NGN migration scenarios can also be classified into four categories:
1. Soft Switch installation at international and high national transit levels;
2. Class 4 Switch replacement at transit level;
3. Class 5 Switch replacement at access level;
4. IMS Overlay.
From a technological point of view, NGN migration scenarios can be divided into two broad categories:
1. Scenarios where NGN is used to carry voice at transit or access levels over a packet-based transport network.
When undertaken by a fixed-line voice incumbent, the transition is generally transparent to end users in terms of the services offered by the legacy telephony network. However, when voice telephony service is offered over an alternative access such as cable, DSL, fibre or Wireles Local Loop (WLL), the Soft Switch may not need to have exactly the same capabilities as those of legacy telephony networks. A specific scenario with LES allows a migration to new VoIP-enabled voice telephony services at the access level without necessitating the introduction of a Class 5 Soft Switch, allowing the existing legacy Class 5 switches to be kept.
2. Scenarios where an NGN IMS-based architecture is used In this case, the same Multimedia Soft Switch, which is functionally equivalent to a Call Session Control Function (CSCF) in IMS terminology, is used both for multimedia and voice communication services. These scenarios necessarily involve a migration of the user to broadband access. The IMS infrastructure can be introduced either as a full replacement of the telephony network, such as in the case of BT’s 21 CN, or more often in overlay mode, where the existing telephony network is kept for legacy voice services.
NGN migration scenarios can also be analyzed on the basis of three service aspects:
1. Continuity of legacy voice telephony service;
2. Availability of new end-user VoIP enabled telephony services;
3. Possibility to offer new multimedia communication services.
In analyzing NGN migration paths, it is important toconsider that existing legacy networks represent significant sunk capital investments to many operators. This may prevent their complete replacement in the immediate future. As such,a phased approach is usually preferred for the migration to NGN. ITU-T Recommendation Y.2261 describes some possible ways of evolving PSTN/ISDN to NGN. Both IMS-based and call-server-based approaches are described. The Recommendation also describes some factors that need to be considered including the evolution of transport, management, signalling and control parts of PSTN/ISDN to NGN.
Source: ITU
วันอาทิตย์ที่ 20 กรกฎาคม พ.ศ. 2551
Migration to NGN: NTT NGN
Japan's NTT is conducting one of the most ambitious FTTH deployment projects in the world. The NTT project aims to deploy almost 30 million FTTH lines by 2010. At the end of 2006, six million lines were already deployed, with four more million lines expected in 2007. The total cost of this programme is expected to reach USD 47 billion.
Services provided to end users are based around B-FLET (Flat Rate Internet Access Service). They include very highspeed Internet access (100 Mbit/s symmetrical) with content and podcasting services, high-quality multiline VoIP services and the possibility of high-definition broadcast TV from 2008.
Due to regulatory constraints, however, NTT is prevented from offering broadcast TV and has to partner with an ISP or a satellite TV provider to offer such services. As NTT is a quasi-monopoly in the fixed-access market in Japan, its main drivers come both from government decisions, such as the e-Japan project and the subsequent u-Japan initiative, and the desire to offer new broadband and FMC services.
NTT’s migration to NGN started in 2006 with the deployment of IP core nodes together with optical wavelength transmission equipment. The second phase, planned for the second half of 2007, will involve the deployment of IP edge nodes, as well as IMS service control functions and the launch of next-generation services such as broadband Internet access, IP telephony, multicast transmission for video distribution and bidirectional video and data communication. NTT’s strategy appears to be based on overlay IMS. The PSTN, however, will be retained for narrowband access for some time.
The third phase is expected to begin around mid- 2009 with the seamless integration of edge nodes of NTT DoCoMo’s mobile “Super 3G” service. Super 3G involves the enhancement of HSDPA from 14 Mbit/s to 100 Mbit/s downlink and 50 Mbit/s uplink, in accordance with 3GPP’s 4G Long- Term Evolution (LTE).
Source: ITU
Services provided to end users are based around B-FLET (Flat Rate Internet Access Service). They include very highspeed Internet access (100 Mbit/s symmetrical) with content and podcasting services, high-quality multiline VoIP services and the possibility of high-definition broadcast TV from 2008.
Due to regulatory constraints, however, NTT is prevented from offering broadcast TV and has to partner with an ISP or a satellite TV provider to offer such services. As NTT is a quasi-monopoly in the fixed-access market in Japan, its main drivers come both from government decisions, such as the e-Japan project and the subsequent u-Japan initiative, and the desire to offer new broadband and FMC services.
NTT’s migration to NGN started in 2006 with the deployment of IP core nodes together with optical wavelength transmission equipment. The second phase, planned for the second half of 2007, will involve the deployment of IP edge nodes, as well as IMS service control functions and the launch of next-generation services such as broadband Internet access, IP telephony, multicast transmission for video distribution and bidirectional video and data communication. NTT’s strategy appears to be based on overlay IMS. The PSTN, however, will be retained for narrowband access for some time.
The third phase is expected to begin around mid- 2009 with the seamless integration of edge nodes of NTT DoCoMo’s mobile “Super 3G” service. Super 3G involves the enhancement of HSDPA from 14 Mbit/s to 100 Mbit/s downlink and 50 Mbit/s uplink, in accordance with 3GPP’s 4G Long- Term Evolution (LTE).
Source: ITU
Migration to NGN: AT&T Lightspeed
In 2004, AT&T announced a USD 4.4 billion project named Lightspeed that involved a first phase of five years that would impact 18 million out of its 60 million fixed-line subscribers. The motivations behind the launch of Lightspeed included increasing competition from mobile operators for consumer voice services and the opportunity to launch digital IP video services. Some analysts have noted that forbearance by the Federal Communication Commission (FCC) from regulating
FTTx also helped pave the way for the migration.The access technology used by Lightspeed essentially involves FTTN which would benefit 17.5 million out of the targeted 18 million end users. The remaining 500 000 end users, located mainly in Greenfield areas, would benefit from FTTH.
The FTTN will be terminated with legacy copper access using ADSL2 or 2+, or VDSL2 technologies. Services provided to end users include high-quality video, which includes one highdefinition stream, high-speed multigrade 1.5, 3 and 6 Mbit/s Internet access, Video-on-Demand, IMS-based voice service,streaming music and other interactive applications.
AT&T plans to follow an IMS overlay strategy to develop these services. To support the migration, AT&T plans to encourage its voice customers to adopt its triple-play bundle, thus allowing the transition of voice lines to the new IMS network. No date has been set for a complete switchover from the legacy network.
Source: ITU
FTTx also helped pave the way for the migration.The access technology used by Lightspeed essentially involves FTTN which would benefit 17.5 million out of the targeted 18 million end users. The remaining 500 000 end users, located mainly in Greenfield areas, would benefit from FTTH.
The FTTN will be terminated with legacy copper access using ADSL2 or 2+, or VDSL2 technologies. Services provided to end users include high-quality video, which includes one highdefinition stream, high-speed multigrade 1.5, 3 and 6 Mbit/s Internet access, Video-on-Demand, IMS-based voice service,streaming music and other interactive applications.
AT&T plans to follow an IMS overlay strategy to develop these services. To support the migration, AT&T plans to encourage its voice customers to adopt its triple-play bundle, thus allowing the transition of voice lines to the new IMS network. No date has been set for a complete switchover from the legacy network.
Source: ITU
Migration to NGN: BT’s 21CN
BT’s 21CN (21st Century Network) or BT NGN project is a unique example of migration from a traditional network to all IP NGN using NGN/IMS architecture. The project plans to migrate all of BT’s 30 million fixed copper lines to a NGN-enabled network by 2012.
The main motivation of BT’s 21CN is to reduce cost by
migrating from the currently 16 independent network
platforms to a single network which supports end-to-end
IP-based network. BT plans to realize annual operational
expenditure savings of around USD 2 billion after the migration.
There are five strategic domains in 21CN network:
1. Access domain refers to the edge of 21CN that links to BT’s existing access network. Multiservice access nodes (MSANs) aggregate the voice, data and video services from end users onto the 21CN core IP-based network. They replace the service-specific equipment of the legacy network. (Approximately 5,500 BT sites in the United Kingdom will house either copper MSANs or fibre MSANs).
2. Metro node refers to nodes that provide the IP routing,Ethernet switching, SDH switching and gateways to existing networks for the unified 21CN. There will be approximately 100 metro nodes in the United Kingdom.
3. Core node refers to high-capacity, large-scale routers that provide cost-efficient connectivity between metro nodes.There will be approximately 20 core nodes in the United Kingdom.
4. i-Node is where the service execution functionality is located, in essence the intelligence that controls services.It includes soft switches, network intelligence and bandwidth management capabilities. There will be approximately 10 i-Nodes in the country.
5. Transmission includes the fibre transport infrastructure that connects all nodes in the 21CN, as well as the electronics that convert the signals carried at high capacity over the cables that connect the MSANs and the metro and core nodes. New fibres of 2,300km are added in the network.
It is important to note that 21CN is not associated per se to an access overhaul. Even though broadband access is mentioned as the basic access mode and IMS multimedia architecture will be used, 21CN’s objective is grounded on network core migration, with its associated cost reductions. However, BT has not exclude the upgrading of their access network with fibre and BWA.
Besides the challenging task of migrating 30 million users
in 5 years, 21CN involves a number of major technical challenges:
• Making eight equipment manufacturers share compatible
network elements and a common goal.
• Making immature technologies work together (e.g.,
21CN’s IMS needs further development with regard to
the integration of BT’s Fusion service, which converges
fixed and mobile services, and BT’s Communicator,
which is a VoIP consumer service).
Source: ITU
The main motivation of BT’s 21CN is to reduce cost by
migrating from the currently 16 independent network
platforms to a single network which supports end-to-end
IP-based network. BT plans to realize annual operational
expenditure savings of around USD 2 billion after the migration.
There are five strategic domains in 21CN network:
1. Access domain refers to the edge of 21CN that links to BT’s existing access network. Multiservice access nodes (MSANs) aggregate the voice, data and video services from end users onto the 21CN core IP-based network. They replace the service-specific equipment of the legacy network. (Approximately 5,500 BT sites in the United Kingdom will house either copper MSANs or fibre MSANs).
2. Metro node refers to nodes that provide the IP routing,Ethernet switching, SDH switching and gateways to existing networks for the unified 21CN. There will be approximately 100 metro nodes in the United Kingdom.
3. Core node refers to high-capacity, large-scale routers that provide cost-efficient connectivity between metro nodes.There will be approximately 20 core nodes in the United Kingdom.
4. i-Node is where the service execution functionality is located, in essence the intelligence that controls services.It includes soft switches, network intelligence and bandwidth management capabilities. There will be approximately 10 i-Nodes in the country.
5. Transmission includes the fibre transport infrastructure that connects all nodes in the 21CN, as well as the electronics that convert the signals carried at high capacity over the cables that connect the MSANs and the metro and core nodes. New fibres of 2,300km are added in the network.
It is important to note that 21CN is not associated per se to an access overhaul. Even though broadband access is mentioned as the basic access mode and IMS multimedia architecture will be used, 21CN’s objective is grounded on network core migration, with its associated cost reductions. However, BT has not exclude the upgrading of their access network with fibre and BWA.
Besides the challenging task of migrating 30 million users
in 5 years, 21CN involves a number of major technical challenges:
• Making eight equipment manufacturers share compatible
network elements and a common goal.
• Making immature technologies work together (e.g.,
21CN’s IMS needs further development with regard to
the integration of BT’s Fusion service, which converges
fixed and mobile services, and BT’s Communicator,
which is a VoIP consumer service).
Source: ITU
NGN Standards: ITU-T NGN
NGN-GSI (studied by ITU-T in 2003 and named as NGN-GSI in 2005), focuses on developing the detailed standards necessary for NGN deployment to give service providers the means to offer the wide range of services expected in NGN. NGN-GSI harmonizes, in collaboration with other bodies, different approaches to NGN architecture worldwide (http://www.itu.int/ITU-T/ngn/).
By end 2006 ITU-T has published about 20 approved NGN recommendations.
It is important to note that 3GPP IMS, ETSI TISPAN and ITU-T NGN standards are not totally independent from each other. These standards are complementary and are based on many common concepts. Membership among the different organizations developing these standards often overlaps. The bodies working on them are addressing mobile, fixed and converged networks and have regional, national and global views.
Source: ITU
By end 2006 ITU-T has published about 20 approved NGN recommendations.
It is important to note that 3GPP IMS, ETSI TISPAN and ITU-T NGN standards are not totally independent from each other. These standards are complementary and are based on many common concepts. Membership among the different organizations developing these standards often overlaps. The bodies working on them are addressing mobile, fixed and converged networks and have regional, national and global views.
Source: ITU
NGN Standards: ETSI TISPAN
IMS architecture was designed specifically for mobile access. Taking as its starting point a 3GPP IMS architecture, the European Telecommunication Standards Institute (ETSI) decided to establish a specific standardization group named TISPAN (Telecom and Internet Services and Protocols for Advanced Networks) to develop a NGN architectural framework larger in scope than IMS.
Through TISPAN, ETSI set about the task of delivering a NGN specification adapted for DSL access by defining the IP connectivity features of the network that were in common with GPRS. In late 2005, it released an IMS-based architectural framework that was adapted for fixed DSL broadband access (Release 1) (see Box 3.10). The TISPAN architecture (www.etsi.org/tispan/ ) also extends the IMS by introducing an emulation subsystem for PSTN/ISDN.
Both 3GPP and ETSI are further developing their IMS based work. In 2005, 3GPP introduced a Release 6 and is currently working on Release 7. TISPAN is now working on Re-lease 2, with a focus on enhanced mobility, new services and content delivery with improved security and network management. Eventually, ETSI envisions a common IMS-based core architectural framework for all kinds of fixed and wireless broadband access.
Source: ITU, ETSI
Through TISPAN, ETSI set about the task of delivering a NGN specification adapted for DSL access by defining the IP connectivity features of the network that were in common with GPRS. In late 2005, it released an IMS-based architectural framework that was adapted for fixed DSL broadband access (Release 1) (see Box 3.10). The TISPAN architecture (www.etsi.org/tispan/ ) also extends the IMS by introducing an emulation subsystem for PSTN/ISDN.
Both 3GPP and ETSI are further developing their IMS based work. In 2005, 3GPP introduced a Release 6 and is currently working on Release 7. TISPAN is now working on Re-lease 2, with a focus on enhanced mobility, new services and content delivery with improved security and network management. Eventually, ETSI envisions a common IMS-based core architectural framework for all kinds of fixed and wireless broadband access.
Source: ITU, ETSI
วันเสาร์ที่ 19 กรกฎาคม พ.ศ. 2551
NGN Standards: 3GPP IMS
The 3rd Generation Partnership Project (3GPP) is a collaboration agreement that was established in December 1998. The collaboration agreement brings together a number of telecommunications standards bodies which are known as “Organizational Partners”. The current Organizational Partners are ARIB, CCSA, ETSI, ATIS, TTA, and TTC (http://www.3gpp.org).
The earliest efforts to standardize NGN architecture originates from the Third-Generation Partnership Project (3GPP), a partnership between different standardization bodies. In 2003, 3GPP finalized the first release of an architecture known as the IP Multimedia Subsystem (IMS) Release 5 (R5). Its original formulation (3GPP R5) represented an approach to delivering "Internet services" or multimedia communication services over GPRS (to mobile end users).
It must be noted that another initiative, named 3GPP2, works on a functionally identical IMS standard adapted for 3G networks originating from CDMA2000 1x RTT 2G radio-based networks.
Source: ITU, 3GPP
The earliest efforts to standardize NGN architecture originates from the Third-Generation Partnership Project (3GPP), a partnership between different standardization bodies. In 2003, 3GPP finalized the first release of an architecture known as the IP Multimedia Subsystem (IMS) Release 5 (R5). Its original formulation (3GPP R5) represented an approach to delivering "Internet services" or multimedia communication services over GPRS (to mobile end users).
It must be noted that another initiative, named 3GPP2, works on a functionally identical IMS standard adapted for 3G networks originating from CDMA2000 1x RTT 2G radio-based networks.
Source: ITU, 3GPP
วันศุกร์ที่ 18 กรกฎาคม พ.ศ. 2551
NGN Standard Organizations
To ensure NGN migration effectively, several standard organizations are working on interoperability issues. These organizations are as follows.
1. the European Telecommunications Standards Institute (ETSI) – specifically TISPAN (the Telecoms and Internet Converged Services and Protocols for Advanced Networks)
2. the ITU Standardization Bureau (ITU-T) – specifically NGN-GSI (NGN Global Standards Initiative)
3. the 3rd Generation Partnership Project (3GPP)
4. 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.
Source: Trends in Telecommunication Reform 2007: The Road to Next-Generation Networks (NGN)
1. the European Telecommunications Standards Institute (ETSI) – specifically TISPAN (the Telecoms and Internet Converged Services and Protocols for Advanced Networks)
2. the ITU Standardization Bureau (ITU-T) – specifically NGN-GSI (NGN Global Standards Initiative)
3. the 3rd Generation Partnership Project (3GPP)
4. 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.
Source: Trends in Telecommunication Reform 2007: The Road to Next-Generation Networks (NGN)
วันพฤหัสบดีที่ 17 กรกฎาคม พ.ศ. 2551
Comparison of telecommunication, NGN and Internet
Telecom network is a Circuit-switched based, dumb terminal, usage-related charges and quality control, interconection at various levels.
NGN networks is a IP based, intelligent terminal, usage-related charges and quality control, interconection at various levels.
Internet is a IP based, intelligent terminal, no usage-related charges and litle quality control, interconection at IP level.
Source: CEPT, 2003
NGN networks is a IP based, intelligent terminal, usage-related charges and quality control, interconection at various levels.
Internet is a IP based, intelligent terminal, no usage-related charges and litle quality control, interconection at IP level.
Source: CEPT, 2003
Components of NGN
NGN is different from PSTN or TDM network in that all information
is transmitted by packets. The best thing of NGN is a single network offering many services.
NGN is designed to separate transport network from the services layer. By separating transport and service layers, a telco can offer new services by defining it directly at the service layer without considering the transport layer. The major components of NGN are transport (core network, access network), service control, service and application layers.
1. Transport: Core Network layer: The core network is a single converged fixed network, which can carry voice and data. The network technology is multi-protocol label switching (MPLS) with all traffic transported as IP.
2. Transport: Access Network layer: The Access Network supports wire and wireless access. It is service independent and can support multi-services.
3. Service Control layer: Service control layer will provide a means for teleco to bring new service to market quickly.
4. Service and Application layer: The service and application layer provide service independent from transport (core and access network) such as VOIP, IPTV, high speed Internet access.
Source: European Telecommunications Platform (ETP)
is transmitted by packets. The best thing of NGN is a single network offering many services.
NGN is designed to separate transport network from the services layer. By separating transport and service layers, a telco can offer new services by defining it directly at the service layer without considering the transport layer. The major components of NGN are transport (core network, access network), service control, service and application layers.
1. Transport: Core Network layer: The core network is a single converged fixed network, which can carry voice and data. The network technology is multi-protocol label switching (MPLS) with all traffic transported as IP.
2. Transport: Access Network layer: The Access Network supports wire and wireless access. It is service independent and can support multi-services.
3. Service Control layer: Service control layer will provide a means for teleco to bring new service to market quickly.
4. Service and Application layer: The service and application layer provide service independent from transport (core and access network) such as VOIP, IPTV, high speed Internet access.
Source: European Telecommunications Platform (ETP)
วันอังคารที่ 15 กรกฎาคม พ.ศ. 2551
What is NGN?
ITU definition of NGN
A Next Generation Network (NGN) is a packet-based network able to provide services including 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 offers unrestricted access by users to different service providers. It supports generalized mobility which will allow consistent and ubiquitous provision of services to users.
NGN is characterized by:
•Packet-based network
•Separation between network and service and application
•Multi-broadband services (both real time and non-real time)
•Multi-protocol
•Multi-Access
•IP-based Network (Secure, reliable, trusted) or managed IP network
•Interoperability between legacy and new network
A Next Generation Network (NGN) is a packet-based network able to provide services including 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 offers unrestricted access by users to different service providers. It supports generalized mobility which will allow consistent and ubiquitous provision of services to users.
NGN is characterized by:
•Packet-based network
•Separation between network and service and application
•Multi-broadband services (both real time and non-real time)
•Multi-protocol
•Multi-Access
•IP-based Network (Secure, reliable, trusted) or managed IP network
•Interoperability between legacy and new network
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