CMRx is the latest version of Trimble’s proprietary format for distribution of GNSS correction data to their rover hardware. A while back I did a quick test to measure the average bandwidth used by CMRx. Here’s a plot of bytes transferred per second for a two constellations (GPS and GLONASS), two frequencies (L1 and L2) stream over 10 day average.
The average figure is 171 bytes/sec. That is about thirty percent less compared to RTCM 3.0.