... the function of voice and data transfer on both GSM-R and 450MHz mode.CIR unit is made up of ... the Control unit,GPS unit,Record unit,GSM-R voice unit,GSM-R data unit,450MHz function unit,Power unit.It ... of main rack:(1)Control the GSM-R Record unit to get the GSM-R voice operation, for example point-to- ... break-in and forced-release etc.(2)Control the GSM-R data unit by wireless data transfer to get the ...