Duration: 6 months
Supervisors: Robert Kooij and Kamal Ahmed
Location: TNO Information and Communication Technology, Delft
INTRODUCTION
Telecommunication service providers are investing heavily in IPTV to complement their existing voice and data services, and compete with cable operators. Before IPTV proliferation and triple play utopia is realized, service providers and network equipment manufacturers must first verify that IPTV services will in fact meet user quality expectations. Viewers have come to expect a predictable level of service quality with their broadcast and satellite TV services and will not be tolerant to service interruptions, picture and sound degradation or long waiting periods to change channels with their new IPTV service. With a plethora of competing IPTV and cable TV service offerings, subscriber churn due to poor quality of experience is a serious risk.
IPTV Quality of Experience (QoE) refers to how well the video service satisfies users' expectations. The IPTV quality experienced by subscribers must be equal to or better than today's cable and satellite TV services or service providers run the risk of significant subscriber churn and the resulting loss in revenue. It is believed that IPTV is the key component to service provider growth and hence service providers are taking IPTV QoE very seriously.
'Measuring' IPTV QoE refers to testing the technical aspects that influence the subscriber's service experience. There are two fundamental areas of IPTV QoE testing:
- Channel zapping measurements
- Media (audio and video) quality metrics
In this project we will only focus on the first area. Channel zapping measurements measure how quickly subscribers can change channels, and verify that they are in fact receiving the correct channel. Acceptable channel zapping delay is generally considered to be approximately 1 second total, end-to-end.
PROJECT
Until recently, there was no knowledge about the explicit relation between zapping time and the QoE as expressed as a Mean Opinion Score (MOS). In order to fill this gap TNO has conducted a number of subjective experiments and proposed a model where the MOS depends on the zapping time on a logarithmic scale.
The objective of this project is to enhance the model suggested by TNO and to back it up with measurements in real-life IPTV networks. The work consists of the following activities:
1. Construct a model that maps zapping time and the variation in zapping time for one channel to QoE expressed in MOS values. In order to construct the model subjective tests will have to be conducted. Multi- dimensional regression will be used to fit subjective data to the model.
2. The model suggested by TNO assumed ‘lean forward’ and ‘channel-by- number’ zapping behavior. The model should be enhanced such that it also takes into account ‘lean backward’ zapping (using a remote control instead of a mouse) and ‘arrow-up/ arrow-down’ zapping
3. Measurements of zapping times in real-life implementations of IPTV. Ideally a test script is developed with which the characteristics of zapping time can be measured.
4. Construction of a model that predicts the zapping times. This model should take into account the impact of IGMP Processing Delay (time to join & leave the appropriate multicast group), buffering delay in the Set Top Box and decoding delay.
What are we looking for?
We are looking for a MSc student with background in electrical engineering, computer science, econometrics or applied mathematics, with a capacity for logical and abstract thinking and an interest in telecommunications. He/she should be able and willing to program and conduct subjective experiments. Affinity with or a willingness to learn programming in Javascript is important.
What do we offer?
We offer an innovative graduation project in an interesting field as well as a young and dynamic environment to work in. You will be assigned one or more supervisors and a coach who will give you support in other issues not directly related to the subject of your project. In case of mutual satisfaction, job opportunities exist after completion of the project and the student’s graduation.
More information
For more details you can contact the main supervisor at TNO ICT: robert.kooij@tno.nl or send your résumé to our recruitment officer: instroom-ICT@tno.nl.