As far as the test I was involved in last summer, this was done, based on the existing systems, simplex mode and conditions that my company faces today, but in NXDN mode, not analog as currently is used. You have to keep remembering, the railroads go all over, everywhere, and have hundereds of thousands of radios and these radios have to mix and match for all employees to communicate with each other. Just like it is almost impossible for a railroad to patrol and/or fence every miles of right of way, it is going to be almost impossible for the railroads to have these hundreds of thousands of radios to be able to work right in the NXDN mode. You have to also remember that it was NOT the railroads idea to go Narrowband and even go digital for that matter, it was FCC's. So knowing that they COULD MAYBE be made to go to this digital stuff, they are doing the experimenting now, so they know what they are up against.