Found this on the Trains.com website which has to do with CSX's transition from wideband to narrowband frequencies.
CSX wideband-to-narrowband radio changeover schedule releasedhttp://trn.trains.com/Railroad%20News/N ... eased.aspx
Published: September 21, 2010
JACKSONVILLE, Fla. — CSX has announced its timetable for transitioning from wideband (25 KHz) to narrowband (12.5 KHz) railroad radio operation, the American Short Line & Regional Railroad Association reported. It is the first Class I railroad to furnish this information for dissemination. The Federal Communications Commission (FCC) has mandated the end of wideband two-way radio transmission for non-military purposes in the U.S. after Jan. 1, 2013. [See Technology, October 2010 TRAINS] The CSX timetable presently calls for the changeover to be completed entirely in 2011.
CSX will transition by operating division, as follows:
April 2011: Atlanta, Florence, Jacksonville, and Nashville Divisions
June 2011: Great Lakes, Huntington, and Louisville Divisions
September 2011: Albany, Baltimore, and Chicago Divisions
The action will have a cascading effect on other railroads. For example, a short line or regional railroad connecting with CSX will need to match the changeover schedule if it interchanges cars or uses CSX trackage rights. While connecting railroads may want to transition their entire railroad at that time, they may have to temporarily maintain two radio systems if they connect with another Class I that has not yet changed from wide to narrowband.