... the function of voice and data transfer on both GSM-R and 450MHz mode.CIR unit is made up ... contains the Control unit,GPS unit,Record unit,GSM-R voice unit,GSM-R data unit,450MHz function unit,Power unit ... ,break-in and forced-release etc.(2)Control the GSM-R data unit by wireless data transfer to get the ... size diagram2.1.3.2 Rack-mountA,B frame are fixed on the 19 inch rack directly. And A subrack ...