User behaviour monitoring using mobile phones to improve 5G services and performance

Abstract 4G has been widely commercialised, and 5G is currently under development. The expected data bandwidth for 5G is 100 times faster than 4G and 500 times faster than 3G; however, the evolution of telecommunication technologies involves both a boost in speed and the enhancement of user experience. The key word used to describe 5G is ‘user-centric’, rather than ‘service-centric’ for 4G, and thus user behaviours of mobile data usage should be further investigated. On the other hand, the testing equipment currently being used for base stations is limited to hardware devices, such as spectrum analysers and power meters. These testing methods do not include the considerable potential variations in data demands due to changes in user behaviours, which could be resolved by presuming that all data resources could be dynamically allocated by real-time events. A complete system has been designed and implemented in this study to investigate current user behaviours regarding mobile data usage. The system consists of three individual parts, including a user iOS application, a web server and an administrative iOS application. Ten devices were tested within the two-month data collection period. Although the sample size was too small to produce any statistical results, it was found that data usage behaviours differ from user to user, with the exception of using more than 10 times the Wi-Fi over WWAN data at all times. The data also proved that some of the usage case families, which are described in the NGMN 5G white paper, do have strong demands, which could not be fulfilled using current telecommunication technologies due to technological gaps. This paper shows that the system proposed is a feasible method to investigate user behaviours of mobile data usage. If the sample size of users involved could be increased in the future, it would be possible to develop a model for real-time simulations of mobile users in specific areas so that limited connection resources could be dynamically allocated. Moreover, the basic communication infra-structures, such as base stations, should be well-planned and developed in advance to fulfill the potential 5G demand.</jats:p

Development of wireless sensor network using Bluetooth Low Energy (BLE) for construction noise monitoring

In this paper the development of a Wireless Sensor Network (WSN) for construction noise identification and sound locating is investigated using the novel application of Bluetooth Low Energy (BLE). Three WSNs using different system-on-chip (SoC) devices and networking protocols have been prototyped using a Raspberry Pi as the gateway in the network. The functionality of the system has been demonstrated with data logging experiments and comparisons has been made between the different WSN systems developed to identify the relative advantages of BLE. Experiments using the WSN for vehicle noise identification and sound location have further demonstrated the potential of the system. This paper demonstrates the versatility of a BLE WSNs and the low power consumption that is achievable with BLE devices for noise detection applications

An optimum design of a double pendulum in autoparametric resonance for energy harvesting applications

In this paper energy harvesting from vibrating surfaces through electromagnetic induction is addressed. A double pendulum subject to base excitations generates electrical energy through energy harvesting coils mounted on the pendulum masses. Optimum double pendulum generates energy at a rate of 9 mW for excitation parameters characteristic of bridge vibration, frequency of 2 Hz and amplitude of 1 mm

Suppression of parasitic resonance in piezoresistively transduced longitudinal mode MEMS resonators

This paper demonstrates the suppression of parasitic resonance in a piezoresistively transduced longitudinal mode MEMS resonator, wherein beams are electrostatically excited in a combined extensional mode with an associated frequency-Q product of 3.28 Ã? 1012. The response of the beam is sensed using both capacitive and piezoresistive transduction principles. The resonator consists of six parallel beams linked to a central anchor and a pair of symmetrical parallel beams that force the beams to vibrate in-phase. The mode suppression in the resonator is compared with other structures by finite element analysis (FEA). The relative distribution of strain energies in both the resonant structure and anchors and in both primary and secondary directions of vibration are proposed as figures of merit to compare this device to previously reported longitudinal mode beam resonators. The design optimization of longitudinal mode beam resonators is also discussed

Ultrasensitive mode-localized micromechanical electrometer

We report a highly sensitive prototype micromechanical electrometer that employs the phenomena of mode-localization and curve veering for monitoring minute charge fluctuations across an input capacitor. The device consists of a pair of weakly coupled, nearly identical single crystal silicon, double-ended tuning fork (DETF) resonators. An addition of charge across an input capacitor on one of the coupled resonators induces a differential axial strain on that resonator relative to the other consequently perturbing the structural symmetry of the nearly periodic system. The resulting shifts in the eigenstates for the same magnitudes of charge input are theoretically and experimentally demonstrated to be nearly three orders of magnitude greater than corresponding resonant frequency variations. The topology chosen may also be adapted for force or strain monitoring thereby widening the relevance of the results reported here to precision inertial sensing as well

Simulation of BOTDA and Rayleigh COTDR systems to study the impact of noise on dynamic sensing

This is the author acepted manuscript. It is currently under an indefinite embargo pending publication of the final version.Dynamic distributed sensing of strain and temperature is the key for real-time structural health monitoring (SHM) across a wide range of geo-engineering challenges, for which Brillouin Optical Time Domain Analysis (BOTDA) and Rayleigh Coherent Optical Time Domain Reflectometry (COTDR) are promising candidates. A noise model with specific parametric simulation of the two systems has been developed. Noise in both laser(s) and detector is independently simulated to identify the key noise sources. In this simulation, although averaging can significantly enhance the signal-to-noise ratio (SNR) in the two systems, it is a barrier to dynamic sensing due to its time-consuming accumulation procedure. The sequence of averaging in the signal processing workflow can vary the SNR for the two systems. The system components should be optimized to reduce the averaging times to achieve the required system specifications, especially the dynamic sensing performance.This project was carried out under the UCL-Cambridge Centre for Doctoral Training in Photonic Systems Development, with funding from EPSRC (EP/G037256/1) gratefully acknowledged. The funding from Cambridge Centre for Smart Infrastructure and Construction is acknowledged

Common mode rejection in electrically coupled MEMS resonators utilizing mode localization for sensor applications

Measuring shifts in eigenstates due to vibration localization in an array of weakly coupled resonators offer two distinct advantages for sensor applications as opposed to the technique of simply measuring resonant frequency shifts: (1) orders of magnitude enhancement in parametric sensitivity and (2) intrinsic common mode rejection. In this paper, we experimentally demonstrate the common mode rejection capabilities of such sensors. The vibration behavior is studied in pairs of nearly identical MEMS resonators that are electrically coupled, and subjected to small perturbations in stiffness under different ambient pressure and temperature. The shifts in the eigenstates for the same parametric perturbation in stiffness are experimentally demonstrated to be over three orders of magnitude greater than corresponding resonant frequency variations. They are also shown to remain relatively constant to variations in ambient temperature and pressure. This increased relative robustness to environmental drift, along with the advantage of ultra-high parametric sensitivity, opens the door to an alternative approach to achieving higher sensitivity and stability in micromechanical sensors

Anchor limited Q in flexural mode resonators

This paper reports a preliminary examination of the effect of anchor geometry design on the quality factor of flexural mode resonators operating in vacuum using both FE simulation and measurements of resonator frequency response. Three types of structures have been considered in this study: an elliptical mode ring, a double ended tuning fork, and a doubly-clamped beam. We consider the relative distribution of strain energies in both the resonant structure and the connecting stem, which is indicative of the measured quality factor. The measured quality factors of the different structures are compared against each other, based on which suggestions are proposed for optimizing the anchor limited quality factor (Q) in flexural mode micromechanical resonators

Dynamic response of water droplet coated silicon MEMS resonators

This paper studies the dynamic response of silicon bulk acoustic mode resonators spotted with water droplets of varying volume on the top surface. Three different cases were compared: (i) bare silicon resonators, (ii) parylene C coated resonators and (iii) hydrophobic self assembled monolayer coated resonators. Experimentally derived variations in quality factor are compared with those obtained analytically for the electrostatically driven square extensional mode resonator. The measured quality factors showed a good agreement with the models

A parametrically excited vibration energy harvester

In the arena of vibration energy harvesting, the key technical challenges continue to be low power density and narrow operational frequency bandwidth. While the convention has relied upon the activation of the fundamental mode of resonance through direct excitation, this article explores a new paradigm through the employment of parametric resonance. Unlike the former, oscillatory amplitude growth is not limited due to linear damping. Therefore, the power output can potentially build up to higher levels. Additionally, it is the onset of non-linearity that eventually limits parametric resonance; hence, this approach can also potentially broaden the operating frequency range. Theoretical prediction and numerical modelling have suggested an order higher in oscillatory amplitude growth. An experimental macro-sized electromagnetic prototype (practical volume of ~1800 cm3) when driven into parametric resonance, has demonstrated around 50% increase in half power band and an order of magnitude higher peak power density normalised against input acceleration squared (293 µW cm−3 m−2 s4 with 171.5 mW at 0.57 m s−2) in contrast to the same prototype directly driven at fundamental resonance (36.5 µW cm−3 m−2 s4 with 27.75 mW at 0.65 m s−2). This figure suggests promising potentials while comparing with current state-of-the-art macro-sized counterparts, such as Perpetuum’s PMG-17 (119 µW cm−3 m−2 s4)