The performance of SD leveled monitoring camera used in CCTV has been developed from Black & White into Color camera. The color camera has been also developed variously to improve picture quality especially focused on Low light, Back light and WDR feature which all made sensor and processing technology developed as a picture quality improvement. But the limitation of resolution on SD leveled (NTSC/PAL) quality couldn't satisfy the needs for high quality image. The market demands for high resolution was led to development of HD leveled sensor and it started to be adopted for CCTV market.

Here if we name previous CCTV as SD-CCTV product, we would define HD leveled CCTV system as HD-CCTV system. And we would call CCTV system using HD-SDI transmission technology as HD-CCTV.

The reason is that HD-SDI transmission technology is being developed into most reasonable technology to transform conventional CCTV into HD-CCTV which is another way of transmitting HD quality picture being distinguished from IP network transmission.

We are introducing the concept of HD-SDI transmission technology briefly. HD-SDI transmission is achieved throughout Coaxial cable. This means that HD leveled image can be transmitted using conventional SD-CCTV cable installed already in fields. For example, camera has HD-SDI output and DVR
support monitoring and recording in a way that conventional SD-CCTV does.

In the future, not only images but also Audio, Control signal and Power can be achieved or transmitted via coaxial cable. For reference there are chip solution supplier about HD-SDI transmission technology such as Gennum Corporation, Mindspeed Technologies and National Semiconductor. At this present HD-SDI transmission technology feature is achieved in Logic device(FPGA) and adopted to product.

Let's check about differences of transmission method between HDSDI and SD method. As you see in below chart, same coaxial cable is being used but there are differences in transmission method between Digital and Analog , differences in frequency and transmission distance.

The below picture is one example for various monitoring cameras using HD-SDI transmission technology become whole HD-CCTV system together with HD-SDI DVR. Here HD-SDI camera, repeater, DVR are being used. HD-SDI repeater is being used in between during transmission to make HD-SDI transmission distance longer.

Technology verified in TV broadcast standard SMPTE-xxx standard defining HD-SDI transmission technology is standard established in SMPTE (the Society of Motion Picture and Television Engineers). SMPTE standards are defined as HD-SDI transmission standard as well. The standard is being used for HD image transmission purpose between devices in worldwide TV broadcast market since 1990 and this transmission technology is technically verified and approved officially in the market at this point. Since that from 2009, there are movement to adopt HD-SDI transmission technology into security market.

Especially since HDcctv Alliance organization was established, it has been dedicating itself to apply HD-SDI transmission standard to security market along with developing SMPTE standard until now. This organization also tries to standardize requirements from cable, connector, measuring instruments and
security products to launch HD-SDI transmission technology into HD-CCTV market successfully.

Furthermore, it introduces certification on product performances to secure product reliability related to this technology. With the effort of HDcctv Alliance and manufacturer HD-CCTV related products such as camera, repeater and DVR are being certified.

This is benefit of HD-CCTV using HD-SDI transmission technology. We would like to focus on relative issues of benefit compared with SD-CCTV or IP based system.

* High resolution
HD-SDI uses 720p or 1080p image with no compression. This is about 6 times as large as SD leveled (D1) picture and this huge differences can be seen in picture below.

* Plug-and-Play

The coax cable used in conventional CCTV can be reused. And there are no need to make additional setting required which will lessen the technical burden of managers running monitoring center. This is because there are no barriers of protocol compatibility and difficulties in configuration as in IP system.

* Monitoring resolution / Latency

It is possible to see images free of corruption since there are no compression required to transmit HD image and effective & fast PTZ control in monitoring
center will be possible for no latency and jammed in control line. This will be free from any difficulties of adopting HD leveled picture quality due to transmission delay or picture corruption.

You may see that HD-SDI camera has 1200TV line in horizontal resolution in the picture below. This is possible since digital image captured by camera is being transmitted throughout coax cable with no compression.

* The reliability of monitoring camera

Monitoring camera is likely to be deployed for outdoor purpose rather than indoor purpose. So it is essential to minimize possible corruption of camera performance being exposed to outside high temperature environment. HD-SDI camera will relatively need minimum power consumption since there are no need for H.264 compression and IP networking feature. This will help lessening performance corruption of monitoring camera in high temperature.

* Easy way to mix system

The system with HD-SDI camera and HD-SDI DVR can be easily integrated or installed with SD leveled CCTV system for use. And it's also easier to combine SD leveled channel and HD leveled channel together in same monitoring center. This solution can be achieved with HD-SDI Hybrid DVR as well. This also can be integrated with IP network system which can make
remote access possible since HD-SDI DVR have network feature.

The below chart is systematic features of HD-CCTV system, CCTV and IP camera.

Started from 2009, HD-CCTV system is being released in the market from early of this year and HD-CCTV will expected to take over market position of conventional CCTV considerably from 2012 to 2015 year. This is because HD-SDI will be satisfying customer's needs not only for price wise but also for HD high picture quality and the most attractive point is that users can manage HD-CCTV products based on previous managing experiences on conventional CCTV. The example is that there are installations of this solution in highway monitoring system, casino, bank where there needs high quality picture.

So it will be easier to see purchase of HD-CCTV products to replace conventional CCTV system and people will meet with major accidents captured by HD-CCTV solution throughout media and news soon. This will be the most satisfactory product toward HD and will take important position in the security market.

* Short range of transmission?
The regular transmission distance of HD-SDI is 150m ~ 200m with small gap based on cables.
For reference, the transmission distance of UTP cable (CAT5) is about 100m. In some ways, coax cable is bit hard to handle than network cable but as specified above the transmission distance is not all about weak point of HD-SDI. Moreover there are devices such as HD-SDI repeater, Optical transmission converter in the market so the transmission distance is no more than limited issue on HD-SDI.

* Remote monitoring (Network) is impossible?
HD-SDI monitoring camera is easily network connectable throughout DVR or server. So network feature compared with IP camera is meaningless for this reason. And HD-SDI monitoring via Mobile Viewer , which is issued recently is achievable too since it is essential for monitoring camera to be connected to recording device.

* Is 1080p resolution not enough?
The most of monitoring devices have 1920x1080 resolution. TV broadcasting system also have same 1920x1080 resolution. Absolutely there are more than 3M picture for special purpose but there should be many limitations following if over 3M from image sensor to be supported such as low frame rate, hard to make proper image processing, lacks of storage solution and smooth playback. So the 1920x1080 image size will be the most suitable solution to satisfy both high resolution and systematic management.