Deutsche Telekom

About: Deutsche Telekom is a company organization based out in Welwyn Garden City, United Kingdom. It is known for research contribution in the topics: Telecommunications network & Terminal (electronics). The organization has 3473 authors who have published 5208 publications receiving 65429 citations. The organization is also known as: DTAG & German Telecom.

Method of determining traffic data by means of mobile radio telephones

Abstract: The invention concerns a method of determining traffic data from vehicles which are each equipped with at least one decentralized unit having at least one mobile communication function and a function for obtaining time information as well as a storage facility. At least one central unit with control and processing functions is associated with a plurality of decentralized units. During travel, the decentralized unit receives and evaluates data characterizing the cells, and other radio and transmission data. Data characterizing a change of cell are recorded together with time marks.

Subjective quality evaluation of tile-based streaming for omnidirectional videos

Abstract: In viewport-adaptive streaming of omnidirectional video, only the field of view is streamed in high quality. While this has significant benefits over streaming the entire 360 sphere, no standard test method for perceived quality and simulator sickness is available to evaluate the quality of experience (QoE) of such streaming approaches. QoE testing is important as tile-based viewport-adaptive streaming technologies are replacing classical approaches because of significant bandwidth savings and increase in viewing quality. In this work, we propose a testbed, a test method, as well as test metrics for QoE tests of viewport-adaptive streaming approaches. The proposed method is validated in two different test setups, using a specific tile-based streaming technology available in the market. The chosen input variables (videos sequences, resolution, bandwidth, and network round-trip delay) are tested for their statistical significance. We found that our test method is suitable for QoE testing of viewport-adaptive streaming technologies. We also found that simulator sickness scores increase with test duration, but that breaks between tests reduce this effect. With our systematic test approach, it is possible to compare metrics among different test setups. On the tested technology, we found that a typical network delay (47 ms) only has a minimal effect on the quality ratings. Furthermore, the magnitude of the network delay does not influence simulator sickness for the system we have tested.

Design and Evaluation of a Proxy Cache for Peer-to-Peer Traffic

Abstract: Peer-to-peer (P2P) systems generate a major fraction of the current Internet traffic, and they significantly increase the load on ISP networks and the cost of running and connecting customer networks (e.g., universities and companies) to the Internet. To mitigate these negative impacts, many previous works in the literature have proposed caching of P2P traffic, but very few (if any) have considered designing a caching system to actually do it. This paper demonstrates that caching P2P traffic is more complex than caching other Internet traffic, and it needs several new algorithms and storage systems. Then, the paper presents the design and evaluation of a complete, running, proxy cache for P2P traffic, called pCache. pCache transparently intercepts and serves traffic from different P2P systems. A new storage system is proposed and implemented in pCache. This storage system is optimized for storing P2P traffic, and it is shown to outperform other storage systems. In addition, a new algorithm to infer the information required to store and serve P2P traffic by the cache is proposed. Furthermore, extensive experiments to evaluate all aspects of pCache using actual implementation and real P2P traffic are presented.

AVT-VQDB-UHD-1: A Large Scale Video Quality Database for UHD-1

Abstract: 4K television screens or even with higher resolutions are currently available in the market. Moreover video streaming providers are able to stream videos in 4K resolution and beyond. Therefore, it becomes increasingly important to have a proper understanding of video quality especially in case of 4K videos. To this effect, in this paper, we present a study of subjective and objective quality assessment of 4K ultra-high-definition videos of short duration, similar to DASH segment lengths. As a first step, we conducted four subjective quality evaluation tests for compressed versions of the 4K videos. The videos were encoded using three different video codecs, namely H.264, HEVC, and VP9. The resolutions of the compressed videos ranged from 360p to 2160p with framerates varying from 15fps to 60fps. All the source 4K contents used were of 60fps. We included low quality conditions in terms of bitrate, resolution and framerate to ensure that the tests cover a wide range of conditions, and that e.g. possible models trained on this data are more general and applicable to a wider range of real world applications. The results of the subjective quality evaluation are analyzed to assess the impact of different factors such as bitrate, resolution, framerate, and content. In the second step, different state-of-the-art objective quality models were applied to all videos and their performance was analyzed in comparison with the subjective ratings, e.g. using Netflix's VMAF. The videos, subjective scores, both MOS and confidence interval per sequence and objective scores are made public for use by the community for further research.

Architecture for identifying electronic threat patterns

Abstract: The invention is a comprehensive conceptual and computational architecture that enables monitoring accumulated time-oriented data using knowledge related to the operation of elements of a computer network and deriving temporal abstractions from the accumulated data and the knowledge in order to identify electronic threat patterns and create alerts. The architecture of the invention supports two main modes of operation: a. an automated, continuous mode for monitoring, recognition and detection of known eThreats; and b. an interactive, human-operated intelligent tool for dynamic exploration of the contents of a security storage service to identify new temporal patterns that characterize such threats, and to add them to the monitoring database. The architecture of the invention can analyze data collected from various sources, such as end-user devices, network element, network links etc., to identify potentially infected devices, files, sub-streams or network segments.