Introduction of IMS for 3G Voice Services and Migration

3GPP release 8 IMS Implementation, Deployment and Testing
Sophia Antipolis, France
Introduction of IMS for 3G Voice Services
and Migration Strategies to ALL-IP Network
Kenya Kusunose
NTT DOCOMO, INC.
Core Network Development Department
24 NOVEMBER 2010
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Agenda
1. Mobile Communication Situation in Japan
2. Network migration to IMS and ALL-IP Network
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-1-
Mobile Communications Situation in Japan
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-2-
Japan’s Cellular Market
Japan’s cellular market entered a mature phase: penetration rate reached over
80% and growth of net additions has slowed to half the previous level.
DOCOMO controls a market share of 49.7% in this market.
Cellular market share
Changes in market environment
(Million subs)
As of June 2010
Total subscriptions:
Annual subscriber
growth: 5 million
100
2.2
2.2％
％
19.9%
80
60
113.7 million
Annual subscriber
growth: 10 million
Mature
phase
40
20
Expansion
phase
96/3
98/3
00/3
28.2％
28.2
％
02/3
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04/3
06/3
49.7％
49.7
％
08/3
-3-3-
Subscriber Migration to 3G Service
• Japan’s cellular phone market is one of the most advanced in the world, characterized by
high percentage of postpaid subscriptions(over 99%) and broad adoption of 3G(over 96%).
• 3G can accommodate larger traffic volumes compared to 2G. A growth in the packet data
traffic volume indicates potential demand for data communications.
No. of Subscriptions:
3G penetration rate:
3G ARPU :
% of postpaid subs.:
(Million subs.)
50
40
2G(PDC)
20
23.5
30.8
3G(W--CDMA)
3G(W
10
0
56.8mil.(As of Sep. 2010)
96.6%(As of Sep 2010)
(As of 2Q/FY2010)
\5,200
Over 99%
57.5
54.6 56.1
53.4
51.1 52.1
53.2 56.2
49.0
43.9
60
30
DOCOMO’s Packet Traffic Volume
Packet Traffic Volume per User per Day
DOCOMO’s 3G Growth
5,000
(Flat-rate Pake-Hodai:
Launched in June, 04)
4,000
3,000
2,000
1,000
3G User Packet Traffic
Volume
2G User
Packet
Traffic
Volume
0
'00 '01 '02 '03 '04
'05 '06
Fiscal Year
'07 '08
‘09 ’10
Forecast
1999
2000
2001
2002
2003
2004
Source： Telecommunications Carriers Association (TCA), WCIS+
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-4-
Network migration to IMS and ALL-IP Network
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-5-
Evolution of All-IP network ~ phased approach
Objective of All-IP network
・Network node cost reduction
・Efficient multi-access handling
・Service enrichment
Phase 1
IP based nodes
Back
ground
Phase 3
Service Enabler Network (SEN)
IT infrastructure
Lifestyle infrastructure
Service infrastructure
・Increase of data traffic
- Flat-rate packet service
- High speed radio access
・Diversified radio access
(3G/HSPA/LTE/…)
・Renewal of the existing switching
system
・Maturation of cellular market
・Entrant of new players,
i.e. service providers
・Network node cost reduction
・Simple NW structure
・Seamless service provision
among radio accesses
・VoIP → Preparation towards
LTE
・Various network service
provisioning with time to
market and low cost
Objectiv
es
Enhance
ment
measures
Phase 2
IMS & SAE
Introduction of IP-based
nodes using general-purpose
servers
Integrated IP NW & call control
among radio accesses (IMS)
Introduction of
Service Enabler Network (SEN)
Dedicated (separated) network
for packet domain
Seamless mobility among
variety of radio access (SAE)
Variety of Network Enablers
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-6-
Phase 0: Pre All-IP Network (Integrated ATM Network) (2001)
At start of 3G (FOMA) service in 2001
• Voice services traffic was dominant and data traffic was relatively small volume.
Network needs to handle;
voice services traffic with high quality, as well as,
both voice services and data traffic simultaneously
• ATM was the best technology to realize above requirements.
Core network
GMSC/GGSN
ATM
Voice & Packet
Radio access network
Integrated core network
MSC/SGSN for both voice & data services
RNC
BTS
User equipment
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-7-
Phase 1: Dedicated Packet Switch domain (2004-05)
Continuous increase of data traffic
Packet NW was separated from integrated ATM NW (around 2004)
in order to scale out the capacity easily to cope with increasing data traffic.
Applying IP-based nodes using routers & general-purpose servers for packet
network
Core network
GMSC
GMSC/GGSN
ATM
Dedicated core network
for voice services
MSC
MSC/SGSN
Voice
Radio access network
GGSN
SGSN
IP
Dedicated core network
for data services
Packet
RNC
BTS
User equipment
(c) 2010 NTT DOCOMO, INC. All Rights Reserved.
-8-
Evolution of All-IP network
Objective of an All-IP network
・Efficient data traffic handling
・Multi-access handling
・Service enrichment
Phase 1
IP based nodes
Back
ground
Phase 3
Service Enabler Network (SEN)
IT infrastructure
Lifestyle infrastructure
Service infrastructure
・Increase of data traffic
- Flat-rate packet service
- High speed radio access
・Diversified radio access
(3G/HSPA/LTE/…)
・Renewal of the existing switching
system
・Maturation of cellular market
・Entrant of new players,
i.e. service providers
・Efficient data traffic
・Network cost reduction
・Simple NW structure
・Seamless service provision
among radio accesses
・VoIP → Preparation towards
LTE
・Various network service
provisioning with time to
market and low cost
Aims
Enhance
ment
measures
Phase 2
IMS & SAE
Introduction of IP-based
nodes using general-purpose
servers
Integrated IP NW & call control
among radio accesses (IMS)
Introduction of
Service Enabler Network (SEN)
Dedicated (separated) network
for packet domain
Seamless mobility among
variety of radio access (SAE)
Variety of Network Enablers
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-9-
Phase 2:Integrated All-IP NW(IMS introduction for 3G voice, around 2010)
IMS introduction for 3G voice services has benefit for operator to reduce CAPEX/OPEX.
• Replace traditional switch to general-purpose server base nodes.
• Only PS domain required. Voice communication can be provided through PS domain.
• Re-use of IMS for other access systems. (e.g. LTE, NGN, WiMAX, ….)
• Smooth migration toward future LTE/4G voice communication (VoIP).
• Preparation for network service enrichment by SEN on IMS (Phase 3) (introduce later)
PS domain
CS domain
Core network
GMSC
ATM
Terminate
S/P-GW
GGSN
IMS
IP
ATM network
MSC
Radio access network
RNC
BTS
SGSN
CS
CS--GW
MME
Voice & Packet
eNodeB
LTE
User equipment
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- 10 - 10 -
Phase2:IMS introduction for 3G voice services
• Migrate the 3G Circuit-Switched network configured with ATM switches to the network that
processes IP-based protocols (SIP, RTP, etc.) in server equipment
• Process the existing radio interface and 3G radio access network, without making changes,
by converting them to IP-based protocols in CS-GW
• Perform unified Call／
／Service control in IMS preparation to LTE Voice call handling
HLR
Bill details
Media
Server
Media
Server
ATM
NW
TMSC
MGW
AS
Service control
GMSC
3G packet
CSCF
Call control
MRF
Applying server tech. Guidance
VoIP on core NW
Accommodate
3G3G-CS
accesses
Unified call control
MSC
GGSN/SGSN
by IMS
GGSN/SGSN
CS-GW
3G packet
RNC
IMS
Call control
Service control
PLMN gate
POI
GMSC
POI
Router
network
Bill details
HLR/HSS
RNC
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RNC
RNC
IP-based protocols
(SIP, RTP)
Protocol
conversion
Existing radio
interface
- 11 -
CS-GW’s function
•CS-GW’s function is to convert CC/MM to SIP.
•With CS-GW all users can use any existing UE in IMS networks.
•With the traditional method (e.g. through GPRS), users can only use SIP functions
provided by the UE.
To IMS through GPRS
SIP
functions
PS
functions
SIP
functions
SIP
SM/GMM
UE
PS
functions
GGSN
CSCF
To IMS through CS-GW
SIP functionality
is NOT needed.
CS
functions
UE
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CC/MM
SIP
functions
SIP
SIP
functions
CS
functions
CS-GW
CSCF
12
Bandwidth control to keep QoS
•To keep QoS of voice service in IMS network the same as in 3G-CS NW, the
proposed IMS network adds a function to control bandwidth virtually.
•The control is executed by bandwidth build-up based on the number of sessions.
•CSCF and CS-GW build up bandwidth in response to each session type (voice or
AV) and control call admission.
CSCF executes bandwidth control on each
route.
AS
INVITE
AS
CSCF
CSCF
CR
INVITE
LCR
LCR
CS-GW
CS-GW
ER
Setup
AR
ER
ER
ER
IP network
AR
CS-GW executes bandwidth control on
a route to AR.
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13
Aggressive schedule for migration(IMS introduction)
We
just launched a plan for IMS introduction last March.
We will complete the plan in two years.
After completing the plan, all 3G voice services are controlled by IMS in DOCOMO’s
network(56 million users).
Percent
Complete
(%)
In Two Years
100
50
0
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- 14 -
Evolution of All-IP network
Objective of an All-IP network
・Efficient data traffic handling
・Multi-access handling
・Service enrichment
Phase 1
IP based nodes
Back
ground
Phase 3
Service Enabler Network (SEN)
IT infrastructure
Lifestyle infrastructure
Service infrastructure
・Increase of data traffic
- Flat-rate packet service
- High speed radio access
・Diversified radio access
(3G/HSPA/LTE/…)
・Renewal of the existing switching
system
・Maturation of cellular market
・Entrant of new players,
i.e. service providers
・Efficient data traffic
・Network cost reduction
・Simple NW structure
・Seamless service provision
among radio accesses
・VoIP → Preparation towards
LTE
・Various network service
provisioning with time to
market and low cost
Aims
Enhance
ment
measures
Phase 2
IMS & SAE
Introduction of IP-based
nodes using general-purpose
servers
Integrated IP NW & call control
among radio accesses (IMS)
Introduction of
Service Enabler Network (SEN)
Dedicated (separated) network
for packet domain
Seamless mobility among
variety of radio access (SAE)
Variety of Network Enablers
(c) 2010 NTT DOCOMO, INC. All Rights Reserved.
- 15 -
- 15 -
DOCOMO’s SEN (Service Enabler Network) Concept
Provide a variety of services to satisfy various user needs with timely manner.
• SEN (Service Enabler Network) is service provision platform on top of IMS Core.
• Enabler is the piece of service function that can be commonly used by multiple services.
• By combining multiple enablers, realize various services (corporate, consumer , etc.)
within reasonable time period and cost.
RCS
Enabler
Presence
IM
Contents
sharing
Combine enablers
ＳＥＮ
(Service--Enabler Network)
(Service
IMS
Core
(Reference 1)
RCS (Services provided by mutually
connecting the IMS among operators in
different countries: First release can realize
instant messaging, presence and contents
sharing by using part of SEN)
All-IP NW
3G area
(c) 2010 NTT DOCOMO, INC. All Rights Reserved.
(Reference 2)
Enabler is a service function part that can be
commonly used by multiple services.
ＬＴＥ
- 16 -
Example of value-added NW service
Combination of standardized enablers and operator-specific enablers, realizes the
specialized services for operator.
Standardization of the mechanism to offer value-added NW services is developed as
the GSMA RCS release 3. DOCOMO is leading a study group.
Operator-specific Enablers
RCS Standard Enablers (Release 1)
Instant
messaging
Content
sharing
Media
Processing
A
Presence
Service
Composition
I guess you are close now.
I’m already here.
Where are you , Aya?
...
Media
Processing
B
Realization of
Value-Added NW Services
I’m at this point now!
I’m getting closer to you!
IMS
Core
Voice call
位置情報シェア
Here
Location Info.
Sharing
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- 17 -
Conclusion
To live up to user’s demand to enrich the mobile services,
mobile systems are continuously evolved.
NTT DOCOMO,
– is going ahead with the migration plan to ALL-IP
network.
– introduce IMS begin by applying 3G voice services.
– replace ATM network with IMS network in two years.
– provide netwok value added services using the IMS.
– Service Enabler Network(SEN) concept.
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- 18 -
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- 19 -