1. An Implementable NGN Architecture and Its CapabilitiesBy
Tilak De Silva
Chief Global & Network Officer
Sri Lanka Telecom Ltd.
09th April 2009

2. PSTN Network
Copper Wires
Switch
MUX
Transmission Network

3. PSTN Network Copper Wires - Access
Switch - Call control, Accounting (CDR)
MUX - Aggregation
Transmission Network - Transport

4. Service Access Aggregation Transport
Authentication, Authorization, Accounting

5. Data Network Eg. Leased Line Access – Copper, WiMAX
Aggregation - Data Node
Transport (TDM Transmission Network)

6. Internet
Access - ADSL
Aggregation - DSLAM
Transport - MPLS
AAA

7. IPTV
Access - ADSL
Aggregation - DSLAM
Transport - MPLS
AAA

8. Vertical Network Scenario
Multiple Platform based Vertical Network Architecture
Services
PSTN Network
CDMA Network
DATA Network
MEN Network
MPLS Network
DSL Network
GSM Network
WiMAX Network
In SLT we have different vertically positioned networks providing different services. They use different access NWs, different transport NWs. If we confined into unified network architecture, we can leverage on present NWs and services. Need to identify and migrate into such network architecture where can give more focused to the seamless rollout of new services/applications

9. Existing Network Structure
TDM Tx Backbone
PSTN / ISDN
MSU/RSU/ELU
TDM Data network
Data Node
Other Operators
IP / MPLS Backbone
IP-DSLAM
Metro Ethernet Network
MEN Node
Different networks for different services … ? ? ?

10. Problems Service wise Access, Aggregation & AAA
Separate staff for each service
More Space & power

11. NGN Structure
IP / MPLS Backbone
NGN
MSAN

12. NGN architecture defined in ITU-T Rec. Y.2012
IMS Functional Architecture Model

13. NGN Architecture Service Stratum
Application Support Function and Service Support Function
Gateway
Authentication & Authorization
Service Control Function
Resource Control
Registration

14. NGN Architecture Transport Stratum Transport Control Function
IP connectivity services to NGN users
Network Attachment Control Functions (NACF)
Resource and Admission Control Functions (RACF)
To get desired QoS for communication
To get permission to access certain resources
Transport Function
Core Transport Functions
Access Transport Functions

15. NGN Architecture Management Function
Manage the NGN network in order to provide NGN services with the expected Quality, Security and Reliability.

16. ITU-T Rec. Y.2012 PSTN and ISDN replacement Multimedia services
NGN architecture supports the delivery of:
PSTN and ISDN replacement
Multimedia services
Content delivery services
Video streaming
Broadcasting etc.
ITU-T Rec. Y.2012

17. Sri Lanka Telecom Architecture

18. PSTN Network Hierarchy
International Networks
ISC
ISC
TSC
TSC
TSC
CDMA/ PLMN
MSU
MSU
MSU
MSU
RSU
RSU
RSU
ELU
RSU

19. Migration & Limitations
End of Life Time
Large customer base
No vendor support
Un repairable hardware/ software faults
Expansion/ Upgrading not possible
Supports only R2 signaling
Frequent failures
No/ Limited CLI capacity
Limited VAS capacity
To NGN
Customer demand for new features
Technology already obsolete
CDR not properly generated for Value Added Services

20. High system capabilities (Call handling, subscriber capacity, traffic handling, etc…..)
Cost effective Operation and Maintenance by means of centralized network management system
Pave the path to fixed Mobile convergence
Why NGN……..
NGN
High competitiveness due to large number of manufactures
Availability of new services. (Unified messaging, IP Centrex/Hosted PBX, etc…)
Less cost for transport network (MPLS backbone) due to transportation of packets
Rapid deployment of new third party applications due to open architecture
Less CAPEX …????
Less OPEX
One network for all services (Voice, Video & Data)

21. SLT NGN Migration PSTN to NGN Migration
Session Control Platform with Enriched Features
Reliable Transport Network in Higher Capacities
Widely Spreaded Access Networks
Transport Access
Session Control
Services

22. Transport & Access Networks
Transport IP Network
Wide Coverage
Resilience Network
Equipment Redundancy
High Capacity
AGW
Aggregation Network
Aggregation Network
AGW
PON
NodeB
WiMAX
AGW - Access Gateway

23. Transport / Aggregation Network
Only Copper to Home
Transport / Aggregation Network
Separate Fiber
to BTS
(2/3G,WiMAX)
AGW
O/F
AGW
Separate Fiber to AGW
O/F
PON for both
AGW & Node B
AGW
PON
OLT
AGW

24. Mobility & Realization of FMC Environment
Increasing mobility
Only one contract /one bill
Seamless services
home zone billing
Subscriber
Acquisition of new subscribers by new services
mainly with existing infrastructure / partly
shared infrastructure
Operator
Operator
Fixed & Mobile services
Mobile
Operator
Fixed
Operator
home-zone billing: whereby customers enjoy a competitive rate, whenever they are in a certain geographical area of their choice
Home location
in Mobile
network
Demand for New FMC features
Mobility in
network
FMC is driven by increasing demand for mobility in all networks

25. Fixed Mobile Convergence
Is concerned with the provision of network and service capabilities which are independent of the access technique
Does not necessarily imply physical convergence of networks
Is concerned with the development of converged network capabilities and supporting standards to offer consistent services, that may be used via fixed or mobile access to fixed or mobile, public or private networks.
An important feature of FMC is the separation of the subscriptions and services from individual access points and terminals and
The possibility of internetwork roaming using the same consistent set of services

26. QoS Speech Quality
An Operator will regard the “Customer‘s view“ as essential;
(e.g. will take into account QoS classification)
Classes:
BEST : Better than today‘s PSTN/ISDN
HIGH : Equivalent to today‘s PSTN/ISDN
MEDIUM : Equivalent to today‘s wireless Networks
BEST EFFORT : Significantly impaired but usable

27. Applications
Service QoS Class
and Priority

28. IP V6
IPv6 is emerging to form the basis of the NGNs and well-defined IPv6 suite will provides considerable flexibility to NGN by
Improving network provisioning and operations, as well as Services to be offered to the NGN providers and users.
IP-based networks relevant to NGN can be classified into
‘IPv6-based NGN’, ‘IPv4-based NGN’, ‘IPv6-based non-NGN’, ‘IPv4-based non-NGN’
Addressing schemes, QoS, Security and Mobility are the key features of IPv6 which may significantly impact on NGN
Overview of IPv6-based NGN

29. IP V6 IPv6 to NGN Enhanced service capabilities
Enables congestion/flow control using additional QoS information such as flow label, etc. The flow label field of IPv6 header enables IPv6 flow identification independently of transport layer protocols
Any-to-any IP connectivity
IPv6 offers the advantages of localizing traffic with unique local addresses, while making some devices globally reachable by assigning addresses which are scoped globally
Self-organization and service discovery using auto configuration
Address auto-configuration of IPv6 protocol will facilitate NGNs to support dynamic address assignments and multiple user/network identities
Multi-homing using IPv6 addressing
IPv6 can handle multiple heterogeneous access interfaces and/or multiple IPv6 addresses through single or multiple access interfaces. Multi-homing can provide redundancy and fault tolerance