top button
Flag Notify
    Connect to us
      Site Registration

Site Registration

What is EMM substate in LTE?

+1 vote
1,416 views
What is EMM substate in LTE?
posted Oct 27, 2017 by Jaganathan

Share this question
Facebook Share Button Twitter Share Button LinkedIn Share Button

1 Answer

+2 votes
 
Best answer

Evolved Mobility Management (EMM) module supports many procedures such as attach, detach, TAU procedures etc.
When any EMM procedure executes between UE and MME, various messages are exchanged. For example: there are main states such as EMM-NULL, EMM-REGISTERED-INITIATED, EMM-REGISTERED, EMM-DEREGISTERD-INITIATED and EMM-DEREGISTERED.
After moving from EMM-NULL to EMM-REGISTERED state, UE can move to any sub-state of EMM-REGISTERED main state.
For example: UE has registered to the LTE network but somehow it is moved to a location where there is no cell. In this case, UE's EMM state will be changed from EMM-REGISTERED main state to EMM-REGISTERED.NO-CELL-AVAILABLE substate of EMM-REGISTERED state. I mean to say UE is still in REGISTERED state but it is moved to sub-state of EMM-REGISTERED state. Here, the difference between these two states is that in the first case UE can communicate to network through eNodeB at any point of time since a cell is available while in the other case, though UE is registered with network at NAS level but it can not communicate right way since there is no radio cell.
I just gave one example here. Actually there are many EMM states which has many sub-state and UE moves to these state because of different reason.

answer Oct 28, 2017 by Harshita
Similar Questions
+1 vote

During a LTE attach, MME may send the UE a EMM Information message with Universal time and local time zone IE. This IE contains Year, month, day, hour, min, sec.
My problem is that I can not find any reference yet about what should be the value of the year. Is it calculated from 1900 or 2000 or as it is ? or there is some other reference year ?
Any reference spec with this particular information will be highly helpful.

+3 votes

When this message is sent by Network to an UE ? There are couple of optional IEs within the message, what significance of their presence within the message ?

...