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Difference between normal attach and combined attach procedure ?

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Difference between normal attach and combined attach procedure ?
posted May 15, 2015 by Vikram Singh

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2 Answers

+1 vote

LTE Case:-
Normal Attach procedure is used to register with only EPS network (e.g LTE Only) where as combined attach procedure is used to registered with EPS and Non-EPS networks simultaneously (e.g for both LTE and WCDMA or GSM).

UMTS Case:--
Normal Attach procedure is used to register with only CS Network only where as combined attach procedure is used to registered with CS and PC networks simultaneously.

why we are using this kind of procedure in UMTS is in order to reduce the additional signalling with network.For LTE this is mainly for CS-Fallback purpose.

answer May 17, 2015 by Sivakumar.d
0 votes

Normal Attach: UE Register only for EPS Services. Attach Type Ie in Attach Request will be EPSAttach.
Combined Attach: UE register for both EPS and Non-EPS Services. The Attach Type will be EPS/IMSI Attach. This is a prerequisite to do a CSFB.

answer Jun 2, 2015 by Anand Yadav
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