Most answered questions under tag s1ap

+3 votes

3 answers

LTE: What the eNodeB does when there is no target eNodeB is available to handover an UE ?

posted Jan 30, 2016 by Vikram Singh

+2 votes

3 answers

LTE: When does an eNodeB send "UE Context Release Request" message for an UE to MME ?

posted Jan 30, 2016 by Harshita

+3 votes

3 answers

How mme will react when it didn't receive WRITE-REPLACE WARNING RESPONSE after sending WRITE-REPLACE WARNING REQUEST.

posted Nov 21, 2015 by M.chandra Sheker

+3 votes

3 answers

Why NAS-PDU is piggybacked within E-RAB setup request message over the S1-AP interface?

posted Oct 8, 2014 by Basabdatta Mukherjee

+4 votes

2 answers

LTE: Does the encoding steps for PLMN vary in case of two and three digits MNC at eNodeB ?

posted Jun 1, 2018 by Vimal Kumar Mishra

+2 votes

2 answers

LTE: Why MME does replay of UE Security Capabilities in the Security mode command message ?

posted Apr 29, 2018 by Harshita

0 votes

2 answers

During S1AP path switch request message, MME releases bearer for QCI 1 with radio network cause 30 and unknown erab id?

posted Aug 9, 2017 by anonymous

0 votes

2 answers

MME behavior when s1 Setup req is received twice from same eNB

posted May 16, 2017 by Sumit Deshmukh

0 votes

2 answers

LTE: What does eNodeB send "RRC establishment cause " in Initial UE message to MME ?

posted Mar 15, 2016 by Harshita

+3 votes

2 answers

LTE: When does an eNodeB send Error Indication message to MME for an UE ?

posted Jan 28, 2016 by Harshita

+5 votes

2 answers

When does a MME trigger UE context modification procedure towards an eNodeB for an UE ?

posted Jan 24, 2016 by Harshita

+3 votes

2 answers

LTE : What MME will do if handover gets failed ?

posted Dec 18, 2015 by Vimal Kumar Mishra

+2 votes

2 answers

Why X2 handover is an optional thing ?

posted May 10, 2015 by Vikram Singh

+3 votes

2 answers

Why S1 handover prepapration fails with cause unknown target?

posted Feb 17, 2015 by Alkesh Mehta

+4 votes

2 answers

Why MME UE S1AP ID is needed ?

posted Nov 17, 2014 by anonymous

+2 votes

2 answers

LTE HO: Is it possible after successful resource allocation at target eNodeB, source eNodeB sends HO Cancel ?

posted May 30, 2014 by Harshita

+11 votes

2 answers

LTE: In RRC connected mode, when an UE moves from one cell to another cell what messaging happen ?

posted Feb 7, 2014 by Vimal Kumar Mishra

+1 vote

1 answer

LTE: Why MME UE S1AP ID is of length 32 bits and eNodeB UE S1AP ID of length 24 bits only ?

posted Jul 17, 2018 by Harshita

+2 votes

1 answer

ERAB modification fail due to radio interface procedure in EnodeB Nokia

posted Jan 26, 2017 by Jalloul Bouchkara

+1 vote

1 answer

LTE: What target eNodeB does in case it receives "Path switch request failure" from MME ?

posted Nov 20, 2016 by Neelam

+3 votes

1 answer

LTE: How does an eNodeB construct ECGI and TAI for an UE while sending messages like "Initial UE message " ?

posted Feb 29, 2016 by Vimal Kumar Mishra

+1 vote

1 answer

LTE: S1AP where can I find the EP CODEs numbering per each procedure

posted Jan 6, 2016 by Dannyispark

+2 votes

1 answer

What is the Significance of Repetition Period and Number of Broadcasts Requested IE's in WRITE-REPLACE WARNING REQUEST

posted Nov 18, 2015 by M.chandra Sheker

+2 votes

1 answer

Why MME has to send Paging Drx in S1AP paging messge?

posted Oct 7, 2015 by Badikela Mahesh

+3 votes

1 answer

What MME shall perform when receiving S1 path switch request (changing tac and lac for the UE) after a NAS tau request?

posted Jul 18, 2015 by anonymous

+3 votes

1 answer

Can a eNB belongs to multiple tracking area if the eNB is shared between two operator under e-UTRAN sharing model ?

posted May 21, 2015 by Sachidananda Sahu

+2 votes

1 answer

What MME does when it receives "S1-setup request" from eNodeB with an unknown TAC ?

posted May 20, 2015 by Vimal Kumar Mishra

+3 votes

1 answer

What is a difference between S1 AP release and ERAB Release command

posted Mar 23, 2015 by anonymous

+3 votes

1 answer

How TAU in source eNB interrupts S1 handover (intra MME S1 HO)?

posted Feb 18, 2015 by Alkesh Mehta

+3 votes

1 answer

Does S1-SETUP procedure run for each cell supported by an eNodeB?

posted Oct 10, 2014 by Nikhil Pandey

+1 vote

1 answer

What kill procedure does in LTE?

posted Oct 9, 2014 by Ganesh

+4 votes

1 answer

What does relay node indicator IE presence in Initial UE message signify ?

posted Oct 7, 2014 by Harshita

+1 vote

1 answer

Does S1AP disconnection affects user traffic?

posted Jul 29, 2014 by anonymous

+1 vote

1 answer

LTE RRC : What may be the purpose of tracing a particular UE in a cell or target cell(s) ?

posted Jun 5, 2014 by Vikram Singh

+1 vote

1 answer

LTE HO : Why two MME UE S1AP IDs present within the S1-AP HO Request message ?

posted May 30, 2014 by Harshita

0 votes

1 answer

LTE: What are actions taken at source eNodeB or MME in case of partial resource allocation as part of HO procedure?

posted May 29, 2014 by Vimal Kumar Mishra

+1 vote

1 answer

LTE: What may be the reason for S1 setup failure ?

posted May 5, 2014 by Ganesh Kumar

+3 votes

1 answer

LTE: Why does "CS Fallback Indicator" IE present in UE Context Modification Request ?

posted Mar 20, 2014 by Harshita

+1 vote

1 answer

LTE: What eNodeB does after receiving S1 setup response ?

posted Mar 16, 2014 by Vimal Kumar Mishra

+3 votes

1 answer

LTE : How to know cell type ?

posted Feb 13, 2014 by Vimal Kumar Mishra

+6 votes

1 answer

LTE: What is the purpose of UE Radio Capability Match procedure ?

posted Feb 12, 2014 by Ganesh Kumar

+3 votes

1 answer

LTE: What is significance of presence of Correlation ID in ICS request message ?

posted Jan 26, 2014 by Harshita

+4 votes

1 answer

LTE: What is the significance of eNodeB configuration procedure ?

posted Nov 15, 2013 by Neeraj Mishra

+1 vote

1 answer

What is the significance of Criticality Diagnostics for S1AP message ?

posted Oct 8, 2013 by Neeraj Mishra

0 votes

0 answers

Troubleshooting steps for slow speed of UE in EPC core?

posted Oct 4, 2018 by Anjan Kumar Behera

0 votes

0 answers

LTE: How many S1-links are established by an eNodeB with MME(s) ?

posted May 20, 2018 by Harshita

+1 vote

0 answers

LTE: Which cause MME sends in s1-setup failure when TAI received in S1-setup request not found at MME ?

posted May 18, 2018 by Vimal Kumar Mishra

+5 votes

0 answers

LTE: Why presence of Tracking Area Identity (TAI) and E-UTRAN CGI (ECGI) IEs is mandatory in Uplink NAS Transport ?

posted May 16, 2018 by Vimal Kumar Mishra

+2 votes

0 answers

When will mme change the security keys and send it in ue context modification request message

posted Jul 26, 2017 by Naren Nishad

+2 votes

0 answers

LTE: Why "Handover Type" IE is included in both handover messages i.e Handover Required and Handover Request ?

posted Nov 19, 2016 by Harshita