3. Introduction
In July 2003, ITU-T organized a NGN workshop.
In considering the results of this workshop, ITU-T Study Group 13
launched an NGN Joint Rapporteur Group (NGN-JRG).
The NGN-JRG identified key issues and developed fundamental
standards for building the frameworks of an NGN.
Recommendations Y.2001 and Y.2011 are the results, and are now
the basis for NGN studies in ITU-T.
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ITU-T: International Telecommunication Union-Telecommunication Standardization Sector
4. Introduction
In parallel with the ITU-T initiatives, several standards organizations
initiated their plans for NGN standards.
Possible incompatibilities among future NGN standards.
After consulting ETSI and other organizations, ITU-T launched its
Focus Group on NGN (FGNGN) in June 2004.
This Focus Group was required to coordinate all aspects of NGN
studies.
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ITU-T: International Telecommunication Union-Telecommunication Standardization Sector
5. Key Aspects
Access to common services across multiple types of access
networks.
Coordination of multiple types of communications from a common
control point in the network.
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6. The Definition of an NGN
Next-Generation Network (NGN):
“A packet-based network able to provide telecommunication services
and able to make use of multiple broadband QoS-enabled transport
technologies and in which service-related functions are independent
from underlying transport-related technologies.”
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7. The Definition of an NGN
It enables unfettered access for users to networks and competing
service providers and/or services of their choice.
It supports generalized mobility that will allow consistent and
ubiquitous provision of services to users.
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10. NGN Architecture Overview
The NGN functions are divided into service and transport strata.
End-user functions are connected to the NGN by the user-to-
network interface(UNI).
Other networks are interconnected through the network-to-
network interface (NNI).
The application-to-network interface (ANI) forms a boundary with
respect to third party application providers.
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11. Transport Stratum Functions
Transport stratum provide IP connectivity for all
components within the NGN.
It is responsible for providing end-to-end QoS.
It is divided into access networks and the core network.
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12. Transport Stratum Functions
Access Functions
Manage end-user access to the network.
They are access-technology-dependent.
Manage end-user access to the network.
They are access-technology-dependent.
Access Transport Functions
They are responsible for transporting information across the access network.
Also provide QoS control mechanisms.
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13. Transport Stratum Functions
Edge Functions
They are used for traffic processing when access traffic is merged into
the core network.
Core Transport Functions
They are responsible for transporting information throughout the core
network.
Also provide QoS control mechanisms.
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14. Transport Stratum Functions
Resource and Admission Control Functions (RACF)
Provide admission control and gate control functionalities.
Admission control involves checking authentication and authorization.
Network Attachment Control Functions
Provide initialization of end-user functions for accessing NGN services.
Assist end-user equipment in registering and starting use of the NGN.
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15. Transport Stratum Functions
Transport User Profile Functions
Represents the compilation of user and other control data.
May be specified and implemented as a set of cooperating databases.
Gateway Functions
Provide capabilities to interwork with other networks.
Media Handling Functions
They are media resource processes for providing services.
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16. Service Stratum Functions
These functions provide session-based and non-session based
services.
Session-based services:
IP Telephony, videoconferencing, and video chatting.
Non-session based services:
Video streaming and broadcasting.
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17. Service Stratum Functions
Service and Control Functions
Include session control functions, a registration function, and
authentication and authorization functions at the service level.
Service User Profile Functions
Represents the compilation of user and other control data.
May be specified and implemented as a set of cooperating databases.
Application Functions
NGN support open APls enabling third-party service providers to
create enhanced services.
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18. Summary
One of the important key features of the NGN is the separation
between different functionalities.
Horizontally, the NGN is broken down into three sections:
Customer equipment, network equipment, and interconnection with
other networks.
Vertically, the NGN is separated into two areas:
The service stratum and the transport stratum.
The NGN is no longer a next generation objective, but is becoming a
present generation reality.
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