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Large-scale science applications generate great volumes of data, which are frequently stored in remote data repositories or shared with cooperating laboratories across the network through the use of advance reservation connections. The groups that utilize these data transfers would benefit from having their applications simultaneously transmit data over multiple channels in parallel. Many of today's...
Wireless sensor networks possess significant limitations in storage, bandwidth, and power. This has led to the development of several compression algorithms designed for sensor networks. Many of these methods exploit the correlation often present between the data on different sensors in the network. Most of these algorithms require collecting a great deal of data before compressing which introduces...
Servers and network contribute about 60% to the total cost of data center in cloud computing. How to efficiently place virtual machines so that the cost can be saved as much as possible, while guaranteeing the quality of service plays a critical role in enhancing the competitiveness of service cloud provider. Considering the heterogeneous servers and the random property of multiple resources requirements...
Recent publications have emphasized the power of high-resolution, low-distance EM measurements for side channel analysis. In this paper, we investigate several aspects of such measurements, e.g. different coil-diameters, probe-to-die distances, bandwidths and spatial measurement resolutions. We use an FPGA-based implementation of an AES s-box as device under test and perform measurements of the magnetic...
Reduced feedback schemes facilitate scheduling and rate adaptation in orthogonal frequency division multiplexing systems while reducing the number of subchannels (SCs) for which channel state information (CSI) is fed back. In the popular selective feedback scheme, each user feeds back CSI about only its strongest SC to the base station (BS). We focus on the less studied, but practically important...
The increasing demand for high quality Content delivery has driven both network and service providers involved in (real time) media streaming to apply appropriate technologies as to offer better Quality of Services (QoS). Since frequently Content Service Providers (CSP) and Network Providers (NP) are separate business entities, it is not always possible for CSPs to obtain detailed network related...
In this article we describe a novel process for blind detection in spectrum sensing taking advantage of the cyclostationary features of any digital modulation that uses a finite number of distinct signals to represent digital data. Traditional models only look at any peak in a cyclic spectrum that satisfies a given threshold, in this method we take advantage of the cyclic spectrum leakage to identify...
In this article we describe a novel process for blind detection in spectrum sensing taking advantage of the cyclostationary features of any digital modulation that uses a finite number of distinct signals to represent digital data. Traditional models only look at any peak in a cyclic spectrum that satisfies a given threshold, in this method we take advantage of the cyclic spectrum leakage to identify...
In dense environments, such as residential, office or industrial sites, the predominant type of link encountered by a radio based real-time localization system (RTLS) is non-line-of-sight (NLOS). Often, the mobile nodes are separated from their related anchor nodes by the building's walls. In Impulse Radio Ultra Wideband (IR-UWB) based localization systems, the penetration of walls can cause significant...
The performance of ultra wideband (UWB) communications are very important for short range wireless communication to consider with matched filter and correlation receivers are evaluated. The rectangular passband, modulated rectangular and modulated Gaussian waveforms, which is satisfied the UWB signal definition and Federal Communications Commission (FCC) indoor and outdoor limit spectral masks, are...
Cognitive radio constitutes a very promising solution to improve spectrum usage of communication systems. However, being equipped with MIMO antennas, the design of CR devices poses tremendous challenges. In this paper, antennas requirements as well as the limitations imposed on the system performance are reviewed. Well decoupled and reconfigurable antennas guarantee the flexibility needed during spectrum...
Network providers are nowadays facing with a big question in allocating network resources due to the constantly increasing of Internet services. While the network resource is not unlimited, users always desire the best quality of experience (QoE) with the huge information exchange. Therefore, finding a justice of network resource allocation based on the user experience is mandatory. In previous studies,...
Most studies on the perceptual quality evaluation of multi-media services are limited to short media samples or epi-sodes, although typical usage of services occurs in a more regular way over longer periods of exposure (weeks, months or years). So far, it is unclear how the experience of individ-ual episodic use is integrated to form an experience of one service as a whole, spanning over multiple...
As the user traffic increases dramatically, wireless local area networks (WLANs) have been evolving to satisfy increasing traffic demands. IEEE 802.11ac, as the latest amendment to the family of WLAN standards, provides data rates on the order of 109. However, due to the large scale deployment of WLANs with such high speeds, their energy consumption has become a critical issue. In this paper, we present...
This paper describes feasibility of RSSI (Received Signal Strength Indicator) based access network detection for multi-band WLAN (Wireless LAN) using 2.4/5GHz and 60GHz aiming at power-saving of multi-band WLAN device and higher spectrum efficiency. The proposed scheme detects 60GHz coverage by using 2.4/5GHz WLAN signals without using 60GHz WLAN signals for on/off control of 60GHz part of multi-band...
Configuration validation is the process of automatically assessing whether the various configuration parameters of a network's devices are set to appropriate values according to a set of formal constraints given beforehand. Virtually all automated validation solutions presented to date assume a centralized and complete knowledge of the network's configuration to perform their analysis. We present...
Wireless communication mainly depends upon the channel through which the signals are travelling. The underwater channel poses numerous challenges for wireless communication. Underwater communication suffers from long propagation delay, multipath and fading, limited bandwidth, and potentially high spatial and temporal variability. This paper analyses the statistical characteristics of underwater channel...
Since 2010 we have been developing a quantum-voltage-calibrated Johnson noise thermometer at NIM to measure the Boltzmann constant k. With recent improvements in grounding and shielding of the electronics, and matching of the noise sources and transmission lines, the effects of electromagnetic interference and variations of fitting parameters with different bandwidths were greatly reduced. By combining...
Sensing technology using radio wave has been attracting attention for various applications such as office/home security and surveillance. Classification of human motion has been extensively studied in these applications. They often utilize Doppler frequency characteristic occurred by human motion. In this paper, range-Doppler distributions by human motion are studied. We show range-Doppler signatures...
A new tap-delay-line (TDL) channel model based on indoor radio wave propagation characteristics and measurement data is developed in this paper. It can estimate the mean power delay profile (PDP) simply and effectively for the LOS and NLOS routes. The model is proven to be consistent with the measurement results. Under the assumption of the WSSUS channels, the tap frequency correlations, tap amplitude...
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