11-1

Leliwa Sp. z o.o.www.leliwa.com

VoLTE Basics

11-2

Emergency call

11-3

Emergency call

The need for support of emergency calls in the IM CN subsystem is determined by national regulatory requirements.

11-4

IP-CAN bearer setup for emergency session (UE EPS registered)

PDN connectivity

req.

(type=emerg

ency)

MME

P-GWS-GW

emergency APN & QoS configuration

emergency IMS

IMS

IP

IP

11-5

IP-CAN bearer setup for emergency session (UE EPS not registered)

Attach r

equest

(type=emerg

ency)

MME

P-GWS-GW

emergency APN & QoS configuration

emergency IMS

IMS

IP

11-6

Emergency IMS registration*

*USIM/ISIM available

REGISTER

MAR/MAA

401 UNAUTH401 UNAUTHORIZED

P-CSCF S-CSCF

UAR/UAA

REGISTER

401 UNAUTH.

REGISTER

Emergency APN

REGISTER

SAR/SAA

200 OK200 OK

UAR/UAA

REGISTER

200 OK

REGISTER

I-CSCF HSS

sos

sos

sos

sos

11-7

E-CSCF in IMS architecture

Gm

Mw

P-CSCF

E-SCC AS LRF

Mw

I4 MI

E-CSCF

S-CSCF

PSAP

Le

Mm/Mw

Mi/Mg

Mm

PSTN

IMS

Public Safety Answering Point

Location Retrieval Function

Emergency – Service

Consistency and Continuity AS

Emergency-CSCF

call setup