MT-SMS-CSI
Mobile Terminated-SMS-CSI
CAMEL Phase 3 introduced the ability for CAMEL interaction with MO (Mobile Originated) SMS. In Phase 4 this has been extended to cover MT (Mobile Terminated) SMS. The MO-SMS-CSI (Mobile Originated-SMS-CSI) and/or MT-SMS-CSI (Mobile Terminated-SMS-CSI) are passed down to the VLR and SGSN from the HLR. This is part of the Update Location Procedure.