Quality of Service for In-Home Digital Networks
(PROGRESS project EES.5653)
The project is focused on the problems surrounding resource sharing in networks of consumer devices, more precisely, of connected real-time embedded systems. We regard these networks as contained domains, meaning that their use is under complete control of its owner. The considered systems are resource constrained since the difference between worst-case and average-case performance is too large to be able to afford over-dimensioning. In addition, resources cannot always be guaranteed as is the case, for example, in wireless networks. The shared resources in our project concern the network, the processing power in terminals and network devices and the memory in these. The domain we study is the domain of networked video, since this represents currently the largest challenge. Because this system must cope with overload situations, it must be possible to adjust the quality in order to avoid failure. The project addresses this graceful quality adaptation by
Three PhD students are working on the project, two are funded by STW and 1 is funded by TU/e.
Dmitri Jarnikov works on scalable video
Sergei Kozlov addresses QoS aware
transport protocols (STW, from
Alina Albu works on
prediction of resource requirements of streaming applications (STW, from
First, taking as a start the ITU-T Recommendation E.800 – Geneva 1994 as the definition of Quality of Service:
Quality of Service: “... is the collective effect of service performances, which determine the degree of satisfaction for a user of a service”
we observe that QoS is then dependent on all system parts. It plays at different timescales and at different layers of the system. Clearly, these different timescales lead to different problems and solutions. For example, rapid bandwidth changes in the millisecond range cannot be solved by system-wide reallocation in the second range. Conversely, structural and long-lasting load changes should not just rely on algorithms and protocols that solve quick bandwidth variations.
Second, we think that convergence towards optimal use is in some cases better than end-to-end guarantees. Internally, the system may use strict resource assignment and enforcement. However, unforeseen external circumstances as well as fluctuations in actual resource requirements must be dealt with such that the resulting behavior converges again to optimal use. This calls for adaptibility which, because of the first point, plays at several layers.
We can demonstrate these issues with the simple example of a video source (encoding component) transmitting to an access point (which does transcoding) and connects through some channel to a terminal that will do decoding. We can have the following changes that the system needs to respond to:
• Variations in terminal load
– competitive applications, additional streams to encode/decode.
– variations in computational effort in codec dependent on the video.
• Variations in available bandwidth, e.g. high, bursty loss in wireless networks
The effect of these variations are that the application (or a part of it) does not get the resources it needs. Sometimes, system software does not deal with this very well. For example, some transport protocols are very sensitive to bursty loss, hence, more suitable protocols should be developed. For the rest, the response to this situation is essentially found in making the application adaptive. This can be done at several places in the chain, viz. at the transport layer, at the encoding/decoding terminals and perhaps in a combination of the two. Tradeoffs could be made between transmitting less information at the expense of more calculation etc. In order to deal with structural load changes a control structure must be able to estimate the new situation and perform admission tests. To that end, good predictive models of the application are needed.
Current work and plans
Our current work addresses the following questions:
· Scalable Video. We look at the issue of changing the quality of the transferred video based on quality variations of the network and variations in processing capacity. Particularly, we address layered video using SNR scalabilty. We develop a feedback-control loop in order to optimize the behavior.
· Adaptive transport protocols. Quick variations in network quality should be tackled by the transport protocol. We look at selective and adaptive retransmission strategies and at smart frame-dropping.
· Predicting resource requirements. When a set of components is activated on a particular node their resource consumption should be known.
are regular demonstrations of the achievements in the involved groups, viz.,
SAN at TU/e and OASIS at Philips Research. There have been cooperations
with product divisions in Philips resulting in more robust demonstrators and
validation of methods. A demonstration has been given on the IST event of the
European Union in the week of
For the project we aim at a combined demonstrator according to the following picture.
By extending to multiple streams we can increase the challenge on the control structure to include admission control.
Meetings, contacts and conference visits
· Weekly meetings on Friday both with the SAN group (the weekly colloquium series) as well as with staff members for supervision purposes.
· Usergroup meeting on May 28, 2004.
· Posters on the Progress workshop of October 2003 (best poster presentation) and October 2004.
· prof. dr. Gerhard Fohler is a regular visitor advising on real-time issues.
· dr. Kurt Wallnau from Carnegie Mellon (SEI) was visiting TU/e in October 2004; discussions of Alina with his staff have started.
· Presence at the EU/IST conference on November 15-17, 2004.
Relevant output so far
· Review on September 30, 2005
4. Sergei’s presentation
5. Dmitri’s presentation
· Review on October 11, 2006
2. Dmitri’s presentation
Posters and presentations
· Poster: M.A. Weffers-Albu, J.J. Lukkien, P.D.V. v.d. Stok, "Towards A Characterization of Real-Time Streaming Systems", SEES Workshop 2005
· Poster: S. Kozlov, Peter v.d. Stok, Johan Lukkien, IFD – a technique for improving the quality of wireless video streaming, SEES Workshop 2005
Poster: M.A. Weffers-Albu, J.J. Lukkien,
P.D.V. v.d. Stok; Analysis of a Time-Driven Chain of Dependent Components;
ECRTS 2006 WIP,
· Presentations by Alina on QoS papers:
· Presentation by Alina: Overview of NCS calculation method, at SAN meeting on 12-11-2004
· Presentation by Alina: M.A. Weffers-Albu, J.J. Lukkien, P.D.V. v.d. Stok, "Towards A Characterization of Real-Time Streaming Systems", ECRTS WIP 2005
Presentation by Alina: M.A.
Weffers-Albu, J.J. Lukkien, P.D.V. v.d. Stok; On A Theory of Media Processing
Systems Behaviour, with Applications; ECRTS 2006,
Presentation by Alina: M.A.
Weffers-Albu, J.J. Lukkien, P.D.V. v.d. Stok; Analysis of a Time-Driven Chain
of Dependent Components; ECRTS 2006 WIP,
Publications and reports
· Paper: Dmitri Jarnikov, Peter van der Stok, Clemens C. Wust, Predictive Control of Video Quality under Fluctuating Bandwidth Conditions. Published at ICME2004.
· Paper: Dmitri Jarnikov, Peter van der Stok, Johan Lukkien, Timely wireless streaming based on a scalability scheme using legacy MPEG2 decoders. Presented IASTED IMSA 2005, Hawaii
· Draft report: M.A. Weffers-Albu, P.v.d.Stok, J.J. Lukkien, "Quality of Service Overview"
· Report: H. de Groot (editor), I. Nitescu, I.C. Kang, D. Jarnikov, P. D.V. van der Stok, Robust scalable video over wireless networks (KISS demonstrator). PR-TN-2004/00160 (Philips Restricted)
Report P.D.V. van der Stok, D. Jarnikov,
· Book chapter Jeffrey Kang, Harmke de Groot, Peter van der Stok, Dmitri Jarnikov, Iulian Nitescu, and Felix Ogg, Robust video streaming over wireless in-home networks, in Dynamic and Robust Streaming in and between Connected Consumer-Electronic Devices, Peter van der Stok editor, pp 193-212, Kluwer, 2005.
· Book chapter Reinder Haakma, Dmitri Jarnikov, and Peter van der Stok, Perceived quality of wirelessly transported videos, in Dynamic and Robust Streaming in and between Connected Consumer-Electronic Devices, Peter van der Stok editor, pp 213-239, Kluwer, 2005.
· Paper: Dmitri Jarnikov, Johan Lukkien, Peter van der Stok, A Framework for Video Streaming to Resource-Constrained Terminals, accepted for publication at EUC2005
· Paper: Dmitri Jarnikov, Johan Lukkien, Peter van der Stok, Adaptable video streaming over wireless networks, accepted for publication at ICCCN2005
· Paper: Dmitri Jarnikov, Peter van der Stok, Johan Lukkien, Influence of network awareness on perceived video quality, published at RM4NES workshop
· Paper: M.A. Weffers-Albu, J.J. Lukkien, E.F.M. Steffens, P.D.V. van der Stok, On Theory of Media Processing Systems Behavior, with Applications, accepted at ECRTS 2006
Weffers-Albu, J.J. Lukkien, P.D.V. v.d. Stok, "A Characterization of
Streaming Applications Execution", Proceedings RM4NES 2005,
· Paper: M.A. Weffers-Albu, J.J. Lukkien, P.D.V. v.d. Stok, "Towards A Characterization of Real-Time Streaming Systems", ECRTS WIP 2005, Palma de Mallorca
· Paper: M.A. Weffers-Albu, P.v.d.Stok, J.J. Lukkien, "NCS Calculation Method for Streaming Applications", Proceedings of the 5th PROGRESS Symposium on Embedded Systems.
Paper: M.A. Weffers-Albu, J.J.
Lukkien, P.D.V. v.d. Stok; On A Theory of Media Processing Systems Behaviour,
with Applications; ECRTS 2006,
Paper: M.A. Weffers-Albu, J.J.
Lukkien, P.D.V. v.d. Stok; Analysis of a Time-Driven Chain of Dependent
Components; ECRTS 2006 WIP,
· Report: BETSY consortium, Betsy deliverable D7, model composition and end-to-end prediction, version 6, 2006
System, receiver, transmitter, method , software for distributing