• View

  • Download

Embed Size (px)




  • 1. Essential Features of Public Network Requirements QoS guarantee High availability Equipment hot-swappable hardware 99.999% availability On-line software upgrades Scalability Based on global (open) standards Support for a new range of applications

2. EXISTING NETWORKS PSTN: The network consists of Local exchange/RSU as a part of Access Network and TAXs as a part of core Network. Already huge amount of money has been invested in PSTN setup CAPEX (Capital Expenditure) and OPEX (Operational Expenditure) 3. PLMN (Public Land Mobile Network) PLMN has been developed to provide voice services for wireless subscribers. Though in recent times many applications has emerged as killer application for mobile. PLMN includes BTS/BSC as access network and MSC as a core Network 4. PSDN/PSPDN This network was basically designed for accessing remote files and servers for defense people and universities but nowadays nobody can think of living without data network services. The basic and most popular application of data networks is Internet. Other applications include E-commerce, online banking, online gaming, E-shopping, IPTV Video on demand and many more. Data network is an assembly of routers, which are responsible for forwarding information from one end to other 5. Drawbacks The separate network infrastructure and no sharing of infrastructure among them. Sharing through Gateways Own service platforms in other words services are tightly coupled with their networks Separate access transport and switching network service provider has to invest in all the three networks separately CAPEX (Capital Expenditure) and OPEX 6. Why NGN ?Why NGN ? Need to converge and optimise the operating networks and the extraordinary expansion of digital traffic (i.e., increasing demand for new multimedia services, increasing demand for mobility, etc.). Slow to develop new features and capabilities. Expensive upgrades and operating costs. Proprietary vendor troubles Large power and cooling requirements. Limited migration strategy to New tech. Model obsolescence. 7. NGN Vision Next Generation Network is the framework where operator will have a common transport network based on Internet Protocol for providing all kinds of telecommunication services. Hence operators will have to install and maintain only a single network, which will reduce its CAPEX and OPEX significantly. Moreover service provisioning will become easier because of the introduction of new and intelligent servers. NGN is able to provide Vendor independence because of the standard protocols it uses for interaction with network elements. 8. NGN Definition ITU-T definition for 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 9. NGN ITU Perspective Next Generation Network (NGN) provides a framework for network evolution, as defined by the ITU-T (Rec. Y.2001) Key Characteristics Packet-based network [generally Internet Protocol or IP] Independence of service-related functions from underlying transport technologies Interworking with legacy networks via open interfaces Generalized mobility Unrestricted access by users to different services and/or service providers 10. ETSI (European Telecommunication Standardisation Institute) defines the NGN as a concept for defining and deploying networks, which due to their formal separation into differentlayers andplanesanduseofopeninterfaces,offers serviceprovidersandoperators a platform, which can evolve in a step-by-step manner to create, deploy and manage innovative services. NGN Definition (ETSI)NGN Definition (ETSI) 11. Fundamental Aspects NGNFundamental Aspects NGN Packet-based transferPacket-based transfer Separation of control functions among bearer capabilities, call/session, andSeparation of control functions among bearer capabilities, call/session, and application/serviceapplication/service Decoupling of service provision from transport, and provision of open interfacesDecoupling of service provision from transport, and provision of open interfaces Support for a wide range of services, applications and mechanisms based onSupport for a wide range of services, applications and mechanisms based on serviceservice building blocks (including real time/streaming/non-real time services andbuilding blocks (including real time/streaming/non-real time services and multimedia)multimedia) Broadband capabilities with end-to-end QoS and transparencyBroadband capabilities with end-to-end QoS and transparency Interworking with legacy networks via open interfacesInterworking with legacy networks via open interfaces Generalised mobilityGeneralised mobility 12. NGN Architecture NGN Concept A unified packet transport layer for all types of services A session based control architecture For user to user voice , video and data services over the packet infrastructure A common Service delivery platform Expectations from NGN Generate new revenue streams by having fast roll out of new multimedia services Secure voice revenue stream by integrating PSTN infrastructure with NGN Provide solution to cater to PSTN obsolescence wherever applicable 13. Requirements for NGN Implementation Equipment and Network Interoperability between various Operators A standards based functional architecture Standard interfaces and protocols Ability to serve Fixed (Copper and fibre), Wireless and Mobile Networks Open Services Architecture Standard interfaces open to third party application service providers QoS Control Mechanism Important for voice and video services Requires bandwidth allocation mechanism at access level as it is shared between various services 14. Requirements for NGN Implementation Need to share management functions like provisioning, metering, billing, QoS monitoring Provide Generalized Mobility features Mobility features at the fixed access, nomadism Provide service continuity between fixed and mobile access leading to convergence Common technology for transport layer IP/MPLS has emerged as the most suitable technology for this layer 15. NGN Concept 16. NGN Concept PSTN PLMN PSPDN Service / Application Layer Control Layer Transport Layer Access Layer Each vertical on the left has to be split into Network Elements that map onto each horizontal on the right 17. NGN Architecture NGN is a layered architecture consisting of transport, access, control and application layer. It is important to note that all the layers are independent from each other. Change in one layer should not affect other layers 18. Interfaces Switching Call Control Call Server / Soft Switch Routers of IP/MPLS Network Gateways PSTN Switch NGN Components PSTN to NGN Mapping TDM Transport Network Common IP MPLS Transport SG / TMG / LAG 19. Service X Service Y Separated control NB Wireless BB Wireless BB Wireline IP/MPLS Transport Core Management Service Layer Control Layer Access Layer Open interfaces SIP H.248 QoS Mechanism FMC Usage Measurement 20. NGN Concept Service / Application Layer Application Layer Transport Layer Access Layer NGN PSTNPLMN 21. Access Layer Access Layers is responsible for direct subscriber attachment function. NGN can support all kind of existing access as well as upcoming access and is capable of processing traffic originated from PSTN, GSM, CDMA, xDSL, WiMAX or any other access system. Depending upon the type of access, protocol conversion and/or media conversion may be required at the NGN Gateways 22. NGN Gateways Media Gateway: Access gateway Signaling gateway. 23. Media Gateway Terminates media, coming from PSTN/PLMN in E1 / STM. Here it is responsible for packetisation of media under the instruction of control layer supports packetized voice and the interface to whatever medium the voice is to be transported on. The MG performs the task of packetizing voice and providing connections from switched circuits (TDM) to packetized circuits (IP, Frame Relay, or ATM). It is responsible for media conversion, resource allocation and resource management, and event notifications. 24. Media Gateway It is responsible for reporting events to the media gateway controller (MGC) within its zone. Between Media Gateways (MGs) and Media Gateway Controllers (MGCs) the protocol used is Megaco/H.248. RTP protocol is used between two MGs for packetized bearer traffic. The purpose of this protocol is to provide communications for call control and call signaling. 25. Media gateway 26. Functions of Media Gateway: Media Conversion: conversion from TDM circuit-switched connections to ATM, IP, or Frame Relay connections Resource Allocation: Resource allocation includes the reservation and release of all resources , under the direction of the MGC Event Notification: maintain the state of all resources and report the state to the MGC. If a particular resource fails, the MG reports the failure to the MGC. The MGC maintains a state table for all resources within the MGs in its zone. 27. Signaling gateway It is a bridge to the PSTN It converts between SS7 addresses (point codes) and IP addresses SIGTRAN architecture is used between Sig Gate Way and Media Gateway Controller. 28. Transport Layer Transport Layer of NGN is based on IP. Transport Layer forms the core of the Network. It basically consists of Routers, which are responsible for carrying traffic originated by access layer. it should be able to make use of bandwidth policies and QoS policies. Opera