ATCS: Advanced Train Control System radio data link design considerations

The American Association of Railroads (AAR) and the Association of Canadian Railroads (ACR) jointly initiated an implementation study of the Advanced Train Control System (ATCS) to improve the efficiency and economics of railroad operations. The data link between locomotives and the dispatcher is identified as a vital link within ATCS. The design of this link includes considerations on modulation, data rates, protocol, access scheme, forward error control, and their impact on spectral needs. The steps taken toward specifying ATCS radio-link design parameters to meet operational requirements of railroads are described. Extensive computer simulations to evaluate suitability of the chosen system parameters such as data rate, access scheme, and coding were made under some realistic mobile channel conditions. Results of this design exercise are summarized.<
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