What receiver are you using on the Rover 252 or 262? They both have the ability to take RTCM as an input, i cannot find documentation on RTCM 3.0. If you have the equpiment try it. however with a trimble base just broadcast CMR b/c it is a default messge from trimble. if you are using another manufacturers base who does not export CMR then RTCM is the next logical choice, however you must have a trimble radio on the base b/c trimble radios only talk to other trimble radios. just b/c its 900 mhz does not mean it will talk to an Leica, Topcon, etc. base station.