Evaluation of HTTP/DASH Adaptation Algorithms on Vehicular Networks

Video streaming currently accounts for the majority of Internet traffic. One factor that enables video streaming is HTTP Adaptive Streaming (HAS), that allows the users to stream video using a bit rate that closely matches the available bandwidth from the server to the client. MPEG Dynamic Adaptive Streaming over HTTP (DASH) is a widely used standard, that allows the clients to select the resolution to download based on their own estimations. The algorithm for determining the next segment in a DASH stream is not partof the standard, but it is an important factor in the resulting playback quality. Nowadays vehicles are increasingly equipped with mobile communication devices, and in-vehicle multimedia entertainment systems. In this paper, we evaluate the performance of various DASH adaptation algorithms over a vehicular network. We present detailed simulation results highlighting the advantages and disadvantages of various adaptation algorithms in delivering video content to vehicular users, and we show how the different adaptation algorithms perform in terms of throughput, playback interruption time, and number of interruptions

Railway Engineering: Timetable Planning and Control, Artificial Intelligence and Externalities

This chapter is a case study of the dissemination of railway engineering research in Latin America developed by a railway engineering research group. The leader of the group is a female researcher. The authors aim to inspire to other women researchers in Latin American and Caribbean (LAC) countries who are trying to develop research in IT areas, many times facing serious difficulties, incomprehension, and great challenges. This chapter is divided in set sections like introduction, background, development of railway engineering research. This third section is divided into subsections like timetable planning and trains control, characterization of Panama metro line 1, dwelling times, fuzzy logic, artificial intelligence, social-economics railway externalities, and environmental railway externalities. The fourth section presents the results of the relationship between research activity and teaching of railway engineering obtained in this case study. Finally, the authors present a brief vision about future and emerging regional trends about railway engineering projects.This chapter is a case study of the dissemination of railway engineering research in Latin America developed by a railway engineering research group. The leader of the group is a female researcher. The authors aim to inspire to other women researchers in Latin American and Caribbean (LAC) countries who are trying to develop research in IT areas, many times facing serious difficulties, incomprehension, and great challenges. This chapter is divided in set sections like introduction, background, development of railway engineering research. This third section is divided into subsections like timetable planning and trains control, characterization of Panama metro line 1, dwelling times, fuzzy logic, artificial intelligence, social-economics railway externalities, and environmental railway externalities. The fourth section presents the results of the relationship between research activity and teaching of railway engineering obtained in this case study. Finally, the authors present a brief vision about future and emerging regional trends about railway engineering projects

A Fuzzy-Based Adaptive Streaming Algorithm for Reducing Entropy Rate of DASH Bitrate Fluctuation to Improve Mobile Quality of Service

Dynamic adaptive streaming over Hypertext Transfer Protocol (HTTP) is an advanced technology in video streaming to deal with the uncertainty of network states. However, this technology has one drawback as the network states frequently and continuously change. The quality of a video streaming fluctuates along with the network changes, and it might reduce the quality of service. In recent years, many researchers have proposed several adaptive streaming algorithms to reduce such changes. However, these algorithms only consider the current state of a network. Thus, these algorithms might result in inaccurate estimates of a video quality in the near term. Therefore, in this paper, we propose a method using fuzzy logic and a mathematics moving average technique, in order to reduce mobile video quality fluctuation in Dynamic Adaptive Streaming over HTTP (DASH). First, we calculate the moving average of the bandwidth and buffer values for a given period. On the basis of differences between real and average values, we propose a fuzzy logic system to deduce the value of the video quality representation for the next request. In addition, we use the entropy rate of a bandwidth measurement sequence to measure the predictable/stabilization of our method. The experiment results show that our proposed method reduces video quality fluctuation as well as improves 40% of bandwidth utilization compared to existing methods