There are numerous views of NGN.
Korea Telecom--Broadband convergence Network (BcN),
BT--21st Century Network (21CN),
Deutsche Telekom --Telekom Global Network (TGN) and
NTT uses Resonant Communication Network Architecture (RENA).
For some, NGN simply means migration from a PSTN to an IP-based network. For others, it is a more specific reference to advances such as international call IP trunking and IP in the local loop.
Some definitions consider an end-to-end network capable of
Supporting bandwidth of 20 Mbps or more as prerequisite on the basis that this amount of bandwidth would be the minimum required to support the next generation of services that cannot be delivered using current broadband technologies.
At the broadest level, NGN can simply refer to a very fast end-to-end IP-based network. At the technical level, NGN is distinguished from legacy or traditional circuit switched networking in that all information is transmitted via packets, which are labelled according to type, such as data and voice, and handled accordingly by traffic management equipment. It can be deployed over a number of platforms such as fibre, cable, wireless and upgraded copper-based networks. This flexibility heralds a shift from a “one network, one service” approach, to a “one network, many services” approach.
A next-generation network is generally divided into two parts: the next-generation core network and the next-generation access network.
It is important to highlight, however, that NGN involves the de-coupling or separation of the transport layer of the network from the services and applications layer that lies on top of that transport. The independence of service and transport
layers has significant implications for competition and pricing.
For example, by separating transport and service layers, a provider can enable new services by defining it directly at the service layer without considering the transport layer. NGN then is a catch-all phrase for the infrastructure that will enable advanced new services, while continuing to support existing services. It will support fixed, mobile and nomadic users as well as have the ability to carry voice, data and multimedia interactive services.
These networks enable a range of new service offerings in a multi-vendor environment. As factors like interoperability and QoS are critical, work is underway in numerous organizations concerned with standards to ensure that NGN evolution and migration is being carried out coherently and effectively. Already, there are various interoperability issues between different VoIP soft-client providers that, if not addressed, will hold back the development of this service segment.
Some of the standards organizations working to address interoperability issues include the European Telecommunications Standards Institute (ETSI) – specifically
the Telecoms and Internet Converged Services and Protocols for Advanced Networks (TISPAN), the ITU Standardization Bureau (ITU-T) – specifically the NGN Global Standards Initiative (NGN-GSI), the 3rd Generation Partnership Project
(3GPP) and the Fixed Mobile Convergence Forum.
There are also many organizations such as the European Regulators Group (ERG), the European Conference of Postal and Telecommunications Administrations (CEPT), ITU and OECD,which are currently engaged in IP and NGN policy and regulatory research. Many projects are also taking place on a regional basis. For example, in Europe the GÉANT project and the Task Force on Next-Generation Networking (TF-NGN)were established for the collective research and deployment of NGN in 2001. The NGN Framework Options Group
(NGN FOG) in Australia, the Ubiquitous Networking Forum (UNF) in Japan and the Next-Generation Convergence Network (NGcN) Forum in Korea are also joint activities related to NGN technology and service development.
As mentioned above, however, while there are certain
characteristics associated with NGN, there is not as yet a single standard or reference point. This may change as work in these organizations continues.
A Next-Generation Network is defined by ITU as “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. It enables unfettered access for users to networks and to competing service providers and/or services of their choice. It supports generalized mobility which will allow consistent and ubiquitous provision of services to users.” Source: ITU-T Recommendation Y.2001.
Source: ITU
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