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    • UG_STF_SC_05r2 European Telecommunications Standards Institute USER-STF Steering Group Meeting 12th – 13th January 2009, Sophia Antipolis - France ETSI User Group; STF360; Analysis of current E2E QoS standardization state Contents 1 NGN Context...............................................................................................................................3 1.1 User centric.................................................................................................................................................4 1.2 Heterogeneous environment.......................................................................................................................5 1.3 General mobility.........................................................................................................................................6 1.4 Conclusion..................................................................................................................................................9 2 User Case...................................................................................................................................10 3 Requirement for QoS continuity................................................................................................12 4 Conclusion.................................................................................................................................13 5 Discussion and next steps..........................................................................................................15 5.1 Control plane solution: QoS signalling.....................................................................................................16 5.2 Management plane solution: QoS interworking.......................................................................................17 5.3 Converging solution: QoS continuity.......................................................................................................17 5.4 QoS informational structure......................................................................................................................17 Annex A: Current work for QoS................................................................17 A.1. SLA.......................................................................................................................................18 A.1.1 SLA definition......................................................................................................................................18 A.1.2 SLA Life Cycle.....................................................................................................................................18 A.1.3 SLA Function........................................................................................................................................19 A.1.4 Conclusion............................................................................................................................................19 A.2. Mobility in homogenous network user-unaware...................................................................19 A.3. Heterogeneous environment and QoS...................................................................................21 A.3.1 IMS Architecture (3GPP).....................................................................................................................22 A.3.2 TISPAN NGN architecture...................................................................................................................26 A.3.3 QoS issue in the IMS--- Policy control management...........................................................................28 A.3.4 Diameter...............................................................................................................................................31 A.3.4.1 Policy Charging Convergence...........................................................................................................31 A.3.4.2 Messages and AVPs...........................................................................................................................32 A.3.5 Conclusion............................................................................................................................................35 A.4. E2E QoS signalling (among the same type of access network):............................................36 A.4.1 SIP 36 A.4.1.1 SIP basic functionalities ....................................................................................................................37 A.4.1.2 SIP entities.........................................................................................................................................37 A.4.1.3 SIP messages and procedure..............................................................................................................38 A.4.1.4 SDP 39 A.4.2 NSIS......................................................................................................................................................40 A.4.2.1 Logic model and protocol messages .................................................................................................41
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 2 of 67 A.4.2.2 QoS Specifications and QoS Models ................................................................................................44 A.4.2.3 Conclusion.........................................................................................................................................45 A.5. User interface to the heterogeneous network for QoS ..........................................................45 A.5.1 Customer Premises Network to TISPAN NGN....................................................................................46 A.5.2 Service scenarios description................................................................................................................48 A.5.3 CPN architecture model interacting with the NGN/IMS networks......................................................49 A.5.4 Conclusion ...........................................................................................................................................51 A.6. QoS Interworking (Mobility in the heterogeneous environment):.........................................51 A.6.1 MIH.......................................................................................................................................................52 A.6.1.1 Media Independent Handover Scope.................................................................................................52 A.6.1.2 Media Independent Handover Function.............................................................................................53 A.6.1.3 Conclusion.........................................................................................................................................57 A.6.2 Mobile IPv6..........................................................................................................................................57 A.6.2.1 Mobile IPv6 architecture....................................................................................................................57 A.6.2.2 Mobile IPv6 smooth handover process..............................................................................................59 A.6.2.3 Mobile IPv6 and QoS........................................................................................................................60 A.6.2.4 Conclusion.........................................................................................................................................60 A.6.3 Y.1541 and Y.1541-QOSM..................................................................................................................60 A.6.3.1 Y. 1541 Class.....................................................................................................................................60 A.6.3.2 Y.1541-QOSM...................................................................................................................................61 A.6.3.3 Conclusion.........................................................................................................................................62 Annex B: Standard & Bibliographical References....................................63
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 3 of 67 1 NGN Context The successor of the 3G network is a single All-IP infrastructure which is referred to as NGN (Next Generation Network). A major characteristic of the Next Generation Network is its ability to handle heterogeneous and mobile environments for users and service providers. One can consider four different types of mobility: User mobility, Terminal mobility, Network mobility and Service mobility. Moreover, heterogeneity exists in user’s terminals, access networks, core networks as well as in services. The ability to provide seamless mobility and adaptive quality of service in such a heterogeneous environment is THE key to the success of Next-Generation Networks. Our analysis of the context led us to highlight innovative properties (§ 1.1). Users wish to have a continuous multimedia service in a single session whether they are moving (terminal mobility) or changing terminal (user mobility). This service session is user- centric, meaning that a user should have a continuity of service based on customization. Next service generation should have the self-management ability to dynamically accommodate user requests by adding or changing service components in a single service session. Figure 1 : NGN context In this chapter, a basic introduction on the three main characteristics of NGN: is provided: the User Centric conception (§ 1.1), the heterogeneous environment (§ 1.2), and the general mobility in NGN (§ 1.3). A conclusion is then proposed at the end of this chapter
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 4 of 67 (§ 1.4) 1.1 User centric Telecommunication evolved from system centric (user must comply with various treatments) to network centric (user must comply with various connections), and now to User centric. User information, QoS requirements and preferences are defined in the user’s profile (Figure 2). In this new context, a common understanding about services, priorities, responsibilities, etc, is needed between the service provider and the user. This is expected to lead in the case of business users, to a formal SLA (Service Level Agreement) or in the case of the general public to QoS commitments of the provider included in the service contract according to the relevant regulation. Figure 2: User centric
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 5 of 67 User centric means that users can access services, in a customized way with a single authentication and “always in a unique user session”. This conception contains four essential requirements, each explained below:  Adaptable accessibility to services regardless the terminal used End users may have several user equipments (UE) in a Seamless Userware vision, for instance a computer, a PDA, a mobile telephone etc, all trying to reach the same service. Each of these equipments has its specific context and conditions of use, and each user has his preferences. In such situation, one key question is how to adapt services to a chosen terminal, complying to user’s preferences.  Unique user session for multimedia services (Continuity of service) During an on-going session, a user can enjoy different services from different providers. For example, during a telephone call, a user can add a Videophone service, or a movie program provided by SP1 (Service Provider #1) which may be transferred to a PDA game program provided by SP2. Users expect such service continuity be provided via a unique user session.  Customization of service The NGS (Next Generation Service) concept considers services as a flexible composition of autonomous service components customizable according to user’s preferences and the user profile. Thus, user’s preference should be taken into consideration while managing service composition across heterogeneous networks.  Better selection of connectivity with QoS Today’s the technology allows a terminal to be able to access services through different access networks (WiFi, GSM, UMTS, etc). This means that a user can switch from one access mode to another one in a dynamic manner according to user’s preferences (QoS, location, availability, etc.). 1.2 Heterogeneous environment With the continuous evolution of services and technologies, the world of telecommunication becomes more and more heterogeneous. Modern telecommunication networks consist of mobile network (such as GSM/GPRS/UMTS), fixed network (such as Public Switched Telephone Network/ISDN), satellite network and wireless access networks
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 6 of 67 (such as wireless LAN (WiFi, WiMax) and Bluetooth networks), etc. The user devices are also becoming more diversified: PDAs, laptops, cell phones, etc which are now commonly used by the general public. The growing number of a variety of services and multimedia applications in converging fixed and mobile IP networks (called Next Generation Networks (NGN)) led to the definition of a Service Delivery Platform architecture known as an IMS (IP Multimedia Subsystem) (with associated protocols: SIP, Diameter and Policy control protocols). IMS was originally specified by 3GPP as part of the vision for evolving mobile networks beyond GSM and extended later for support of other networks such as fixed line, WLAN, etc. by a number of standardization organizations, such as the ITU-T and ETSI TC TISPAN; meanwhile the number of service providers and operators is growing. Figure 3 highlights the NGN heterogeneous environment. Figure 3 : NGN heterogeneous environment These heterogeneities have increased the complexity of the overall infrastructure. Problems of interoperability between the various systems and handover/roaming between different accesses and providers should be solved according to the QoS commitments. 1.3 General mobility Mobility gives users ability to connect from anywhere, anytime to any service with any type of terminal. In the NGN context, mobility allows users to communicate regardless of location, device, access mode and network across multiple spatial domains. The existing
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 7 of 67 solutions for mobility include horizontal handover (HHO) and vertical handover (VHO). The horizontal handover is provided via mode L3 through the technology "Mobile IP". Media Independent Handover (MIH) is intended to manage seamless connectivity with different wireless networks in MAC and PHY layers. Four kinds of mobility exist in such a NGN context: • Terminal Mobility refers to the ability of a terminal, while in motion, to access telecommunication services from the same different networks, and the capability of the commercial networks to identify and locate that terminal . Figure 4 a: Mobility classifications according to network service quality. Source from [ITU-T Q.1706/Y.2801] Figure 4 b: Terminal Mobility
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 8 of 67 • User Mobility refers to the ability for the user to move to different physical locations and be able to use one or more devices connected to one or more access networks to gain access to their services without interruption . Figure 5 : User Mobility • Network mobility refers to the ability of networks, where a set of fixed or mobile nodes are networked to each other, to change, as a unit, its point of attachment to the corresponding network upon the network’s movement itself. (this kind of mobility is out of our scope of research), ex. Ad-hoc network, military network. • Service Mobility refers to the ability of services to be accessible and deliverable independently of network, terminal or geographical location attributes . It includes the ability of the service level to consistently provide customized services to the user, with the expected QoS, regardless of the user’s location. This allows users to maintain access to their services even while moving or changing of devices or network service providers.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 9 of 67 Figure 6 : Service mobility The key issue to achieve seamless mobility is for Service Providers to comply with the QoS contract. 1.4 Conclusion As networks become more and more complex and as new services emerge continuously, the requirement for an end to end QoS management offering a transparent experience to the end user is growing. These new services (e.g. data services, multimedia services) can be used by different users in different manners. Users are no longer satisfied with a simple phone call service but are interested to have as many services available as possible included in a customized service composition. These requirements imply not only the possibility to always have these services accessible in a unique session when the user is moving in an heterogeneous environment but also to have the QoS guaranteed for different types of applications simultaneously. To maintain E2E QoS continuity for users, as expected, the means to provide cooperation between the different networks are needed.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 10 of 67 2 User Case Figure 7 : User case Figure 7 shows a typical user case. In the heterogeneous and generic mobile environment, user enjoys different types of media in one session with E2E QoS continuity according to his preference. Table 1 below presents the user case description and the pertinent capabilities.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 11 of 67 User case description Capability 1.At home, Bob uses the home ① Home Network Environment network made up of customer network gateway (CNG) and customer network devices (CND) to access the service. 2.At 8:30h, user launches a session on ② One session from 8:30h to 11h his desktop for web service provided by SP1 according to his preferences (AS12: the first number after AS identifies function, second number identifies the QoS level defined by the provider). ③ User mobility 3.According to Bob’s preference, when he leaves home for work, he uses his PDA to continue surfing internet in the same service session. ④ Vertical handover 4.The PDA accesses to the service through another type of access ⑤ Terminal mobility network. ⑥ Service composition 5.On the way to work, user calls his business partner confirming the video conference and discusses some issues, so the data flow and voice flow is loaded in the same session. The service broker in SCIM manages the interaction of AS12 (Web service) and AS33 (Voice service) provided by SP1 according to the user profile ⑦ Horizontal handover configured in the Home Subscriber Server (HSS). 6.When Bob arrives at his office, his PDA accesses through another access point of the same access network, ③ User mobility while web service and voice service continue. 7.According to user’s preference, Bob continues his work on the laptop at his office while continuing to talk ⑧ Service mobility with his partner. 8.Within his office, his laptop accesses another access point. To maintain E2E QoS according to user’s preference, the system changes the AS 12 and AS 33 to AS 11 and AS 31 which are provided by SP2. 9.For the user, all the treatments are transparent.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 12 of 67 Table 1 : User case description Conclusion: Our objective is to achieve E2E QoS continuity for a customer in one unique user multimedia session. This user case illustrates terminal mobility, user mobility and service mobility with QoS continuity while the user moves across heterogeneous networks according to his preferences. Moreover, E2E is considered from the user equipment everywhere (even in his Home Network Environment) up to the service layer with QoS mapping, according to the user’s preference. That is, in an "E2E user-centric session" vision, a user could have an E2E QoS continuity of global multimedia services in a customized way. 3 Requirement for QoS continuity Figure 8 : From existences to concerned problem The following numbers are referring to the ones in the domains in the above circles. 1. User requirements and preferences: In terms of continuity of multimedia services and all personal information (usage, SLA, security etc.). 2. Mobility, which refers to terminal mobility, user mobility, service mobility and network mobility 3. Heterogeneity, which represents the heterogeneity of networks and terminals, as well as the heterogeneity of services which contribute to the heterogeneity of QoS mechanisms.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 13 of 67 QoS issues are then analyzed between each two sub fields: 4. A proper E2E QoS signalling which insures user continuous services within a mobile environment. 5. The user connectivity to heterogeneous networks which is expected to always comply with the SLA where the user preferences are defined. 6. An inter-working QoS to enable terminal mobility across heterogeneous networks. 7. QoS continuity taking into consideration the mobility across heterogeneous environments. The advanced management information covers the mobility management information (User mobility, terminal mobility, service mobility, network mobility and session mobility), QoS information and AAA information (Authentication, Authorization, and Accounting). 4 Conclusion Evolution of networks and services requires to consider end to end flow while offering transparency of information to the end users.. Users and services are interconnected by several networks which may be trans- organizations. In order to achieve the expected behaviour, means are needed to provide cooperation between different networks in order to achieve end to end QoS. There are already some works aiming to solve QoS problems in one or several aspects of the context. They are SLA, Policy control, QoS classification, MIPv6, SIP, NSIS, IMS, MIH and Diameter. (Detailed descriptions are in Annex A).
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 14 of 67 Figure 9 : Related work for QoS 1. SLA implementation is a mechanism of QoS in the management plane and in the informational dimension. The QoS contract between the provider and the user is static. When dealing with the complexity of the NGN context which contains mobility and heterogeneity, a dynamic contract will most probably become the trend. 2. IMS provides a standardized, well-structured way of delivering services, legacy inter- working and fixed–mobile convergence. TISPAN uses IMS to cater, for fixed network operators, E2E multimedia services. In the TISPAN NGN architecture, not only core networks but also access networks or even terminals on the user side have QoS related control and management functions. In IMS architecture, it uses Diameter to carry the information of authorization, charging etc. The QoS related information can also be mapped to Diameter AVP. IMS is classified as an architectural dimension solution for QoS issue of NGN. It implements the QoS mechanisms in management and control planes, i.e. policy control in the management plane and admission control in the control plane. 3. SIP has been designed in conformance with the Internet model. It is an end-to-end oriented signalling protocol. Moreover, the SIP can filter (select) according to the User Profile to implement application servers before establishment of a session but cannot re-select
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 15 of 67 services during a session SIP is a signalling protocol which is classified into the control plane. For QoS, although the SDP describes the session and negotiates with the QoS requested, it must nevertheless integrate QoS signalling protocol to achieve QoS guarantee for the session. 4. The attributes of Y.1541 QoS Classes encompass major IP application categories; they are able to support QoS negotiation among systems. 5. For the service and network providers, the CPN speeds up broadband deployment and multi-service implementation. More importantly, the QoS related entities in the CPN gives the possibility to deal with the QoS issue on the user side in an End-to-End session with QoS continuity. 6. IEEE 802.21 helps Handover Initiation, Network Selection and Interface Activation during Vertical Handovers for next generation wireless All-IP networks. The 802.21 enables Co-operative Handover decision making between Clients and Network. But how to solve the vertical handover in the wireless and fixed network is not covered in the scope of MIH. 7. Mobile IPv6 allows easier configuration, better security and optimization; it minimizes the control traffic needed to effect mobility. But Mobile IP is not a complete mobility solution; it needs to cooperate with other mobility management protocol. 8. NSIS assumes a scalable architecture signalling in two layers and reuses the existing transport and security. It uses a session ID which is independent of the flow identifier for the state management. The Session ID (SID) used in NSIS signalling enables the separation of the signalling state and the IP addresses of the communicating hosts. This makes it possible to directly update a signalling state in the network due to mobility without being forced to first remove the old state and then re-establish a new one. It works on both control and management planes in a protocol dimension. In the NGN context, the change of route or IP addresses in mobile environments is typically much faster and more frequent than traditional route changes caused by node or link failure. The question is whether NSIS is sufficient for the self-management and self-adaptation to whatever change in the user-centric session? 5 Discussion and next steps Different solutions could be considered to achieve the E2E QoS: To achieve the E2E QoS we can consider (Figure 10) a signalling based solution (such as SIP/SDP, NSIS) or a management based solution (such as DIAMETER or Policy Control) but for a dynamic management as shown in the Figure 11, the convergence of these two solutions should be studied.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 16 of 67 Figure 10 : QoS related work in three planes Dynamic Management Conception E2E QoS Provisioning Transfer Management Instrumentation Monitoring Lifecycle of QoS management Figure 11 : Dynamic management 5.1 Control plane solution: QoS signalling - User QoS requirements information - Identification of InterWorking unit (IWU) - QoS and user-centric E2E session (User case) - SIP - NSIS - Interaction on user system - User E2E Measurement
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 17 of 67 5.2 Management plane solution: QoS interworking - QoS parameters mapping for the demanded QoS of the end user’s preference. - From static SLA to dynamic/proactive SLA (Diameter). - Checking achievement of required QoS inter-working among the different administrate domains which have different releases or types of QoS contract. 5.3 Converging solution: QoS continuity - Trigger parameters for QoS decision - Terminal mobility - User mobility - Service mobility - User E2E Measurement 5.4 QoS informational structure - User profile information details - Environment profile information details Annex A: Current work for QoS Figure 12: Respective current work in three aspects Note: 1’, 2’, 3’ mean the zone not overlaid In the first chapter, we have introduced the three main characteristics of NGN (User, Mobility and Heterogeneity) which are relevant to our frame of work. In this chapter, we will report on the work currently done on each of these three
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 18 of 67 characteristics. In order to clearly show the related work done on QoS along with the increasing complexity of the context, we will begin by considering the zones which do not overlay (numbers 1’, 2’ and 3’ as shown in Figure 12, before considering the zones which overlay (the numbers 4, 5, 6 and 7 as shown in Figure 12). In this chapter, we will also introduce the QoS mechanism in User aspect: SLA (§ 1), and then present the horizontal handover solution when mobility occurs in the homogeneity network (§ 2). Finally, the IMS architecture will be explained as the architectural dimension of the QoS solution for the convergence of the heterogeneity environment (§ 3) A.1. SLA SLA (Service Level Agreement) is an abbreviation often used in the context of contract between business users and their providers. In this document, the meaning of SLA has been extended to cover as well the case of the QoS commitments implied in the provision of telecommunication services to the general public. A.1.1 SLA definition The TeleManagement Forum defines a SLA as “a formal negotiated agreement between two parties, sometimes called a service level guarantee. It is a contract (or part of one) that exists between the service provider and its customer, to create a common understanding about services, priorities, responsibilities, etc...” A.1.2 SLA Life Cycle Figure 13 below shows the SLA life cycle: Figure 13: SLA Life Cycle
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 19 of 67 1. SLA Development: In this phase the SLA templates are developed. 2. Negotiation and Sales: In this phase the SLA is negotiated and the contracts are notified. 3. Implementation: where the SLA is generated. 4. Execution: The SLA is executed, monitored, and maintained. 5. Assessment: Evaluation of the SLA performance. In this phase, a re-evaluation of the initial SLA template might be done. A.1.3 SLA Function First of all, an implementation of a SLA can help service providers (including third-party service providers) and service users to clarify some of the services responsibilities regarding the expected quality. QoS (Quality of Services) indicators should avoid any ambiguity in understanding the quality of service. In addition, in the process of SLA, there is a commitment to quantify the quality of service (QoS indicators), and meanwhile, to perform regular statistics, analysis, reporting and management. Then, the system provides customers with real value added service as well as regular report of the initiative "SLA illegal" regularly. These initiatives can guide the customer to explore the potential consumer demand, to achieve maximum “user benefit”. A.1.4 Conclusion SLA implementation is a mechanism of QoS in the management plane and in the informational dimension. This contract between the provider and the user is static. When dealing with the more complex context of NGN which encompasses mobility and heterogeneity, the trend will be to get a dynamic contract. A.2. Mobility in homogenous network user-unaware QoS is mostly a Connection Admission Control and Scheduling problem, while mobility is a routing problem. In a mobility environment, QoS is rather a problem of how QoS state is re-established in different kinds of mobility? As shown in Figure 12, zone 2’ highlights the mobility in an homogenous network user- unaware. The solution in an homogeneous network is a horizontal handover (HHO). Horizontal handover is defined as handover within same access networks. Generally it is referred to as the Intra-AN handover. Relatively, vertical handover (VHO) is defined as
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 20 of 67 handover across heterogeneous access networks. Generally, it is referred to as the Inter-AN handover . Figure 14 shows the difference between HHO and VHO. Figure 14: Horizontal handover and Vertical handover Horizontal Handover (HHO) The solution for mobility in an homogenous network is an horizontal handover. It refers to a terminal whose location changes i.e. that moves among various access points in one network or moves among different network access points, while maintaining access to one set of services. Such mobility should allow the relocation of the terminal without any break. The change in the point of attachment sometimes temporary disconnects the mobile terminal and disrupts the communications in progress while the objective is to ensure seamless communications. The procedure for horizontal handover is handled mostly in layer 2. A layer 2 handover occurs when a mobile host’s connection changes from one access point to another. The procedure of this type of handover involves releasing the connection from the former access point, establishing a connection to the new access point (though not necessarily in this order), and updating the binding between a mobile host’s IP address and its temporary layer 2 identifier (e.g. a MAC address) on the sub-network at the access router. Two types of procedures are proposed : • Break-before-make handover: the former connection is released before the new connection is established; data reception is interrupted for a short period of time. The service disruption can be avoided. • Make-before-break handover: if the mobile host is capable of establishing
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 21 of 67 connections to multiple access points simultaneously, can connect to the new access point before breaking its connection from the former access point Broadly speaking, the handover will be conducted by analyzing the signal received from the two related cells frame by frame involved and the best frame will be accepted. Several handover definitions have been proposed. For instance, in UMTS (Universal Mobile Telecommunications System) , three different handovers have been defined: hard handover, soft handover, and softer handover.  Hard handover It means that all the old radio links in the UE are removed before the new radio links are established. Hard handover can be seamless or non-seamless. Seamless hard handover means that the handover is not perceptible to the user. In practice a handover that requires a change of carrier frequency (inter-frequency handover) is always performed as hard handover.  Soft Handover It means that the radio links are added and removed in a way that the UE always keeps at least one radio link to the UTRAN. Soft handover is performed by means of macro diversity, which refers to the condition that several radio links are active at the same time. Normally soft handover can be used when cells operated on the same frequency are changed.  Softer Handover Softer handover is a special case of soft handover where the radio links that are added and removed belong to the same Node B. In softer handover, macro diversity with maximum ratio combining can be performed in the Node B, whereas generally in soft handover on the downlink, macro diversity with selection combination is applied. A.3. Heterogeneous environment and QoS The QoS problem in an heterogeneous environment is how to interoperate the QoS state. The policy could be used to adapt QoS according to particular goals in heterogeneous networks. Such policy could be used for:  optimal access network selection in case of handover, routing and connection redirection  resource and service adaptation in heterogeneous network environment
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 22 of 67  management of the interactions between heterogeneous networks for QoS provisioning IP Multimedia Subsystem (IMS) has emerged as an overlay service provisioning platform that operates on a heterogeneous network environment. The IMS is defined by the 3rd Generation Partnership Projects (3GPP and 3GPP2) and is an overlay service architecture that enables the efficient provision of an open set of highly integrated multimedia services, combining web browsing, e-mail, instant messaging, VoIP, video conferencing, telephony, multimedia content delivery, etc. Figure 15 below highlights the topology of the IMS: Figure 15: IMS topology A.3.1 IMS Architecture (3GPP) IMS decomposes the networking infrastructure into separate functions with standardized interfaces. Each interface is specified as a “reference point”, which defines the protocol over the interface and the functions between which it operates. The standards do not mandate which functions should be co-located, as this depends on the scale of the application, and a single device may contain several functions. The 3GPP architecture is split into three planes (Figure 16), each of which is described by a number of equivalent names: Service or Application Layer, Control or Signalling Layer, and User or Connectivity Layer .
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 23 of 67 Figure 16: IMS architecture The service layer consists of application and content servers to execute value-added services for the user. Generic service enablers as defined in the IMS standard (such as presence and group list management) are implemented as services in a SIP Application Server.  configuration storage, identity management, user status (such as presence and location), which is held by the Home Subscriber Server (HSS)  Billing services, provided by a Charging Gateway Function (CGF) (not shown)  Control of voice and video calls and messaging, provided by the control plane. The control layer consists of network control servers for managing call or session set-up, modification and release. The most important of these is the CSCF (Call Session Control Function), also known as a SIP server. This layer also contains a full suite of support functions, such as provisioning, charging and operation & management (O&M). Inter- working with other operators’ networks and or other types of networks is handled by border gateways. At the core of this plane is the Call Session Control Function (CSCF), which consists of the following functions:  The Proxy-CSCF (P-CSCF) is the first point of contact for users with the IMS. The P-CSCF is responsible for security of the messages between the network and the
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 24 of 67 user and allocating resources for the media flows.  The Interrogating-CSCF (I-CSCF) is the first point of contact from peered networks. The I-CSCF is responsible for querying the HSS to determine the S-CSCF for a user and may also hide the operator’s topology from peer networks (Topology Hiding Inter-network Gateway, or THIG).  The Serving-CSCF (S-CSCF) is the central brain. The S-CSCF is responsible for processing registrations to record the location of each user, user authentication, and call processing (including routing). The operation of the S-CSCF is controlled by policy stored in the HSS. Figure 17 below shows the signalling flow path for establishing a call session: Figure 17: Signalling flow path for establishing a call session The call signalling flows from the caller pass through the P-CSCF in the home network to his S-CSCF. The signalling then passes onto the called party via his S-CSCF. Home Subscriber Server: The HSS contains a subscription database for the IMS, including subscription-related information to support the network entities that actually handle calls or sessions. It supports IMS-level authentication and authorization and holds the IMS subscriber profiles. The HSS also stores the currently assigned S-CSCF. Breakout Gateway Control Function: A breakout gateway control function receives session requests forwarded by an S-CSCF or another BGCF, and it selects the network in which PSTN breakout is to occur. It selects a local MGCF or peer BGCF in another network. This ability to select a BGCF in another network provides the capability to optimize routing from the visited network to the PSTN, where desired and supported by the operators involved. Media Resource Function Controller: The MRFC controls the media stream resources
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 25 of 67 of the MRFP. It interprets information from an AS or SIP endpoint and controls the MRFP accordingly to support media services such as trans-coding and conferencing. The MRFC may be collocated with an AS to provide specialized AS services. Media Resource Function Processor: The MRFP provides resources under the control of the MRFC for media processing. It supports media stream mixing, tone and announcement generation, trans-coding, media analysis, and other functions. Subscription Locator Function: The SLF serves as a front-end for distributed HSS systems. It may be queried by an I-CSCF during registration and session setup to get the name of the HSS containing the required subscriber-specific data. The SLF may also be queried by the S-CSCF during registration, or by the AS in conjunction with the Sh interface. The SLF is not required in a single-HSS environment, or in certain other HSS environments such as server-farm architecture. It is also not required when an AS is configured and managed to use a predefined HSS. The connectivity layer comprises routers and switches, both for the backbone and the access network. This infrastructure is designed to provide a wide range of IP multimedia server-based and P2P services. IMS reference points : Cx reference point: Supports information transfer between CSCF and HSS. Gm reference point: Supports communication between the MT and the IMS. Mn reference point: Communication interface between the MGCF and IMS-MGW. Equivalent to the Mc interface in the CS domain. Mg reference point: Allows the MGCF to forward incoming session signalling (from the PSTN) to the CSCF for the purpose of inter-working with PSTN networks. Uses SIP for signalling. Mr reference point: Supports information transfer between CSCF and MRFC. Uses SIP for signalling. Mp reference point: Allows an MRFC to control media stream resources provided by an MRF. Similar to the Mc interface in the CS domain. Mw reference point: Allows the communication and forwarding of SIP signalling messaging between CSCFs. Go reference point: Allows the Policy Decision Function (PDF) to apply policy decisions to bearer usage in the GGSN. The Policy Decision Function (PDF) is a logical entity in the P-CSCF.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 26 of 67 Mi reference point: Allows the Serving CSCF to forward the session signalling to the BGCF for the purpose of inter-working with PSTN networks. Uses SIP for signalling. Mj reference point: Allows the BGCF to forward session signalling to the MGCF for the purpose of inter-working with PSTN networks. Uses SIP for signalling. Mk reference point: Allows the BGCF to forward session signalling to another BGCF. Uses SIP for signalling. Dx reference point: The CSCF and SLF interface is used to retrieve the address of the HSS which holds the subscription date for a given user. Not required in a single HSS environment. Mb reference point: Used to access IPv6 network services for user data transport. ISC reference point: The interface between the CSCF and application servers for access to IMS services. Sh reference point: Used for communication from the SIP or OSA application server to the HSS. Si reference point: Used for communication from the CAMEL application server to the HSS. A.3.2 TISPAN NGN architecture TISPAN uses IMS specified by 3GPP to cater for fixed network operators to provide end to end IP based multimedia services. Figure 18 is the overview of TISPAN NGN functional architecture. The TISPAN NGN functional architecture can be divided into two layers : 1. Service layer, consisting of Application Servers (AS). 2. Transport layer, consisting of the user equipment (UE), Access Network, Next Generation Network (NGN) core. TISPAN adds the transport control sub-layer for registration/ initialization of user equipment (NASS: Network Attachment Subsystem) and reservation the resources from access network (RACS: Resource and Admission Control Subsystem) .
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 27 of 67 Figure 18: TISPAN NGN Architecture The service layer is composed of the following components:  The IP Multimedia subsystem core components. IMS Functional Architecture is specified in  The PSTN/ISDN Emulation Subsystem (PES) .  Other multimedia subsystems (e.g. IPTV , etc.) and applications. It should be noted that the ETSI TC TISPAN also specified another option for the IPTV ar- chitecture than that one defined in . It is based on the support of the IPTV func- tions by the IMS subsystem .  Common components used by several subsystems such as those required for ac- cessing applications, charging functions, user profile management, security man- agement, routing databases etc. In the transport layer: The NASS provides the following functionalities :  Dynamic provision of IP addresses and other terminal configuration parameters;  Authentication taking place at the IP layer, prior or during the address allocation procedure;  Authorization of network access based on user profiles;
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 28 of 67  Access network configuration based on user profiles;  Location management taking place at the IP layer. RACS is the TISPAN NGN subsystem responsible for the implementation of procedures and mechanisms handling policy-based resource reservation and admission control for both unicast and multicast traffic in access networks and core networks. Besides acting as a resource control framework, RACS also includes support for controlling Network Address Translation (NAT) at the edge of networks and assisting in remote NAT traversal. Furthermore, RACS also covers aspects related to the setting and modification of traffic policies, end to end quality of service and transport-level charging. In core network, there are two main types of Border Gateway Function (BGF):  The Core BGF (C-BGF) that sits at the boundary between an access network and a core network, at the core network side;  The Interconnection BGF (I-BGF) that sits at the boundary between two core net- works. On the user side, the User Equipment (UE) consists of one or more user controlled devices allowing a user to access services delivered by NGN networks. Different components of the customer equipment may be involved depending on the subsystem they interact with. As for the Custom Network Gateway (CNG), we will introduce it on detail in § 5.1. A.3.3 QoS issue in the IMS--- Policy control management In the IMS, the procedure of reserving resources for the purpose of QoS provisioning starts with the application indicating its requirements and ends with the resources being committed over the radio channel and into the core network. The IMS must implements resource policy control in the management plane, admission control in the control plane, and makes sure that proper policy enforcement is available in the network for the QoS guaranteed issue. By these network functions, it is ensure that IMS sessions can only be established when enough resources are available. The 3GPP has taken approach to the QoS matter by defining four separate traffic (QoS) classes that will be handled according to the operator’s requirements on each of the traffic classes. The 3G traffic classes are shown in Table 2 below:
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 29 of 67 Table 2: 3G traffic classes defined in the 3GPP Using these classes, the packets can receive different treatment with respect to various QoS aspects such as flow priority or packet drop precedence. In addition, policy can be used to specify the packet forwarding based on various classification criteria. The policy controls the set of configuration parameters and forwarding for each class or admission conditions for flow reservations depending on the QoS scheme used e.g. RSVP, DiffServ. Once the policies for a domain are specified, all new sessions should enforce the QoS policies on the routers before the User Equipment is registred in the IMS. Figure 19 shows the policy-based control in IMS and the Figure 20 shows the message flow in the process of one policy-based session’s establishment with the QoS guarantee . Figure 19: Go interface architecture model (3GPP TS 29.207 R6)
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 30 of 67 Interface Function Protocol Go Provides information to support: COPS - Control of service-based policy "gating" function in GGSN - UMTS bearer authorization - Charging correlation related function Gq Transports policy set-up information between the Diameter application function(P-CSCF) and the PDF Table 3: Policy based control in the IMS Figure 20: Message flows for guaranteed QoS provisioning (1) The P-CSCF receives the SDP (Session Description Protocol) parameters defined by the User Equipment within an SDP offer in SIP signalling. (2) The P-CSCF identifies the connection information needed (IP address of the down link IP flow(s), port numbers to be used, etc.). (3) The P-CSCF forwards the SDP offer in SIP signalling. (4) The P-CSCF gets the negotiated SDP parameters from the terminating side through SIP signalling interaction. (5) The P-CSCF identifies the connection information needed (IP address of the up-link media IP flow(s), port numbers to be used, etc.). (6) The P-CSCF forwards the derived session information to the PDF and requests an
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 31 of 67 authorization token by sending a request for authorization (using Gq Interface). (7) The PDF authorizes every component negotiated for the session. An authorization token is generated by the PDF. (8) The PDF sends the authorization token to the P-CSCF (using Gq Interface). (9) Upon successful authorization of the session the SDP parameters and the authorization token are passed to the UE in SIP signalling. (10) The UE sends an Activate PDP (Packet Data Protocol) Context request to receive the authorization token. (11) Using the Go Interface the Policy Enforcement Point, sends a COPS request to the PDF. (12) The PDF sends the configuration parameters to be enforced by the PEP through the Go Interface. (13) The PEP enforces the policies and sends an activate PDP context response to the UE. (14) The session with guaranteed QoS parameters begins. A.3.4 Diameter A.3.4.1 Policy Charging Convergence In the IMS R7, the policy control function (SBLP) and the flow based charging function (FBC) are combined as an entity Policy and Charging Control function (PCC). The PDF and CRF are integrated into one entity which is called the PCRF. The Policy Enforcement Function (PEF) and Traffic Plane Function (TPF) are enforced in the PCEF. The Gq interface and the Rx interface are integrated as the Rx+ interface, and the Go interface and Gx interface are integrated as the Gx+ interface.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 32 of 67 Figure 21 : Evolution of IMS R7 The effect of such convergence goes beyond the simple addition of the two functions. Indeed, by the fusion of the two functions, a charging coherent with the strategic decision and tactic will be possible. For example, we would have a rule, indicating the charging change on real-time when any QoS change occurs. A.3.4.2 Messages and AVPs Convergence of policy decision and charging (PCRF and PCEF) entities in the Rel-7 makes it possible to transfer the QoS and charging information with homogenous AVPs (Attribute-Value-Pairs) at the same time. The related charging protocols and interfaces are Diameter-based reference point Rx+, Gx+, Gy and Ro. The Gy and Ro interfaces are used for the online charging. We will explain in the following the messages and the AVPs used in the corresponding interfaces.  Messages and AVPs in the Rx+ Interface Reference point Rx+ is between the entities P-CSCF (AF) and PCRF. It enables the transport of application level session information from AF to PCRF, i.e. IP filter information to identify the service data flow for policy control, differentiated charging and media/application bandwidth requirements for QoS control. Four pairs of messages are used in this interface: AA-Request/Answer is used to transfer the session information; Re-Auth-Request/Answer is used to indicate specific re-authorization
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 33 of 67 actions; Session Termination-Request/Answer is used to indicate a session should be terminated. And Abort-Session-Request/Answer is used to indicate that the bearer of the established session is unavailable. As mentioned before, the interface Rx and interface Gq are integrated into the interface Rx+. The former interfaces Rx and Gq are both diameter-based. Therefore, most of AVPs’ definitions in Rx+ are based on Rel-6 with some possible modifications applied to the Rel-7. Figure 22: AVPs in Rx+  Messages and AVPs in the Gx+ Interface Reference point Gx is located between the PCEF and the PCRF. It enables a PCRF to have dynamic policy and charging control over the PCC behavior at a PCEF. Two pairs of messages are used in this interface are: Credit-Control-Request/Answer is used to indicate bearer or PCC rule related events or the termination of the IP CAN bearer, etc. Re-Auth-Request/Answer is used to do the PCC rules provisioning and event triggers for the session, etc. Gx and Go interfaces are integrated into interface Gx+. Go and Gx use different protocols. Go is COPS-based and Gx is diameter-based. Thus the messages used in the Go should be changed into the Gx diameter-based messages. Furthermore, the Gx+ application has its own specific Diameter application (Diameter Credit Control session for an IP-CAN session).
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 34 of 67 Figure 23: AVPs in Gx+  Messages and AVPs in the Gy and Ro Interface The Gy reference point resides between the OCS and the PCEF. The Ro reference point is used between the OCS and CTF (IMS-GW, MRFC, AS). The two reference points allow online credit control for service data flow based charging . There are six pairs of messages in Ro interface: • Credit-Control-Request/Answer; • Re-Auth-Request/Answer; • Capabilities-Exchange-Request/Answer; • Device-Watchdog-Request/Answer; • Disconnect-Peer-Request/Answer; • Abort-Session-Request/Answer.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 35 of 67  Credit Control AVPs Figure 24 : Credit control AVP Figure 24 shows all of the Diameter AVPs defined in the credit-control application. These AVPs could be used in the Credit-Control messages, i.e. CCR/CCA. We are interested in the four AVPs related to user equipment and multiple service which are circled in red: Multiple-Service-Credit-Control; Multiple-Service-Indicator; Requested-Action and User- Equipment-Info. A.3.5 Conclusion The IMS is a standardized NGN architecture for an Internet media-services capability defined by the European Telecommunications Standards Institute (ETSI) and the 3rd Generation Partnership Project (3GPP). The IMS standard is being adopted by a growing number of companies of the telecom community. IMS provides a standardized, well-structured way of delivering services, legacy inter-working and fixed–mobile convergence. TISPAN uses IMS to cater for fixed network operators for E2E multimedia service for fixed network operators. In the TISPAN NGN architecture, not only core network but also access network and even terminal from the user side have QoS related control and management functions. In IMS architecture, it uses Diameter to carry the information of authorization, charging etc. The QoS related information can also be mapped to Diameter AVP. IMS is classified as an architectural dimension solution for QoS issue of NGN. It implements the QoS mechanisms in management and control planes, i.e. policy control in the
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 36 of 67 management plane and admission control in the control plane. A.4. E2E QoS signalling (among the same type of access network): How to make a mobility solution User aware with QoS, in other words, how to design personalized service ensuring seamless QoS when the users and the terminals move? A session based E2E QoS signalling is a solution. IETF has proposed SIP (Session Initiation Protocol) and NSIS (Next Steps in Signalling) as the signalling protocols for session-based service which have their own way to transfer the QoS parameters. In this chapter, we will first introduce SIP protocol (§ 4.1), and then NSIS protocol is presented (§ 4.2) A.4.1 SIP SIP is an application-layer control protocol to create, modify and terminate sessions with one or more participants. It has been designed and developed within the IETF. The specification is available through several RFCs, the most important one being RFC3261 which contains the core protocol specification. It should be noted that 3GPP specified a call control protocol for use in the IP Multimedia (IM) Core Network (CN) subsystem based on the Session Initiation Protocol (SIP), and the associated Session Description Protocol (SDP) [41]. This specification has been endorsed by the ETSI TC TISPAN [42]. Here, the necessary modifications to [41] are provided with respect to the use of SIP/SDP in the NGN. By sessions we understand a set of senders and receivers that communicate and the state of which is kept in during the communication. Examples of a session can include Internet telephone calls, distribution of multimedia, multimedia conferences, distributed computer games, etc. SIP can also invite participants to already existing sessions, such as multicast conferences. Media can be added to (and removed from) an existing session. SIP transparently supports name mapping and redirection services, which supports personal mobility - users can maintain a single externally visible identifier regardless of their network location.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 37 of 67 A.4.1.1 SIP basic functionalities SIP supports five facets of establishing and terminating multimedia communications: • User location: determination of the end system to be used for communication; • User availability: determination of the willingness of the called party to engage in communications; • User capabilities: determination of the media and media parameters to be used; • Session setup: "ringing", establishment of session parameters at both called and call- ing party; • Session management: including transfer and termination of sessions, modifying ses- sion parameters, and invoking services. A.4.1.2 SIP entities SIP uses server/client architecture, the entities in the establishment of a SIP session can be classified into two categories: user agents (terminal) and intermediate servers. Agents (User Agents---UA): These agents usually reside on end-user equipment in form of an application, but can be also user’s terminal, such as phones, PDAs and so on. Intermediate servers: These intermediaries are logical entities through which pass SIP messages to reach the destination. They are used to route and redirect these messages. These servers include: • Register Server (RS) is a database that contains location information of a UAs area. • Proxy Server (PS) is the link between the UA and the RS. It decides next hop and forwards request, relays call signalling, operates in a transactional manner, saves no session state. • Redirect Server that enables proxy server to redirect queries to recipients who are in different domains. Figure 25 shows the relation of each SIP entities:
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 38 of 67 SIP Registar Server SIP Proxy Server A A 1 2 10 SIP User Agent A (Client) 3 9 4 SIP Redirect 8 Server 7 6 SIP Proxy Server Operator’s 5 B SIP User Agent B (Server) Network SIP Registar Server B Figure 25 : SIP entities A.4.1.3 SIP messages and procedure Figure 26 : Session establishment procedure SIP provisioning messages are exchanged for the establishment of the session. During this procedure of initialization (application resources reservation), the negotiation of application types, parameters of the session and capacity of the two interlocutors (end-users)
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 39 of 67 is done (F1 to F12 shown in Figure 26). At the end of the reservation procedure of application resources that starts the transmission of media data. Two protocols that are most often used with SIP are RTP and SDP. RTP protocol is used to carry the real-time multimedia data (including audio, video, and text) and makes it possible to encode and split the data into packets and transport such packets over the Internet. A.4.1.4 SDP Another important protocol is SDP, which is used to describe and encode capabilities of session participants. Such a description is then used to negotiate the characteristics of the session so that all the devices can participate (that includes, for example, negotiation of codec used to encode media so that all participants will be able to decode it, to negotiate the transport protocol used and so on). The purpose of SDP is to convey information about media streams in multimedia sessions to allow the recipients of a session description to participate in the session. SDP is primarily intended for use in an internetwork, although it is sufficiently general that it can describe conferences in other network environments. Thus SDP includes: • Session name and purpose • Time(s) the session is active • The media comprising the session • Information to receive those media (addresses, ports, formats and so on) As resources necessary to participate in a session may be limited, some additional information may also be useful: • Information about the bandwidth to be used by the service • Contact information for the person responsible for the session In general, SDP must convey sufficient information to be able to join a session (with the possible exception of encryption keys) and to announce the resources to be used to non- participants that may need to know. 4.1.5 Conclusion SIP has been designed in conformance with the Internet model. It is an end-to-end oriented signalling protocol which means, that all the logic is stored in the end devices (except
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 40 of 67 routing of SIP messages). For QoS, although the SDP describes the session and negotiates with the QOS requested, it must nevertheless integrate QoS signalling protocol to achieve QoS guarantee for the session. Moreover, the SIP can filter (select) according to User Profile to implement application servers before establishment of the session but can not re-select services during a call. A.4.2 NSIS To fulfill the needs of signalling over IP-based networks, the Internet Engineering Task Force (IETF) developed the Resource Reservation Protocol (RSVP) which is designed and applied to resource reservation for both integrated services (IntServ) and later differentiated services (Diff-Serv), rather than more general signalling services. In 2001, the IETF formed a new working group---Next Steps in Signalling (NSIS), to search for a flexible IP signalling architecture and protocols. As a result, an extensible IP signalling architecture was developed also referred to as NSIS. It consists of two layers: the lower layer provides a generic transport service for different signalling applications (QoS NSLP, NAT/Firewall NSLP, Metering NSLP), which reside in the upper layer. This kind of Two-layer model is used to separate the transport signalling from the application signalling. This allows more flexibility, such as the ability to use standard transport layer and security protocols. In transport layer of NSIS---NTLP (NSIS Transport Layer Protocol), the main composition is known as GIST (General Internet Signalling Transport Protocol). It ensures the transport of signalling messages. The GIST runs on standard protocols for transportation and security. Examples of such transport protocols are UDP, TCP, SCTP (Stream Control Transmission Protocol), and DCCP (Datagram Congestion Control Protocol). In signalling layer of NSIS (NSLPs: NSIS Signalling Layer Protocols), the protocols execute the application-specific signalling. For instance QoS NSLP for reserving resource, NAT / firewall NSLP for configuring middle box and etc. Figure 27 below shows the organisation of NSIS:
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 41 of 67 Figure 27 : Organisation of NSIS A.4.2.1 Logic model and protocol messages Logic model The figure below presents a logical model for the operation of the QoS NSLP and associated provisioning mechanisms within a single node.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 42 of 67 Figure 28 : Logic model for the operation Incoming messages are captured during input packet processing and handled by GIST. Only messages related to QoS are passed on to the QoS NSLP. GIST may also generate triggers to the QoS NSLP (e.g. indications that a route change has occurred). The QoS request is handled by the RMF (Resource Management Function), which coordinates the activities required to grant and configure the resource. It also handles policy-specific aspects of QoS signalling. The grant processing involves two local decision modules: policy control and admission control. Policy control determines whether the user is authorized to make the reservation. Admission control determines whether the network of the node has sufficient available resources to supply the requested QoS. If both checks succeed, parameters are set in the packet classifier and in the link layer interface (e.g., in the packet scheduler) to obtain the desired QoS. Error notifications are passed on back to the request originator. Admission control, packet scheduling, and any part of policy control beyond simple authorization have to be implemented using specific definitions for types and levels of QoS. A key assumption is made that the QoS NSLP is independent of the QoS parameters. These are captured in a QoS Model and interpreted only by the resource management and associated functions, and are opaque to the QoS NSLP itself. The final stage of processing for a resource request is to indicate to the QoS NSLP protocol processing that the required resources have been configured. The QoS NSLP may
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 43 of 67 generate an acknowledgment message in one direction, and may forward the resource request in the other. Protocol messages The QoS NSLP uses four message types: RESERVE: The RESERVE message is the only message that manipulates QoS NSLP reservation state. It is used to create, refresh, modify and remove such state. The result of a RESERVE message is the same whether a message is received once or many times. QUERY: A QUERY message is used to request information about the data path without making a reservation. This functionality can be used for reservations or for the support of certain QoS models. RESPONSE: The RESPONSE message is used to provide information about the result of a previous QoS NSLP message. This includes explicit confirmation of the state manipulation signaled in the RESERVE message, the response to a QUERY message or an error code if the QNE or QNR is unable to provide the requested information or if the response is negative. The RESPONSE message does not cause any reservation state to be installed or modified. NOTIFY: NOTIFY messages are used to convey information to a QNE. They differ from RESPONSE messages in that they are sent asynchronously and need not refer to any particular state or previously received message. The information conveyed by a NOTIFY message is typically related to error conditions. Examples would be notification to an upstream peer about state being torn down or to indicate when a reservation has been pre- empted. QoS NSLP messages are sent peer-to-peer. This means that a QNE considers its adjacent upstream or downstream peer to be the source of each message. QoS NSLP messages contain three types of objects:  Control Information: Control information objects carry general information for the QoS NSLP processing, such as sequence numbers or whether a response is required.  QoS specifications (QSPECs): QSPEC objects describe the actual resources that are required and depend on the QoS model being used. Besides any resource description they may also contain other control information used by the RMF's processing.  Policy objects: Policy objects contain data used to authorize the reservation of re- sources.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 44 of 67 A.4.2.2 QoS Specifications and QoS Models The QoS NSLP provides flexibility over the exact patterns of signalling messages that are exchanged. Various QoS models can be designed, and these do not affect the specification of the QoS NSLP protocol. Only the RMF specific to a given QoS model will need to interpret the QSPEC. A QoS Model defines the behaviour of the RMF, including inputs and outputs, and how QSPEC information is used to describe resources available, resources required, traffic descriptions, and control information required by the RMF. A QoS Model also describes the minimum set of parameters QNEs should use in the QSPEC when signalling about this QoS Model. The QSPEC carries a collection of objects that can describe QoS specifications in a number of different ways. A generic template is defined in and contains object formats for generally useful elements of the QoS description, which is designed to ensure interoperability when using the basic set of objects. All QSPECs should follow the design of the QSPEC template. Figure 28 below illustrates how the QSPEC is composed of up to four QSPEC objects, namely QoS Desired, QoS Available, QoS Reserved and Minimum QoS. Figure 29 : QSPEC Template • QoS Available: it contains parameters describing the available resources. They are used to collect information along a reservation path. • QoS Desired: it contains parameters describing the desired QoS for which the sender requests reservation. • QoS Minimum: it allows the QNI to define a range of acceptable QoS levels by in- cluding both the desired QoS value and the minimum acceptable QoS in the same message.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 45 of 67 • QoS Reserved: it contains parameters describing the reserved resources and related QoS parameters. At each QNE, the content of the QSPEC is interpreted by the Resource Management Function and the Policy Control Function for the purposes of traffic and policy control (including admission control and configuration of the packet classifier and scheduler). A.4.2.3 Conclusion NSIS assumes a scalable architecture signalling in two layers and reuses the existing transport and security. It uses session ID independent of the flow identifier for the state management. The Session ID (SID) used in NSIS signalling enables the separation of the signalling state and the IP addresses of the communicating hosts. This makes it possible to directly update a signalling state in the network due to mobility without being forced to first remove the old state and then re-establish a new one. In the NGN context, the change of route or IP addresses in mobile environments is typically much faster and more frequent than traditional route changes caused by node or link failure. Is NSIS sufficient for the self-management and self-adaptation to whatever change in the user-centric session? A.5. User interface to the heterogeneous network for QoS In the NGN context chapter, we have mentioned the user-centric requirements for the Next Generation Service. We should extend QoS research from core to edge. In such End-to- End session, the user connectivity to heterogeneous network for the service with QoS is considered as an important part of resolving the E2E QoS in the NGN. TISPAN has proposed the Home Networking conception which contains Customer Network Device (CND) and Customer Network Gateway (CNG), to interact with TISPAN NGN for variety of services in the home environment. TISPAN began to cover home devices and home networking issues from 2006 and a specific working group (WG5) was created in TISPAN to develop service requirements, functional architectures and protocols for the entities involved in the home network environment. In this section, we will provide an overview of service scenarios in Home Networking (also named customer premises network or CPN in TISPAN) (§ 5.1.1), the way it interacts
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 46 of 67 with the NGN-IMS networks which is described in the ETSI TISPAN Release 1 standards (§ 5.1.2) and the QoS related blocks in the CPN architecture (§ 5.1.3). A.5.1 Customer Premises Network to TISPAN NGN The use cases can be grouped in the following categories : 1) Broadband connection The user wants to access the Internet from a number of PCs at home, and may also decide to subscribe to new services (e.g. parental control, online audio streaming, etc.) offered by his ISP (Internet Service Provider) or an ASP (Application Service Provider), via email or online. From the service provider point of view, the service must be remotely activated via auto- provisioning, the necessary connectivity to deliver the service, including QoS should be guaranteed and there should be the possibility of remotely debug the customer problems. 2) Communication Communication services can be divided at least in three categories: 1. Person-to-Person communication (P2P) P2P communication is intended as voice or voice/video communication and it could be performed in five different ways: • Voice / VoIP with IP phone • Voice over IP with legacy analogue phone. • Video Communication • Text communication with legacy text telephone • Computer-originated text communication to PSTN The service provider must guarantee the necessary connectivity to deliver the voice, voice/video, or text service, as well as the necessary quality of service. 2. Person-to-Machine communication (P2M) A typical P2M communication use case is, for example to remotely access a device to access the home media server and upload or download one's photos. 3. Machine-to-Machine communication (M2M) One of the typical use cases for M2M communication from the customer network and NGN standpoints is the automatic electricity meter reading business. With this approach, network operators can reuse the NGN security functions in CNG (Customer Network Gateway) and electricity charging server to deliver secure data service between customers'
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 47 of 67 electricity meters and electricity companies' charging servers. 3) Home worker In this use case various members of a family simultaneously use the broadband infrastructure. In particular, parents are connected to their respective corporate intranets over a secure link and perform a number of actions, including upload and download of documents, placing VoIP calls for work. They expect to have a simple mechanism by which they can easily switch from private to corporate calls (billing will be different). While the parents are working, children must be able to watch video streaming, or browse the Internet. All these simultaneous applications have to live up to the experiential expectations of the user. Hence the necessary priorities have to be taken into account within the customer network environment. 4) Home Management and Security Two different sub cases are proposed for this category: The first one is related to the access/parental control. The user wants to make sure that he has an overview on the children communication and entertainment activities and be able to control the access to these activities. An access control service can be built up with the following capabilities: Content check, Cost check, Usage check, Time check. The user must have the capability to check the configuration of the access control service via a terminal (e.g. a PC) and to change the parental control configurations by himself as administrator. From the service provider point of view, a number of mechanisms for service activation, billing and web based consumer support in case of problems must be ensured. The second sub case is to the personal monitoring. In this use case the user must be able to access images coming from a camera installed at home, via an Internet browser on a remote PC or/and via a mobile Internet connection. 5) Provisioning and Service configuration A set of parameters shall be configured on UE (device that contains the SIP UA) to access to IMS network. These parameters should be provisioned on UE in order to the user to make seamlessly the UE registration to IMS. There are four kinds of configurations: • First Provisioning (Manual) • First Provisioning (Automatic) • Manual Re-Configuration • Self Re-Configuration Service 6) Entertainment and information
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 48 of 67 Three specific use case scenarios are proposed for this category. The first one is related to the broadcast IPTV service usage inside the house, the second one to the access the contents stored in a media gateway, the third one to gaming. 7) Remote Access When a user is away from its customer network, it is in many situations valuable to be able to access services on the customer network. Remote access can be divided into two categories: access of devices and access of services. An example of the first category is uploading the latest vacation pictures or films to a storage server on the customer network or when a user sends a message to his home to turn on/off a device. An example of the second category includes accessing a surveillance camera service to check that everything is in order. A.5.2 Service scenarios description In this sub-section, we detail the TISPAN Architectural Model for the CPN and interactions with NGN-IMS entities. The CPN is composed with Customer Network Gateway (CNG) and Customer Network Device (CND) entities. Examples of Customer Network Devices may be connected to the CNG: a) Analog phones connected through the CNG to the NGN network. b) IMS Customer Network Devices connected through a CNG to the NGN network. c) Non IMS SIP IETF Customer Network Devices. d) ISDN Customer Network Devices through the CNG to the NGN network. Different types of Customer Network Devices may be involved in Intra CPN communication through a CNG. The list of Customer Network Devices which are likely to be connected to the CNG is provided by the . The CNG functional entities which are used to interact with TISPAN NGN network are shown in Figure 30 below, as well as the reference points between each function.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 49 of 67 Figure 30 : IMS Customer Network Device connected to the NGN-IMS network through a CNG The entities and interfaces in red are network attachment functions, admission control function, policy control function, authentication function, and location function etc. The entities and interfaces in green are for the transport of the service media. The entities and interfaces in pink are dedicated to the service layer functions. Meanwhile, in the CNG, there are interfaces among the three level entities to allow for exchanges of pieces of information. A.5.3 CPN architecture model interacting with the NGN/IMS networks In the CNG, it has defined some QoS related entities, for instance: 1. CNG-PCF: CNG-Policy Control Function The CNG-PCF may integrate a database containing the access profile. This includes bandwidth and QoS parameters for the CNG Customer Network Device side applications and terminals, which could be configured by a user. For instance, congestion issues within the CPN may be solved defining resources for several SSID. 2. CNG-ACF: CNG-Admission Control Function The CNG-ACF should receive and send QoS messages from/to the CNG-SIP proxy B2BUA Function. In particular it should: a) Check resources availability on each link/device involved in the communication
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 50 of 67 requesting a QoS reservation/allocation, through an internal database ; b) Perform the appropriate resources reservation, through the CNG-PCF. Thus, the CNG-ACF should manage session limitations for instance or the priority of media streams. This applies to upstream flows but there may also be an opportunity to do so for downstream flows. The module is considered as optional (as Gm' and Gm interfaces related to the SIP proxy). The objective is to guaranty the quality of service for each new session and existing sessions previously established. The B2BUA extracts from SIP messages the SDP offer and announced capabilities (codec audio, video, etc.). It asks to the CNG-ACF if announced capabilities are compliant with the available resources. The CNG-ACF module returns 3 responses: a) OK: a) The resource is available for all announced codecs. b) The initial SIP message is forwarded without any change on SDP part. b) OK with restriction: a) The initial SIP message is modified (incompatible codecs are suppressed from SDP part) and then forwarded. b) The session can be established with an acceptable codec for network resource. c) Not OK: a) The B2BUA rejects the session establishment. Figure 31 below shows the procedure of admission control in CNG: Figure 31 : Admission control within the CNG
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 51 of 67 3. CNG-UIF: CNG-User Interface Function The CNG-UIF entity should allow the user to configure many CNG parameters for the transport layer: a) Firewall rules, possibly defined for each user (e.g. parental control); b) CNDs authorized within the CPN, with possible bandwidth restrictions. The operator shall be able to prevent a user from modifying a specific subset of CPN parameters. Thus this entity may have reference points with the CNG-AuF and the CNG-NFF of the CNG. A.5.4 Conclusion For the service and network providers, the CPN speeds up broadband deployment and multi-service implementation. More important, the QoS related entities in the CPN give the possibility to deal with the QoS issue on the user side in an End-to-End session with QoS continuity. Therefore, we should take it into account in our STF 360 work. A.6. QoS Interworking (Mobility in the heterogeneous environment): In the heterogeneous networks, network technologies differ in the bandwidth, latency, cost and QoS classification used. Mobility occurs between these access networks to maintain minimum QoS contracts for different applications. Supporting this seamless mobility, or interconnection and interoperation across the heterogeneous networks (QoS interworking) is seen as one of the key issues in the management of heterogeneous networks. There is already some work done related to this issue, for example, SIP, which we have presented in the precedent chapter and which is proposed as the session based signalling protocol working on application layer to support session mobility. The purpose of the Media Independent Handover is to manage the seamless connectivity with different wireless networks (§ 6.1). Mobile IPv6 is a protocol working on network layer to support not only horizontal but also vertical handover (§ 6.2). The three protocols work on respective layer of OSI, shown in Figure 32.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 52 of 67 Figure 32 : Related work in mobility management in OSI architecure Moreover, QoS class definition which could be interpreted by different network technologies is a key point for QoS interworking. Therefore, Y. 1541 class will be introduced in § 6.3. A.6.1 MIH IEEE 802.21 introduces the concept of MIH (to carry out the handover between heterogeneous technologies). This standard is under development. Its main purpose is to manage seamless connectivity with different wireless networks. This standard is managing the handover between cellular networks, WiFi and Bluetooth etc. A.6.1.1 Media Independent Handover Scope In our context of heterogeneous networks, we must consider the vertical handover because it allows adaptation between different network technologies in a flexible manner. Mobility management is primarily concerned with handover initiation and network selection. Admission control is an inherent part of the handover execution stage and governs access to the chosen network. The MIH is in the scope of the first two steps: handover initiation and handover preparation, as shown in Figure 33. The IEEE 802.21 standard defines the framework that is needed to exchange information between handover participants to provide mobility. It also defines functional components taking handover decision.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 53 of 67 Figure 33 : 802.21 scope A.6.1.2 Media Independent Handover Function The IEEE 802.21 framework offers the method and procedure for handover between heterogeneous networks. This handover procedure uses the information from both mobile terminal and network infrastructures. The IEEE 802.21 framework informs the available network nearby of the mobile terminal and helps the mobile terminal to detect and select the network. This information includes link layer information. Figure 34 : 802.21 Functional Components
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 54 of 67 The core of 802.21 lies in MIHF (Media Independent Handover Function) which plays the role of intermediate operation between layer 2 and layer 3. It presents homogeneous interfaces independent from access technologies. This interface charges the communication between the upper layer and the lower layer. Figure 34 shows the media independent handover functional components. MIHF provides three services: MIES (Media Independent Event Service), MICS (Media Independent Command Service), and MIIS (Media Independent Information Service). • MIES MIES proffers the local or remote event to the upper layer. The MIES supports the transfer, filtering and classification of dynamic changes on the link layer. It may transfer the link level event to the proper application or process and then pass on to the higher layers. The events are generated locally or by a remote peer MIHF entity. Figure 35 shows the framework for both local and remote event exchange. Figure 35 : Media Independent Event Service Link Events are classified into four categories: o State change event, for example, MAC and Physic state change event ( Link_up or Link_down) and Link parameter events which are generated due to change in link parameters (Link Parameter Change) o Predictive events, which provide the likelihood of change in the link properties in future based on present and past conditions (Link Going Down) o Link Synchronous events which provide information about actual link layer activit- ies, like handover decision at the link layer o Link transmission events which indicate the status of the transmission of higher
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 55 of 67 layer PDUs by the link layer Example link events which are proposed in 802.21 are shown in the following Table 4 Table 4 : Proposed link events in 802.21 • MICS The MICS offers the functions to control and manage the link layer. If the MIH application wants handover and mobility, it can control the MAC layer by using MICS to configure, control and get information. Commands flow from higher to lower layers. Figure 36 shows the MICS function framework. MIH users use MIH commands to determine the status of a link. This service enables users to implement an optimal handover policy. Figure 36: Media Independent Command Service
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 56 of 67 • MIIS Figure 37 : Media Independent Information Service The MIIS offers information that is needed to perform the handover. Information is maintained in Information Server in the network (Figure 37). This information includes the name of network and operator, supported QoS, address of point of attachments, available applications and nearby available access networks etc. Information Service can help with Network Discovery and Selection for specific QoS leading to more effective Handover decisions. Table 5 shows the information elements defined in MIIS. Table 5 : Information elements The information is represented in a common form across different networks using TLV (Type, Length, and Value). Figure 38 shows an example of a MIIS message.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 57 of 67 Figure 38 : MIIS Message A.6.1.3 Conclusion IEEE 802.21 helps with Handover Initiation, Network Selection and Interface Activation during Vertical Handovers for next generation wireless All-IP networks. The 802.21 enables Co-operative Handover decision making between Clients and Network. But how to solve the vertical handover in the wireless and fix network is not covered in the scope of MIH. A.6.2 Mobile IPv6 Mobile IPv6 allows a mobile node to move from one link to another without changing the mobile node's "home address". Packets may be routed to the mobile node using this address regardless of the mobile node's current point of attachment to the Internet. The mobile node may also continue to communicate with other nodes (stationary or mobile) after moving to a new link. The movement of a mobile node away from its home link is thus transparent to transport and higher-layer protocols and applications. One can think of the Mobile IPv6 protocol as solving the network-layer mobility management problem. Some mobility management applications -- for example, handover among wireless transceivers, each of which covers only a very small geographic area -- have been solved using link-layer techniques. A.6.2.1 Mobile IPv6 architecture There are some general design requirements for Mobile IP : 1. Detection: the mobile node must detect it has moved 2. Address Configuration: the mobile node must discover or configure its care-of- address 3. Binding Update: the mobile node must inform the home agent about its new care- of address
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 58 of 67 4. Tunnelling: the home agent must forward packets from the home network to the mobile node’s care-of address Figure 39 shows the architecture of Mobile IPv6 Figure 39 : Mobile IPv6 Architecture • Home Agent (HA) A router on the home network which represents the MN while it’s not attached with the home network • Home Address (HoA) A (static) IP address out of the mobile nodes home network • Mobile Node (MN) Could change its point of attachment while still being reachable via HoA • Foreign Agent (FA) A router in the foreign network which represents the MN while it’s attached with the foreign network Unlike in Mobile IPv4, in Mobile IPv6 there are not foreign agents in the foreign network, just the IPv6 router. • Care of Address (CoA)
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 59 of 67 The physical IP address of a MN while visiting a foreign network • Correspondent Node (CN) A peer node with which a MN is communicating, the CN may be either mobile or stationary • Binding Association of the home address with the Care-of address of a MN A.6.2.2 Mobile IPv6 smooth handover process Figure 40 : Mobile IPv6 smooth handover process Mobile IPv6 has four new destination options :  Binding Update Used by an MN to inform its HA or any other CN about its current care-of address  Binding Acknowledgement Used to acknowledge the receipt of a Binding Update  Binding Request Used by any node to request an MN to send a Binding Update with the current care-of address  Home Address Used in a packet sent by a mobile node to inform the receiver of this packet
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 60 of 67 about the mobile node’s home address Figure 40 presents the process of handover when the MN moves between different access networks: (1) MN sends a Binding Update to an HA on previous network (2) HA returns a Binding Acknowledgement (3) HA tunnels packets to MN (4) MN sends a Binding Update to CN A.6.2.3 Mobile IPv6 and QoS In the IPv6 header, it has two QoS-related fields. They are:  20-bit Flow Label Used by a source to label sequences of packets for which it requests special handling by the IPv6 routers Geared to IntServ and RSVP  8-bit Traffic Class Indicator Used by originating nodes and/or forwarding routers to identify and distinguish between different classes or priorities of IPv6 packets Geared to DiffServ Moreover, Mobile IPv6 has a new IPv6 option: QoS Object. QoS Object describes QoS requirement, traffic volume and packet classification parameters for MN's packet stream Included as a Destination Option in IPv6 packets carrying Binding Update and Biding Acknowledgment messages A.6.2.4 Conclusion Mobile IPv6 allows easier configuration, better security and optimization; it minimizes the control traffic needed to effect mobility. But Mobile IP is not a complete mobility solution; it needs to cooperate with other mobility management protocol. A.6.3 Y.1541 and Y.1541-QOSM A.6.3.1 Y. 1541 Class Y.1541 QoS classes quantify user application needs in terms of IP network performance. ITU-T Y.1541 QoS classes are defined based on metrics defined in ITU-T Y.1540. Y. 1540 defines four criteria: IP Packet Transfer Delay (IPTD): upper bound on the mean end-to-end delay. IP Packet Delay Variation (IPDV): upper bound on the 1-10-3 on the IPTD minus the minimum IPTD.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 61 of 67 IP Packet Loss Ratio (IPLR): upper bound on the packet loss probability. IP Packet Errored Ratio (IPER): upper bound on the number of corrupted packets per total packets sent. Figure 41 presents the detail information of 8 QoS classes of Y.1541 : Figure 41 : Y.1541 IP QoS Class Definitions and Network Performance Objectives These classes enable SLAs to be defined between customers and network service providers with respect to QoS requirements. The service provider then needs to ensure that the requirements are recognized and receive appropriate treatment across network layers. A.6.3.2 Y.1541-QOSM QoS model (QOSM) for NSIS QoS signalling layer protocol (QoS-NSLP) application is based on ITU-T Y.1541 Network QoS Classes and related signalling requirements . Y.1541 currently specifies 8 classes of Network Performance objectives, and the Y.1541- QOSM extensions include additional QSPEC parameters and QOSM processing guidelines. Figure 42 shows the translation considerations of QoS Model to Y. 1541 and Y. 1541-QOSM, also the specific parameters in other standards (802. 16, 802.20)
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 62 of 67 Figure 42 : Translation of QoS Metrics to other specific parameters A.6.3.3 Conclusion The attributes of Y.1541 QoS Classes encompass major IP application categories, relate to IP network QoS mechanisms, and are able to support QoS negotiation among systems. Therefore, Y.1541 QoS class meet the need for QoS interworking.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 63 of 67 Annex B: Standard & Bibliographical References [1] ETSI EG 202 132 V1.0.0 (2004-08): Human Factors (HF); User Interfaces; Guidelines for generic user interface elements for mobile terminals and services [2] TeleManagement Forum, http://www.tmforum.org [3] ITU-T Recommendation Q.1706/Y.2801 (2006), Mobility management requirements for NGN [4] J.Manner, M.Kojo et al. RFC 3753: Mobility Related Terminology, June 2004 [5] 3GPP TR 25.832 V4.0.0 (2001-03): "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Manifestations of Handover and SRNS Relocation (Release 4)" [6] Grilles Bertrand, “The IP Multimedia Subsystem(IMS)-An overview” [7] ETSI TS 123 228 V8.6.0 (2008-10): "Digital cellular telecommunications system (Phase 2+); Universal Mobile Telecommunications System (UMTS); LTE;IP Multimedia Subsystem (IMS); Stage 2(3GPP TS 23.228 version 8.6.0 Release 8)" [8] ETSI ES 282 001 V2.0.0 (2008-03) NGN Functional Architecture [9] ETSI TS 129 208 V6.7.0 (2007-06): Digital cellular telecommunications system (Phase 2+); Universal Mobile Telecommunications System (UMTS); End-to-end Quality of Service (QoS) signalling flows (3GPP TS 29.208 version 6.7.0 Release 6)"
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 64 of 67 [10]Th. Magedanz Senior Member IEEE, F.C. de Gouveia, “IMS-the IP Multi- media System as NGN Service Delivery Platform”, Bektrotechnik & Inform- ationstechnik (2006), pp. 271-276 [11]ETSI TS 129 214 V8.2.0 (2008-10): "Universal Mobile Telecommunica- tions System (UMTS);Policy and charging control over Rx reference point (3GPP TS 29.214 version 8.2.0 Release 8)" [12]ETSI TS 129 212 V8.1.0 (2008-10): "Universal Mobile Telecommunica- tions System (UMTS);Policy and charging control over Gx reference point (3GPP TS 29.212 version 8.1.0 Release 8)" [13]RFC 4006: Diameter Credit-Control Application (2005-08) [14]RFC 3261: SIP(Session Initiation Protocol) (2002-06) [15]RFC 2327: SDP(Session Description Protocol) (1998-04) [16]RFC 4080: NSIS Framework, June 2005 [17]NLSP for QoS : http://www.ietf.org/html.charters/nsis-charter.html [18]QoS NSLP QSPEC Template : http://www.ietf.org/html.charters/nsis- charter.html [19]ETSI TS 185 005 V2.0.0 (2007-07): "Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); Services requirements and capabilities for customer networks connected to TISPAN NGN". [20]ETSI TS 185 006 V2.0.0 (2008-03): "Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); Customer Devices architecture and Reference Points" [21]IEEE 802.21: Media Independent Handover; QOS Framework and para- meters, February 17, 2006
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 65 of 67 [22]RFC 3344: Mobility Support in IPv4, (2002-08) [23]RFC 3775: Mobility Support in IPv6, (2004-06) [24]ITU-T Y.1541: Network Performance objectives for IP-based services, (2006-02) [25]IETF Y.1541-QOSM -- Y.1541 QoS Model for Networks Using Y.1541 QoS Classes, (2008-02) http://tools.ietf.org/html/draft-ash-nsis-y1541-qosm-00 [26]ETSI TS 129 213 V8.1.1 (2008-11) "Digital cellular telecommunications system (Phase 2+); Universal Mobile Telecommunications System (UMTS); Policy and charging control signalling flows and Quality of Service (QoS) parameter mapping (current version: 3GPP TS 29.213 version 8.1.1 Release 8)" [27]ETSI TS 123 234 V7.7.0 (2008-06): Universal Mobile Telecommunications System (UMTS); 3GPP system to Wireless Local Area Network (WLAN) in- terworking; System description (current version: 3GPP TS 23.234 version 7.7.0 Release 7) [28]ETSI TS 123 207 V7.0.0 (2007-06): Digital cellular telecommunications system (Phase 2+); Universal Mobile Telecommunications System (UMTS); End-to-end Quality of Service (QoS) concept and architecture (current version: 3GPP TS 23.207 version 7.0.0 Release 7) [29]ETSI TS 129 208 V6.7.0 (2007-06): Digital cellular telecommunications system (Phase 2+); Universal Mobile Telecommunications System (UMTS);End-to-end Quality of Service (QoS) signalling flows (current ver- sion: 3GPP TS 29.208 version 6.7.0 Release 6) [30]RFC 2748: “The COPS (Common Open Policy Service) Protocol,” IETF, Tech. Rep., 2000.
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 66 of 67 [31]ITU-T Y.1251 General architectural model for interworking, 08/2002 [32]ITU-T H.360: An architecture for end-to-end QoS control and signalling, 03/2004 [33]RFC 4094: Analysis of Existing Quality-of-Service Signalling Protocols may 2005 [34]ETSI ES 282 004 V2.0.0 (2008-02): “Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); NGN Functional Architecture; Network Attachment Sub System (NASS).” [35]ETSI ES 282 003 V2.0.0 (2008-05): “Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); Resource and Admission Control Sub-system (RACS); Functional Architec- ture” [36]ETSI ES 282 007 V2.1.1 (2008-11): “TISPAN: IP Multimedia Subsystem (IMS): Functional Architecture.” [37]ETSI ES 282 002 V1.1.1 (2006-03): "Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); PSTN/ISDN Emulation Sub-system (PES); Functional architecture" (see also TS 182 012) [38]ETSI TS 182 028 V2.0.0 (2008-01): "Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); IPTV Architecture; Dedicated subsystem for IPTV functions" [39]ETSI TS 182 027 V2.0.0 (2008-02): "Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); IPTV Architecture; IPTV functions supported by the IMS subsystem"
    • ETSI/USER-STF Steering Group Meeting UG_STF_SC_05r2 Sophia Antipolis, 12 January 2009 page 67 of 67 [40]3GPP TS 24 229 V2.0.0 (2002-02): "3rd Generation Partnership Project; Technical Specification Group Core Network; IP Multimedia Call Control Protocol based on Session Initiation Protocol (SIP) and Session Descrip- tion Protocol (SDP) Stage 3 (Release 5)" [41]ETSI ES 283 003 V1.1.1 (2006-07): Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); IP Multimedia Call Control Protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP) Stage 3 [3GPP TS 24.229 (Re- lease 7), modified] [42]ITU-T Y.1540 (11/2007): Internet protocol data communication service – IP packet transfer and availability performance parameters.