Choosing the best

By Harun Özerdem, Geutebrück-Eurasia

Some advice on selecting the optimum CCTV system for your application

Nowadays a CCTV system is considered as an essential facility for any industrial area.  For several decades analogue CCTV systems had a successful track record of securing assets.  More recently, as digital technologies found their way into every corner of life, CCTV system suppliers have also changed their approach to solution design by adding IP systems to their product ranges.  This has provided many new options but it has also generated many new considerations for customers trying to select the optimum CCTV system solution. 

The selection process has not been helped by the polarisation between traditional security suppliers and the IT-based newcomers, nor is it made any easier when marketing messages focus unnecessarily on the technology per se rather than on what the technology delivers.  Here I offer some advice on how the system purchaser should proceed in order to find the best solution for his situation.

Pros and cons

Looking at analogue and digital systems from my standpoint in a security company which embraced IT technology at a very early stage, I see a variety of advantages and disadvantages for both technologies.

Analogue has in its favour that there is a very wide variety of equipment available and it is guaranteed compatible.  Analogue systems deliver real time video and support latency-free pan/tilt operation.  They achieve high reliability by using dedicated networks.  Security industry professionals have much more experience in analogue than in IP.  But on the down side, analogue has limited flexibility after installation and limited potential for expansion.  The rates of innovation and improvement are also low.

Pure digital systems offer considerable advantages as a result of their greater flexibility and their ability to operate with higher picture resolution.  They are also easy to install and offer high levels of innovation.  However, the non-compatibility and complexity encountered when integrating different types of equipment and systems present difficulties in using this technology.  Besides this, there is the practical consideration that there is still a general lack of competence and experience in this technology in the industry.

Best solution for complex problems

If you are wanting to protect high risk areas and valuable assets, then it makes sense to combine the advantages of both technologies and to choose a hybrid system.  In my experience, hybrid systems are usually the best available solution to complex security problems.  They are very flexible, future proof and enable the selection of the most reliable elements and proven technologies.

Rather than be distracted by the technical arguments for one CCTV technology or another, it is important that you, the user, focus on what you want your system to do.  The whole idea of modern video systems is that they should provide just the right information at just the right moment.  Achieving this critical task is not just dependent on good system planning but on the accurate definition of the user’s needs and then the application of the appropriate selection criteria to fulfil them.  Finding the best system involves using both ‘hard’ functional criteria and ‘soft’ selection criteria.

In planning a hybrid CCTV system involving both analogue and digital elements, the main ‘hard’ considerations should focus on features such as bandwidth management, scalability, compatibility with different IP cameras, easy and transparent operation, provision of a transparent and homogeneous setup, effective picture analysis options, open and documented interfaces, as well as the robustness and stability of the system.

In the ‘soft’ category come such selection criteria as:  the continuity and stability of the supplier, the quality of the consulting service offered, issues of trust and reliability, the reliability and compatibility of the products, the potential for expanding and making system enhancements at a later date, and the support structure which is available.

Legacy and longevity

A hybrid system should still give operators and administrators uniform interfaces with the same ease of use, look and feel, whatever the technology behind them.  A well designed and implemented system can combine legacy equipment with innovation, deliver top performance and flexibility while keeping your options open by providing a smooth cost-efficient migration route to pure IP if that is what the future demands. 

Standards versus implementations

Many of the ‘hard’ selection criteria listed above are influenced by the video data compression process employed.  So it is tempting to think that a sensible approach would be to decide on the best compression standard and limit subsequent searching to systems which use that.  However this would be to seriously misunderstand what compression standards are. — Contrary to what you might expect, a video standard does not define the specific process used to encode the image data.  In fact different CCTV systems using the same standard may produce superb, good, bad or awful video quality depending on how the standard has been implemented!  And ‘new’ does not necessarily mean ‘better’ either.  Implementations of older standards can be just as good or better than implementations of new standards.

So why is this? — The best way to explain standards is to use an analogy.

Standard toolkit analogy

Think of a video standard as a toolkit.  Just as a carpenter might use a saw, a plane, a hammer, drills and chisels from his toolbox to make a piece of furniture, so the developer uses tools from the video standard toolkit to create an encoding process.  The carpenter is free to decide what he is going to make, which tools to use, how, and in what order.  Similarly, the developer can encode for multi-media, mobile phone, CCTV or other purposes; he can choose which of the tools to use, and how and when to use them.  And, just as the utility and quality of the finished piece of furniture depends on the design skills and craftsmanship of the carpenter, so the performance of an encoding process depends on the specialist knowledge, aims and expertise of the developer. 

You can think of each new video standard as a new toolbox with a slightly different selection of tools.  Some tools remain the same, or are slightly upgraded versions of previous ones. – This might equate to the carpenter acquiring a new diamond toothed saw and a power drill.  They enable him to work faster but they rely on the same creativity and skill. – Some of the new tools in the toolbox are intended for specific purposes, so whether they are useful or not depends very much on the product in view.  Just as the carpenter is unlikely to see welding gear as a positive addition to his toolbox, the developer may not find mobile phone imaging tools much help in creating high quality CCTV video.  And a tool which delivers greater compression but reduces image quality and processing speed is probably better left in the box! 

Practicalities

Once you appreciate that the performance of a CCTV system is not dependent on the standard but on the developer’s implementation, you can see why it makes sense to focus on what a CCTV system delivers rather than on the particular technology standard.  Even for the encoding experts among us judging a good implementation is about comparing performance in action and about using experience and professional judgement.  In practical terms it’s about defining what quality criteria are important for the specific situations and tasks in your application, then getting suppliers to show you how their systems match up to your requirements.  You can differentiate quality implementations with questions like:  How many live screens can be supported at once?  What happens when there is a lot of movement in the scene - are the pictures still just as clear and sharp?  Is the movement fluent at all speeds, forwards and backwards?  Is there a significant processing delay or is the encoding fast enough to support normal PTZ control?  As always, if you are wise you’ll want to see it done!  There is no substitute for demonstrations with footage and situations from applications similar to your own! 

More information

If you would like information on Geutebruck’s range of hybrid video recorders and the video compression system it has developed to give optimum performance for CCTV applications please visit www.geutebrueck.com

Author’s profile:
As Geutebruck’s area manager for Eurasia, Harun Özerdem is responsible for sales activities in Turkey, the Middle East and the Balkan countries.  He is an electronic engineer with 14 years experience in the security industry in Germany and Turkey. 

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