Greediness control algorithm for multimedia streaming in wireless local area networks

This work investigates the interaction between the application and transport layers while streaming multimedia in a residential Wireless Local Area Network (WLAN). Inconsistencies have been identified that can have a severe impact on the Quality of Experience (QoE) experienced by end users. This problem arises as a result of the streaming processes reliance on rate adaptation engines based on congestion avoidance mechanisms, that try to obtain as much bandwidth as possible from the limited network resources. These upper transport layer mechanisms have no knowledge of the media which they are carrying and as a result treat all traffic equally. This lack of knowledge of the media carried and the characteristics of the target devices results in fair bandwidth distribution at the transport layer but creates unfairness at the application layer. This unfairness mostly affects user perceived quality when streaming high quality multimedia. Essentially, bandwidth that is distributed fairly between competing video streams at the transport layer results in unfair application layer video quality distribution. Therefore, there is a need to allow application layer streaming solutions, tune the aggressiveness of transport layer congestion control mechanisms, in order to create application layer QoE fairness between competing media streams, by taking their device characteristics into account. This thesis proposes the Greediness Control Algorithm (GCA), an upper transport layer mechanism that eliminates quality inconsistencies caused by rate / congestion control mechanisms while streaming multimedia in wireless networks. GCA extends an existing solution (i.e. TCP Friendly Rate Control (TFRC)) by introducing two parameters that allow the streaming application to tune the aggressiveness of the rate estimation and as a result, introduce fair distribution of quality at the application layer. The thesis shows that this rate adaptation technique, combined with a scalable video format allows increased overall system QoE. Extensive simulation analysis demonstrate that this form of rate adaptation increases the overall user QoE achieved via a number of devices operating within the same home WLAN

Multimedia in mobile networks: Streaming techniques, optimization and User Experience

1.UMTS overview and User Experience 2.Streaming Service & Streaming Platform 3.Quality of Service 4.Mpeg-4 5.Test Methodology & testing architecture 6.Conclusion

Telemedicine

Telemedicine is a rapidly evolving field as new technologies are implemented for example for the development of wireless sensors, quality data transmission. Using the Internet applications such as counseling, clinical consultation support and home care monitoring and management are more and more realized, which improves access to high level medical care in underserved areas. The 23 chapters of this book present manifold examples of telemedicine treating both theoretical and practical foundations and application scenarios

Call Admission Control and traffic policing mechanisms for the wireless transmission of layered videoconference traffic from MPEG-4 and H.263 video coders

We explore, via an extensive simulation study, the performance of Call Admission Control (CAC) and traffic policing mechanisms proposed for transmitting multiple-layered videoconference movies over a wireless channel of high capacity, depending on the user's needs and requests. We focus both on MPEG-4 and H.263 coded movies, and, in the latter case, our scheme achieves high aggregate channel throughput, while preserving the very strict quality of service (QoS) requirements of the video traffic

Call admission control and traffic policing mechanisms for the wireless transmission of layered videoconference traffic from MPEG-4 and H.263 video coders

Summarization: We explore, via an extensive simulation study, the performance of call admission control (CAC) and traffic policing mechanisms proposed for transmitting multiple-layered videoconference movies over a wireless channel of high capacity, depending on the user's needs and requests. We focus both on MPEG-4 and H.263 coded movies, and, in the latter case, our scheme achieves high aggregate channel throughput, while preserving the very strict quality of service (QoS) requirements of the video traffic.Παρουσιάστηκε στο: 3th IEEE International Symposium on Personal, Indoor and Mobile Radio Communication