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Project Proposal Mobile access to interactive multimedia applications over the Internet Version 0.5 2000-11-01 1. Motivation The rapid growth and evolution of wireless networks and the uncontested success of the Internet will result in ubiquitous access to the Internet independently of time and location. An important issue in the Internet, and consequently in every network connected to it, is the support for multimedia applications. However, wireless/mobile Internet access brings in a number of complications on the network level that are not well considered for the usage of those applications. These complications include: the available bandwidth is narrow (especially during movements) in comparison to wireline access communication conditions such as error rate change dynamically due to the effect of fading on small devices, the capabilities are restricted due to portability In this context, the support of interactive multimedia applications has additional requirements: asynchronous traffic patterns for upstream/downstream real-time support for both, short-lived interactions and content delivery mostly one-to-many multicast communication pattern Our project focuses on network topics for mobile access to interactive multimedia applications (e.g. intelligent online classrooms, interactive games, interactive TV and radio, online customer care) with respect to multicast, mobility management, Quality of Service (QoS) support, routing, and their interrelationship to each other, see Figure 1. multicast routing mobility management Quality of Service Figure 1 1 The goals of this project are twofold. First, the networking requirements for seamless mobile access to interactive multimedia applications will be examined with respect to 3rd and 4th (and beyond) generation of wireless networks. The applicability of IP centric functionality with respect to multicast, QoS support, mobility management, and routing is investigated to derive solutions, which could also be seen as building blocks for future generation of all IP-based wireless networks. Second, after prototypical implementations, a real scenario based on an intelligent classroom application is set up to verify our achieved results. 2 2. Research Evolving Internet technologies and the current effort to increase the capacities of the access networks (especially for wireless networks), as well as the core network create the vision of ubiquitous access to interactive multimedia applications independently of time and location. We assume the following constraints: an arbitrary number of users at any time different simultaneous downstream media streams (audio, video) arbitrary number of upstream user interactions (text, audio) different wireless technologies for access networks devices with different capabilities concerning processing power, display and memory size. Within this context the proposal is concentrating on the 4 topics Multicast, Mobility, QoS, and Routing and their interrelationship within a provider domain without neglecting the end-to-end scope. Currently, these topics are discussed rather autonomously in the appropriate working groups of the IETF (Internet Engineering Task Force). That means their interrelationship is only considered where necessary (e.g, routing and mobility), but not in a broader sense for mobility and interactive media streaming. Therefore we focus on the examination of these topics with respect to wireless LANs, 3 rd and 4th (and beyond) generation networks. The seamless support for mobile access of interactive multimedia application on the Internet is subject of the IP layer (and above) and the specific wireless access network technology. Therefore it is necessary to explore this issues from several perspectives, see Figure 2. Mobile Node QoS support multicast mobility routing QoS support multicast mobility routing Mobile Network QoS support multicast mapping and mobility provisioning routing Server wireless access network QoS support multicast mobility routing Server Internet backbone 3rd, 4th generation, others Figure 2 3 The most important issues are: the major IP centric building blocks for the envisioned scenario (multicast, mobility, QoS, and routing) must be adapted to specific wireless access network technologies without loosing the end-to-end scope although the main focus of the networking effort is to support seamlessly interactive multimedia applications, the inter-working of the major IP centric building blocks must be guaranteed for all sort of applications and communication pattern. Multicast Most interactive multimedia applications use a one-to-many communication model. This means that several streams of data have to be delivered from a specific source to many recipients. Most of these streams will be live audio or video. With live content, this data must be delivered to the recipients at about the same time. To make efficient use of the network resources, it is crucial to use some form of multicast. With multicast, two trends can be observed: Application level multicast and IP multicast. Application level multicast uses streaming proxies, as often used by content delivery networks. This technique avoids the complexity at the network level and the requirement to support IP multicast for any intermediate network at the cost of additional servers in the access network (connected to a certain overlay network in the Internet backbone), necessary configuration management, and mostly inefficient network resource usage via unicast. On the other hand IP multicast is very efficient with respect to network resource usage, but is rather complicated and not well deployed throughout the Internet. The efficient usage of the resources of wireless access networks with a combination of both approaches with respect to QoS and mobility support without neglecting the end-toend scope is the main objective of the multicast work package. We focus on the following topics: development of a framework to support both multicast approaches either seamlessly working together along the end-to-end path or dynamically selection of one during the initial phase specification of multicast deployment with respect to different wireless access networks development of an efficient group membership management with respect to mobile scenarios including mobile devices and networks Quality of Service Interactive multimedia applications have specific requirements in terms of delay and bandwidth. Especially on wireless links with their restrictions concerning bandwidth and error rates, we assume the necessity of resource reservations in advance to cope with different network situations at different locations. Resource reservations in advance require signaling to the network including a quantitative description for the requested service. Neither exists this quantitative description on IP layer for wireless networks, nor exists the necessary mapping to the most important current and future wireless access technologies. Furthermore, any solution for resource reservation in advance must be 4 aligned with the mobility management to ensure the efficient usage of network resources along the path. We focus on the following topics: development of a framework for reservations in advance with respect to different wireless technologies specification and evaluation of the framework with respect to 3rd and 4th generation wireless access networks specification of the mapping of the framework to IP QoS mechanism (e.g. Differentiated Services (DiffServ) and/or Multi Protocol Label Switching (MPLS) ) on the access core network and/or Internet backbone derivation of the necessary parameters for the quantitative description of the service class with respect to mobility and wireless access technologies examination of the applicability of end-point admission control mechanism for shortlived interactive flows Mobility Management The term mobility management refers to the capability of a network to route packets to and from mobile nodes. Frequently changed routes across provider and technology boundaries have a big impact on the multicast tree, the underlying routing mechanisms, and available QoS on the involved routes. Mobile access to interactive multimedia applications requires at least fast handoffs, fast routing table updates, and fast multicast group membership mechanisms. Furthermore, mobility management must be aligned to support resource reservation strategies to ensure a certain service level along the path of a mobile node or networks. We focus on the following topics: definition of a framework for a hierarchical mobility management incorporating the QoS in advance framework specification of fast handoffs with respect to the QoS in advance framework performance analysis of the TCP/ UDP / IP protocol suite for vertical and horizontal handoffs (different technologies, different provider) examination of the applicability of MPLS for mobility management Routing IP Routing refers to the path selection for the packet forwarding process and to maintain the tables on which this selection is based on. Currently, certain metrics are used to select the shortest path between the router and the destination and routing protocols keep this information up to date. The approach to separate the packet forwarding and routing table update was motivated by saving processing power and by wired networks, where routes are not changed very often. This does not apply for wireless access networks at all. Combining the forwarding process and routing table updates within access networks is a promising technology to provide a solution for fast table updates without distorting the packet forwarding process. This mechanism is referred to as active routing. We are restricting the scope of active routing to the access network, because routing table updates triggered by incoming packets require a trustworthy scenario, which is likely be provided only within a single provider domain. Furthermore, frequent routing table 5 updates will happen much more likely in the access networks as in the Internet backbone. We focus on the following topics: definition of framework for active routing for wireless access networks including mechanisms for mobile ad-hoc networks (i.e. network in a car) specification of necessary building blocks for active routing comparison of performance parameters for active and traditional routing Our overall architecture is depicted in Figure 3. The egress and ingress devices mark the boundary of the wired part of the wireless access network. For instance in GPRS, they are referred to as SGSN and GGSN. Similarities apply for other wireless access networks. Base Stations Server Site 1 Provider 1 egress device Server Site Internet backbone ingress device core Site 2 Provider 1 Site 1 Provider 2 Figure 3 6 3. Application To verify our achieved results for the mobile access to multimedia application, we are using a real application in the context of distance learning. Nevertheless, the developed network architecture is neither related only to this application, nor does it prevent from any usage of other applications or services. Distance learning is composed of asynchronous activities for retrieval of lectures and synchronous activities for online sessions (active participation in lectures and tutorship). We assume most activities are asynchronous, nevertheless provision of direct interactions between the students and the teaching entity is a major issue of an integrated solution in such a scenario. Therefore, the seamless support from the network for both kinds of online interactions enables the creation of an intelligent classroom. We assume to use available applications and enhance and optimize them for the following features: computer assisted support of the teaching entity during synchronous mode (e.g. online request filtering and storage, media conversion from text to voice and vice versa) efficient and automated recording and storage for the different media types user-friendly retrieval system class room device handling (automated setup and usage during online sessions) virtual meeting rooms for students for collaborative working provision of an appropriate user interface adaptable to the capabilities of different end systems ranging from cellular phones up to multimedia PCs use of adaptation mechanisms to cope with heterogeneous network conditions (e.g. hierarchical video coding) provision of novel monitoring and analysis functions “easy to use” built-in features (encryption, user authentication) for security The system has to be flexible enough to cover different learning specifications (e.g. university degree courses, company courses, and individual customer care instruction lectures) with respect to the number of users, security aspects, and communication patterns. The overall scenario is shown in Figure 4. Intelligent Class Room ICR enhanced Internet architecture ICR Server Figure 4 7 4. Project Based on the worldwide significance of the project we propose a new collaboration model between leading research institutions and companies from Europe and USA. The linkage between both worlds will be provided by the International Computer Science Institute (ICSI). The ICSI is an independent, non-profit basic research institute affiliated with the University of California Berkeley (UCB). ICSI, founded in 1988, provides an open, international platform for industrial and academic researchers in computer science and engineering. The Institute receives support from a range of international collaborations, US Federal grants and direct industrial sponsorship. We assume synergy potential in the common work of European and US companies and universities. Furthermore the project will help to understand the requirements of distributed projects. This is an important key element for the European industry with respect to the emerging globalization trend. The different categories of the involved partners is shown in Figure 5. European companies research institutions European sponsors of ICSI European sub-contractors Contributions Co-ordination P R O J E C T Results US companies and research institutions (US funding) Figure 5 The following partners are considered to be potential members of the Consortium. All of them have significant experience and available results in specific topics of the proposal. European companies and research institutions: universities from Germany, Spain, and Sweden DaimlerChrysler, Germany 1 Frauenhofer Gesellschaft 8 1 GMD, Germany Iberia, Spain KPN, Netherlands Tekes National Technology Agency of Finland, Finland Siemens, Germany 1 with locations in USA US companies and research institutions AT&T Cisco Georgia Institute of Technology University of California Berkeley (UCB) The project will help to understand the requirements of mobile access to interactive multimedia application on the Internet. We identify 4 building blocks which should be explored with respect to both, the requirements of the applications and the wireless access via different wireless technologies. Special attention is on the 3rd and 4th generation of wireless networks. The deep theoretical examination via simulations, the practical examination via prototypes and the investigation of a real field trial guarantees the best results for practical usage. Major focus is the dissemination of the results to standardization bodies (e.g. IETF). The provision of a seamless solution for multimedia content delivery from the Internet for the next generation of wireless networks is of major interest for providers, because these networks rely heavily on the provisioning of new services (besides voice) due to their huge costs. With this specific application of an intelligent classroom as an example of an interactive multimedia application the results will be beneficial to communities, companies and residents, because it helps to save travel expenses, to save space in the class rooms, and to reduce archiving and teaching preparation costs. In addition, the integrated solution for the intelligent classroom will help to simplify the use of the “online classroom” thus saving costs in device and classroom setup. The sharing of lectures and teaching material between faculties of different universities is of major interest and this application aims to be a solution for this important topic. Furthermore, a well-accepted integrated solution for the “online classroom” will increase the online access, thus reducing commuter traffic, especially in cities with universities. Despite the fact that the “online classroom” is not typical accessed by moving users, the selection was motivated by the following reasons: typical representative of an interactive multimedia application the importance and the ongoing effort in many institutions on this topic enabling easy access and setup of field trials The collaborative work of companies and research institutes from Europe and USA will help to understand the requirements of service provisioning over the current Internet with its heterogeneous provider and networking technology. Future research topics for our scenario could deal with language translation for the retrieval system, online language translation, and automated computer-based teaching in 9 virtual classrooms on the application level. Another topic could be the integration of our system into e-commerce applications. But these topics are out of scope of the current proposal. The project is considered for a duration of 3 years with an estimation of 72 MY in total. Contact: Joachim Sokol Siemens AG, ZT IK2 / Int. Computer Science Institute Tel.: +1 510 666 2921 [email protected] 10 11