What is Telemonitoring?

Remote monitoring can be understood literally into two parts: "supervision" and "control", where "supervision" refers to the information obtained through the network; and "control" refers to the method of operating a remote computer through the network, and remote control The computer restarts, shuts down, and other operations, and also includes the daily settings of the remote computer. ^[1]

Remote monitoring

Remote monitoring can be understood literally into two parts: "supervision" and "control", where "supervision" refers to the information obtained through the network; and "control" refers to the method of operating a remote computer through the network, and remote control The computer restarts, shuts down, and other operations, and also includes the daily settings of the remote computer. ^[1]

For the field of video surveillance, the general working principle is as follows.

First, input video signals from each camera

Monitoring center

The system generally consists of three parts: front-end equipment, image processing and transmission equipment, and network client.

The front-end equipment consists of cameras, gimbals, decoders, protective covers, brackets,

The video surveillance system has been developed for more than 20 years. Analog surveillance is hot and digital surveillance is in the ascendant. Network video surveillance has undergone tremendous changes. With the gradual unification of IP technology globally today, we need to re-understand the development history of video surveillance systems. From a technical point of view, the development of video surveillance systems is divided into the first generation of analog video surveillance systems (CCTV), the second generation of "PC + Multimedia Card" -based digital video surveillance systems (DVR), and the third generation of completely IP-based video surveillance System (IPVS). The first generation of video surveillance: traditional analog closed-circuit video surveillance systems (CCTV): relied on specialized equipment such as cameras, cables, video recorders and monitors. For example, a camera outputs video signals through a dedicated coaxial cable. Cables connect to dedicated analog video equipment such as video screen dividers, matrixes, switchers, cassette recorders (VCR), and video monitors. Analog CCTV has a lot of limitations: limited monitoring capabilities only support local monitoring, which is limited by the analog video cable transmission length and cable amplifier. Limited scalability systems are usually limited by the input capacity of the video picture splitter, matrix, and switcher.

Video-loaded users must remove or replace new video tapes from the recorder to save them, and video tapes are easily lost, stolen, or accidentally erased.

Poor video quality Video is the main limiting factor. Video quality decreases as the number of copies increases.

Second-generation video surveillance: current "analog-digital" surveillance system (DVR): video surveillance

"Analog-digital" surveillance system is a semi-analog-semi-digital solution with a digital hard disk video recorder DVR as the core. Coaxial cables are still used to output video signals from the camera to the DVR. The DVR simultaneously supports recording and playback, and can support limited IP network access Due to the variety of DVR products and no standards, this generation of systems is a non-standard closed system, and DVR systems still have a lot of limitations:

Complex cabling The "analog-digital" solution still requires a separate video cable on each camera, resulting in cabling complexity. Limited scalability A typical limitation of a DVR is that it can only expand up to 16 cameras at a time.

Limited manageability You need external servers and management software to control multiple DVRs or monitoring points.

Limited remote monitoring / control capabilities You cannot access any camera from any client. You can only access the camera indirectly through the DVR. Risk of Disk Failure Compared with RAID redundancy and tape, the "analog-digital" scheme recordings are not protected and are easily lost. Third Generation Video Surveillance: Future Complete IP Video Surveillance System IPVS:

Compared with the previous two solutions, the all-IP video surveillance system has significant differences. The advantage of this system is that the camera has a built-in web server and directly provides an Ethernet port. These cameras generate JPEG or MPEG4 data files that can be accessed, monitored, recorded, and printed by any authorized client from anywhere on the network, instead of generating images in the form of continuous analog video signals.