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Workshop on "End-to-End QoE/QoS" |
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Abstracts |
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Workshop on "End-to-End QoE/QoS"
Geneva, 14-16 June 2006
Contact: tsbworkshops@itu.int
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Session 1: Introduction and tutorial session |
Speaker: Sebastian Möller, Deutsche Telekom Labs, TU Berlin and Alexander Raake, Deutsche Telekom Labs, TU Berlin
Title of Presentation: A taxonomy of quality prediction models recommended by the ITU-T
Although it is well-known that valid and reliable measurements of quality require the involvement of human (test) users, the
ITU-T currently recommends a set of quality prediction models in order to gain estimates of quality in the network planning,
set-up and operation phases, e.g. in Rec.s P.862, P.862.2, P.562, P.563 and G.107. Such models estimate average quality judgments
which could have been given by prototypical users, either for a one-way voice transmission situation, or for a (two-way) speech
communication situation. Estimates are based on one or several signals extracted from prototypical implementations, on signals
or protocol information logged in operating networks, or on parameters which have been extracted from such measurements or which
are assumed for network planning. The quality estimates are called “objective” measures – in contrast to “subjective” judgments
obtained from test users.
In the presentation, we will provide an overview of the existing and of future models, and classify them according to a taxonomy
of quality prediction models. It will be shown that the classical differentiation between “objective models” and “network planning
models” is not really justified. Instead, it is proposed to make use of the taxonomy to guide users of the different quality
prediction approaches. The model predictions are analyzed with respect to potential sources of errors, and necessary accuracy
analyses are pointed out.
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Speaker: Volker Sypli, Federal Network Agency (Germany)
Title of Presentation: Overview on ITU-T Handbook on QoS and Network Performance
This presentation provides a brief summary and explanation of the recently updated ITU-T Handbook on QoS and Network Performance.
The Handbook offers an overview about the terms, issues and trends in the provisioning of QoS. It was created for providing an
introduction to the QoS framework established by various ITU-T Recommendations and a basis for the development of QoS and
Network Performance assessment and measurement strategies.
The presentation also gives an outlook on present activities within ITU-T Study Group 2 that have been started as continuation
of the QoS work after finalizing the Handbook.
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Session 2: Inter-domain QoS |
Speaker: Olivier Dugeon FTR&D
Title of Presentation: End-to-end QoS over heterogeneous network
The IST/EuQoS project release its first set of architecture in order to provide an initial view on how end to end QoS is provided
over multiple and heterogeneous networks. The EuQoS end to end Architecture has two views; a network deployment view across a
number of autonomous systems (AS) domains and a software view within an AS. It was funded on a division of the end to end QoS
paradigm along a vertical axis - Service, Control and Transport plane – and an horizontal axis – network division between the
various technology especially Core and Access networks. The solution is based on the concept of end to end path build, used
and managed by three processes: Provisioning, Invocation and Operating Maintenance (OAM).
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Speaker: Kathleen Nichols (Pollere LLC)
Title of Presentation: Border Crossings: Evolving Interdomain QoS in a Heterogeneous World.
Delivering IP QoS via Differentiated Services depends critically on what happens at the network borders. Even though there are
only a small number of packet treatments available inside a network, border controls allow a service provider to construct a huge
range of sophisticated services. IETF RFCs 2475 and 3290 have standardized the basic border control building blocks but the lack
of standardized methods for composing, configuring and controlling these mechanisms has become the main barrier to progress in
IP QoS. This talk will describe a simple, scalable architecture that allows construction, communication, quantification and
enforcement of traffic service agreements between domains of very different capabilities and internal structure.
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Session 3: Interoperability testing and terminal issues
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Speaker: H. W. Gierlich, HEAD acoustics GmbH
Title of Presentation: Speech Quality Testing for VoIP Terminals and Gateways: Input from ETSI “Plugtest” Speech Quality Test Events
The speech quality tests as organized by ETSI “Plugtest” are single vendor tests and not interoperability tests between
different manufacturers. Speech quality measurements are performed on the VoIP equipment of participating manufacturers.
The idea behind the ETSI VoIP test events is to measure, analyze and compare speech quality parameters for VoIP equipment.
All conversational aspects like speech sound quality, echo measurements, double talk performance and the transmission quality
in the presence of background noise are considered. In addition typical network impairments are considered.
As a result every manufacturer receives his individual test result including detailed information about potential improvements.
The test results of all participants achieved under identical conditions are summarized in an anonymous test report. Comparison
can be made between the individual results achieved by each manufacturer and to the published results the results of former SQTEs.
The testbed and the test procedures are introduced, typical results will be discussed.
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Speaker: William Lupton (2Wire)
Title of Presentation: The TR-069 protocol and its ability to manage QoS policies on the CPE
The DSL Forum’s TR-069 remote management protocol is being widely implemented and deployed. The TR-069 Internet
Gateway Device data model gives the service provider fine-grained control over the Gateway’s QoS policy, and other
TR-069 data models, such as TR-104 for VoIP phones, allow control of QoS settings on managed end devices.
This presentation gives an overview of the DSL Forum’s DSLHome initiative, of TR-069 and related standards,
and of TR-069 data model support for managing QoS policy.
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Session 4: Home Networking QoS/QoE
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Speaker: Duncan Bees, PMC-Sierra
Title of Presentation: Home Gateway Initiative QOS Architecture
The Home Gateway Initiative (HGI) is an open forum comprised of telcos and manufacturers. The aim of HGI is to release
specifications for the home gateway that enables end to end delivery of services. The QOS group within HGI has developed a
QOS strategy for the HGI Release 1 comprising traffic classification, queuing, and management of QOS functions within the
gateway. Our strategy ensures reliable delivery of value added services while enabling interaction with the subscriber’s
existing home networks, and provides a foundation for more advanced QOS features in future HGI specifications.
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Speaker: Michael van Hartskamp, Philips
Title of Presentation: Home Network QoS with UPnP-QoS
IP-based home networking is becoming increasingly popular. This home network
is based on both wired and wireless technologies. For a successful growth
into a mass-market, a QoS solution is needed. The problem of achieving QoS
is complicated by the heterogeneity in layer 2 technologies and the
heterogeneity in home networking devices from different manufacturers and
vendors.
A standardized solution for discovery and description of the QoS
capabilities in the home network is therefore needed. In the UPnP forum,
UPnP-QoS was developed to provide such a solution.
The UPnP-QoS versions 1 and 2 bring policy-based prioritized QoS to the
home. The ongoing work on version 3 brings QoS management to users on the
basis of admission control and scheduled access.
In this presentation we review the problem of home network QoS and how the
various flavors of UPnP-QoS address the problem.
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Session 5: QoE
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Speaker: Kamal Ahmed, TNO Information- and Communication Technology, the Netherlands
Title of Presentation: Perceived quality of channel zapping
The end user experience of service quality is critical to the success of a service provider’s IPTV deployment program. A
key element involved in validating IPTV quality of experience (QoE) is how quickly and reliably users can change TV channels,
often referred to as channel zapping. Currently there is no knowledge about the explicit relation between zapping time and the
user perceived quality as expressed as a Mean Opinion Score (MOS). We have proposed a model where the MOS depends on the zapping
time on a logarithmic scale. In order to validate our model we have conducted a number of subjective tests in order to get
insight in this relation. The tests were performed by 21 test subjects at TNO and at ACREO (Sweden). It turns out that the
correlation between the subjective data and the perceptive model is very high (0.99). Therefore we conclude that our perceptive
model is very useful for assessing the perceived quality of zapping.
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Speaker: Frédéric Gabin, NEC Technologies (UK) Ltd.
Title of Presentation: 3GPP Packet Switch Streaming Quality of Experience
In this presentation we are addressing the QoE aspects of the 3GPP Packet Switch Streaming (PSS) service. After focusing on voice,
video-telephony and plain IP data connectivity, 3GPP identified streaming as a strong requirement from 3G operators.
Streaming is available over the web for a long time and the challenge was to offer the same service to users on their mobile
terminals. The 3GPP PSS service provides a client-server framework to operators and service providers in order to offer real-time
audio/video and multimedia content over 3G mobile networks. The service, as seen from the user point of view, requires that session
establishments are short, content of good quality, with good rendering quality and unnoticeable radio impairments. PSS protocols,
formats, codecs and radio bearers are designed to enable this seamless experience.
After first PSS services were deployed, standards tools to evaluate the user experience were seen as essential for network
tuning and customer care. The PSS QoE metrics were specified to enable operators to monitor some aspects of the user experience
(e.g. initial buffering time, frame rate deviation). Both the PSS and QoE were recently reused within 3GPP broadcast service
specifications.
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Speaker: M. Angela Sasse & Hendrik Knoche
Title of Presentation: Quality of Experience in Mobile TV Services
Mobile TV Services are becoming increasingly common, but users are not always satisfied with the Quality of Experience.
Over the past 3 years, we have conducted a series of experiments to investigate how the Quality of Experience can be improved.
Our results show that factors that influence the quality experienced vary by content type and the type of device on which
are viewed. There are minimum requirements for different types of content in terms of encoding bandwidth, image resolution,
video frame rates, and image size. We have also investigated the impact of specific techniques for improving news content
(where text legibility is paramount) and sports content (where some shot types are more problematic than others). Our research
shows that to deliver an acceptable QoE, a service needs to be carefully configured for its intended audience, content, and mobile
device on which the content is consumed.
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Speaker: Luis Sousa Cardoso, Portugal Telecom
Title of Presentation: Quality and Security Usability
Telecommunications industry's customers are demanding comprehensive security solutions. A secure network should be protected
against malicious and inadvertent attacks and should have high availability, appropriated response time, reliability, integrity,
scalability, and provide accurate billing information. Security must not only be a thread of concern for each product or service,
but must be developed in a manner that promotes the interweaving of security capabilities in the overall end-to-end security
solutions. To achieve such a solution in multi-vendor environment, network security should be designed around a standard security
framework. For the majority of users and applications, increased security cannot be achieved with technology that decreases
usability. Then, it is essential that the human interface be designed for ease of use, so that users routinely and automatically
apply the protection mechanisms correctly. Also, to the extent that the user’s mental image of his protection goals matches the
mechanisms he must use, mistakes will be minimized
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Session 6: New services
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Speaker: Riccardo Fiandra (Fastweb)
Title of Presentation: IPTV QoE requirements: technical challenges
The presentation will focus on IPTV and Quality of Experience that has to be offered to a customer. In this respect, it will
be addressed how Quality of Experience targets translate into IP transport requirements and the challenges and trade offs that
an IP operator has to face in order to meet such requirements. Relevant backbone and xDSL access network features will be
highlighted to evidence the behavior of the end-to-end packet loss, which by far is the most important IP transport parameter
affecting the IPTV QoE. Specific to an ADSL access, it will be shown some detail about the trade off that has to be reached
among service penetration and the Quality of Experience that the Operator needs to deliver. Some considerations about error
correction strategies and their impact on the service will also be given.
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Speaker: Andrea Saks, Independant Accessibility Consultant
Title of Presentation: Quality of conversation experience in sign language, lip-reading and text
Multimedia telephony with real-time text, video and voice communication enhances communication for all, and is essential for some
users. People with sensory related disabilities may depend on specific quality characteristics of video, text and voice for
successful communication. ITU-T Q.26/16 has worked since long with language communication for people with disabilities and
defined suitable services and performance requirements. By fulfilling these requirements, the communication systems get suitable
for all, resulting in larger markets, more satisfied users and fulfilled policy goals.
This presentation describes the findings of quality requirements for sign language, lip reading and real-time text usage coming
from deaf, deaf-blind, hearing-impaired and speech impaired users, but having very valid relevance for all users for example in
noisy environments and with spoken language differences.
The requirements for conversation in sign language and lip reading is documented in ITU-T H Series Supplement 1, where the
requirements in technical terms also are deducted back to human characteristics. Explained examples from sign language are
shown in order to make opportunities and threats with new networks and communication tools clear.
Similarly, text requirements for conversation are documented in ITU-T F.700 and F.703, explained in factors such as delay and rate
of corrupted or lost characters. A demonstration is made of the risk of severe quality degradation of traditional text conversation
introduced with VoIP and the solution with text communication with good performance in new networks explained.
Some practical examples are presented of design pitfalls and success stories in quality of language experience.
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Speaker: Patrick Luthi, Tandberg
Title of Presentation: Recent developments in QoE aspects of videoconferencing services
This presentation will provide an overview of recent developments in SG16 standardization that significantly enhanced the
videoconferencing user's quality of experience. Standards defining new features such as dual video streams (H.239), advanced
video coding (H.264), advanced audio coding (G.722.1 Annex , AAC-LD), NAT/firewall traversal methods (H.460.18,19), and H.324m
call setup acceleration techniques (H.324m Annex K) have definitely improved the perception of quality of a video call even if
end to end QoS is not guaranteed when using the Internet as a transport network. This presentation will also highlight the
important issues of latency and packet loss "friendliness" and how it can affect QoE
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Speaker: Claude Lamblin, Vice Chair ITU-T SG 16, France Telecom, France
Title of Presentation: ITU-T Recent Developments in Media Coding
In order to provide a Universal Multimedia Access to users, various networks and terminals are interconnected with different access
technologies. To cope with this heterogeneity, media coding development has aimed to quality enhancement and flexibility
improvement. In audio compression, after decades of bit rate lowering, there is now a clear evolution toward more bandwidth
for a higher Quality of Service. In video coding, though compression is still important but less so than it used to be, higher
resolution is now desirable. A major flexibility improvement is brought by scalable codecs, especially the embedded coding schemes.
After a brief introduction to the ITU-T media coding history, this presentation shows how the recent ITU-T media coding
developments intent to answer these needs and details the latest standardized media coders: ITU-T H.264 and ITU-T G.729.1.
ITU-T H.264 (also known as MPEG-4 AVC), includes the most advanced video coding tools providing the coding efficiency significantly
better than that of the most widely deployed standard today - MPEG-2.
ITU-T G.729.1 (also dubbed G.729EV) is an 8-32 kbit/s scalable audio coder bitstream interoperable with G.729 offering highly
flexible fine bit rate granularity both in narrow band and wideband and providing a standardized solution for packetized wideband
voice applications that allows a smooth transition from narrowband to wideband telephony.
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Session 7: NGN-related QoS and the accumulation of network impairments
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Speaker: Hui-Lan Lu, Lucent Technologies
Title of Presentation: Resource and Admission Control for NGN
Next Generation Networks (NGN) are characterized, among other things, by the prevalent use of a general packet transport for
delivering a wide range of applications. The advent of such networks gives rise to the need for supporting quality of service
as requested by various applications dynamically. The presentation will give an overview of an emerging ITU approach to dynamic
application-driven transport resource management—the Resource and Admission Control Functions (RACF). Augmenting the native
transport QoS support, RACF allows edge-to-edge or end-to-end transport congestion to be managed in the service control layer.
The presentation will focus on the architectural aspects of RACF and examine the related issues.
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Speaker: Lianshu ZHENG, Huawei Technologies Co., Ltd
Title of Presentation: Ranged Impairment Allocation
According to Rec. Y.1541, the network QoS classes with end-to-end objectives have been defined. To achieve the desired end-to-end
performance across multiple network operators is a challenge. Approaches for impairment allocation of UNI-UNI objectives have been
studied in G.FEPO. The ranged impairment allocation is a signaled approach which finds out the range of impairment budget for each
network section along the data path. According to this approach, every segment itself can choose an appropriate value within its
allocated budget range under the consideration of optimizing its resource utilization.
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Speaker: Al Morton, AT&T
Title of Presentation: A practical approach to e2e QoS using managed impairment accumulation
Users of communications services require assurance from providers that their needs will be met, in other words, that their
communications applications will perform satisfactorily. Their needs must be translated into network bandwidth and packet
transfer performance requirements. When multiple network operators must work together to meet their user’s needs, then there
must be a process in place to achieve the end-to-end packet transfer objectives.
We see serious issues for service providers with the various pre-allocation methods proposed, and prefer a different approach
to achieve end-to-end performance levels. Impairment Accumulation differs from allocation-based approaches in its consistency
with current service provider practices as well as envisaged e2e QoS Signaling procedures in IP-based networks. While we note
that all approaches have several common aspects, such as requiring end-to-end network objectives, supporting measurements, and
motivating individual operators to perform well, we believe that Impairment Accumulation is more likely to be successfully
implemented by the service provider community. Impairment Accumulation takes advantage of many successful standards, but will
require some additional developments in the areas of Resource Allocation and Signasling.
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Session 8: Quality prediction
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Speaker: Quan Huynh-Thu, Psytechnics Ltd
Title of Presentation: Recent developments in objective voice and video quality assessment models
With the increasing complexity of telecommunication networks and the competition for the offering of emerging multimedia services,
quality becomes a key market differentiator. The right balance between end-user quality of experience and bandwidth costs is
becoming increasingly vital for the industry. Objective quality assessment algorithms are computational methods that analyze a
signal in order to predict its quality. A quality metric has many applications such as network monitoring, codec performance
benchmarking and optimization. However, a quality metric is only useful if it has a high correspondence with user judgement.
In recent years, important progress has been made in the development of perceptual quality metrics.
The presentation will cover recent standards for voice quality assessment and the current efforts for standardizing new video
quality assessment models. An overview of the current projects within the Video Quality Experts Group will be given.
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Speaker: Akira Takahashi (NTT)
Title of Presentation: Standardization activities for multimedia opinion model: G.OMV
Videophone service is one of the key services in future telecommunication services over NGN (Next Generation Networks).
Designing and managing the quality of such services properly is essential because IP networks generally do not guarantee
transmission quality. However, subjective quality assessment, which evaluates the fundamental aspect of the quality of audio
and visual communication services, is time-consuming and not applicable especially to quality management which requires
real-time assessment. Therefore, developing an objective quality assessment method that estimates subjective quality based
solely on physical characteristics of the telecommunication system is indispensable. ITU-T SG12 has launched a new study
item under Question 13 that develops a new Recommendation for estimating overall multimedia quality of videophone services.
The concept is similar to the E-model, which deals with telephone-band speech communication services. This presentation
introduces the framework of the new Recommendation that is being currently discussed under Question 13. Then, the performance
of a model proposed by NTT, which complies with the framework, is demonstrated.
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Speaker: David Hands, BT
Title of Presentation: Quality Assurance for IPTV
In preparing and distributing IPTV content, it is desireable that service providers perform quality checks at specific
points in the distribution chain (e.g. after encoding to ensure quality is adequate for delivery to customers, at strategic
points in the network, at the STB to check the received video quality has been maintained). Existing quality assurance tools
typically examine the syntax of the video, perhaps alongside some crude quality measure. The QA tool presented here offers an
alternative method for assuring the quality of IPTV services. BT has developed a QA tool that uses a novel bit-stream based
quality metric to measure the quality of the encoded video. The tool provides real-time, accurate quality measurements of IPTV
services. This tool can be used to quality check all content prior to ingestion and onward transmission to customers. The value
of the tool is that it provides measurements that relate directly to the customer experience. The tool allows operators to
identify and rectify poor quality video before transmission occurs.
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Session 9: Regulatory aspects of QoE/QoS in NGNs
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Speaker: Bela HAZKOTO, National Communications Authority, Hungary
Title of Presentation: To regulate or not to regulate?
The roles of NCA in the field of supervision, measuring or regulation in the electronic communications market are decided by
the communications law and the authorization of NCA. In Hungary, as a member state of European Union the basis of communications
law is the “new” regulatory framework.
The possibilities of member states in field of QoS are written in directive 2002/22/EC (Universal Service Directive). The limits
of possibilities are to draw in the directive 2002/21/EC (Framework Directive). Member states concerning regulation of QoS must
to mind rules the directive 98/34EC (98/48/EC), too. We can to declare, the European regulation is a light regulation basically
with way of competition of communications market.
The Hungarian laws and decrees in field of electronic communications contain regulations harmonized with legislation of European
Communities. The basis is Act C of 2003 on electronic communications. Important legal materials are Decree 8/2004 (IV. 20.) IHM
on detailed conditions and technical requirements of universal services and Government Decree 345/2004 (XII. 22.) on the
requirements related to the quality of electronic communications services in relation to the protection of consumers. The
authority with a view the protection of the interests the users carry out market surveillance activity by way of official
supervisory checks. In the event of violation of the law explored in the course of a market surveillance procedure, the authority
shall apply sanctions. The measurements are for booth voice, data, internet, broadcast, etc. services.
The evolution of regulation QoS in future is dependent on change of European framework, technical development, etc. The goal is
the continuous improvement of quality of services in favor of users.
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Speaker: Christine Mugimba, Uganda Communications Commission
Title of Presentation: Role of Regulatory Bodies and Their Importance in QoS issues
Regulatory bodies (Regulators) are established as a result of enactment of National laws. These laws often spell out the functions
and powers of the Regulator.
For the Communications sector, Regulators often exist to ensure that quality communication services are available to all at
affordable prices. Their role as regards Quality of Service (QoS) is geared to protection of consumers, encouragement of efficient
operations by the service and network providers, promotion of fair competition and informed consumer choices. The strategies adopted
are dependant on a number of factors which include policies, level of competition, priorities of the government and economic aspects
of regulation.
One of the importance of Regulators in QoS issues is that as independent bodies, Regulators act as a bridge between consumers
and service and network providers in addressing QoS issues. Regulators play a big role in setting QoS parameters and targets for
service and network providers that are appropriate to the market and environment they regulate. Regulator represent governments at
international and national level and play an advocacy and decision making role in policy and law formulation to ensure the
interests of the governments are met by encouraging growth of the sector and protecting consumers.
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Speaker: Nuno Encarnacao, OFCOM
Title of Presentation: Future Networks & Services, Standards & Regulation, private and public domains, general aspects
The author starts from European frame legislation, considers central goals and definitions and observes trends on
the evolution of the electronic communications market.
Through the presentation some relevant topics are suggested, e.g.:
- there are main trends in the present development towards future oriented networks
- one is basically a vertical integration between Networks and Services (NGN)
- another is an Internet based evolution (NGI)
- private (home & business) domain seems to be an attractive market with many tending to dilute the borderline between private and public domains
- there is an apparent contradiction between the private domain devices increasing intelligence and the
centralization of many functions in some NGN visions;
- this can be understood by the present insufficient performance of internet based solutions for some particular services, but it is believed that the two basic alternative solutions will co-exist and may converge later
- the likely impairment for the end-to-end service quality if per connection more than a service provider is
involved; in successive network-network interfaces;
- the impairments will be decreased if service level agreements will foresee some form of having a single master service provider per connection
- the need of better studying the difficulties (e.g. for emergency or lawful interception) associated
particularly for NGI solutions is also suggested
Some relevant entities, associated modules and corresponding interfaces are identified before citing some typical
regulatory requirements. It is also suggested to study a matrix assignment of these regulatory requirements to each
one of the identified entities.
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Speaker: Slavica Nasteska, M.Sc., Head of Telecommunications Department, Agency for electronic communications of Republic of Macedonia
Title of Presentation: Regulatory aspects for Quality of public communication services in Republic of Macedonia
This Presentation describes the current status of the Public Electronic Communications Networks and Services in Republic of
Macedonia from a Legislative and Regulatory point of view. It presents the new Electronic Communications Law which was adopted
in 2005 and a by-law document based on this law which is related to providing public electronic communications services. In the
presentation all responsibilities of the established Agency for Electronic Communications as National Regulatory Authority are
given, with special focus on responsibilities regarding the Quality of Public Electronic Communications Services. Current status
on Quality of Public Fixed Telephony and Public Mobile Telephony Services is described. Some of the existing questions to be
solved are highlighted. The Presentation also gives future directions in the process of establishing appropriate regulation for
Quality of Public Communication Services in Republic of Macedonia.
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Speaker: Volker Sypli, Federal Network Agency (Germany)
Title of Presentation: Regulatory aspects of QoS with regard to IP and NGN
This presentation highlights regulatory aspects of QoS within an IP-based network environment and in the advent of upcoming NGNs.
Due to the change of network infrastructure and technologies regulatory bodies are confronted with new issues different to the
traditional circuit-switched telecommunication environment. This includes e.g. issues of the availability of the Universal
Service, overall end-to-end quality and interoperability of services, interconnection regulations.
Regulatory bodies have to adopt their working methodologies to the changing situation.
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