NEXT GENERATION NETWORKS
A view on migration paths from existing
fixed and mobile networks
Souheil MARINE
Jean-Marie BLANCHARD
Why Next Generation Networks ?
>
Convergence between the packet-based Internet and
telephony networks
•
•
>
Take the best from each
•
•
>
Service provision of the telephony network model
Openness and flexibility of the Internet model
Possible Definition of a Next Generation Network
•
>
Driven by technological evolution
Demand for a universal service network
A packet transport based network where the transport, control and
service layers are separated from each other and interact through
open interfaces
The target is well defined but how to get there ?
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 2
All rights reserved © 2002, Alcatel
Migration Rationale
>
Migration of current telephony networks (2 billion users
worldwide) should preserve the existing investments
>
Key investments in any network are in provisioning access for
end-users to the network services (80% of the costs)
•
>
Migration must be driven by basic principles
•
•
•
>
Any technological changes become costlier when they get closer to
end-users and should be justified by added value brought with them
Continuity of services offered to end-users
Inter-working between new and old technologies
Cost control of the migration process
Migration should above all be driven by economic considerations
•
•
Network consolidation and optimization and/or
New revenues driven from new services
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 3
All rights reserved © 2002, Alcatel
Proposed Migration Approach
>
Approach in 5 steps where each is justified by new services or
advantages brought from consolidation
>
Application of each step to the specific case of fixed and
mobile (GSM and future 3G UMTS) networks
>
The proposed migration steps are generic
•
•
•
>
Application of each step depends on the specific operator context
All are not compulsory and do not follow in the same sequence
There is no “one size fits all” migration scenario
Network views of migration steps are not exhaustive
•
Emphasis put on significant network elements needed for service
provision, on signaling relations between end-users and the
network and between network entities
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 4
All rights reserved © 2002, Alcatel
Step 1 Fixed: Access to the Internet and Converged
Internet/Telephony services
Parlay, JAIN, SIP
ApGW
Application
Servers
WWW
Servers
Internet
INAP
Transit
STP
SS7
‘PINT’, ‘SPIRITS’
SCP
ISUP
ISDN/PRA
Transit
ISUP
TDM
NAS
Local
BAS
Local
Access Node
Voice
Data
Signaling
Dial-up DSL
Modem Modem
POTS,
ISDN
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 5
Packet
Network
All rights reserved © 2002, Alcatel
DSLAM
Step 1 Fixed: Access to the Internet and Converged
Internet/Telephony services
>
Basic telephony service and its associated supplementary
services
•
•
>
Intelligent Network Services
•
>
Calling Cards, Free phone,Voice virtual private networks,…
Internet access
•
>
TDM based transport
SS7 based signaling
In dial-up mode or in broadband mode with DSL technology
Converged Voice/data services
•
•
Benefit from the simultaneous availability of a telephony access and
Internet access in the case of broadband Internet access
Examples of converged services: Click-to-Dial, Internet Call Waiting,
Web Augmented Calling, Unified Messaging,...
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 6
All rights reserved © 2002, Alcatel
Step 1 Mobile: Introduction of GPRS Packet Services
Mobile Core Circuit Switching
MSC/VLR
PSTN
BTS
HLR
Gs
A
BTS
Border
Gateway
Abis
BSC
Gb
Ater
BTS
Mobile Radio
GPRS
Box
IP
SGSN
Gn backbone
DNS /
DHCP
Charging
Gateway
GGSN
Gi
Internet /
Intranet
WAP
Gateway
Mobile Core Packet Switching
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 7
All rights reserved © 2002, Alcatel
Step 1 Mobile: Introduction of GPRS Packet Services
>
General Packet Radio Service (GPRS) introduced as a solution
for offering an always-on access mode to data services for
mobiles
•
Optimized use of the scarce radio resource
–
–
>
No modification of the existing radio and core infrastructure for
voice services
•
•
>
Share the bandwidth for data services between users of a given radio
coverage zone (cell)
Radio resources are not monopolized during idle periods
GPRS adaptation equipment added to existing radio infrastructure
GPRS specific core infrastructure re-usable in further evolution
steps
GPRS service platform
Offers access to Internet/Intranet data networks and to service
portals (first step towards future UMTS services)
All rights
reserved services
© 2002, Alcatel
• Optimize
provision
of 2G
data
like Short Messages (SMS)
Séminaire TIC/IMT-2000,
Abidjan, 9-12 Septembre
2002— 8
•
Step2 Fixed: Network consolidation and introduction of
new multi-service access nodes
SCP
Internet
INAP
STP
SS7
ISUP
TDM
Transit
Packet
Network
ISUP (IMT)
ISUP
Local
V5.2 or Local
proprietary
Access Node
Voice
Data
Signaling
NAS
V5.2
V5.2 Voice
Multi-service
Access
Nodes
ATM, IP
POTS,
ISDN
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 9
All rights reserved © 2002, Alcatel
BAS
DSLAM
ADSL-NT
Step 2 Fixed: Network consolidation and introduction of
new multi-service access nodes
>
Switch consolidation
•
•
>
Maximize number of line, minimize number of nodes
Upgrade of switch fabric and processors for higher capacity and
speed
Access Consolidation
•
Add NGN-ready multi-service access nodes
–
–
–
>
End-user in native packet access mode
DSL but also other alternative next generation local loop technologies
(cable networks, wireless local loop, satellite,…)
Introduce Voice-over-DSL (loop emulation service) and extend voice
service offer without modification of the legacy switches
Optimize interconnection to the data network for dial-up access
•
•
Interconnection at local exchanges level (offload transit level)
Use of ISUP and Inter Machine Trunks (IMT) instead of ISDN/PRA
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 10
All rights reserved © 2002, Alcatel
Step 2 Mobile: Introduction of UMTS Radio Access
Networks
SCP
SGSN
GSM
RAN
HLR
MSC
PSTN
QoS-enabled IP backbone
Internet
Core
Router
GGSN
UMTS
RAN
Optical Core
Edge
Router
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 11
All rights reserved © 2002, Alcatel
Edge
Router
Step 2 Mobile: Introduction of UMTS Radio Access
Networks
>
Initial introduction of 3G UMTS radio access network (UTRAN)
as coverage islands
•
>
Combined 2G/3G HLR, MSC, SGSN and GGSN network
equipment support both types of access (Alcatel’s approach)
•
>
Rest of the network coverage kept with legacy GSM 2G/2.5G radio
Smooth upgrade of early 2G equipment
Backbone data network introduced with QoS features
•
Edge router concentrates ATM streams coming from UTRAN
–
–
•
>
Front-end for both packet and circuit streams
Evolves into an access gateway in future evolution steps
Core router switches IP traffic with MPLS/DiffServ support
New service capabilities with location based service support
•
Enhanced intelligent network interfaces for mobiles towards SCP
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 12
All rights reserved © 2002, Alcatel
Step 3 Fixed: Voice over Packet for Trunking
INAP
ISUP, BICC, SIP-T
SCP
Internet
INAP
STP
SS7
H.248
ISUP
Transit ISUP
Packet
Network
TDM
BICC
Switch with MGC
function or
Softswitch
Local or
Transit
Local or
Transit
Integrated
Gateway
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 13
All rights reserved © 2002, Alcatel
Voice
Data
Voice/Packet
Signaling
Step 3 Fixed: Voice over Packet for Trunking
>
Gradually offload voice trunking traffic to the packet network
>
Network consolidation by removal of an upper transit level or
optimization within a transit level
•
•
•
•
>
First mastering of voice over packet technology at aggregate level
•
>
Voice-over-Packet trunking through integrated gateways in the
LEX/TEX
Alternative solution based on external trunking gateways controlled
by a Switch with Media Gateway Control (MGC) function or a
Softswitch
Use of SS7 based BICC signaling for co-existence with PSTN/ISDN
services
Reuse of existing IN services for business continuity
Simpler Quality of Service issues
Service transparency of Voice over Packet use for end-users
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 14
All rights reserved © 2002, Alcatel
Step 3 Mobile: Voice service over Packets (Core and
Access)
HLR
Co
La ntr
ye ol
r
SCP
UMTS
RAN
GMSC
server
H.248
Co
n
La nec
ye tiv
r
ity
GSM
RAN
BICC
MSC
server
H.248
PSTN
A-MGW
T-MGW
AMR/AAL2
Internet
Core
Router
Edge
Router
GGSN
Edge
Router
Optical Core
SGSN
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 15
QoS-enabled IP backbone
All rights reserved © 2002, Alcatel
Step 3 Mobile: Voice service over Packets (Core and
Access)
>
Generalization of UTRAN access
•
>
Voice coming in packet mode (ATM/AAL2) from the access
network
Leverage on the QoS-enabled IP backbone to support voice
services in NGN way
•
Keep voice in original packet mode for mobile-mobile calls
–
•
•
>
Avoid unnecessary and quality decreasing encoding/decoding
Evolution of 2G/3G integrated MSCs into MSC servers (Alcatel’s
approach)
Use of the H.248 open interface to control Media gateways
Media gateways for Access and Trunking functionality
•
•
Based on the same platform as the Edge Router
Mediation device for voice applications over ATM/AAL2
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 16
All rights reserved © 2002, Alcatel
Step 4 Fixed: Voice over packet up to access level
Switch with MGC
function or
Softswitch
SCP
INAP
STP
ISUP
ISUP
SS7
H.248
Transit
Voice/Packet
Gateway
Internet
TDM
Access Node
Voice
Data
Voice/ Packet
Signaling
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 17
Packet
Network
Local
AN
Multi-service
Access Node
with Integrated
Access Gateway
All rights reserved © 2002, Alcatel
DSLAM
Centralized
Access Gateway
Step 4 Fixed: Voice over packet up to access level
>
Extend use of packet transport to the access network for voice
services
•
Introduction of Access Gateways
–
–
•
Access gateways are controlled by a switch with MGC function or
a softswitch
–
–
>
Integrated within next generation multi-service access nodes or
Standalone centralized access gateways
Same services portfolio as on the PSTN/ISDN
Tighter integration of voice and packet services
Improved network consolidation
•
•
control of the voice traffic from fewer MGC Switches or
Softswitches
Voice traffic gradually moved from the control of old generation
switching equipment to the control of upgraded MGC switches or
Softswitches
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 18
All rights reserved © 2002, Alcatel
Step 5 Fixed: Multimedia Services
Application
Servers
SCP
Portal
INAP
STP
HTTP
SIP
Parlay
JAIN
SIP
Internet
ISUP
ISUP
ISUP
SS7
H.248
Softswitch
SIP, H.323
Transit
TDM
Local
Voice
Data
AN
Voice/Packet
Signaling
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 19
WWW
Servers
All rights reserved © 2002, Alcatel
Packet
Network
BAS
DSLAM
Step 5 Fixed: Multimedia Services
>
End-users connected through next generation multi-service
access nodes will adopt IP terminals for multimedia services
•
>
New IP terminals will be controlled by Multimedia Softswitches
through a new type of NGN signaling
•
•
>
Better benefit of the high bandwidth, always-on and interactivity
associated with such next generation access networks
SIP or H.323
Access network will focus on resource provision under the
softswitch control depending on the service used
A multimedia softswitch offers network services but also third
party services through portals and open interface
•
Network operator becomes the intermediary broker between
application providers and their clients
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 20
All rights reserved © 2002, Alcatel
Step 5 Mobile: Multimedia Services
3rd party
Application
3rd party
Application
3rd party
Application
Integrated
Management
Application layer
Portal
Service Co-ordination layer
Multimedia
Softswitch
HSS
Session layer
V/G-MSC
Server
HLR
Media
server
T-MGW
A-MGW
UMTS
RAN
SGSN
PSTN
GGSN
Internet
Optical Core
SIP Terminals
Transport & connectivity layer
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 21
QoS-enabled IP backbone
All rights reserved © 2002, Alcatel
Step 5 Mobile: Multimedia Services
>
IMS is the operator solution to differentiate from commoditypriced best-effort data services
•
•
Offering end-to-end Quality of service
Network operator as the broker of added-value services
–
•
>
Services can be offered by 3rd party service providers
New business model unlocking new revenue sources
Multimedia Softswitch providing new services
•
•
Re-use of the currently deployed packet switched IP backbone
and network equipment (SGSN and GGSN)
New NGN signaling with new type of end-user terminals
–
•
•
SIP protocol with proper extensions to ensure end-to-end QoS per
service invocation
Open interfaces towards 3rd party service provider
Inter-working with voice services through interface with MSC
Server
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 22
All rights reserved © 2002, Alcatel
Conclusions
>
Migration to NGN is an evolution of existing networks
>
Driven by
•
•
>
Speed of migration depends on
•
•
>
Enhanced capabilities of Broadband access
Demand for new services from customers
Widespread acceptance and appropriation of new services
But also on the maturity of the newly introduced technologies
There is no universal migration scenario
•
•
•
Each migration depends on specific operator conditions, strategy,
and…available budget
Migration process must be self-financed by revenue from new
services and/or cost reductions from network optimization
Interoperability with the installed base is a key condition for
success
Séminaire TIC/IMT-2000, Abidjan, 9-12 Septembre 2002— 23
All rights reserved © 2002, Alcatel
www.alcatel.com
Thank You !
Questions ?