Download - Voice Services Over LTE EPC
voice services over lte/epc
>Introduction
LTE/EPC is only Packet (IP)
› LTE/EPC › Telephony is treated as any other IP
based service/application
Circuit Domain
Packet Domain
2G/3G RAN2G/3G RAN
Voice
Internet Access
CS Bearer
PS Bearer
Packet Domain
LTE RAN
Voice or TV
Internet AccessPS Bearers
Packet Domain
LTE RAN
Voice or TV
Internet AccessPS Bearers
2G/3G and CDMA› Specific management of CS telephony
through the whole system
CS Services in LTE
MMTel IMS-based Multimedia Telephony.•SR-VCC (Single Radio Voice Call Continuity)
•ICS (IMS centralized service)
CS Fallback (CSFB)
Objectives› Describe CS Fall Back solution› Describe MMTel solution
– Single Radio Voice Call Continuity– IMS centralized services
>Overview
1. Subscriber registered in MSC but roam in LTE
2. CS domain updated of subscribers whereabouts through
CS signaling over MME-MSC (LUP, SMS etc.)
Payload6. Page response
and call setup over 2G/3G
radio
5. Release with redirect
CS FallbackMSS as voice engine for LTE subscribers
SGs
4. Page over SGs-interface
3. Incoming call to subscriber in LTE
CS signaling
What is MMTel? IMS based solution for IP multimedia telephony
Voice and videoHigh Quality
Image/file transfer
Supplementary Services &
Conferencing
Text chat
mMTel over LTE/EPCBasic Architecture
MMTel over LTEIMS centralized services
›Classical CS network without MMTel capabilities => IMS Centralized Services (ICS)
›MMTel deployed in the 2G /3G network => Single Radio Voice Call Continuity (SRVCC).
GSM/WCDMA or CDMA
LTE island
LTE
LTE
LTE
LTELTE
IMS Centralized services (ICS)
› ICS enables IMS service control when using CS access for the media bearer.
› It provides the same end user experience to subscribers, as if they were using LTE access.
› It enables support of the MMTel service engine over legacy CS access from an MMTel/ICS device
SRVCC R9Call handover and re-establishment phase
SvA
B
3b. The MSS set up a call leg to the SCC AS
4. The SCC AS finds the anchored call and executes session transfer
5. The UE tunes in to GSM or WCDMA
3a. The MSS and RAN prepares to receive a handover
1. UE sends measurements, the eNodeB decides to do SRVCC HO
2. The MME handles the SRVCC HO via the Sv interface
SCC
AS
>Summary
Summary of VOICE Services in LTE/EPC› CS Fallback
› MMTelEPC MMTel
(IMS)E-UTRAN
GERAM/UTRAN/CDMA
E-UTRAN