High Definition over COAX


Upgrade to HD without changing the cabling infra-structure

Analog CCTV users can now enjoy HD resolution while safeguarding their investment in existing cabling infrastructure. This revolutionary technology supports latency-free 1080P HD over up-to 500 metres of coaxial cable and offers seamless compatibility with traditional SD cameras,

What is HD over Coax?

High Definition Serial Digital Interface (HD-SDI, CVI, TVI), is an interface standard that allows the transmission of high definition video over coaxial cable at speeds of around 1.485 Gbit/s. The cable length will vary depending on the quality of the video you require and the quality of the cable used. The maximum cable length for HDcctv™ 720p and 1080p standard is 100 metres. If you do not require HD resolutions, cable lengths can be up to 300metres can be used. This broadcast television technology has been technically proven through application in television studios worldwide since the late 1990’s.

Since many organizations have existing coaxial based analogue CCTV networks, the upgrade path to High Definition CCTV will be less expensive by utilizing HD over coax technology rather than IP.

(HD-SDI, CVI, TVI) has the potential to solve many common issues associated with both conventional analogue CCTV and IP based systems, some of these being scalability to High Definition and implementation complexity and cost.


HD-CVI is a similar to HD-SDI, but delivers on many of the promises promoted by the other ‘HD-SDI’ based CCTV technologies. HD-CVI stands for High Definition Composite Video Interface, it is a CCTV transmission technology that allows high definition video to be transmitted over a coaxial cable of lengths up to 500 metres @ 720p and 300 metres @ 1080p with little or no latency.

HD-CVI modulates video signals, transmitting a base-band and quadrature amplitude modulation. HD-CVI avoids cross talk of CVBS and completely separates the brightness signal & hue signal, to enhance video quality. HD-CVI comes in two versions 1920H (1920×1080) and 1280H (1280×720) resolutions; which are compatible with 1080p & 720p.

HD-CVI also allows multiple-signals to be transmitted over one COAX cable, both audio signals and 2-way data communication signals are embedded in a blanking zone, which enhances the synchronization with the video signal; and supports a 44.1kHz sampling rate. The forward and reverse data channels in the frame blanking zone, allow for two-way end-to-end transmission to support control features like camera configuration, camera focus, PTZ control and alarm sending all over a single COAX cable.

The price of HD-CVI systems compared to old SD analogue systems is almost the same, and therefore this technology is likely to replace traditional SD analogue systems.

The upgrade path to HD-CVI allows you to keep your existing COAX cabling and replace only the recorder/s and cameras. If you are using a Multi-Platform VMS software like Freedom VMS™, this upgrade can be transitional as budgets become available, you could have a mix of SD analogue system/s and HD-CVI system/s at the same site, managed under one software platform.


HD-TVI (High Definition Transport Video Interface) is the latest in line of HD over coax technologies. Very similar to HD-CVI but is to be compatible.

Benefits of HD over Co-ax technologies

  • Works with existing coaxial cabling

  • Near zero latency – Very smooth motion

  • No network configuration or modification needed

  • Recording is immune to IP network interruptions

  • Less complex than IP based systems

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