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Multimedia service delivery over the Internet is a success. The number of services available and the number of people accessing them is huge. In this paper, we investigate multimedia streaming services over the Internet. Our analysis is based on traffic measurement in live access fiber-to-the-home networks. We study parameters like traffic volume and flow characteristics for selected services. Esp
The pervasive use and insatiable demand for high-performance wireless devices globally are driving the development of new communication technologies and standards. In this chapter, we present advancements in the area of terminal antenna systems and describe how they play a major role in enabling strict performance requirements to be met in future systems. As opposed to conventional systems that do
An increasing demand from e.g. real-time multimedia applications (IPTV, OTT) adds strains on especially DSL based access links. In this paper we argue why it is important to study DSL link impairments and their impact on QoS parameters on higher layers. We discuss the need for establishing methods for quality of service estimation with cross layer techniques and present some initial results.
Pattern reconfigurability is a desirable feature of mobile handset antennas, as it enables the antennas to adapt to non-stationary propagation environments. However, it is difficult to vary the radiation pattern of a handset antenna at frequencies below 1 GHz because the entire chassis commonly acts as the main radiator. Hence, designing pattern reconfigurability based on the antenna element (seco
We present a comparative exploratory analysis of two proximity networks of mobile phone users, the Proximates network and the Reality Mining network. Data for both networks were collected from mobile phones carried by two groups of users. Periodic Bluetooth scans were performed to detect the proximity of other mobile phones. The Reality Mining project took place in 2004-2005 at MIT, while Proximat
In this paper, we propose a directed and weighted graph model for describing P2P networks using BitTorrent protocol. Then, we analysis the topological properties of the model based on complex networks theory. We find that the node strength follows a power-law distribution and that there exists a positive correlation between flow betweenness and out-strength. We also include some other findings abo
MIMO systems ideally achieve linear capacity gain proportional to the number of antennas. However, the compactness of terminal devices limits the number of spatial degrees of freedom (DOFs) in such systems, which motivates efficientantenna design techniques to exploit all available DOFs. In this contribution, we present a compact six-port dielectric resonator antenna (DRA) array which utilizes spa
Background: Spot pricing is considered as a significant supplement for building a full-fledged market economy for the Cloud ecosystem. However, it seems that both providers and consumers are still hesitating to enter the Cloud spot market. The relevant academic community also has conflicting opinions about Cloud spot pricing in terms of revenue generation. Aim: This work aims to systematically ide
The growing complexity of industrial robot work-cells calls for the use of advanced orchestration techniques to promote flexibility and reusability. This paper presents a solution based on service-oriented platforms that endorses the separation of concerns, coordination and execution. The execution is kept inside each individual device and their functionality is exposed via automatic generation of
Abstract in UndeterminedAn efficient technique is introduced to reduce mutual coupling between two closely spaced PIFAs for MIMO mobile terminals. The proposed mutual coupling reduction method is based on a T-shape slot impedance transformer and can be applied to both single-band and dual-band PIFAs. For the proposed single-band dual PIFAs, the 10 dB impedance bandwidth covers the 2.4 GHz WLAN ban
Multi-antenna enabled terminal devices are required to comply with the standards for limiting human exposure to electric fields. However, when compared to traditional single-antenna terminals, a comprehensive evaluation of specific absorption rate (SAR) for multi-antenna terminals is impractical. This is because both the power allocation and phase of the electric fields from different antennas are
We have implemented a compiler for key parts of Modelica, an object-oriented language supporting equation-based modeling and simulation of complex physical systems. The compiler is extensible, to support experiments with emerging tools for physical models. To achieve extensibility, the implementation is done declaratively in JastAdd, a metacompilation system supporting modern attribute grammar mec
TV-on-Demand services have become one of the most popular Internet applications that continuously attracts high user interest. With rapidly increasing user demands, the existing network conditions may not be able to ensure a low start-up delay of video playback. Prefetching has been broadly investigated to cope with the start-up latency problem, which is also known as user perceived latency. In th
Many full-reference objective metrics require that the original and the degraded video contain the same number of frames. Most codecs are not able to decode the video properly when the video is subject to packet losses and produce incomplete video files with lower number of frames than the original video. In this paper we present a simple method to reconstruct the degraded videos so that it has th
MIMO technology has facilitated tremendous performance improvements in wireless communications, allowing the data rate to increase linearly with the number of antennas used, at no additional expense in transmit power or spectrum. However, the tremendous performance gain can only be achieved by multi-antenna designs that provide low coupling and correlation, as well as high total efficiency. Such d
Video content constitutes a large share of residential Internet traffic. The major source of video content as of today is YouTube. In this paper, we analyse the user demand patterns for YouTube in two metropolitan access networks with more than 1 million requests over three consecutive weeks in the first network and more than 600,000 requests over four consecutive weeks in the second network. In p
In this paper an approach for improving robot machining accuracy through simulation-assisted path planning within Computer-Aided Manufacturing (CAM) tools is investigated. The method comprises modeling of dynamic robot behaviour under influence of process forces and a subsequent simulation of the robot motion which results in an offline prediction of deflection errors during the machining task. Th
Finger tapping to isochronous pacing stimuli is a well established experimental paradigm first described in the late 19th century. Two variables of common interest in rhythmic tapping tasks are timing variability and constant error. However, a difficulty when estimating these variables is that at interstimulus intervals longer than 2 seconds participants regularly overshoot the target interval and
