SMS can be sent either in CS or PS path.
– How is this adjusted on the RNCs ? – Are there broadcast messages guiding the UE whether to use CS or PS path to send the SMSc?
– or the UE just chooses what it wants ?
as i know, the decision wether SMS is sended over CS or PS is independant from RNC, and for each subs TS21GPRS and TS22GPRS should be assigned @ HLR side to decide wether send SMS over PS (through SGSN) or over CS (MSC). this is concept in 2G i think in 3G it should be same. anyway if the subs is not attached to the PS network even the SMS will be sent over MSC and so on.