Download Project Title: UbIquitous mobile Communication in diStance

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:
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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:
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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
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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.
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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:
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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
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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:
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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
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aligned with the mobility management to ensure the efficient usage of network
resources along the path. We focus on the following topics:
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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:
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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
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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
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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
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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
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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
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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]
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