Influence of distortions of key frames on video transfer in wireless networks

In this paper it is shown that for substantial increase of video quality in wireless network it is necessary to execute two obligatory points on modernization of the communication scheme. The player on the received part should throw back automatically duplicated RTP packets, server of streaming video should duplicate the packets containing the information of key frames. Coefficients of the mathematical model describing video quality in wireless network have been found for WiFi and 3G standards and codecs MPEG-2 and MPEG-4 (DivX). The special experimental technique which has allowed collecting and processing the data has been developed for calculation of values of factors.Comment: 6 pages, 4 figures, 2 Table

Relationship between IoT Service User Quality and Network QoS Factors

The Internet of Things (IoT) is a complete network of networked computer devices, digital and mechanical equipment, and the capacity to send data over the Internet based on machine to machine interaction. It is also known as the Internet of Everything (IoE). The Internet is a packet-switched network, which means that the Quality of Service (QoS) elements (such as packet loss, latency, jitter, and so on) have an influence on the Quality of Experience (QoE) for the Internet of Things services. This research used a subjective evaluation method in order to evaluate the relationship between the quality of service (QoS) measures such as packet loss, latency, and jitter and the quality of experience (QoE) for Internet of Things services. In addition to that, a mapping model from quality of service to quality of experience was suggested. According to the results of this research, there is a close connection between the subjective opinion score and the quality of service (QoS) variables such as packet loss, latency, and jitter. The results of this investigation open up possibilities for additional research into the quality of experience of Internet of Things services

Multipath and Rate Stability

Originally Published In Proc. IEEE Globecom Conference - CQRM: Communication QoS, Reliability & Modeling Symposiu

No-reference bitstream-based visual quality impairment detection for high definition H.264/AVC encoded video sequences

Ensuring and maintaining adequate Quality of Experience towards end-users are key objectives for video service providers, not only for increasing customer satisfaction but also as service differentiator. However, in the case of High Definition video streaming over IP-based networks, network impairments such as packet loss can severely degrade the perceived visual quality. Several standard organizations have established a minimum set of performance objectives which should be achieved for obtaining satisfactory quality. Therefore, video service providers should continuously monitor the network and the quality of the received video streams in order to detect visual degradations. Objective video quality metrics enable automatic measurement of perceived quality. Unfortunately, the most reliable metrics require access to both the original and the received video streams which makes them inappropriate for real-time monitoring. In this article, we present a novel no-reference bitstream-based visual quality impairment detector which enables real-time detection of visual degradations caused by network impairments. By only incorporating information extracted from the encoded bitstream, network impairments are classified as visible or invisible to the end-user. Our results show that impairment visibility can be classified with a high accuracy which enables real-time validation of the existing performance objectives

Continuity-Aware Scheduling Algorithm for Scalable Video Streaming

The consumer demand for retrieving and delivering visual content through consumer electronic devices has increased rapidly in recent years. The quality of video in packet networks is susceptible to certain traffic characteristics: average bandwidth availability, loss, delay and delay variation (jitter). This paper presents a scheduling algorithm that modifies the stream of scalable video to combat jitter. The algorithm provides unequal look-ahead by safeguarding the base layer (without the need for overhead) of the scalable video. The results of the experiments show that our scheduling algorithm reduces the number of frames with a violated deadline and significantly improves the continuity of the video stream without compromising the average Y Peek Signal-to-Noise Ratio (PSNR)

A System for Using Perceiver Input to Vary the Quality of Generative Multimedia Performances

Generative Multimedia (GM) applications are an increasingly popular way to implement interactive media performances. Our contributions include creating a metric for evaluating Generative Multimedia performances, designing a model for accepting perceiver preferences, and using those preferences to adapt GM performances. The metric used is imprecision, which is the ratio of the actual computation time of a GM element to the computation time of a complete version of that GM element. By taking a perceiver's preferences into account when making adaptation decisions, applications can produce GM performances that meet soft real-time and resource constraints while allocating imprecision to the GM elements the perceiver least cares about. Compared to other approaches, perceiver-directed imprecision best allocates impreciseness while minimizing delay.Ph.D.Committee Chair: Schwan, Karsten; Committee Member: Ahamad, Mustaque; Committee Member: Howe, W. Gerry; Committee Member: Ramachandran, Kishore; Committee Member: Yalamanchili, Sudhaka

Measuring quality of video of internet protocol television (IPTV)

141 p.La motivación para el desarrollo de esta tesis es la necesidad que existe de monitorizar la calidad de experiencia del vídeo que se proporciona en una red IPTV (Internet Protocol Television). Esta necesidad surge del deseo de los operadores de telecomunicaciones de proporcionar un servicio más satisfactorio a sus clientes y alcanzar mayor penetración en el mercado. Los servicios sólo pueden tener éxito si la calidad de experiencia se garantiza. Las redes IPTV (Television sobre IP) son por naturaleza susceptibles a pérdidas de paquetes de datos que afectan a la calidad del vídeo que recibe el usuario. Entre los factores que contribuyen a la existencia de pérdida de paquetes de datos se encuentran la congestión de red, una planificación de red inadecuada o el fallo de algún equipamiento de la red. La calidad de experiencia de un vídeo se ve afectada por una serie de factores como por ejemplo la resolución, la ausencia de errores en las imágenes, la calidad de la televisión, las expectativas previas del usuario y muchos otros factores que se estudian en esta tesis