How does SMS OVER LTE works?

Question

If Replay protection will not be supported then what will impact ?

Answer 1

There are two views on this -

1) (LTE) UE --> eNodeB --> MME --> MSC --> SMSC
2) (VoLTE) UE -->eNodeB -->MME -->IP-SM-GW -->SMSC (SIP Encapsulated SMS Message)

for more details please check http://blog.3g4g.co.uk/2012/02/high-level-view-on-how-sms-works-in-lte.html

Answer 2

• SMS over SGs which actually uses the old CS infrastructure and NAS signalling (TS 23. 272 describes it)
• SMS over IMS in which the SMS is transported using SIP.