The Gotschna Tunnel, opened at the end of 2005 with a length of 4.2 km, is part of the Klosters by-pass and the federal highway A28 extension between Landquart and Davos. The tunnel reduces travel time to tourist destinations and the traffic burden of local communities. Safety technology is state-of-the-art: fire alarm systems, emergency lights, a hydrant pipeline, measuring equipment for CO2 concentration and visibility regulation, traffic control and video monitoring facilities, SOS telephones, fire extinguishers, tunnel radio technology for police and maintenance services.

Video monitoring as a challenge
Video monitoring of the Gotschna Tunnel is part of traffic safety for the Cantonal Police of Grisons; images reach the police force's control room in Chur - more than 30 kilometres away. Emergency situation analysis and adequate response depend on outstanding images. The canton's Civil Engineering Office faced the challenge of selecting video monitoring and data transmission equipment for the 29 analogue cameras distributed through the length of the Gotschna Tunnel. A Gigabit Ethernet connected to an ATM network, standard upon installation five years ago, would be used to transfer image data and control signals.

Analogue-digital-analogue
Video-over-IP offered a viable solution for data transmission, with the most important criteria being image quality and cost/performance ratio, followed by the possibility to eventually replace analogue equipment with digital. The resulting solution was a virtual video matrix, which could digitalise analogue camera signals using an encoder, transfer them via the Ethernet network and subsequently convert digital signals to analogue using a decoder.

Best in test: the SISTORE CX video codec
"The Civil Engineering Office of Grisons subjected four systems to tests under simulated conditions. The intelligent digital video codec SISTORE CX was the clear winner" explains Sandro Mura, responsible for information technology at the Grisons Civil Engineering Office. He continues - "The decisive factors were the excellent image quality and a convincing cost/performance ratio".

Flexibly scalable and versatile
SISTORE CX is an encoder and decoder, providing video motion detector, streaming and recording on a digital platform. Its flexible scalability and versatile implementation provide advantageous options. Web-based access across the entire network is simple via LAN/WAN. Image data is compressed using MPEG4, enabling real-time recording and optimum transmission in DVD quality.

In each of the two sub-stations in Selfranga and Drostobel, three SISTORE CX units extract image data to be encoded from a single matrix. At the Cantonal Police Headquarters in Chur, the same number of SISTORE CX units scan the data from the WAN, decode and transfer it to the ATM network (and therefore to the control room) using a codec.

SISTORE CX4/CX8
SISTORE CX is an intelligent digital video codec, capable of carrying out various functions simultaneously: transmission, recording and analysis. MPEG4 technology enables rapid transmission and excellent image quality. SISTORE CX from Siemens provides users with various real-time modes. It can be operated as an up to a four-camera receiver (decoding) and eight-camera transmitter (encoding). A combination mode allows for simultaneous operation with four inputs and two outputs (transceiver). SISTORE CX is available with various hard disk sizes for local video recording. Web-based operating software makes SISTORE CX especially user-friendly. It can be conveniently installed and configured via the SISTORE CX home page. This not only shortens the installation time, but also simplifies subsequent configuration and maintenance. SISTORE CX integrates existing analogue cameras into a variety of system and communication infrastructures. The ergonomic user interface is designed as a "virtual matrix" and allows intuitive drag-and-drop operation.