ITUITU-BDT Regional Seminar on Fixed Mobile
Convergence and new network architecture for the
Arab Region
Tunis, Tunisia, 2121-24 November 2005
Network Architecture consolidation
towards NGN
Oscar González Soto
ITU Consultant Expert
Strategic Planning and Assessment
November 2005
Lecture - 1.3.5 - slide 1
ITU/BDT Network Architecture consolidation - O.G.S.
Network Architecture towards NGN
Content
• Key factors
for the evolution towards NGN
• Services and revenue motivations. Requirements
• Network architecture consolidation at transit, local
and access levels
• Topology and migration
• Network optimization based on planning methods and
tools
• Support to Design
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 2
Network Architecture towards NGN
Key Factors: Motivation
• New services and revenue increase with multimedia services:
- Compensate voice revenue reduction and increase BB related
business
• Cost reductions by sharing network infrastructure and systems
- Savings are a function of network scenario, equipment
modernization status and customers grow speed
• Simplification of O&M, thus lowering OPEX
- Integrated operation platforms, maintenance and training
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 3
Network Architecture towards NGN
Key Factors: Operator Requirements (I)
• Business continuity required to maintain ongoing dominant services
and customers that require carrier-grade service
• Flexibility to incorporate existing new services and react quickly to the
ones that appear on real time (main advantage of IP mode)
• Profitability to allow feasible return on investments and in the best
practices market values
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 4
Network Architecture towards NGN
Key Factors: Operator Requirements (II)
• Survivability to allow service assurance in case of failures and external
unexpected events
• Quality of Service to guarantee the Service Level Agreements for
different traffic mixes, conditions and overload.
• Interoperabilty across networks to allow to carry end to end services
for flows in different network domains
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 5
Network Architecture towards NGN
Key Factors: Issues to care
• Introduction of new services based on profitability
• Interworking with existing PSTN and other operator's networks
• QoS for guaranteed services and critical business customers
• Tariff principles as a function of market demand and consumption of
network resources (Backward Cost Assignment)
• Universal Service Obligations for basic services and internet
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 6
Network Architecture towards NGN
Content
• Key factors
for the evolution towards NGN
• Services and revenue motivations. Requirements
• Network architecture consolidation at transit, local
and access levels
• Topology and migration
• Network optimization based on planning methods and
tools
• Support to Design
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 7
Network Architecture towards NGN
Architecture Consolidation: Topology
Topological changes impact on infrastructure and are slower
to implement than technology substitution
• Less network nodes and links due to the higher capacity of systems
(one order of magnitude).
• Same capillarity at access level due to identical customer location
• Topological connectivity higher for high capacity nodes and paths for
security
• High protection level and diversity paths/sources in all high capacity
systems, both at functional and physical levels
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 8
Network Architecture towards NGN
Existing networks and architecture
NMC
• 5 different network types to handle
telecom services
SCP
IN
SS7
• TDM for fixed and mobile networks
working in circuit mode with end to
end reserved paths
Mob
LEX/TEX
NAS
TDM
Data
ATM/IP
LEX
PCM
RSU
POTS
MUX/DSLAM
• SS7 and IN network working with
message switching mode
• Data network working with leased
lines and packet mode with different
and conventional IP protocols
ISDN
HDSL/XDSL
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 9
Network Architecture towards NGN
Existing networks and architecture
TRANSIT NETWORK
NATIONAL LAYER
REGIONAL LAYER
LEX
LAYER
RU
LAYER
customers
LAYER
November 2005
• Hierarchical topology with 4 to
5 layers, connectivity to the
upper next layer and within each
layer as a function of economical
optimization
• Number of nodes as a function
of O/D traffic and nodes capacity
• Service handling for media,
signaling and control at all
exchange nodes
•Carrier grade quality with well
defined QoS criteria and
standardized engineering rules
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 10
Network Architecture towards NGN
Architecture: NGN Layers
Legacy Network
Signaling/Service
Network
Independent
Services
Legacy Network
Media
November 2005
Lecture - 1.3.5 - slide 11
ITU/BDT Network Architecture consolidation - O.G.S.
Network Architecture towards NGN
Architecture migration: Topology
What changes from current scenario towards target network ?
NMC
OSS
SCP
IN
SS7
LEX/TEX
NAS
TDM
Distributed Switching
Transport/Media
Data
ATM/IP
LEX
Access
gateway
Packet
Network
IP/MPLS/CAC
Access
gateway
RSU
Trunk
gateway
Other
Networks
Access
gateway
DSL
PCM
POTS
Softswitch
Control
Mob
Services
MUX/DSLAM
ISDN
Wireless
gateway
DLC
HDSL/XDSL
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 12
Network Architecture towards NGN
Architecture Consolidation: Topology
TRANSIT NETWORK
NATIONAL LAYER
REGIONAL LAYER
LEX
LAYER
RU
LAYER
Single-layered
Structure
Simplification
NATIONAL/REGIONAL
LAYER
TRANSIT NETWORK
LEX/GW
LAYER
RU
LAYER
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 13
Network Architecture towards NGN
Architecture Consolidation: Access
Access dominated by physical infrastructure cost and
deployment time
• Quick deployment of DSL and Multimedia Services
• FO closer to customer when implementing new outside plant or
renovating existing one
• New Wireless technologies for low density customer scenarios
• Shorter LL length than classical network to be prepared for high
bandwidth Multimedia services
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 14
Network Architecture towards NGN
Architecture Consolidation: Wireline Access
Typical historical Access Network structure
Local: ~ 40 km
Distribution: mean value ~1,7 km
Drop: mean value ~300 m
branching cables
.
.
main cable
SDF
SDF
drop line
.
.
FDF
SDF
MDF
NTBA
SDF
LEX
drop line
LEX
MDF
FDF
SDF
Local Exchange
Main Distribution Frame
Feeder Distribution Frame
Subscriber Distribution Frame
November 2005
Lecture - 1.3.5 - slide 15
ITU/BDT Network Architecture consolidation - O.G.S.
Network Architecture towards NGN
Architecture Consolidation: Access evolution
Typical Access Network evolution
Local: ~ 40 km
Distribution: mean value ~1,7 km
Drop: mean value ~300 m
branching cables
FO
Optical
Interface
LEX/GW
LEX
GW
MDF
DLC
SDF
FO
.
DLC
SDF
.
.
SDF
drop line
.
.
.
SDF
DLC
drop line
NTBA
.
.
Local Exchange
Gateway
Main Distribution Frame
Digital Loop Carrier
Subscriber Distribution Frame
Fiber Optic
DLC
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 16
Network Architecture towards NGN
Architecture Consolidation: Local
Dominated by functions migration investment and
interoperability
• Move from joint switching and control to separated control and media
GW
• Introduce Multimedia Services at all areas
• Optimize number, location of nodes and interfaces among existing and
new network
• Requires longer time and higher investments due to variety of geoscenarios and geographical distribution
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 17
Network Architecture towards NGN
Architecture Consolidation: Local
Softwitches/ MGCs
located in few sites
Packet
mode
network
Trunking
gateway
TEX Layer
Trunking
gateway
Access
gateway
IP links
Access
gateway
LEX Layer
Exchange A
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Exchange A
subscriber
“Growth”
Lecture - 1.3.5 - slide 18
Network Architecture towards NGN
Architecture Consolidation: Core
Dominated by high capacity and protection level
• Overlay deployment for full coverage in all regions
• Quick deployment needed for homogeneous end to end connections
• Strong requirements for high quality, protection and survivability
• Importance of the optimization for location and interconnection
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 19
Network Architecture towards NGN
Architecture Consolidation: Core
Softwitches /MGCs
in few sites
Trunking gateway
in each regional
site
Regional Level
IP links
Packet
mode
network
short
distance
LEX Layer
Local Exchanges
Remote Units
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 20
Network Architecture towards NGN
Architecture Consolidation: Core
Softswitches/MGCs
located in few sites
IP links
Long
distance
Packet
mode
Regional layer
network
Trunking gateway
in each local site
Local Exchanges
LEX Layer
Remote Units
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 21
Network Architecture towards NGN
Architecture Consolidation: Combined Segments
Where to start and how to co-ordinate migration?
Network “consolidation”
Cost Optimisation of the network
- Reducing nodes and increase their capacity
- Deployment of ADSL and multiservice access
Network expansion
NGN solution :
- Cap and Grow; this means keeping the existing PSTN network as it is, and
grow demand with NGN equipment
Network replacement
Replacement of out-phased (end of life) TDM equipment
- gradual replacement : this means coexistence of the two technologies
- full accelerated replacement with a short transition period
Need to optimize overall network evolution: technically and economically
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 22
Network Architecture
towards
NGN
Smooth
Smooth
migration
migration
to NGN
to NGN
Architecture Consolidation: Combined Segments (I)
RSP
DS
International
Core
IN
Data
Mux
PSTN Class 4
SSP
Core
PSTN Class 5
Multiservice
Node
Subscriber unit
Edge
Access
Customers
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 23
Network Architecture towards NGN
Architecture Consolidation: Combined Segments (II)
Softswitch
Optical
NGCR
NGER
International
Core
AGW
Core
Associated
TK GW
Multiservice
node
MM
Subscriber unit
Edge
Access
Customers
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 24
Network Architecture towards NGN
Architecture Consolidation: Combined Segments
Overall impact of evolution on network CAPEX and OPEX
CAPEX
OPEX
•
TDM and NGN CAPEX are
close
•
OPEX in NGN trends to be
lower
•
NGN CAPEX in the first
years driven by geographic
coverage
•
•
Access systems represent a
large part of CAPEX
Migration scenarios will have a
mix of TDM OPEX (installed
base) and NGN OPEX
(substitution and growth)
•
Significant impact of
manpower cost due to
convergence in operations
– similar values in TDM
and NGN
Key factors for the evaluation: Geo-scenarios, Network grow rates,
Aging of equipment, New services
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 25
Network Architecture towards NGN
Cost drivers and trends
•
Network physical infrastructure as a function of location and density
(costs proportion around 70% in the access segment)
•
Volume of customers per category
•
Bandwidth demand per origin/destination
•
Packet processing rates for control related functions
•
Variety of applications/services and related platforms
•
Content storage and location within the network
•
Leasing of physical or communication resources
Fundamental importance of economies of scale by volume and convergence
at network resources, service platforms and OSS
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 26
Network Architecture towards NGN
Architecture Consolidation: Scenario evaluation
•
Net Present Value (NPV) for the overall migration project is the
best global evaluator
NPV for C4 Scenario in alternative A
NPV for C5 Scenario in alternative B
50 000
20 000
15 000
-
10 000
(5 000)
2004
2005
2006
2007
2008
(50 000)
5 000
2004
2005
2006
2007
2008
delta CAPEX
Opex savings
cumulated DCF
(10 000)
delta CAPEX
Opex savings
cumulated DCF
(100 000)
(150 000)
(15 000)
(200 000)
(20 000)
(25 000)
(250 000)
A large variety of country scenarios and transition strategies generate major
differences in the economical results
Planning to be performed per
country and operator
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 27
Network Architecture towards NGN
Content
• Key factors
for the evolution towards NGN
• Services and revenue motivations. Requirements
• Network architecture consolidation at transit, local
and access levels
• Topology and migration
• Network optimization based on planning methods and
tools
• Support to Network Design
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 28
Network Architecture towards NGN
Support tools: Design and Optimization (I)
Required functionality for Technical design
tools
•
Service demands characterization and traffics for VoIP and NGN
multiservice flows
•
Conceptual Network Design and Capacity Planning
•
•
Comparison of different network structures
Routing flows for most typical cases including OSPF, shortest path,
widest path and weighted cost functions.
•
Optimizing locations and connections of network gateways
•
Cost, Performance and Reliability Analysis
•
Estimation of investment costs for the rollout and the extension of the
investigated multi-service network
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 29
Network Architecture towards NGN
Support tools: Design and Optimization (II)
Required functionality for Technical
design tools
• Estimation of end-to-end delays
• Technical Site and System Planning
• Allocation of the IP or MPLS links
• Formation of virtual networks
• Routing over ATM links or PDH/SDH systems or tunneling via
other IP links
• Sub-networking and addressing
• Configuring the network elements (IP router)
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 30
Network Architecture towards NGN
Support tools: Design and Optimization
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 31
Network Architecture towards NGN
Support tools: Design and Optimization
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 32
Network Architecture towards NGN
Support tools: Design and Optimization
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 33
Network Architecture towards NGN
Support tools: Design and Optimization
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 34
Network Architecture towards NGN
Support tools: Design and Optimization
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 35
Network Architecture towards NGN
Summary of Key Factors
• Plan business and services first, later the network with
proven solutions.
• Implement pilot cases before network migration due to
the many new technical issues
• Differentiation to competitors on new services and quality
• Design financial performance with best business
practices: compare and optimize NPV.
November 2005
ITU/BDT Network Architecture consolidation - O.G.S.
Lecture - 1.3.5 - slide 36