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Downlink exposure to electromagnetic fields due to cellular base stations in urban environments is studied using the stochastic geometry framework. A two-dimensional Poisson Point Process is assumed for the base station distribution. Mathematical expressions of statistics of exposure are derived from a simple propagation model taking into account the height of the base stations. The error on exposure made by taking a limited number of base stations, instead of the whole set, is quantified. The relative impact of the model parameters on the statistics of exposure is highlighted. The method is then applied and the model parameters are calibrated using experimental data obtained by drive-tests in two Brussels municipalities, in Belgium, for the 2100 MHz and 2600 MHz frequency bands. It is shown that the proposed model fits experimental values, paving the way to a new methodology to assess general public exposure to electromagnetic fields, for any frequency band. An insight is given on how to apply the methodology to a real case without access to experimental data., info:eu-repo/semantics/published

Exposure to electromagnetic fields due to cellular networks in an urban environment is studied using stochastic geometry. We describe a simple but functional and realistic semi-empirical model based on the modeling of base station patterns as Poisson Point Processes and applied to two Brussels municipalities. Using this model, a study of the impact of base station densification is performed according to two theoretical scenarios. From simple assumptions, it is concluded that global exposure is expected to remain approximately constant in the case of intelligent network evolution involving the densification of macro cells and the addition of a network of low-power small cells.

Exposure to electromagnetic fields due to cellularnetworks in an urban environment is studied using stochasticgeometry. We describe a simple but functional and realisticsemi-empirical model based on the modeling of base stationpatterns as Poisson Point Processes and applied to two Brusselsmunicipalities. Using this model, a study of the impact of basestation densification is performed according to two theoreticalscenarios. From simple assumptions, it is concluded that globalexposure is expected to remain approximately constant in thecase of intelligent network evolution involving the densificationof macro cells and the addition of a network of low-power smallcells., info:eu-repo/semantics/published

The introduction of the Bluetooth Low Energy(BLE) standard significantly streamlines the developmentof the Internet of Things (IoT) applications. These applicationsoften require the sensor positioning to link themeasurements with its location. Therefore, it is essential toconduct studies on BLE transmitter positioning methods.Power fingerprinting transmitter positioning approachesare commonly used in BLE network. However, thesemethods have their own limitations in terms of practicaluse and ease of implementation. The purpose is to developa simple BLE transmitter positioning of high accuracy.In this paper, a BLE transmitter positioning method isproposed based on Angle of Arrival (AOA) estimation.Multiple Signal Classification (MUSIC) algorithm is usedfor angle estimation due to the high angular resolutionand sensitivity. Several experiments have been conductedin an indoor environment and the results compared withsimulation results. Experimental results show that ourproposed BLE transmitter positioning method achieves apromising positioning accuracy., info:eu-repo/semantics/published

In this paper, we present a theoretical investigation on the radiation efficiency of small on-body antennas in the context of Body Area Networks. In particular, we show that operation at frequencies above 20 GHz experiences less human-tissue losses than below 6 GHz, and could therefore be a suitable candidate for more efficient off-body wireless communications., SCOPUS: cp.p, info:eu-repo/semantics/published

A 6.6 dBi-gain Substrate Integrated Waveguide (SIW) horn antenna is used for off-body channel measurement at 60 GHz. Statistical scenario-based measurements are more suitable to assess Body Area Network (BAN) communication since they include both the environment and the antenna behaviors. Measurements are performed for four scenarios and two antenna positions. Results are discussed and compared with measurements at 4 GHz using a SkyCross monopole antenna in terms of link outage probability using receiver performance from the literature. In particular, it is shown that in all considered scenarios, results at 4 GHz and at 60 GHz led to outage of less than 15% and less than 8% respectively., info:eu-repo/semantics/published

info:eu-repo/semantics/published

info:eu-repo/semantics/published

info:eu-repo/semantics/published

A wideband indoor channel model between an external base station and a worn receiver on the user body at 60 GHz has been developed based on indoor measurements. The results are presented for three different receiver locations: head, wrist, and belt. A Saleh-Valenzuela impulse response is proposed as numerical model for this scenario. Also path loss and delay spread results are driven out in order to discuss the node location for assessing an off-body communication., SCOPUS: ar.j, info:eu-repo/semantics/published

In this paper, we present a theoretical investigation on the radiation efficiency of small on-body antennas in the context of Body Area Networks. In particular, we show that operation at frequencies above 20 GHz experiences less human-tissue losses than below 6 GHz, and could therefore be a suitable candidate for more efficient off-body wireless communications., info:eu-repo/semantics/published

Performance of impulse radio-based ultra-wideband (IR-UWB) communications in wireless body area networks are investigated using the dedicated IEEE 802.15.6 standard. An IR-UWB transceiver system is implemented for both on-off keying and differential binary phase-shift keying modulations. Bit error rates are determined from measurements for different on-body links with different data rates. It is shown that that using a 25 dB-gain LNA at the receiver, reaching an uncoded BER of 10-3 was not possible for some links operating at higher data rates. Power and energy consumption issues are then addressed and results in terms of required pJ/bit to achieve a certain quality of communication are given and discussed., SCOPUS: ar.j, info:eu-repo/semantics/published

Millington effect for on-body propagation enhancement is presented in the 60-GHz band. Millington's equations are developed to describe propagation above a flat inhomogeneous surface. This study focuses on mixed paths (human skin-metallic) for on-body scenarios. It is shown that adding metallic paths on the human skin can improve the power link budget between two nodes placed on the body. Two different schemes are studied experimentally to assess the analytical model using a flat phantom with electric properties of human skin and different lengths of metallic inserts. The first scheme considers a metallic plate between the transmitting and receiving antennas, while the second scheme proposes locating the metallic plates under the antennas. It is shown that the second scheme yields a better link budget than the first one for the same length of metal. Moreover, a numerical study is performed to assess the impact of the following different parameters: the location of the metal plate, size of the plate, and the height of the antennas. Excellent agreement between numerical and experimental results has been shown. In the best cases, the presented techniques allow to improve the path loss of 10-20 dB., SCOPUS: ar.j, info:eu-repo/semantics/published