Next Generation Network Report

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A Seminar Report on

Next Generation Network Prepared by : Patel Harit A. Roll No.

: 62

Class

: B.E.IV (Electronics & Communication Engineering.)

Semester

: 8th Semester

Year

: 2009-2010

Guided by

: Mr. Bhargav Shah

Department Of Electronics & Communication Engineering Sarvajanik College of Engineering & Technology Dr R.K. Desai Road, Athwalines, Surat - 395001, India. 2

Sarvajanik College of Engineering & Technology Dr R.K. Desai Road, Athwalines, Surat - 395001, India.

Department Of Electronics & Communication Engineering

CERTIFICATE This is to certify that the Seminar report entitled Next Generation Network is prepared & presented by Mr. Harit A. Patel Class Roll No 62 of B.E.IV Sem VIII Electronics & Communication Engineering during year 2009-2010. His work is satisfactory. Signature of Guide

Head of Department Electronics Engineering

Signature of Jury Members 3

ACKNOWLEDGEMENT With this acknowledgement I take this opportunity to thank all those people without whose support this seminar would not have reached its true destination. My heartiest thanks to my guide Mr. Bhargav Shah who helped me to reach to the depth of the topic. I would also like to thank Mr. Pritesh Saxena and Mr. Dhiren Bhagat for their timely advices. As a final word, I am thankful to the staff members of E&C department, for their help to the completion of my seminar. Patel Harit A.

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ABSTRACT Traditionally there are multiple networks to provide multiple services to the people all around the world but the technological advancements in telecommunication is forcing a trend towards unification of network & services, setting up a stage for the emergence of Next Generation Network (NGN). NGN is essentially an Internet Protocol (IP) based network that enables to receive wide range of services such as voice, data and video over the same network. The service layer in NGN is independent of underlying network and access is enabled across a wide range of broadband technologies, both wireless such as Wi-Fi (Wireless Fidelity), WiMax (Worldwide Interoperability for Microwave Access) and wire line such as cable, fiber etc. A single IP network replaces the different transport networks. The key technique for NGN is scalable video coding and Quality of Service (QoS) to adapt to the various requirements such as quality, spatial and temporal resolution and bandwidth variation in heterogeneous networks. NGN would employ a meshed core, having embedded intelligence which would provide scalability, throughput and enhanced revenue generation by providing optimized connection, service, flexibility and efficient network management thus providing QoS.

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INDEX 1. Introduction to NGN............................................................................................................1 2. NGN architecture .................................................................................................................2 2.1 Overview ......................................................................................................................... 2 2.1 Transport functions ......................................................................................................... 2 2.2 Service functions ............................................................................................................. 3 2.3 Management functions .................................................................................................... 4 2.4 End-user functions .......................................................................................................... 4 2.5 IP multimedia subsystem (IMS) ..................................................................................... 4 2.5.1 IMS architecture....................................................................................................... 5 2.5.2 IMS Functional Entities ........................................................................................... 5 3. NGN Protocols ......................................................................................................................8 3.1 H.323............................................................................................................................... 8 3.2 SIP ................................................................................................................................... 9 3.3 MGCP ............................................................................................................................. 9 3.4 H.248............................................................................................................................... 9 3.5 SIGTRAN ..................................................................................................................... 10 3.6 PARLAY/ JAIN ............................................................................................................ 10 4. NGN Services ......................................................................................................................11 4.1 Enhanced internet quality ............................................................................................. 11 4.2 NGN Service Matrix ..................................................................................................... 11 5. Performance measure ........................................................................................................14 5.1 Quality of Service ......................................................................................................... 14 5.1.1 Network Centric Parameters .................................................................................. 14 5.1.3 Customer Centric Parameters ................................................................................ 14 5.1.4 Comparison of different network architectures ..................................................... 15 6. NGN Challenges .................................................................................................................16 Conclusion ..............................................................................................................................17 Acronyms ................................................................................................................................18 References ...............................................................................................................................20

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List of Figures Figure 2.1: NGN architecture overview [7] .............................................................................. 2 Figure 2.2: Network partitioning with respect to IMS [7] ........................................................ 5 Figure 2.3: IMS functional entities and reference points [7] .................................................... 6 Figure 3.1: Protocols used in NGN [5] ..................................................................................... 8 Figure 4.1: NGN Service Drivers [6] ...................................................................................... 12

List of Table Table 5.1: Comparison of different network architectures ..................................................... 15

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1. Introduction to NGN The ITU defines a Next Generation Network (NGN) as a packet-based network able to provide services including telecommunications services and able to make use of multiple broadband, Quality of Service (QoS) enabled transport technologies and in which servicerelated functions are independent from underlying transport-related technologies. It offers unfettered access by users to different service providers. It supports generalized mobility which will allow consistent and ubiquitous provision of services to users. The Next Generation Network concept defines telecommunications network architectures and technologies. It describes networks that cover conventional Public Switched Telephone Network (PSTN) type of data and voice communications as well as new types of service such as video. All information is carried in packet switched form, as is done in the Internet. Packets are labeled according to their type and forwarded in the network based on their QoS and security parameters. The NGN makes a clear separation between the transport and services, which is advertised to allow smooth introduction of new services. When a provider wants to launch a new service, the service is defined directly at the service layer without considering the transport layer, i.e. services are independent of the transport technology.

What is NGN?     

A multi-service Network able to support Voice, Data and Video. A network with a control plane separated from the Transport/ Switching plane. A network with open interfaces between transport, control and applications. A network using packet mode technology to transport of all kind of information. A network with guaranteed QoS for different traffic types.

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2. NGN architecture 2.1 Overview Due to the separation of transport and services, the NGN functions are divided into service and transport layers. End user functions are connected to the NGN by the user to network interface (UNI), while networks are interconnected via the network to network interface (NNI). The application to network interface (ANI) is defined to allow third party application implementations. Figure 2.1 illustrates the overview of the NGN functional architecture.

Figure 2.1: NGN architecture overview [7]

2.1 Transport functions The transport layer functions provide connectivity for all components and physically separated functions within an NGN. Internet Protocol (IP) is seen as the most obvious NGN transport technology and therefore the transport layer will provide IP connectivity for end user equipment (residing outside an NGN) and various controllers and enablers that are

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usually located in servers within the area of an NGN. The transport layer is further divided into access and core network. Access functions, which are access technology dependent, manage the end user access to an NGN network. Access transport functions are responsible for carrying information across the access network. They also offer QoS control mechanisms for NGN Edge functions are used for traffic processing when access traffic is merged into the core network. Core transport functions ensure information transport through the core network. They provide the means to differentiate the quality of transport by interacting with the transport control functions. Network attachment control functions (NACF) provide registration at the access level and initialization of end user functions to allow access to NGN services. They support network level identification and authentication, manage the IP address space of the access network, and authenticate access sessions. Resource and admission control functions (RACFs) offer admission control and gate control functionality, such as control of network address and port translation (NAPT) and management of differentiated services field code points (DSCPs). Admission control includes, e.g. user profile based checking of authentication and authorization, considering also operator specific rules and resource availability. Resource availability checking implies that the admission control function verifies weather a resource request is allowable, as opposed to resources that are already provisioned or used. Transport user profile functions comprise the user and other control information that forms a single “user profile” function in the transport layer. This function may be specified and implemented as a set of cooperating databases with functionality residing in any part of an NGN. Gateway functions support capabilities to interwork with other networks, such as PSTN/ ISDN based networks and the Internet. Interworking with other NGNs, owned and operated by other administrators, is also included. Media handling functions supply services, such as tone signal generation, transcoding and conference call bridging.

2.2 Service functions NGN services will include session based and non-session based services. Examples of the session based services are IP telephony and video conferencing, and examples of the nonsession based services are video streaming and broadcasting. The NGN supports also 3

network functionality associated with existing PSTN/ISDN services and capabilities and interfaces to legacy customer equipment. Service and control functions include session control functions, a registration function as well as authentication and authorization functions at the service level. Service user profile functions cover the user and other control information that form a single user profile function in the service layer. The function may be specified and implemented as a set of cooperating databases with functionality located in any part of an NGN. Application functions, either trusted or untrusted, are used by third party service providers to access NGN service layer capabilities and resources through servers or gateways in the service layer. These functions are needed, because NGNs support open APIs that enable third party service providers to use NGN capabilities in creating enhanced services for NGN users.

2.3 Management functions The management functions enable an NGN operator to manage the network and provide NGN services with the required quality, security and reliability. These functions are distributed to each functional entity and they interact with the network element management, network management and service management functional entities. The management functions include charging and billing functions, which interact with each other to collect resource utilization information. This information enables the operator to bill users properly. The collected charging and billing information can be used for online interactions, such as for prepaid services, and for offline interactions.

2.4 End-user functions Interfaces to the end-user are either physical or functional interfaces, as shown in Figure 2.1. The ITU specifications do not limit the types of customer interface that can be connected to an NGN network. The NGN supports all kinds of customer equipment categories from single line legacy telephones to complex corporate networks. Additionally, the end-user equipment may be either mobile or fixed.

2.5 IP multimedia subsystem (IMS) The IMS has a central role in providing session based services for the NGN. IMS is based on IP protocols defined by Internet Engineering Task Force (IETF). The 3rd Generation Partnership Project (3GPP) defined IMS for mobile networks and it was also introduced for the NGN. IMS is mostly independent of the access network technology, although there are some transport specific aspects. The basic signaling protocol used by IMS is the Session Initiation Protocol (SIP), which is used to create, modify and terminate sessions. 4

2.5.1 IMS architecture IMS makes separation between the core and access network. The separation comes from 3GPP‟s original IMS definitions, i.e. from the wireless network model in which one or more radio access networks are connected to a common core network. The radio access networks provide connections between terminals and services available in the core. An access network is a collection of entities providing IP transport connectivity between a user domain and a core transport network. Different sorts of access networks are distinguished based on the underlying technology, ownership or administrative partitioning. IMS defines a collection of core network functional entities that the core uses in offering IP transport connectivity between an access network and a core transport network, between two access networks or between two core networks. The core network also offers connectivity to service layer entities. The core networks can differ from one another according to the underlying technology, ownership or administrative partitioning. One of the fundamental characteristics of an IMS is the support of user mobility. In this context, the distinction between the core and access networks has significance, especially when dividing the functions necessary to support an IMS.

Figure 2.2: Network partitioning with respect to IMS [7]

2.5.2 IMS Functional Entities Figure 2.3 shows the collection of functional entities and reference points of the IMS functional architecture. The purpose of each entity is explained shortly in the following.

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Figure 2.3: IMS functional entities and reference points [7]

An application server (AS) provides service control for the IMS. The AS may be directly connected to a serving call session control function (SCSCF) or via an Open Services Architecture (OSA) gateway for third party based applications over an ISC reference point. The ISC interface is SIP based and SIP messages may be carried over this interface to or from an SCSCF. The AS may interact with the home subscriber server (HSS) over the Sh interface to obtain subscriber profile information. Application servers are used to support various Telephony type services. A breakout gateway control function (BGCF) receives session requests forwarded by an SCSCF (or another BGCF) and selects the network in which a PSTN attachment point is located. It also selects a local MGCF or a peer BGCF in another network. The ability to select a BGCF in another network enables to optimize routing from a visited network to the PSTN. Call Session Control Functions (CSCF) is responsible for the control of session features, routing and resource allocation in cooperation with other network elements. When a SIP enabled terminal initiates a call, CSCF allocates resources and routes the SIP invite message to the called terminal. If the called side is a traditional PSTN phone number then CSCF routes SIP messages to the Breakout Gateway Control Function (BGCF). BGCF selects the Media Gateway Control Function (MGCF), which perform necessary signaling conversion. The IMS architecture supports three types of CSCFs:  Serving CSCF (SCSCF),  Interrogating CSCF (ICSCF) and  Proxy CSCF (PCSCF). Home Subscriber Server (HSS) contains a subscription database for the IMS. It supports IMS level authentication and authorization as well as keeps record of the IMS subscriber profiles. The HSS also stores the currently assigned SCSCF. A home network may contain 6

one or several HSSs. The number of HSSs depends on the number of subscribers, the capacity of the equipment and the organization of the network. Media Gateway Control Function (MGCF) supports interworking between the IMS and the PSTN. MGCF performs the translation between SIP messages and Integrated Service Digital Network User Part (ISUP) messages. MGCF also controls MGW. Media Gateway (MGW) terminates bearer channels from circuit switched networks and media streams from packet switched networks and performs media conversion functions such as transcoding. It also offers dual tone multi frequency (DTMF) detection and generation. Media Resource Function Controller (MRFC) controls MRFP‟s media stream resources. It interprets information from an AS or SIP endpoint and controls the MRFP accordingly to support media services such as transcoding and conferencing. The MRFC may be collocated with an AS to support specialized AS services. Media Resource Function Processor (MRFP) supports functions such as media stream mixing, tone and announcement generation, transcoding and media analysis. Subscription Locator Function (SLF) acts as a front end for distributed HSS systems. It may be queried by an ICSCF during registration and session setup to get the name of the HSS, which contains the required subscriber specific data. The SLF may also be queried by the SCSCF during registration or by the AS in connection with the Sh interface. The SLF is not needed in a single HSS environment or in certain other HSS environments, such as server farm architecture. User Equipment (UE) represents the functionality of user terminals. It supports the specific capabilities of the access network to which it is connected. It also supports the user agent capabilities of an IMS client. The UE supports SIP methods/functions as defined by the IMS.

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3. NGN Protocols NGN architecture is characterized by the separation of service, transport and control layers, which are inter connected by open interfaces and use standards protocols. Legacy TDM networks are interconnected with NGN via interfaces based on open standards and protocols. A protocol stack typically used in NGN is shown in figure 3.1.

Figure 3.1: Protocols used in NGN [5]

3.1 H.323 H.323 is an ITU Recommendation that defines "packet-based multimedia communications systems." It defines a distributed architecture for creating multimedia applications, including VoIP. The H.323 protocol is best known as the original call signaling protocol that made real time voice and video over IP possible. Being the first solution to work, H.323 is the most widely deployed protocol in the market and through its veteran 8

status and wide acceptance provides telecommunication equipment with the benefits of a highly mature and completely interoperable signaling solution.

3.2 SIP Designed by the IETF, the Session Initiation Protocol (SIP) is an application-layer control protocol for multimedia communication over IP network. It is used for creating, modifying and terminating two party sessions, multiparty sessions and multicast sessions (one sender and many receivers). These sessions include audio, video and data for multimedia conferences, instant messaging, Internet telephone calls, distance learning, telemedicine, multiparty real time games etc. Sip defines telephone numbers as URLs (Uniform Resource Locators), so that web pages can contain them. This allows a click on a link to initiate a telephone call. These addresses take the form of user@host, similar to e-mail addresses. The user part, which is left of the “@” sign, may be user name or a telephone number and host part, which is right of the “@” sign, is a domain name or IP address. SIP addresses may be obtained out-of-band, learned via media gateways, recorded during earlier conversations, or guessed (since they‟re often similar to E-mail addresses. SIP may be used in conjunction with other call setup & signalling protocols and has a verity of other features like caller reachability, call screening, encryption and authentication etc.

3.3 MGCP Media Gateway Control Protocol (MGCP) is a control protocol that uses text or binary format messages to setup, manage, and terminate multimedia communication sessions in a centralized communications system. This differs from other multimedia control protocol systems (such as H.323 or SIP) that allow the end points in the network to control the communication session. MGCP is specified in RFC 2705. MGCP is, in essence, a master/slave protocol, where the MGs are expected to execute commands sent by the MGCs.

3.4 H.248 H.248 is an ITU Recommendation that defines „Media Gateway Control Protocol‟. It is the result of a joint collaboration between the ITU and the IETF. It is also referred to as IETF RFC 2885 (MEGACO), which defines a centralized architecture for creating multimedia applications, including VoIP. In many ways, H.248 builds on and extends MGCP. It is used as a media gateway control protocol between a Media Gateway Controller (MGC) and a Media Gateway (MG). The ITU-T, the IETF, the International Softswitch Consortium (ISC), and other standardization organizations are optimizing the H.248 protocol currently. Telecommunication equipment vendors are investing much in the development and application of the H.248 protocol. Compared to the MGCP protocol, the H.248 protocol is more flexible and can support more types of access technologies and mobility of terminations.

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3.5 SIGTRAN SIGTRAN (Signaling Transport) is a protocol stack defined by the SIGTRAN workgroup of the Internet Engineering Task Force (IETF) for transport of switched circuit network (SCN) signaling over IP networks. This protocol stack supports the inter-layer standard primitive interface defined in SCN signaling protocol hierarchy model so as to ensure utilization of the existing SCN signaling application without modification. It uses the standard IP transport protocol as the transmission bottom layer, and satisfies the special transmission requirements of SCN signaling by adding its own functions.

3.6 PARLAY/ JAIN Parlay/JAIN is a suite of open, standard, APIs designed to facilitate easier access to core network capabilities from outside of the network. The opening up of the network in a secure manner by such APIs allows the existence of new business models, which allow applications to be developed and provided by vendors outside of the network operator‟s domain.

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4. NGN Services 4.1 Enhanced internet quality Although the NGN utilizes the same technology as the Internet, there are additions that make the NGN at least a slightly different from the Internet. The main difference is the IMS, which builds on the IETF protocols, but implements specific profiles and enhancements to provide a robust multimedia system. The enhancements and operational profiles offer support for operator control, billing and security. Additionally, IMS requires a set of vertical interfaces to provide the following:  common interfaces to application servers for accounting, security, subscription data, service control and to service building blocks  coordinated and enforced QoS (session layer negotiation can be matched with resources granted at the transport layer, per operator policy)  session based media gating under operator control  correlated accounting and charging among the service, session and transport layers The above capabilities make IMS and thus the NGN different from the Internet on session control point of view. A network operator controls access to the network and a service provider controls access to the services. This feature is contradictory to the usual Internet model in which the network is transparent and all services are provided by endpoints. Users get an improved experience with managed QoS, single sign on security and customer support, at least in theory. Thus it can be concluded that the NGN, despite of its complex structure, is more controllable and therefore more reliable than the usual Internet.

4.2 NGN Service Matrix NGN platform provides variety of services. A matrix showing various services is shown in figure 4.1. NGN is able to fulfill all the sophisticated communication service demands. Voice Telephony – NGNs will likely need to support various existing voice telephony services. However, NGNs are not trying to duplicate each and every traditional voice telephony service currently offered. Rather, they will likely attempt to support only a small percentage of these traditional services, with an initial focus on the most marketable voice telephony feature and the features required from a regulatory perspective. Data (Connectivity) Services –Allows for the real-time establishment of connectivity between endpoints, along with various value-added features

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Figure 4.1: NGN Service Drivers [6]

Multimedia Services – Allows multiple parties to interact using voice, video, and/or data. This allows customers to converse with each other while displaying visual information. It also allows for collaborative computing and groupware. Virtual Private Networks (VPNs) – Voice VPNs improve the inter location networking capabilities of businesses by allowing large, geographically dispersed organizations to combine their existing private networks with portions of the PSTN, thus providing subscribers with uniform dialing capabilities. Data VPNs provide added security and networking features that allow customers to use a shared IP network as a VPN. Public Network Computing (PNC) – Provides public network-based computing services for businesses and consumers. For example, the public network provider could provide generic processing and storage capabilities. The public network provider would charge users for the raw processing and storage used, but would have no knowledge of the specific content/application. Alternatively, the public network provider could provide specific business applications or consumer applications, with all or part of the processing/storage happening in the network. The public network provider could charge based on an hourly, daily, weekly, etc. licensing fee for the service. Unified Messaging – Supports the delivery of voice mail, email, fax mail, and pages through common interfaces. Through such interfaces, users will access, as well as be notified of, various message types, independent of the means of access.

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Information Brokering – Involves advertising, finding, and providing information to match consumers with providers. For example, consumers could receive information based on prespecified criteria or based on personal preferences and behavior patterns. E-Commerce – Allows consumers to purchase goods and services electronically over the network. This could include processing the transactions, verifying payment information, providing security, and possibly trading. Home banking and home shopping fall into this category of services. This also includes business-to-business applications. Call Center Services – A subscriber could place a call to a call center agent by clicking on a Web page. The call could be routed to an appropriate agent, who could be located anywhere, even at home. Voice calls and e-mail messages could be queued uniformly for the agents. Agents would have electronic access to customer, catalog, stock, and ordering information, which could be transmitted back and forth between the customer and the agent. Interactive gaming – Offers consumers a way to meet online and establish interactive gaming sessions. Distributed Virtual Reality – Refers to technologically generated representations of real world events, people, places, experiences, etc., in which the participants in and providers of the virtual experience are physically distributed. These services require sophisticated coordination of multiple, diverse resources. Home Manager – With the advent of in-home networking and intelligent appliances, these services could monitor and control home security systems, energy systems, home entertainment systems, and other home appliances. Imagine you‟re watching television and the doorbell rings – no problem – you just use the TV‟s remote to get a view of your front entrance to see who‟s there. Or imagine monitoring your house while you‟re away on a trip, or your in-house nanny watching your children while you‟re at work.

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5. Performance measure 5.1 Quality of Service For successful delivery of quality to the end-user across NGN there should be Classes of Application QoS that are mapped into specific Network QoS classes. QoS Parameters are service specific. For example, call set-up delay, call completion rate and speech quality is some of the parameters for real-time voice service whereas for IPTV service, Jitter and the zap time could be important parameters. QoS is complex in converged networks.

5.1.1 Network Centric Parameters Network Performance as per ITU-T standard is measured in terms of parameters which are meaningful to the network provider and are used for the purpose of system design, configuration, operation and maintenance. 

Latency: Latency or IP Packet Transfer Delay (IPTD) is the time between the occurrences of two corresponding IP packet reference events.

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Jitter: Jitter or IP Packet Delay Variation (IPDV) is the variation in IP packet transfer delay.

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Packet Error: Packet Error or IP Packet Error Ratio (IPER) is the ratio of total errored IP packets outcomes to the total of successful IP packet transfer outcomes plus errored IP packet outcomes in a population of interest.

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Packet Loss: Packet Loss or IP Packet Loss Ratio (IPLR) is the ratio of total lost IP Packets outcomes to total transmitted IP packets in a population of interest.

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Toll Quality: The voice quality resulting from the use of a nominal 4-kHz telephone channel.

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Call Completion Rate: It is the ratio of established calls to call attempts during time consistent busy hour (TCBH).

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Availability of Network: Measure of the degree to which network is operable and not in a state of failure or outage at any point of time for all users.

5.1.3 Customer Centric Parameters Customer centric parameters are Service Activation Time, Service De-activation Time, Service Restoration Time, Clarity of Tariff Plans, Ease of switching between plans, 14

Ease of getting Billing information, Ease of Bill payments, Ease of getting refunds, Network Availability, Billing Accuracy, Security of customer information, Grievance Redressal, Access to senior executives/ officers, Round the clock availability of customer care, Fault Repair Service, Redressal of Excess Metering Cases, Service availability etc. There are already existing regulations for Basic Services, Mobile Services and Broadband Services.

5.1.4 Comparison of different network architectures The following table shows the comparison of various parameters of different network architectures.

Security Scalability Latency Management Adaptability Cost/Complexity Networking

Best-of-Breed Appliances Low Low Low

Traditional Chassis High Medium Low Low High Medium Low

Multi Service Gateways High High Low Medium

Table 5.1: Comparison of different network architectures

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NGN Architecture High High High High High High High

6. NGN Challenges There are various issues in implementation and deployment of NGN in place of existing network. The causes of the issues differ from operator to operator and county to country. Some of the common issues are listed below.  Standardization is not yet universal  Laws in each country needs to be suitably amended  Incumbents and other telecom/ internet service providers will have cost issues  Developing countries are not yet well versed with the advancements  Convergence is the order of the day at back end - front end too this will need to be borne in mind while producing user end tools/ products/ services There are few challenges in deploying NGN with other existing independent networks like GSM, CDMA, etc. Mobiles and Internet have convergence possibilities though technology is not the problem, the unit byte cost for riding on the GSM lines are still whopping. Though user end devices of mobiles (CDMA or GSM), peer-to-peer devices are now also being tested for remote areas. These tools become extremely valuable for transmitting content relating to health, education, disasters, etc, yet entertainment interests the content industry more than the development aspects. There are many internetwork issues exist when more than one operator comes into service plane.  There will be issues related to Firewall traversal, Security, translation of protocols in two networks (interoperability), and lawful interception of calls.  Session Border Controllers (SBC) will be required at borders, between two NGN operators.  Calling party identification must be mandatory for routing the call in NGN networks

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Conclusion NGN is a new global platform for all kinds of voice & data services. It provides plenty of options to subscriber to choose applications of their choice. Also it opens up new doors of revenue for service providers and operators. It removes the redundant hardware and connectivity present in the old PSTN. Deployment of NGN also becomes mandatory in order to accommodate increasing traffic across the world. By 2015 almost all the PSTN will converge into NGN.

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Acronyms 3GPP ANI AS BGCF CDMA CSCF DSCPs DTMF GSM HSS ICSCF IETF IMS IP IPDV IPER IPLR IPTD ISC ISDN ISUP ITU MG MGC MGCF MGCP MGW MRFC MRFP NACF NAPT NGN NNI OSA PCSCF PNC PSTN QoS RACF SBC SCN SCSCF

3rd Generation Partnership Project Application to network interface Application server A breakout gateway control function Code division multiple access Call Session Control Functions Differentiated services field code points Dual tone multi frequency Global System for Mobile Communications Home subscriber server Interrogating Call Session Control Functions Internet Engineering Task Force IP Multimedia Subsystem Internet Protocol IP Packet Delay Variation IP Packet Error Ratio IP Packet Loss Ratio IP Packet Transfer Delay International Softswitch Consortium Integrated Services Digital Network Integrated Service Digital Network User Part International Telecommunication Union Media Gateway Media Gateway Controller Media Gateway Control Function Media Gateway Control Protocol Media Gateway Media Resource Function Control Media Resource Function Processor Network attachment control functions Network address and port translation Next Generation Network Network to network interface Open Services Architecture Proxy Call Session Control Functions Public Network Computing Public Switched Telephone Network Quality of Service Resource and admission control functions Session Border Controllers Switched Circuit Network Serving Call Session Control Functions 18

SIGTRAN SIP SLF TCBH TDM UE UNI URLs VoIP VPNs Wi-Fi WiMax

Signaling Transport Session Initiation Protocol Subscription Locator Function Time Consistent Busy Hour Time Division Multiplexing User Equipment User to network interface Uniform Resource Locators Voice over Internet Protocol Virtual Private Networks Wireless Fidelity Worldwide Interoperability for Microwave Access

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References [1] ITU-T Recommendation Y.2001, “General overview of NGN”. [2] ITU-T Recommendation Y.2011, “General principles and general reference model for Next Generation Networks.” [3] ITU-T Recommendation Y.2012, “Functional requirements and architecture of the NGN release 1.” [4] ITU-T Recommendation Y.2021, “IMS for Next Generation Networks.” [5] Telecommunication Engineering Centre Recommendation, “NGN Protocols.” [6] A Telcordia Technologies Recommendation “Next Generation Network (NGN) Services.” [7] Knightson, K. Morita, N. Towle, T., “NGN architecture: generic principles, functional architecture, and implementation.” IEEE Communications Magazine, Volume: 43, Page(s): 49 – 56. [8] Dharwadkar, S.N.; Dale, M.P.; Masood, N.; Joshi, M.A.; “NGN need and challenges.” Wireless, Mobile and Multimedia Networks, 2008. IET International Conference on, Pages(s): 30 - 33

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