printer friendly version

Specifying and selecting video surveillance systems

This guide focuses on the video surveillance systems which are used for protecting buildings, sites and people and which may also be referred to as video monitoring systems, CCTV (closed-circuit television) or video security systems. Those designed for traffic monitoring, investigative surveillance or the quality monitoring of industrial processes known as machine vision are significantly different and fall outside the scope of this guide.

A video surveillance system generally consists of many different components. The illustration below shows the logical components, all or most of which can be included in a system. Since the advancing digitalisation and the increased use of high performance processors together with software or firmware components have produced enormous increases in both the flexibility within systems, and the performance capability of individual components, there are now often several logical components combined within an individual device.

Katharina Geutebrück.

For example we find compact cameras in weather-proof housings with built-in LED lighting; video analysis or storage functions in network cameras; video analysis options in recording devices; picture display and operation offered as a software package on a computer etc. The Technical Essentials section of this paper describes the technicalities of individual components and systems in more detail.

Good preparation and planning is vital

It is vital that each component is selected to meet the particular requirements of the application, and to be compatible with all the other components. Since the multiplicity available in the market seems endless and is difficult for the user to survey, good preparation and planning is all the more important. Only with good preparation and planning can the real requirements be formulated and suitable quotations invited. Let’s look at each planning stage separately.

Determining the aims

It is usual for a comprehensive security concept to already exist and for it to include the organisation’s protection targets, before the issue of video security ever arises. So the aims of the video security system can usually be drawn from this.

The most important question of all is: what do we need which information for, and when? Essentially, a video surveillance system does not supply anything other than picture information, so you need to answer this question as precisely as possible. Installing a camera first and then considering who should look at which pictures, is certainly not to be recommended as it usually leads to excessive costs and fewer benefits.

The majority of pictures generated by video cameras are totally irrelevant for the user and are never viewed. The key advantage of a modern video surveillance system is that it reliably provides picture information which is relevant, quickly and easily accessed, or better still switched to the screen when required.

The more precisely you can formulate your requirements, the greater the benefits the system will deliver. As is so often true, as far as pictures go, less is more!

Analysing the basic conditions

Most video surveillance systems are not planned and built on a greenfield site. There are often basic conditions which have to be considered, for example:

* Existing video components which are to be used again, such as existing cameras.

* Existing or planned third-party security systems to which interfaces need to be provided, for example access control or fence detection systems.

* Existing legal regulations which have to be observed, such as the German BGV C9 Kassen regulations.

* Legal limitations on the use of the system, such as data protection rules.

* Legal requirements for approval of the system, e.g. legal frameworks for worker participation and consultation.

* General and application-specific regulations and standards.

* The organisation surrounding the use of the system: issues such as whether you will use your own staff or a contractor, switch to a internal centre or external control centre at particular times of day, whether the police or others will also evaluate images etc.

* The time period within which a critical event should be, or can be, evaluated.

* These general conditions may give rise to limitations or to additional technical requirements for the design of the system. Even the organisational user framework may be affected. All these requirements need to be put down in writing and considered at an early stage.

Determining the necessary functions

As a result of the knowledge gained from the first planning steps you can now formulate some concrete technical requirements. Basically there are two ways of proceeding from here:

(1) You could request different suppliers to develop and offer plans for technical solutions on the basis of the information you have so far. When you compare them, of course, you will see very different approaches which will be very different technically as well as in terms of price.

(2) You could specify your technical minimum requirements on the basis of your own technical knowledge of video surveillance and request different suppliers to formulate specific offers. This way you can compare the prices better, but you will not necessarily get the best possible design for your needs, and additional costs may be incurred if you have not adequately considered or formulated all points.

The ideal seems to be to combine these two approaches with a further criteria or selection stage: Specify just the minimum technical requirements. The checklist in Figure 1 will help you do this. Now you can go to various suppliers seeking an initial quote for a price comparison. The manner in which they deal with your request will tell you if the supplier is right for you or not.

Figure 1.

If your enquiry elicits a very brief quote and a price without any further consultation, then this supplier is only right for you if you have a strong technical background and already know very precisely what you want. If the supplier offers advice or wants to know more about your application and the practical demands on the video system, then you have found a supplier who wants to provide the best design.

Next you need to check out whether the after sales service, product quality and reliability as well as the investment security are acceptable. A video security system is a long-term investment. There should be long-term service arrangements covering devices and components for defects, and allowing for changes to system requirements or system expansions. Finally, depending on the size of the investment, it might make sense to follow up references and maybe go with short-listed suppliers to see some installations.

In the next article, Geutebrück discusses some of the technical essentials to consider in specifying and selecting a surveillance solution.

Share this article:

Further reading: