Sunday, September 7, 2008

AAR moving forward with 6.25 kHz standard

The Association of American Railroads (AAR) has come out in support of moving from the current 25 kHz channel spacing to 6.25 kHz. As many of our readers know, there are currently three digital technologies available in the USA for Land Mobile Radio (LMR) use (MotoTRBO, NXDN, and P25). Of the three, only NXDN and P25 offer full mixed mode operation that allows migration from analog to digital, and only NXDN provides operation on 6.25 kHz channel spacing, commonly known as Very Narrow Band (VNB).

Although there is no immediate requirement for users to move to VNB, the Association of American Railroads, after evaluating their long term requirements, and current scarcity of frequencies has recommended to their members to bypass an interim upgrade from 25 kHz to 12.5 kHz, but to move directly to 6.25 kHz. This sends a clear signal to industry watchers that the defacto digital standard is rapidly evolving to NXDN.

In a prepared statement, the AAR announced that for interoperability, the Wireless Communications Committee recommends that any railroad purchasing VHF tri-mode radios for use in the 160 MHz band should specify NXDN compliance for 6.25 kHz Very Narrowband (VNB) operation.

Clearly, this will have impact on the purchasing decisions, not only for Class 1 railroads but for Short Lines and railroad service providers as well. Additional information on NXDN is available in an earlier comment on this Blog (Click here for details). Of the two current suppliers of NXDN equipment, ICOM is in the lead (at least in our opinion) with second generation technology. Falcon Direct will be participating in the introduction of the NXDN products and service both the Short Line Radios and railroad suppliers. Additional information is available by calling us at 800.489.2611 or emailing