Tune in to wire-less CCTV

The introduction of Town/City Centre cameras has proved the effectiveness of CCTV surveillance in reducing crime. However, it has led to the phenomenon of crime displacement, often referred to as 'fallout'. This has resulted in crime increasing in surrounding areas where cameras are absent.

To continue to be effective, surveillance must be extended to outlying areas. This is usually achieved by installing additional cameras linked to the CCTV network via fibre-optic or microwave links — a costly and disruptive solution.

Against this background, the benefits of having access to a more flexible CCTV surveillance system that allows cameras to be relocated easily, quickly and inexpensively are obvious.

Petards' SWIFT Rapid Deployment Camera System has been developed for this purpose. Wire-less transmission technology is used to carry real-time video and data signals between the camera and a receiver. As a result, the SWIFT camera can be relocated from one position to another with ease. And users can deploy CCTV surveillance to cover specific events which might otherwise not warrant permanent coverage.

The most significant limitation is the transmission distance and the possibility of signal interference. The transmission distance between camera and receiving point is typically between one and two kilometres (although in some cases distances of four kilometres can be achieved). In many cases this will not be sufficient, but a number of local authorities have found they can overcome this problem by installing radio receivers linked to microwave transmitters, fibre optic cabling or even telephone lines to carry the signal back to their control room.

When using a licence exempt radio frequency (1.394 GHz or 2.4 GHz), interference from other devices is always a possibility. However, uprating the aerial receiving equipment and switching between frequencies within the licence exempt bands can overcome this.

Wire-less transmission will not be appropriate for all surveillance needs. But its flexibility and cost-effectiveness already benefits many users.

"It has been extremely successful when deployed at major events and when used to deal with temporary rises in crime in localised areas," says Mr C Denyer, emergency planning and risk manager at the London Borough of Hammersmith and Fulham.

Mr D Hinton, a crime prevention officer with the Metropolitan Police Service says the transmission system has "enhanced our ability to monitor and respond to potential issues more quickly".

Mr A Blackmoor, a crime prevention officer with Kent County Constabulary sums up the simplicity of the system when he says: "We took delivery of two SWIFT camera units together with a remote receiver 'suitcase' on a Friday morning. After a training session carried out by Petards personnel, we deployed the system on the following Sunday evening to monitor a crime hot spot within the town. In using the system for the first time, we were able to make four arrests for drug related offences, supported by good videotape evidence."