ITU/ BDT «Training and Trials on Network
Planning Tools for Evolving Network Architectures»
Architectures»
June 44-8 2007
Moscow, Russian Federation
Network Architectures for Planning and
Technological alternatives. NGN: What and How
Oscar González Soto
ITU Consultant Expert
Strategic Planning and Assessment
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 1
Network Architectures and NGN
Content
• Modeling of the network by layers and segments for planning
purposes
• Technology solutions for Access and Core architectures
• NGN: What and how
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 2
Network Architectures and NGN
Network Modeling
• High complexity of the
whole Network requires a modeling and
splitting in subnetworks to facilitate analysis and design.
• By Layers in a vertical dimension following the client-server
relation (one layer is supported in the layer below and provides
resources for the layer up). Physical, Transmission, Switching, etc.
• By Segments or splitting of the end to end communication into
subareas as customer premises, access, core national, core
international
• By Technologies or underlying technique as PDH, SDH, PSTN,
ATM, IP, NGN, GSM, 3G, WiMAX, etc.....
• Network Planning follows the same splitting or partitioning to
allow treatment of the problems and adaptation to associated
June 2007
slide 3
ITU/BDT Network Architectures and NGN - O.G.S.
Network Architectures and NGN
Access Network: Wireline
Typical Access Network structure: (classical)
<40 km
mean value ~1,7 km
mean value ~300 m
(50 % <1,2km, 90 % <3,7 km)
(50 % <200 m, 90 % <500 m)
branching cables
.
.
main cable
.
.
Regional
Exchange
June 2007
SDF
drop line
.
.
NTBA
ISDN
basic rate
FDF
Local
Exchange
SDF
MDF
FDF
SDF
SDF
FDF
.
.
MDF
SDF
Main Distribution Frame
Feeder Distribution Frame
Subscriber Distribution Frame
SDF
drop line
.
.
ITU/BDT Network Architectures and NGN - O.G.S.
slide 4
Network Architectures and NGN
Access Network: Wireline Evolution: FTTx
Typical Access Network evolution towards BB and Convergence
Local: ~ 40 km
Distribution: mean value ~1,7 km
Drop: mean value ~300 m
branching cables
SDF
.
.
SDF
drop line
.
.
.
DLC
.
FO
SDF
NTBA
Optical
Interface
DLC
drop line
LEX/GW
LEX
GW
MDF
DLC
SDF
FO
.
.
Local Exchange
Gateway
Main Distribution Frame
Digital Loop Carrier
Subscriber Distribution Frame
Fiber Optic
DLC
June 2007
slide 5
ITU/BDT Network Architectures and NGN - O.G.S.
Network Architectures and NGN
Access Network: x.WIP
Point-to-multipoint
END
USER
Mux
Transport
SDH/ADM
IP
POC
Border router
BAS
AU-RE
POP
SU-RT
10 BaseT
Z
SDH / ATM/
IP
SU-NI
AU
SU
10
BaseT
SS7
E3
Other Networks
PSTN/ISDN
IP
Internet
BS
ACCESS
SU: Subscriber Unit
SU-RT: Subscriber Unit Outdoor Unit
SU-NI: Subscriber Unit Indoor Unit
June 2007
POI
EDGE
BS: Base Station
AU: Access Unit
AU-RE: Radio Front-end
MGW: Media Gateway
Aggregation
BS traffic
(ATM/SDH) or IP
POC: Point of Concentration
POP: Point of presence
POI: Point of Interconnection
BAS: Broadband Access Server
ITU/BDT Network Architectures and NGN - O.G.S.
MGW
CORE
Note: The current Network
description shows the ATM approach
(BAS is needed). A fully IP scenario is
also feasible (BAS is not needed)
slide 6
Network Architectures and NGN
Access Network: HFC
Analog/Digital
broadcasting
Coax Access
Network
TV
Controlled IP
Network
TV
Set Top
Box
FN
TV
Head-end
FIBER RING
(Redundant)
Cable
Modem
Hub
Internet
CMTS
Amplifiers &
Taps
PC
VoD
Gateway
IN
V5
E1 .2
Voice Circuit
Switch
PSTN
Hub
MTA
≈400 Homes /
Fiber Node
MTA: Multimedia Terminal Adapter
FN: Fiber Node
CMTS: Cable Modem Termination System
VoD: Video on Demand
IN: Intelligent Network
June 2007
slide 7
ITU/BDT Network Architectures and NGN - O.G.S.
Network Architectures and NGN
Access Network: xDSL
ISAM
MDF
TV
Set Top
Box
PC
xDSL
Modem
Copper
Local Loop
<≈ d km *
Controlled IP
Network
BAS
IP mode network
ATM
Splitter
MDF DSLAM
PSTN
SS7
IN
Voice Circuit
Switch
* Bandwidth/distances per solution
ADSL: up to 4/8 Mbps/800 kbps d <= 3/1,5 km
ADSL plus: up to4/ 8 Mbps/800 kbps d <= 4.5/2,1 km
SHDSL: up to 2.3 Mbps symmetric d <= 1.8 km
VDSL: up to 52 Mbps Assym/ 26 Mbps Sym d <= 300m
(In all cases, higher distances imply less bitrate following
bandwidth shape curve)
June 2007
MDF: Main Distribution Frame
DSLAM: Digital Subscriber Line Access Multiplexer
IN: Intelligent Network
BAS: Broadband Access Server
ITU/BDT Network Architectures and NGN - O.G.S.
slide 8
Network Architectures and NGN
Access Network : Multiservice Nodes
Any
network
Residential
Ethernet
Regional Ring/Network
Internet
ISAM
Business
Central
Office
Residential dispersed
Business Area
ADM
PDH DLC
ISDN/4xE1/STM-1
STM-1/STM-4 Access Ring
POP
SDH DLC
Nx2Mb/s
(optical
or HDSL)
ISDN/4xE1/STM-1
SDH Hub
Business Park
STM-1
LL
PDH DLC
BAM
Business
Residential
Multitenant
Residential
DLC:Digital Loop Carrier
June 2007
slide 9
ITU/BDT Network Architectures and NGN - O.G.S.
Network Architectures and NGN
Access Network : FTTU
Central Office or
Remote Terminal
Fiber
Distribution
Passive Outside
Plant
20 km
MS
P-OLT
1490nm
1310nm
622 Mb/s >>
Splitters
<< 155 Mb/s
H-ONT
1550nm
V-OLT
FTTU:Fiber to the User
ONT: Optical Network Termination
OLT: Optical Line Termination
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 10
Network Architectures and NGN:
Technological alternatives at core
Scenario A
Circuit based
Scenario B
Packet based
Managed
Dark
Fiber Lambda Bandwidth
Multiservice
ATM/FR/IP
ATM VPN, IP VPN
IP
IP
Internet
Gbit access
IP VPN
Ethernet
ptp
LAN to LAN
connection
GigE,10/100BT
GigE,10/100BT
Ficon,Escon,
Ficon,Escon,
Fibre Ch..
ATM/FR
ATM/FR
IP
IP Routing
Routing
SDH
SDH
Optical
Optical switching
switching
DWDM
DWDM equipment
equipment
Ethernet
Ethernet
GigE
Optical
Optical fiber
fiber
Physical
Physical Infrastructure
Infrastructure
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 11
Network Architectures and NGN:
Evolution towards NGN
NGN concept
•A multi-service network able to support voice, data and video
•A network with a control plane (signaling, control) separated from
the transport/switching plane
•A network with open interfaces between transport, control and
applications
•A network using packet technology ( IP) to transport of all kind of
information
•A network with guaranteed QoS for different traffic types and SLAs
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 12
Network Architectures and NGN:
Evolution towards NGN
NGN layers
Legacy Network
Signaling/Service
Network
Independent
Services
Legacy Network
Media
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 13
Network Architectures and NGN:
Evolution towards NGN
NGN : Why
• Flexibility for service building and offering
• Expectation of cost reductions by sharing infrastructure and
systems
• Simplification of O&M, thus lowering OPEX.
• Use of open interfaces leads for:
- quick deployment of services and applications
- new services (third parties)
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 14
Network Architectures and NGN
Modeling issues for NGN and 3G
– New models to represent multiservice flows
– New dimensioning methods for resources handling multimedia
services with QoS
– New measurement procedures for aggregated multiservice traffics
– New multicriteria dimensioning for 3G and xG combining coverage
by frequency, service speed and data traffic capacity
– Which procedures to ensure interoperability and end-to-end
performance across multiple domains?
– Which units to define dimensioning and costing units for
interconnection?
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 15
Network Architectures and NGN
QoS and Performance Issues
• Quality of Service (QoS) domains to be modeled, defined and/or
extended for NGN and 3G. Measured in waiting time and/or loss
probabilities
• Domains for QoS evaluation:
- Service accessibility: capability to access a service
- Connection establishment: Capability to get connection
- Information transfer: Quality of information delivery
- Reliability: Failure probability
- Availability: Probability of system being active
- Survivability: Capability to provide service in abnormal conditions
- Security: Information and systems protection level
- Qualitative: Intelligibility, audibility, visualization ... of information
content as derived from user perception (MOS)
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 16
Network Architectures and NGN
Traffic flow types for QoS based dimensioning
– T1) QoS constant stream: bandwidth transmission at a
constant speed with a specified delivery and jitter (ie: video
distribution)
– T2) QoS variable stream : bandwidth transmission at a variable
speed derived from a user information and coding algorithm which
requires guaranteed quality and specified jitter (ie: VoIP, Video
streaming, audio streaming, etc.)
– T3) QoS elastic: bandwidth transmission at a variable speed
without jitter restrictions and asynchronous delivery (ie: browsing,
file transfer, mail, UMS, etc.)
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 17
Network Architectures and NGN
Traffic units for aggregated flows
Proposal of NGN units in multiservice
networks/interfaces for demand/dimensioning/costing :
– Equivalent Sustained Bit Rate (ESBR) or aggregated
equivalent rates for same QoS category flows efficiently
carried in a common reference busy period (ie. 5 minutes)
– Computed as weighted average for the services at QoS
category (i) and customer classes (j) at each network element:
∑i ∑j ESBRij
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 18
Network Architectures and 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
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 19
Network Architectures and NGN
Existing networks and architecture
TRANSIT NETWORK
NATIONAL LAYER
REGIONAL LAYER
• 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
LEX
LAYER
RU
LAYER
customers
LAYER
June 2007
• 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 Architectures and NGN - O.G.S.
slide 20
Network Architectures and NGN
Architecture migration: Topology
What changes from current scenario towards target network ?
NMC
OSS
SCP
IN
SS7
Softswitch
Control
Mob
Services
Distributed Switching
Transport/Media
LEX/TEX
NAS
TDM
Access
gateway
Data
ATM/IP
LEX
Access
gateway
Trunk
gateway
Other
Networks
Access
gateway
DSL
PCM
RSU
POTS
Packet
Network
IP/MPLS/CAC
DLC
Wireless
gateway
MUX/DSLAM
ISDN
HDSL/XDSL
June 2007
slide 21
ITU/BDT Network Architectures and NGN - O.G.S.
Smooth
Smooth
migration
migration
to NGN
to NGN
Network Architectures
and
NGN
Evolution towards NGN
Current end to end architecture
IN
SSP
RSP
RCP
PSTN Class 4
DS
Data
Mux
PSTN Class 5
Multiservice
Node
Subscriber unit
Internatinal
Core
Core
Edge
Access
Customers
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 22
Network Architectures and NGN:
Evolution towards NGN
Target end to end architecture for NGN
Softswitch
NGCR
Optical
NGER
International
Core
AGW
Core
Associated
TK GW
MM
Multiservice
node
Subscriber unit
Edge
Access
Customers
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 23
Network Architecture towards NGN
Architecture Evolution: 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
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 24
Network Architectures and NGN:
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
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 25
Network Architectures and NGN:
NGN:
Cost drivers and trends
Cost trends for NGN
•
Cost reduction in CAPEX due to technological economy of scale by
larger capacities
•
Similar values for costs in the physical civil infrastructure
•
OPEX in NGN trends to be lower due to the integrated operation and
maintenance
•
Plan higher investments in security/survivability with diversity paths
and protection for large capacity systems
Check and validate correct cost modelling with fixed and variable
components as a function of economy of scale
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 26
Network Architectures and NGN
Unified IMS Model for Mobile and Fixed Convergence
What is IMS?
•
Why IMS ?
Concept:
– Application of 3GPP’s IMS
architecture and protocol
extensions for fixed and
converged networks
•
Key actors:
•
Deliver person-to-person real-time IPbased multimedia communications
– Person-to-person, person-tomachine
•
Fully integrate real-time with non-realtime multimedia communications.
– i.e., live streaming and chat
•
Easy user setup of multiple services in
a single session, or multiple
synchronized sessions
•
Operators have better control of
service value chain
– End-to-end QoS
– Operators
– ETSI, TISPAN, VASA, ITU-T
– Equipment vendors
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 27
Network Architectures and NGN
IMS Architecture
June 2007
ITU/BDT Network Architectures and NGN - O.G.S.
slide 28
Network Architectures and NGN
Evolution to IMS: Benefits
- First advantage is the higher flexibility of the IMS functionality to adapt to the
customer services, irrespective of the technology they use and the access method to
reach the network.
- Saving in effort and time for the development and deployment of a new service
is considerably reduced once the architecture is ready at the network, implying
economic savings and better Time to Market for a given service provider in a
competitive market.
- Efficient introduction on new services at a lower cost will increase the service
provider revenues and ARPU which is the major business driver for the healthy
operation, market grow and financial results.
- Higher utilization of services and better personalization of functions to specific
requirements from the end customers’ point of view, a common use and feel for all
services and applications
June 2007
slide 29
ITU/BDT Network Architectures and NGN - O.G.S.
Network Architectures and NGN
Evolution to IMS: Phases
Convergence to
NGN infrastructure
End to End
NGN
NGN IP core
PSTN
Open Service Architecture, Basic
HSS, VoIP, LBS, PBS, IM, PtS,
etc.
Pre - IMS
PSTN emulation/simulation
Full HSS, P2P video,
Service broker, Service blending,
RACF, ICD, etc.
PSTN Architecture
Current Service
functionality
June 2007
Full IMS “SIP” Services
Convergence to
IMS services
Partial IMS functionality
and/or coverage
ITU/BDT Network Architectures and NGN - O.G.S.
Full IMS coverage
slide 30
Network Architectures and NGN
Summary Remarks
• Multiservice flows impose a set of requirements on models
and tools for NGN and 3G.
Interoperability and interconnection require special effort
to players and planners to ensure end-to-end performance
•
•
•
June 2007
Migration of existing architectures to the new generation
ones require techno-economic planning for each country
scenario
Complexity of converged networks require the use of high
quality support tools
ITU/BDT Network Architectures and NGN - O.G.S.
slide 31