5G/NR - Initial Aattach Home : www.sharetechnote.com
SA Initial Attach Sequence
Following is high level sequence of call processing with SA(Stand Alone) initial attach process. For the simplicity, I have listed the sequence that is exchanged between UE and NW(Network) over the air (OTA). In reality, there are a lot of other signalings happending in corenetwork during the attach process. For corenetwork side signaling, refer to ref  from event Helix which is very nicely written sequence diagram.
The detailed mechanism for each of these step is very complicated process which cannot be described in the single page. Try follow through the hyperlink at each step if you want further details. Notice that there are multiple linkes even at single step. I am just trying to provide just high level / skeleton in this page.
Example 01 > NR SA Initial Registration Sequence - Amarisoft
Following is a sample protocol sequence for NR SA Registration kindly provided by Amarisoft in its web based log viewer
For the example of the contents of these messages click on the message link shown in the above table.