HTNMote: A Platform for on-board real-time monitoring of railcars

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Abstract:

<p>The safety of rail transport has always been the top priority for the Federal Railroad Administration (FRA). Legacy technology, like wayside monitoring, is still in place and is largely relied upon for detection of faults. Modern technology like Radio Frequency Identification (RFID) has been introduced recently. However, this is largely used to detect a particular railcar rather than to monitor it for problems. Wireless Sensor Network (WSN) technology is being evaluated by the railroads for real-time or near real-time monitoring of the status of railcars for timely response to problems and also for trend analysis.
ZigBee has been the networking protocol of choice for the railroads for its low power consumption and cost of implementation. The railroad scenario presents a long linear-chain like network topology which ZigBee was not designed to handle. It has been found that a ZigBee-only network in the railroad environment suffers from drawbacks like long synchronization delays, severe problems with route discovery and maintenance, aggregation of data errors leading to unacceptable packet loss rates, lack of a mechanism to decide traffic priority for critical packets, like alarm, so that they can reliably traverse the network to the collecting node in the locomotive etc.
Hybrid Technology Networking (HTN) protocol has been suggested which addresses the shortcomings of ZigBee in the railroad scenario. It proposes a standards-based multi-protocol approach that is well-suited for the railroad scenario. The current crop of sensor platforms does not provide an integrated environment for the implementation of HTN.
A new hardware platform, HTNMote, is developed to implement the HTN protocol in the resource constrained, high stress railroad environment to enable fine-grained and near real-time monitoring of railcar parameters.</p>