Design and Implementation of a Hybrid Technology Networking System
Sushanta Mohan Rakshit · Lincoln (University of Nebraska) · 2013
The safety of rail transport has always been the top priority for the FederalRailroad Administration (FRA). Legacy technology, like wayside monitoring, is stillin place and is largely relied upon for detection of faults. Modern technology likeRadio Frequency Identification (RFID) has been introduced recently. However, thisis 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 lowpower 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 whichaddresses the shortcomings of ZigBee in the railroad scenario. It proposes astandards-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. In this research work an integrated hardware platform for the implementationof the HTN protocol is designed and implemented. The guiding principle has been the adherence to standards. The test results using the hardware show that it provides inter-operability with available sensor platforms, can interface with other sensing hardware using standard protocols and provides communication capabilities exceeding that needed by HTN. Advisor: Hamid R. Sharif-Kashani