FXC E1/T1 Card: Transmission Unit when there is no MW solution.It can Provide 4xE1(4x2M). Usually used when we have BTS near the BSC or when we want to use HDSL modem. (E1=Europe Standard for 2M,T1=US and some other countries standard)
FXC RRI Card: Transmission Unit when MW solution is available. It to Flexbus. Each FlexBus can connect to seperate ODU(OutDoorUnit like FlexiHopper or MetroHopper). It can provide totaly 16xE1 and ability to work as a Single or HotStandBy(HSB).
FIU 19: Transmission unit when you want to diMultiplex your signal from MW to E1(PCM). It has diffrent configuration
2IDU+2ODU= High Protection
1IDU+2ODU= HSB Protection
Single = witout Protection