FRA 160MHz Study

[ComradeGlock]

Below is a link to a document by the FRA released in February 2023 that despite its title, shows the amount of research going into studying “RF spectrum scarcity”. This project by the FRA focuses on the 160MHz band used by the Railroads and whether or not it’s suitable for some of the data activity either on or planned for in the 220MHz band.

The article is a pretty interesting read thru (document) page 9, then it devolves into a technical morass and you really don’t come up for air again until doc page 49 for the conclusion.

Bottom line, (spoiler alert): “These findings set the stage for the next project phase, which will focus on the design and development of a universal software radio framework for the rail industry. The 160 MHz design will be used as a case study to realize the transceiver design as a fully featured implementation that will then be used for real-world field testing”.

My reading between the lines here (ymmv) is if this testing (and others like it) is successful and the FRA and Railroads believe that existing and/or planned wireless systems/processes can be moved or started in the 160MHz band as opposed to the already full 220MHz band, then that’s when the voice comm’s will move to VNB and free up needed bandwidth in the 160MHz band. Now, this may not be right around the corner, but I believe it will be sooner rather than later and will happen way before the FCC mandates anything.

I would guess the “transceiver design” they mention is for data comms as that is clearly the future of railroading. The move from reactive sensors to predictive sensors is a very high priority, and all of those extra sensors need to be able to talk to a wireless network, and that requires bandwidth. And lots of it.

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[iceman977th]

There is a line in the Current Status document you posted regarding discussion of 802.16t on both VHF and 900MHz for "expanded voice and data applications" 802.16t I believe falls under the WiMAX broadband standard. This makes me think the railroads are exploring a new system that doesn't use conventional two-way radio. The days of scanners and radio feeds may be coming to an end in the distant future.

Mike

 

[ComradeGlock]

There is a line in the Current Status document you posted regarding discussion of 802.16t on both VHF and 900MHz for "expanded voice and data applications" 802.16t I believe falls under the WiMAX broadband standard. This makes me think the railroads are exploring a new system that doesn't use conventional two-way radio. The days of scanners and radio feeds may be coming to an end in the distant future.

Mike

You're absolutely right. In fact, the FRA is researching the viability of an SDR (see link) covering all of the RR bands and protocols operating thru a single multi-band antenna. (Apparently space on a current loco cab roof is becoming scarce too). Some options they're looking at is either a total replacement of all the different radios in the loco cab or as a backup to the current radio setups. PTC is multi-generational now and is offering possibilities not originally planned for. The recent discussion around crew cab size even mentioned running road trains without a crew based on new PTC (and other) automation developments. The FRA ended that debate, but imagine the cab crew becoming the backup to the "system" (PTC and others) on road trains and actually running the train much like an airplane crew now with auto-pilot.

As I've mentioned before, data is king on the Class 1's. You can buy as much processing power and storage as you have money for, but you can't buy bandwidth, you have find it the old fashion way, you have to steal it. And the RR's with 160MHz VNB will have some options now in that range assuming their testing continues to show positive results.

Obviously switching and train building will always require voice comms, but road trains will probably be majority data unless an issue with the train arises. And even then, the future of those voice comms may be to confirm with the crew what the "system" is already doing.

https://railroads.fra.dot.gov/sites/fra.dot.gov/files/2020-09/SDR-A.pdf