SMS 3.pptx

Short Message Service SMS Example: short message (SM) E MS1 MS2 Submit SM MSC1 + VLR D MSC2 + VLR Forward MO SM Ack SMSgwy C + SMSC HLR Ack Send routing info Routing info Forward MT SM Nack (MS2 switched off) Report SM waiting Ack MS2 switched on Report ready for SM Forward MT S...

Short Message Service SMS Example: short message (SM) E MS1 MS2 Submit SM MSC1 + VLR D MSC2 + VLR Forward MO SM Ack SMSgwy C + SMSC HLR Ack Send routing info Routing info Forward MT SM Nack (MS2 switched off) Report SM waiting Ack MS2 switched on Report ready for SM Forward MT SM Deliver SM Ack Ack Ack Alert SMSC Ack SMS over LTE/5G • No. SMS over IMS is not the only way for the SMS to be transmitted in 4G/5G. • In both 4G and 5G (SA) architectures you can send an SMS in two ways: over IP/IMS, or over NAS (SG-SMS). • So for the equipment to send an SMS over IMS you need to first register on IMS (either VoLTE or VoWifi) including +g.3gpp.smsip parameter into the Contact header of your IMS SIP REGISTER. • If you do not inform SMS over IMS capability to the network in that registration, you'll send/receive SMS over NAS. It's very similar to an SMS sent over 2G/3G network, in the sense that the data/text is sent into a control channel and not a data channel. • The ideal way is to send SMS over IP/IMS (IMS is meant to transfer any type of data: text/audio/video/etc.), but there's the fallback solution in both 5GS and 4G networks which is SMS over NAS signaling. Because IMS capability varies a lot from operator to operator, the SMS over NAS is a very common scenario.