Where UE AS Layer is present ?is it present above NAS?

Question

In LTE, if a NAS packet is going to be sent, the encryption is followed by integrity protection in NAS layer, but in RRC/PDCP layer, When RRC messages are being sent, they are integrity protected first and then encrypted before being sent, unlike NAS messages were. Why the integrity and encryption protection order is different in NAS and AS layer?

Answer 1

In protocol stack, AS layers sit at lower side and NAS layer sits at higher side. Application layer is the top most layer in UE stack.

Comments

lower side means below phy layer ?