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The response of personal exposimeters (PEMs) is studied under diffuse field exposure in indoor environments. A numerical model and a setup for on-body calibration measurements in a reverberation chamber (RC) is proposed for 897–5500 MHz. The proposed numerical simulations are in good agreement with measurements. A difference around 2 dB between their 50% prediction intervals is observed.
Industrial WiFi network planning for a very large industrial hall is performed and results are compared for two planning approaches, namely an experimental site survey and a software-based automated planning. A software-automated process and a site survey yield comparable results. Reliable results can be obtained using an automated network planner with much less effort than when executing a time-consuming...
A geometry-based reference model for Second Order Scattering Fading (SOSF) distributed multiple-input-multiple-output (MIMO) channels is proposed for mobile-to-mobile scenarios. From this model, a spatial correlation function is derived. The time-variant nature of channel statistics is modeled by using a Hidden Markov Model (HMM) based approach. The proposed method enables to implement a generator...
The power consumption of wireless access networks is an important issue. In this paper, the power consumption of LTE base stations is optimized. We consider the city of Ghent, Belgium with 75 possible LTE base station locations. We optimize the network towards two objectives: the coverage maximization and the power consumption minimization. We propose a design framework based on Differential Evolution...
This paper presents a location tracking system that improves its performance by mitigating the influence caused by the human body of the user being tracked. The presence of such a user will influence the signal path between a body-worn mobile device and a receiving node. This influence will vary with the user's location and orientation and, as a result, the performance will deteriorate. By making...
In this work a real-time indoor localisation system based on the Viterbi algorithm is developed. This Viterbi principle is used in combination with semantic data to improve the accuracy: i.e., the environment of the object that is being tracked and an adjustable maximum speed. The developed algorithm was verified by simulations and with experiments in a building-wide testbed for sensor and WiFi experiments...
An analysis of delay-Doppler characteristics in the presence of moving people is presented for short-range communications in an indoor environment. Channel sounding measurements have been carried out at 3.6 GHz in a crowded university-hall during short and long breaks between courses. The measurements reveal a difference between the RMS Doppler spread of both breaks, indicating a distinctive power...
We present a multi-objective optimization approach for indoor wireless network planning subject to constraints for exposure minimization, coverage maximization and power consumption minimization. We consider heterogeneous networks consisting of WiFi Access Points (APs) and Long Term Evolution (LTE) femtocells. We propose a design framework based on Multi-objective Biogeography-based Optimization (MOBBO)...
Thanks to the active development of IEEE 802.11, the performance of wireless local area networks (WLANs) is improving by every new edition of the standard facilitating large enterprises to rely on Wi-Fi for more demanding applications. The limited number of channels in the unlicensed industrial scientific medical frequency band however is one of the key bottlenecks of Wi-Fi when scalability and robustness...
Mobile video consumption through streaming is becoming increasingly popular. The video parameters for an optimal quality are often automatically determined based on device and network conditions. Current mobile video services typically decide on these parameters before starting the video streaming and stick to these parameters during video playback. However in a mobile environment, conditions may...
A full-polarimetric model of the power delay profile (PDP) is proposed in a large hall scenario and validated with polarimetric measurements of a large open hall radio channel under Line-of-Sight conditions at 1.3 GHz. The measured radio channels were processed by the high-resolution parametric estimator RiMAX to estimate both the polarimetric specular multipath components (SMC) and dense multipath...
Large scale growth of wireless networks and the scarcity of the electromagnetic spectrum are imposing more interference to the wireless terminals which jeopardize the Quality of Service offered to the end users. In order to address this kind of performance degradation, this paper proposes a novel experimentally verified cognitive decision engine which aims at optimizing the throughput of IEEE 802...
In critical healthcare applications, there is a need for reliable wideband mobile communication links, implemented by portable units with sufficient autonomy. We present the latest generation wearable antenna systems for invisible and comfortable integration in patients' or caregivers' garments. These active textile modules boast excellent performance and reliability, thanks to innovative antenna...
When developing future networks, both power consumption and exposure of human beings will become important parameters. Here, a capacity based deployment tool is proposed whereby the developed network is optimized towards power consumption, power consumption while satisfying a certain exposure limit, or exposure accounting for coverage and capacity requirements. Applying this tool on a realistic suburban...
This paper presents an analysis of the polarization characteristics of specular and dense multipath components (SMC & DMC) in a large industrial hall based on frequency-domain channel sounding experiments at 1.3 GHz with 22 MHz bandwidth. The RiMAX maximum-likelihood estimator is used to extract the full polarimetric SMC and DMC from the measurement data by taking into account the polarimetric...
The increased use of wireless local area networks has led to an increased interference and a reduced performance, as a high amount of access points are often operating on the same frequency channel. This paper presents a network planning algorithm that minimizes the number of access points required for a certain throughput and optimizes the frequency allocated to each AP, leading to reduced interference...
In this work, an analysis of the Doppler characteristics for Ultra-Wideband indoor communication is presented. Channel sounding measurements ranging from 3.1 to 10.6 GHz were performed over the course of several days in an occupied office environment, with the help of a network analyzer. Based on these measurements, we analyze the behavior of both the Doppler spread and RMS Doppler spread in the Ultra-Wideband...
The electromagnetic reverberation time characteristics are investigated at UltraWide Band (UWB) frequencies, i.e., from 2 to 10 GHz. The reverberation time is bandwidth independent and decreases as the frequency increases. Besides, the reverberation ratio - the contribution of the diffuse fields in the total power - is addressed as well. The reverberation ratio increases also with larger Tx-Rx separation,...
As the wireless medium is becoming more and more congested, a better use of the scarce frequency spectrum is needed to deliver the required Quality of Service (QoS) to clients. Especially in unlicensed bands, wireless systems suffer from intra-network interference [1], e.g., in professional wireless conferencing environments [2]. Therefore, cognitive solutions are being developed, both on radio and...
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