streaming media server software: video forwarding management, network transmission control management, and internal and external network exchange control management;

Network storage management server software: Centralize storage, backup, and management of real-time images and historical recordings of monitored devices, and provide centralized retrieval services;

Alarm forwarding server software: provides alarm reception and forwarding services for monitoring devices managed by the system;

⑵ Network storage section

The storage of videos plays an important role in ensuring the retrieval of historical alarm events and facilitating post event evidence collection. So the resolution of the image is crucial, and the backend video storage device should be configured with IPSAN network storage devices to achieve centralized management and digital recording of the front-end monitoring points. The stability of the device determines the overall performance of the system, and the resolution of the image must reach 1080P (1980 × 1080) or above to ensure the clarity of video playback details. Due to the need for separate storage and retrieval in two locations, two sets of storage devices are required.

◆ Single set video capacity storage calculation

Calculated based on single channel 1080P image quality, 8M/S bitrate, and 30 day video storage:

Single channel capacity=3600 seconds x 24 hours x 30 days x 1 channel x 8M ÷ 1024 ÷ 1024 ÷ 8=2.47T

170 channel capacity=2.47T x 170 (channels)=419.9T, with additional hard disk redundancy and RAID5, etc;

Total capacity=558T

⑶ Display section

The image display unit is configured with a 3 × 4 46 inch DID splicing screen in the middle, each display screen has single screen display, 4-screen display, and rotation function.

　　System Features

1) Characteristics of Digital Matrix

◆ It is a pure hardware non compressed embedded high-definition digital matrix, with no loss or delay in video;

Modular structure and support for mixing multiple business boards in any combination, making the system flexible; Easy to expand and upgrade in the later stage;

Support video signals with different interfaces such as HDMI/DVI/VGA/AV/SDI/IP, which can be simultaneously connected to mixed signals for arbitrary switching;

◆ It has graphic processing capabilities and supports video display, segmentation, and other functions;

Specialized control software or user customizable SDK for easy system integration.

◆ Configure a dedicated control keyboard, considering usage habits and on-site hardware environment. The keyboard functions should be centralized, comprehensive, and easy to operate. The center of the keyboard joystick should be equipped with an image capture button to capture dynamic images in real time. The number of input and output interfaces provided by the matrix needs to be surveyed on site, and full consideration should be given to the expansion and application of the later access system.

2) High platform integration

This system adopts mainstream video surveillance platform products and professional video application technology, fully realizing the basic functional requirements of security monitoring. Based on this, by applying the design concept of "system networking" and using mature network video management platform products, the video networking function is perfectly achieved, while meeting the requirements of this project in terms of image resource reusability, system scalability, and compatibility with heterogeneous devices.

3) Strong compatibility

Due to historical reasons and competitive needs, different manufacturers and encoding formats of encoding and decoding devices are often used in the same network video management system. From the perspective of design and requirements, users also require different encoding and decoding devices. Users need an open system video management system that meets flexible applications and is highly stable.

The system supports a new type of digital device that requires the implementation of new drivers without the need for design changes or complex custom development. It has successfully implemented support for digital devices from multiple manufacturers such as Hikvision, Bokang, Dahua, DVMUX, etc. It can support the mixing of different types of digital devices in the same system. And support fast interconnection of alarm hosts and matrices from different manufacturers and models.

4) Reliable recording

This system adopts professional storage products, which can simultaneously record and play videos on a single machine, support error prevention redundancy, and have been successfully applied in multiple large-scale projects.

The system adopts advanced storage solutions, which have a higher performance price ratio than early storage systems. It supports RAID5, hot swapping, and power redundancy, ensuring the stability of video data. It provides complete storage management software and can achieve various functions of large-scale storage systems.

5) Massive streaming media distribution

One characteristic of this project application is the need to support multi-level forwarding and concurrent recording of large capacity digital images. On the basis of technology, the platform software is required to have large capacity and stable streaming media service capabilities.

Streaming media refers to a continuous stream of audio/video data transmitted and played in chronological order over a data network, characterized by continuity, real-time, and continuity. To ensure the quality of streaming media, it is necessary to apply professional techniques to solve a series of problems such as encoding caching, network transmission, network reception, and concurrent access.

This system integrates mature streaming media server technology in the IPTV field, which can achieve a maximum available bandwidth of 700M on a gigabit network. The video forwarding server can achieve up to 250 concurrent channels on a single machine, fully meeting user needs.

6) Powerful network management function

The security system system with multiple subsystems requires the interconnection of multiple subsystems. The initial installation and debugging may require the configuration of thousands or even tens of thousands of parameters. In actual operation, it is often necessary to add equipment or adjust parameters. These tasks cannot be completed through simple command-line statements. Relying on developers to complete system setup and maintenance will result in a significant increase in system implementation costs and the inability to complete handover to the owner.

The system provides professional configuration management software, maintenance management software, and network management software, which centralize relevant concepts through consistent graphics and tables across the entire network, making complex configuration and maintenance management simple and feasible.

The system detects the addresses of all digital devices through programs and can directly configure, manage, and control them through the network. All management functions can be performed remotely through the network. Digital devices have plug and play functionality, simply connect to Ethernet to allocate an IP address, and connect to a camera to observe remote images at any time; Through software, the status of all codecs can be monitored, making it easy to locate faulty devices. Maintenance, repair, and upgrades can be performed on each codec while the system is running, without affecting the entire system.

7) Integrated management of alarm information

In the video system, the alarm system can be used as an independent device or included in a unified platform management. Users do not need to purchase separate alarm software. The video management control server can directly receive various types of alarm signals transmitted by the alarm host through RS232/485 or IP network, achieve local alarm linkage function, and forward the alarm signals to the management control system of the core platform for centralized processing. It can display a list of alarm input and output information on designated PC clients, set the order of alarm display, and support alarm linkage worksheets and alarm parameter settings.

8) Post expansion functions

The development of the security industry is high-definition and intelligent, while traditional monitoring equipment is based on control and content independent processing devices. After analyzing the industry development trend, it is believed that digitalization of monitoring will inevitably require monitoring equipment to have more video intelligent processing capabilities.

Therefore, the digital matrix adopts high-performance programmable video processing chips, which can analyze and process videos at the pixel level, providing an excellent platform for intelligent processing; This provides a feasible platform for the increasing demand in the security field, such as behavior analysis, intelligent content indexing, and facial recognition.