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Item type:Publication, Access status: without files , Extending On-the-fly Network Coding by Interleaving for Avionic Satellite LinksStill today, aircraft disappear and crash without communicating their last position. Looking into details, satellite communications currently seems to be the only reliable way to connect and send data on long-distance flights. However, geostationary satellite systems suffer from high propagation delays making Forward Error Correction (FEC) schemes beneficial compared to error handling by retransmissions. In this paper, Random Linear Network Coding (RLNC) is proposed as a packet level FEC technique for high delay satellite communication. Using emulation, it is shown that correlated losses typical for a satellite channel result in a high variation in the number of redundant symbols required to decode a generation. This can be improved by using interleaving, which comes by the cost of an increased delay. A novel approach is introduced that combines On-the-fly Coding and interleaving. This can significantly reduce the average delay introduced by interleaving and allows to efficiently overcome correlated losses in combination with Network Coding for time-critical applications.Publicationtype: Conference Paper462 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Blended Learning and Problem Based Learning in a multinational and multidisciplinary setting(Aalborg Universitetsforlag, 2017-07); ; ; The paper presents the results from the second year of the Erasmus+ Strategic Partnership Collaboration and Innovation for Better, Personalized and IT-Supported Teaching, where seven universities and three companies work together on the joint course Future Internet Opportunities (5 ECTS). In the project and the course, we intend to tackle some of the major challenges we experience with university teaching today: An increasing number of students and more diversity among the students enrolled, an increasing pressure to ensure that the students are ready for the labour market after finishing university, and at the same time the challenges faced when it comes to adopting new technologies. The course consists of two parts: A course module part with 10 modules, which provides the students with broad knowledge on Future Internet Opportunities from social, technical and business perspectives, and a project part where the students work in groups across nationalities and disciplines on real-world Projects posed by companies. This paper presents the evaluations carried out by all participating students, and discusses the experiences with the different learning components including different features of the Learning Management System Moodle, which was used for the modules. Moreover, it introduces the concept of just-in-time resources for Problem Based Learning, where we tackle the challenge of providing the students with methods and tools to be used in the projects just when they need it.Publicationtype: Conference Paper77 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Engineering Design Methodology Input for Interdisciplinary Bachelor-Project - Open Topic(2017-05); ; ; ; Publicationtype: Conference Paper118 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Coding schemes for heterogeneous communication links using channel bundlingCommunication over geostationary satellite links is improved by introducing end-to-end Forward Error Correction (FEC) and simultaneous transmissions over two links (channel bundling). The main objective of this work is to investigate to which degree the goodput and the reliability can be enhanced using the mentioned techniques. The performances of the two FEC schemes Reed-Solomon Codes and Random Linear Network Coding are compared. Uncorrelated and correlated packet errors are considered, the latter with a Gilbert-Elliot channel model. Experiments are conducted in a testbed consisting of a single PC with virtual network interfaces to determine the influence of various parameter settings on performance. Results are compared against a scenario with one link offering the same capacity as the two links together. It is concluded that using two heterogeneous links is beneficial for the goodput and losses for generation sizes larger than 20 for three correlated lost packets on average.Publicationtype: Conference Paper207