WLAN Enables Constant Connectivity Between Moving Trains and Trackside

The link between the fast-moving train and the broader fixed trackside infrastructure has always been one of the key components of a train communications network. A major rail operator in Japan sought to build a trackside infrastructure that will offer a corridor of wireless coverage on and around the track. This would give the wireless clients on the train constant high-speed connectivity to support applications both onboard and along the rail line. There are numerous issues to face before this network is ready to tackle challenging CBTC operations: - seamless roaming is needed to provide uninterrupted communications, - EMI/EMC compliance is critical to ensure that there is no system performance degradation due to harsh wayside operating conditions. System Requirements • Constant high-speed connectivity along the track • Optimized AP coverage along a 20 km route • Seamless roaming between trackside APs • Open standards secure future upgrade path • Compliant with rolling stock and trackside standards

In this application, the backhaul network needed to be powerful enough to support communications between the on-train data network and the track-side fiber network. The trackside infrastructure consisted of ten stations placed along a 20 km route. Multiple AWK-6222s outdoor dual RF access points were deployed at 200 to 400 m intervals on poles. The data from each AWK-6222 is routed to different operational control sites via a fiber network connection, which was formed with two IMC-101 media converters. This provides each AP with fast and reliable connection to the wired backbone. Onboard the train, a AWK-5222 dual RF client was installed in the front and rear carriage to support the passenger information system and provide control and monitoring links with the trackside network. Moxa's fast Turbo Roaming technology and redundant RF mode secure the train-to-trackside communications link. With Turbo Roaming technology, the onboard clients are agile enough to keep up with the fast-moving train and can seamlessly maintain a connection with the trackside network. What's more, Moxa's AWK series products have undergone extensive vibration, shock, and EMC testing to confirm their resilience in demanding railway environments. Product Solutions: 1. AWK-5222 Series: Industrial IEEE 802.11a/b/g Dual-Radio Wireless AP/bridge/client 2. AWK-6222 Series: Industrial IEEE 802.11a/b/g IP68 dual-radio wireless AP/bridge/client