Market of video surveillance systems is currently saturated with lots of options for solutions created using different technologies and equipment. All technologies have similarities and differences, as well as the advantages and disadvantages, but it is necessary to mention HDCCTV family, which already includes such well-known solutions as HDTVI and HDCVI, and now Analogue HD (AHD). At the exhibition Security Essen 2014 which was held in Germany, Partizan for the first time introduced the range of equipment based on AHD technology to its customers. We also stress that in some CIS countries, where the brand is already well represented, Partizan is the first manufacturer which introduced this technology to video surveillance market. In this article, we describe this technology and its benefits more detailed.

AHD is technology for transmitting HD / FullHD video, audio, and control signals over common coaxial cable at distances up to 500 m without delays and loss of quality. AHD technology was developed by a well-known in the market of video surveillance systems Korean company NEXTCHIP, the components of which are widely used in video recorders and cameras of most manufacturers of video surveillance systems.

Key features of the AHD technology:

• High quality images at Full HD (1920x1080) and HD (1280x720) resolution. This technology uses progressive scan at signal formation and separation of Luminance and Chrominance (Y/C) components of the analogue signal. This enables eliminating blur and flicker, and improving colour reproduction.

Fig.1 Supportedresolutions

• Easy and reliable connection. AHD data transfer technology does not specify strict requirements to the quality of communications, namely to the coaxial cable. The principle of system construction is similar to generally known analogue systems.
• High transmission range. Video image can be transmitted up to 500 m without loss of quality.
• Transfer video without delay. The ability to transmit high-definition video without any delay, typical for IP video surveillance systems.
• The versatility of the system. Thanks to hybrid operation modes of DVRs Partizan AHD can connect three types of cameras: analogue cameras D1/960H, AHD camera 720p/1080p, IP Camera 720p/1080p. This enables easy implementation of AHD technologies into existing systems. In addition, analogue cameras can be easily replaced by AHD cameras due to the ability to switch camera modes Analogue ↔ AHD.
• The modernization of existing systems. As mentioned previously, AHD cameras replace analogue cameras without any difficulties at the sites of any complexity, as the cost of AHD cameras is identical to the cost of analogue cameras.
• Compatibility with third-party manufacturers’ equipment. AHD technology is open to all manufacturers, which enables combining equipment of different brands in a common system. 

Comparison table for video surveillance system technologies.

According to the comparison table of technologies it is seen that three technologies: HDCVI, HDTVI and AHD will be the leaders of video surveillance systems market in the near future.

It is worth saying that HDCVI technology is closed and this aspect imposes certain restrictions on its development and distribution. That is, the owner company of technology - Dahua is a complete copyright and monopolist for HDCVI technology. Dahua Company has an enormous advantage over companies that can purchase the rights to use HDCVI, because it completely controls the development and sale of the technology.

At the same time HDCVI, HDTVI and AHD technologies do not have fundamental differences at the first glance, but you can easily identify the main advantages for the systems based on AHD technology:

• Ability to switch operation modes of AHD cameras, namely, the camera operates both in AHD, and in the standard analogue. Enables easy replacing of existing analogue cameras
• Ability to use twisted pair video transmission. To transmit the video, you can use transceivers identical to analogue systems.
• Hybrid operation modes of Partizan AHD DVRs enable easy implementation of AHD technology into existing systems.
• Ability to use sensor video switchers and video splitters in the system.

These important aspects make AHD technology the most demanded at the market of video surveillance in the coming years. Because AHD technology can not only fully replace the existing analogue system, but also greatly improve due to higher camera resolution, comparable to IP. Excellence in image quality and identical hardware price will help the AHD technology effortlessly supplant familiar to all analogue from video surveillance market.

Summarizing, it can be noted that if you require from the system:

• high-quality images;
• recording and reproduction of sound;
• control of PTZ devices at distances up to 500 meters;
• not high cost, easy maintenance;
• no video signal delay;
• no risk of unauthorized access to the system from external networks;

then AHD technology is a good choice and you should pay attention exactly to this technology first.