The products
The STREAM 5Ghz Wireless product range can provide up to 80mbps across a distance of up to 60KM. These highly secure and reliable links offer a low cost alternative to fiber lines and their high bandwidth and versatility means they have endless applications when it comes to transport.
The requirements
The customers aim was to improve the safety of the public when using the South Korean subway system. Of particular importance was trackside safety and the visibility of the platform to train drivers both entering and leaving the station. Conventional methods such as platform end monitors, mirrors and leaky feeders can provide limited views of the platform to the driver, and a more reliable view was necessary. This was to be achieved using wireless equipment to transmit images to the drivers cab. There could be little or no latency as real time images were critical to a safety system. As Line of Sight (LOS) was not always achievable and the trains would be traveling at speed, a special solution was required.
Development of a system
The STREAM range (including the STREAM-LITE) was an obvious choice due to the high bandwidth it can offer, which is ideal for supporting video over IP. After several meetings the development engineers went to work on the STREAM range, tailoring it to meet the very different and specific needs of the customer.
Access points were mounted on the platform along with cameras. CPE's were placed into the carriages of the train. Our specially developed fast handover function allowed the CPE hundreds of metres away on the train to connect to an Access Point located at a platform in as little as 5 milliseconds. This meant that the wireless link could remain stable along the length of the track and cope with the high speed of the train entering the station. It also meant that the CPE could connect to the next AP at the next approaching station incredibly quickly.
As the train approaches the station, up to three real time images can be transmitted to the drivers cab simultaneously. This allows the driver to become aware of any objects or people on the track or too close to the edge of the platform before arriving.
 |
| SilverNet's solution allows train drivers to view real-time images and watch out for people too close to the track |
As Broadcast DVB-T technology is used, high resolution images can be transmitted for up to 2KM without Line of Sight (30KM when there is LOS), which is ideal when there are curves in the track.
The system was configured to allow train to track transmission, meaning that images from within the carriage could be transmitted to the platform and then on to a control room. This function further improved security and public safety as security personnel could see into any carriage in real time.
This is a great example of how SilverNet can tailor products to suit your individual needs.
More about the STREAM range
The range includes links for distances from 2KM up to 60KM. The STREAM-MINI is ideal for shorter links, whilst the STREAM-MID and the STREAM-MAX can provide high bandwidth solutions over much longer distances. The STREAM-MAX300 provides the highest throughput, up to 300mbps over long range. This makes the STREAM range ideal for video over IP solutions.
The range of products are low cost without compromising on quality or post sales support. The products are versatile and our staff are always happy to discuss potential applications of our wireless ranges with you.
