第一代
first generation
传统模拟闭路视监控系统（CCTV）：
Traditional analog closed-circuit television (CCTV) system:
依赖摄像机、线缆、录像机和监视器等专用设备。例如，摄像机通过专用同轴缆输出视频信号。缆连接到专用模拟视频设备，如视频画面分割器、矩阵、切换器、卡带式录像机（VCR）及视频监视器等。
It relies on special equipment such as cameras, cables, video recorders and monitors. For example, the camera outputs video signals through a dedicated coaxial cable. The cable is connected to dedicated analog video devices such as video picture splitter, matrix, switcher, VCR and video monitor.
模拟CCTV存在大量局限性：
Analog CCTV has many limitations
有限监控能力只支持本地监控，受到模拟视频缆传输长度和缆放大器限制。
The limited monitoring capability only supports local monitoring, which is limited by the transmission length of analog video cable and cable amplifier.
有限可扩展性系统通常受到视频画面分割器、矩阵和切换器输入容量限制。
Limited scalability systems are usually limited by the input capacity of video frame splitter, matrix and switcher.
录像负载重用户必须从录像机中取出或更换新录像带保存，且录像带易于丢失、被盗或无意中被擦除。
The video load is heavy, users must take out or replace the new video tape from the video recorder to save, and the video tape is easy to be lost, stolen or inadvertently erased.
录像质量不高是主要限制因素。录像质量随拷贝数量增加而降低。
Poor video quality is the main limiting factor. Video quality decreases with the number of copies.
第二代
Second generation
当前“模拟-数字”监控系统（DVR）：
Current "analog digital" monitoring system (DVR)
“模拟-数字”监控系统是以数字硬盘录像机DVR为核心半模拟-半数字方案，从摄像机到DVR仍采用同轴缆输出视频信号，通过DVR同时支持录像和回放，并可支持有限IP网络访问，由于DVR产品五花八门，没有标准，所以这一代系统是非标准封闭系统，DVR系统仍存在大量局限。
"Analog digital" monitoring system is a semi analog semi digital scheme with DVR as the core. From the camera to the DVR, coaxial cable is still used to output video signal. Through DVR, video recording and playback can be supported, and limited IP network access can be supported. As DVR products are various and there are no standards, this generation of system is non-standard closed system, and there are still many DVR systems Limit.
复杂布线“模拟-数字”方案仍需要在每个摄像机上安装单独视频缆，导致布线复杂性。
Complex cabling "analog digital" solutions still require the installation of separate video cables on each camera, resulting in wiring complexity.
有限可扩展性DVR典型限制是一次最多只能扩展32个摄像机。
The typical limitation of limited scalability DVR is that it can only expand up to 32 cameras at a time.
有限可管理性您需要外部服务器和管理软件来控制多个DVR或监控点。
Limited manageability you need external servers and management software to control multiple DVRs or monitoring points.
有限远程监视/控制能力您不能从任意客户机访问任意摄像机。您只能通过DVR间接访问摄像机。
Limited remote monitoring / control capabilities you cannot access any camera from any client. You can only access the camera indirectly through the DVR.
磁盘发生故障风险与RAID冗余和磁带相比，“模拟-数字”方案录像没有保护，易于丢失。
Disk failure risk compared with raid redundancy and tape, "analog digital" video recording is not protected and easy to be lost.
第三代
The third generation
未来完全IP视频监控系统IPVS：
Future full IP video surveillance system IPVS:
全IP视频监控系统与前面两种方案相比存在显著区别。该系统优势是摄像机内置Web服务器，并直接提供以太网端口。这些摄像机生成JPEG或MPEG4数据文件，可供任何经授权客户机从网络中任何位置访问、监视、记录并打印，而不是生成连续模拟视频信号形式图像。全IP视频监控系统是它的巨大优势。 简便性－所有摄像机都通过经济高效有线或者无线以太网简单连接到网络，使您能够利用现有局域网基础设施。您可使用5类网络缆或无线网络方式传输摄像机输出图像以及水平、垂直、变倍(PTZ）控制命令（甚至可以直接通过以太网供）。
There are significant differences between all IP video monitoring system and the former two schemes. The advantage of this system is that the camera has built-in web server and provides Ethernet port directly. These cameras generate JPEG or MPEG4 data files, which can be accessed, monitored, recorded and printed by any authorized client from any location in the network, instead of generating images in the form of continuous analog video signals. All IP video monitoring system is its great advantage. Simplicity - all cameras are simply connected to the network via cost-effective wired or wireless Ethernet, enabling you to take advantage of your existing LAN infrastructure. You can use category 5 network cable or wireless network to transmit camera output image and horizontal, vertical, zoom (PTZ) control commands (even directly via Ethernet).
强大中心控制－一台工业标准服务器和一套控制管理应用软件就可运行整个监控系统。
Powerful central control - an industrial standard server and a set of control and management application software can run the whole monitoring system.
易于升级与全面可扩展性－轻松添加更多摄像机。中心服务器将来能够方便升级到更快速处理器、更大容量磁盘驱动器以及更大带宽等。
Easy to upgrade and fully scalable - easily add more cameras. In the future, central servers can be easily upgraded to faster processors, larger capacity disk drives, and greater bandwidth.
全面远程监视－任何经授权客户机都可直接访问任意摄像机。您也可通过中央服务器访问监视图像。
Full remote monitoring - any authorized client can access any camera directly. You can also access the surveillance images through a central server.
坚固冗余存储器－可同时利用SCSI、RAID以及磁带备份存储技术永久保护监视图像不受硬盘驱动器故障影响。
Rugged redundant memory - enables simultaneous use of SCSI, raid, and tape backup storage technologies to permanently protect surveillance images from hard drive failures.