||Dynamic Spectrum Access research and development in South Africa
||Albert A. Lysko
||The submission discusses the achievements and trends in the dynamic spectrum access (DSA) research and development efforts in South Africa and some African countries. This starts with cognitive radio lab, television white space (TVWS) trials and now leads into the DSA and 5G.
||DWG1, DWG2, EWG-RA
||UWB Millimeter-Wave and Terahertz Monostatic Near field Synthetic Aperture Imaging
||María-Teresa Martínez-Inglés, Jose-Maria Molina-Garcia-Pardo, Davy P. Gaillot, J. Romeu, L. Jofre
||Millimeter-wave and Terahertz frequencies offer unique characteristics to simultaneously obtain good spatial resolution and penetrability. In this paper a robust near-field monostatic focusing technique is presented and successfully applied to the internal imaging of different penetrable geometries. Two sets of measurements have been performed in the bands of 100GHz (75 to 110GHz) and 300 GHz (220 to 330 GHz). Results show spatial resolutions of mm in both range (longitudinal) and cross-range (transversal) dimensions. The imaging quality in terms of spatial accuracy and target material parameter will be investigated and optimized.
||Load balance performance analysis with a quality of experience perspective in LTE networks
||María Luisa Marí Altozano, Salvador Luna Ramírez, Matías Toril Genovés
||Due to the huge increase in traffic and services in mobile networks, network management has changed its main focus from Quality of Service (QoS) to Quality of Experience (QoE). In addition, SON (Self Organising Networks) techniques have been developed to automate network management, being load balancing a key use case. Load balancing aims to balance the traffic among adjacent cells in the hope that this balance will decrease the overall blocking ratio, thus increasing the total carried traffic in the network. Nevertheless, this technique may fail when QoE perspective is considered. In this work, a QoE network sensitivity analysis is performed in a LTE network with different services and traffic conditions. Different traffic sharing techniques are tested and limitations of classical cell load balancing algorithm are shown when a QoE performance perspective is considered.
||Low-Complexity Equalization for Orthogonal Time and Frequency Signaling (OTFS)
||Thomas Zemen, Markus Hofer and David Loeschenbrand
||Recently a new precoding technique called orthogonal time-frequency signaling (OTFS) has been proposed for time- and frequency-selective communication channels. OTFS can be used on top of orthogonal frequency division multiplexing (OFDM) and uses 2-D linear spreading sequences in time and frequency which are the basis functions of a symplectic Fourier transform. OTFS allows the utilization of delay and Doppler diversity but requires maximum likelihood decoding to achieve full diversity. In this paper we show performance results of a low-complexity equalizer using soft-symbol feedback for interference cancellation after an initial minimum-mean square error equalization step. Performance results for an implementation in the delay-Doppler domain and in the time-frequency domain are compared.
||Measurement based Spatial Characteristics of MPCs in Train-to-Train Propagation
||Paul Unterhuber, Thomas Jost, Wei Wang, Thomas Kurner
||Railway operators all over the world, whether for high speed trains, commuter trains or subways, request for applications to increase the density and efficiency on their rails. One of those future applications is virtual coupling based on a train-to-train (T2T) link. To characterize the propagation effects between two moving trains a T2T channel sounding measurement campaign was performed. For post-processing our data, we use the Kalman enhanced super resolution tracking (KEST) algorithm to detect and track the multipath components (MPCs). For pure SISO measurements, as performed in our measurements with moving transmitter train and moving receiver train, only the complex amplitude, delay, phase and life time of the MPCs can be derived. First results of the post-processing and possibilities to mitigate ambiguities of the scattering positions are presented in this paper.
||Scenarios and Architectures for RRM and Optimization of Heterogenous Networks
||Sofia C. Sousa, Fernando J. Velez, Kazi Huq, Shahid Mumtaz and Jonathan Rodriguez
||This work summarizes the state of the art information related to scenarios and architectures from Energy-efficient High-speed Cost Effective Cooperative Backhaul for LTE/LTE-A Small-cells (E-COOP) technologies. One of the proposed architectures exploits infrastructure based on small cell deployment using RRU technology which is connected to the core network using backhaul technology based on fibre optic links. In E-COOP, we go beyond this by addressing four key scenarios in terms of fronthaul deployment strategy (scenario 1) for C-RAN and carrier aggregation (scenario 2). The third scenario exploits the C-RAN architecture to firstly split the control/ data plane where the macro base station improves the signalling service for the whole area. Also, mobile small cells (SCs) are cooperatively specialized towards delivering data services for high-rate transmission with light overhead control and appropriate air interface (mmWave) – scenario 3. This raises significant research challenges in terms of mobile small cell coexistence, and mobility management. In scenario 4, we consider SON in LTE-A for HetNets with ultra-dense small cell deployment with imperfect backhaul. A Primary Network is considered that is overlaid with a cognitive network of Small Cell Networks, performing local sensing and local self-configuration and -optimization algorithms.
||Angle of Elevation dependence on building entry loss models
||Satyam Dwivedi, Jonas Medbo, Dennis Sundman
||In this TD we describe our work on evaluating elevation angle dependence on the building entry loss model. We describe the measurement campaign and further analysis to evaluate this dependence. Finally, we propose a excess loss model for elevation angle dependence.
||Effect of Human Body Morphology on Measurement Uncertainty of A Multi-Band Body-Worn Distributed-Exposimeter
||Reza Aminzadeh, Arno Thielens, Patrick Van Torre, Sam Agneessens, Mathias Van den Bossche, Stefan Dongus, Marloes Eeftens, Anke Huss, Roel Vermeulen, René de Seze, Paul Mazet, Elisabeth Cardis, Hendrik Rogier, Martin Röösli, Luc Martens, and Wout Joseph
||For the first time, a multi-band body-worn distributed exposimeter (BWDM) calibrated for simultaneous measurement of the incident power density (Sinc) in 11 frequency bands, is proposed. The BDWM consists of 22 textile antennas integrated in a garment and is calibrated on five human subjects in an anechoic chamber to assess its measurement uncertainty in terms of 68% confidence interval (CI68) of the on-body antenna aperture. The BWDM has a CI68 range of 2.7-8.8 dB for the five subjects participating in calibration measurements. The results show that using a combination of two antennas on the body leads to a maximum 0.1-3.2 dB difference in CI68 values for different body morphologies.
||5G for Factories of the Future: an Introduction to H2020 Clear5G Project
||In this short presentation, I’d like to introduce the new H2020 Clear5G project. Clera5G aims to empower the future use of wireless technologies for machine-type communication in Factories of the Future (FoF), in a converged manner. Clear5G addresses technological challenges at PHY, MAC and Networking layers of 5G radio networks. It studies, develops and demonstrates suitable solutions using testbeds/facilities available in both Europa and Taiwan. The major technical challenges addressed are low latency, high reliability and dense connectivity.
||Volume Integral Equation Based In-Building Propagation Modelling
||Ian Kavanagh and Conor Brennan
||The transition towards next generation communications has increased the need for fast and accurate propagation models that can predict all aspects of the wireless channel. This paper presents a novel approach to propagation modelling for indoor environments. The model is based on the 2D formulation of the volume electric field integral equation (VEFIE). The VEFIE is solved using the method of moments (MoM) and an iterative solver accelerated with the fast Fourier transform. The MoM solution of the 2D VEFIE is heuristically corrected to account for 3D propagation effects. Accurate predictions can be computed significantly faster using this approach over full 3D methods. The model is compared with the 3D VEFIE and validated against measurements against which it demonstrates a high level of accuracy while requiring a fraction of the runtime. The computation of accurate time domain predictions, that would be unfeasible with a full 3D frequency domain solution, is demonstrated also and compared against an approximate model based on reverberation theory.
||Radio Resource and Service Orchestration for Virtualised Multi-tenant Mobile Het-Nets
||Behnam Rouzbehani, Luis M. Correia, Luísa Caeiro
||Virtualisation as a promising technology for future mobile communications enables the principle of customised services and multi-tenancy by providing a shared resource platform to all the tenants in an isolated manner. This paper proposes a model of radio resource management in virtualised heterogeneous mobile networks comprised of different access technologies. To realise the concept of virtualisation, the roles of Infrastructure Providers (InPs) and network operators are separated. A virtualisation platform is responsible to aggregate and virtualise all the radio resources from different access technologies owned by InPs and to distribute the total capacity among various Virtual Network Operators (VNOs) in the role of tenants, according to service priorities and some fairness criteria, with the aim of satisfying their Service Level Agreements (SLAs). The model considers two VNOs with the capability of providing different service classes and SLAs in a multi access technology environment. Results under different channel conditions and traffic intensity confirms a level of isolation in the performance of each VNO, while the SLAs are addressed to the highest possible level. Furthermore, almost always 100% of the aggregated capacity is utilised independent of the variation of different network parameters.
||Measurements of High-Speed Data Transmission Radio Link for Special Applications
||Pawel T. Kosz, Piotr Rajchowski, Krzysztof K. Cwalina, Jacek Stefanski, Jaroslaw Sadowski
||In the article measurements of high-speed data transmission radio link for special applications were presented. Build measurement stand, measurement scenario and obtained results were briefly described. All conducted research work took place in real maritime environment.
||Radio Channel Measurements in Off-Body Communications in a Ferry Passenger Cabin
||Pawel T. Kosz, Slawomir J. Ambroziak, and Luis M. Correia
||This paper presents an off-body radio channel measurements in a ferry passenger cabin at 2.45 GHz band, for static sleeping scenarios with different body orientation and on-body antennas placements, and also for upper and lower sleeping berths. The measurements have been performed with two types of on-body wearable receiving antennas: FlexPIFA (flexible planar inverted F antenna), and FlexNotch (flexible adhesive-backed notch antenna) and one patch off-body transmitting antenna. The measurement equipment, measurement environment and investigated scenarios are described. A preliminary analysis of the results – the mean value (μ) and standard deviation (σ) – is presented. In general, the propagation path loss mainly depends on the type and location of the receiving antennas, and also on the body orientation during sleeping and surrounding elements of environment. The lowest mean path loss values (both below 56 dB) were obtained for upper sleeping berth and scenario, where receiving FlexPIFA antennas were mounted on chest and back during lying on the left side. In contrast, the highest values (both over 70 dB) were obtained for upper sleeping berth and scenario, where FlexNotch antennas were mounted on chest and right wrist during lying on the left side. Moreover, the standard deviation varies in a range from 3.7 dB up to 8.0 dB for all cases.
||Research and Analysis of High-Speed Data Transmission Radio Link Designed for Maritime Environment
||Piotr Rajchowski, Krzysztof K. Cwalina, Pawel T. Kosz, Jacek Stefanski, Jaroslaw Sadowski
||In these article, the realization of digital radio link for high-speed data transmission was presented. Its concept and practical realization, using USRP devices from National Instruments, were described. Developed software for generation and reception of digital signals in baseband, including description of modulation types, and time and frequency synchronization mechanisms, was presented. Moreover, an operation of designed radio link in laboratory conditions was also subscribed.
||New Method for Increasing Precision of Position Estimation of a Moving Person in Hybrid Inertial Navigation System
||Piotr Rajchowski, Jacek Stefański, Jarosław Sadowski
||In this article a new method for increasing precision of position estimation of inertial navigation in hybrid localization system with reduced number of reference nodes for radio distance measurements is presented. Measuring tests were carried out to verify precision of position estimation of moving person in indoor environment.
||Localisation and Tracking,SEWG-IoT
||Increased reliability of outdoor millimeter-wave link simulations by leveraging Lidar point cloud data
||Julien Stéphan, Yoann Corre, Romain Charbonnier and Yves Lostanlen
||Exploitation of the millimeter-wave (mmWave) band for both the small-cell radio access (RAN) and in-street backhauling must contribute to strongly increase the capacity of next-generation outdoor wireless networks. Besides the numerous technological challenges faced by the equipment manufacturers, the definition of deployment requirements and the elaboration of efficient network design procedures are key issues for future network providers and the refinement of business models. The work reported in the present paper is part of research activity on small-cell and wireless backhaul design methodologies. The authors analyze how digital geographical data and radio propagation models may be enhanced and tailored to answer new mmWave simulation requirements. Three different methods are compared in an urban 60-GHz scenario: based on free building database, traditional high-resolution map data, or Lidar point cloud. The advantage of the multi-paths prediction versus direct-path is also investigated, using the Lidar point cloud as a simulation input.
||Vibration Effects of Train Wagons on the mmWave Wagon-to-Wagon Channel
||Mohammad Soliman, Youssef Dawoud, Emanuel Staudinger, Stephan Sand, Andreas Schütz and Armin Dekorsy
||In this paper we analyze the mechanical aspects of vibrations on train locomotives and coupler areas and their effect on the wireless train wagon-to-wagon channel. We study the effect of vibration on mm-wave wireless systems between train wagons by performing a measurement campaign and analyzing the logged vibration data. We show the effect of vibrations on Doppler shifts, Doppler spread, and channel coherence time. We show that the coherence time values are large enough to keep the channel static for short packets used in wagon-to-wagon wireless train control and management systems (TCMS).
||Channel Capacity Analysis of Indoor Environments for Location-aware Communications
||Anh Nguyen Hong, Michael Rath, Erik Leitinger, Stefan Hinteregger, Khang Nguyen Van, and Klaus Witrisal
||Location awareness is a key factor for a wealth of wireless applications. Ultra-wideband (UWB)-based localization achieves centimeter-level accuracies in harsh indoor environments that are characterized as dense multipath propagation channels. Individual multi-path components (MPCs) can be resolved and used for accurate and robust positioning. In our previous research, tracking filters have been developed that can estimate the parameters of individual MPCs from measured channel impulse responses for this purpose. In this paper, we analyze the channel capacity of these individual propagation paths to assess the robustness of an indoor wireless link and its predictability by means of this resolved channel model. The relation between the capacity and the model parameters is evaluated through the analysis of experiment data. It is shown that the variability of the overall channel capacity can be closely approximated by the proposed statistical model.
||Localisation and Tracking
||On Mutual Information of Measured 60 GHz Wideband Indoor MIMO Channels: Time Domain Singular Values
||Jiri Blumenstein, Roman Marsalek, Tomas Gotthans, Ronald Nissel and Markus Rupp
||This paper presents a report on mutual information based on measured indoor millimeter-wave (mmWave) channels with multiple antennas at input and output (MIMO). We show that for fixed indoor communication systems, an optimal antenna element spacing can be found such that the measured mutual information almost reaches the capacity of a perfectly orthogonal (theoretical) MIMO channel (with the same number of receiver (RX) and transmitter (TX) antennas). Secondly, we present, that even though the measured channel transfer functions (CTFs) exhibit large fluctuations (i.e., temporal dispersion), the mutual information is mainly determined by the mean singular value of the line-of-sight (LOS) components. Due to their strong variations over frequency mmWave channels are tedious when describing them with classical methods in the frequency domain. An approximation by numerous flat subbands leads to an error in mutual information (MI) by 2bit/s/Hz. Our proposed method in the time domain, however, offers a notably smaller error when compared to MI.
||A new QoE-based approach for HO parameter tuning in LTE networks
||C. Gijón, S. Luna-Ramírez, M. Toril
||The increase in traffic and services in mobile network has lead network management to become a very complicated task. This fact has motivated the development of many algorithms in a Self-Organized Network (SON) framework, such as Mobility Load Balancing (MLB). MLB achieves to solve congestion problems by sharing traffic demand among neighbour cells through the modification of handover parameters. However, it presents some limitations in current LTE networks. This limitations have a negative impact on end-user throughput and thus in Quality of Experience (QoE) perceived by end-users. In this paper, a sensitivity analysis of throughput according to HandOver (HO) margins is presented and an alternative criteria for tuning HO margins is introduced, focusing on end-user throughput. The assessment is carried out in a pilot LTE network. Results show that the proposed indicator improves network performance in terms of end-user throughput from that obtained with classical MLB algorithms.
||Control-aware Scheduling Policies for Energy Harvesting Sensors
||Miguel Calvo-Fullana, Carles Antón-Haro, Javier Matamoros, and Alejandro Ribeiro
||In this paper, we study wireless networked control systems with energy harvesting sensors. Multiple sensors share a wireless medium over which they transmit measurements to their respective controllers, and due to the shared medium, packet collisions occur if sensors transmit simultaneously. To alleviate this problem, we propose random access policies that satisfy a desired control performance on each control loop, while also satisfying the energy constraints imposed by the energy harvesting process. The optimal scheduling policy is shown to follow a simple thresholding operation. Moreover, we provide a stochastic dual method for their computation, which is shown to be decoupled across sensors. Finally, we verify numerically the properties of the proposed policy.
||Robust Near-Field 3D Localization of an Unaligned Single-Coil Agent Using Unobtrusive Anchors
||Gregor Dumphart, Eric Slottke, Armin Wittneben
||The magnetic near-field provides a suitable means for indoor localization, due to its insensitivity to the environment and strong spatial gradients. We consider indoor localization setups consisting of flat coils, allowing for convenient integration of the agent coil into a mobile device (e.g., a smart phone or wristband) and flush mounting of the anchor coils to walls. In order to study such setups systematically, we first express the Cram\’er-Rao lower bound (CRLB) on the position error for unknown orientation and evaluate its distribution within a square room of variable size, using 15 x 10cm anchor coils and a commercial NFC antenna at the agent. Thereby, we find cm-accuracy being achievable in a room of 10 x 10 x 3 meters with 12 flat wall-mounted anchors and with 10mW used for the generation of magnetic fields. Practically achieving such estimation performance is, however, difficult because of the non-convex 5D likelihood function. To that end, we propose a fast and accurate weighted least squares (WLS) algorithm which is insensitive to initialization. This is enabled by effectively eliminating the orientation nuisance parameter in a rigorous fashion and scaling the individual anchor observations, leading to a smoothed 3D cost function. Using WLS estimates to initialize a maximum-likelihood (ML) solver yields accuracy near the theoretical limit in up to 98% of cases, thus enabling robust indoor localization with unobtrusive infrastructure, with a computational efficiency suitable for real-time processing.
||Localisation and Tracking
||Localization for Capsule Endoscopy at UWB Frequencies using an Experimental Multilayer Phantom
||Martina Bambi, Sofia Perez-Simbor, Concepcion Garcia-Pardo, Sergio Castelló-Palacios, Carlos Andreu, Alejandro Fornes-Leal, Narcís Cardona
||Localization inside the human body using ultra-wideband (UWB) radio frequency transmission is gaining importance in a number of applications such as capsule endoscopy. Performance analysis of RF based localization techniques are mainly conducted through simulations using numerical human models or through experimental measurements using homogeneous phantoms. One of the most common implemented RF localization approaches uses the received signal strength (RSS). However, no experimental measurements employing multilayer phantoms are currently available in literature. This paper investigates the performance of RSS-based technique for two-dimensional (2D) localization by employing a two-layer experimental phantom model. Preliminary results on the estimation of the in-body antenna coordinates show that RSS-based method can achieve a location accuracy on average of 0.5-1 cm within a certain range of distances between in-body and on-body antenna.
||EWG-IoT,Localisation and Tracking,SEWG-IoT
||Ray-tracing Based Fingerprinting for Indoor Localization
||Olivier Renaudin, Thomas Burgess, Thomas Zemen
||Fingerprinting is currently one of the most efficient localization methods in indoor environments. In that case, the received signal strength (RSS) of multiple beacons is compared to ones contained in a previously-constructed database. These reference fingerprints are usually obtained via extensive measurement campaigns and are used to construct suitable radio maps of the environment of interest. However, this approach is highly site-specific and the RSS-based fingerprint database needs therefore to be regularly updated in order to keep track of the various environment dynamics, what is extremely time and resource demanding. Hence, to alleviate these limitations and permanently replace the measurement equipment required for this task, ray-tracing (RT) simulations are used in this paper in order to (i): predict deterministically the radio wave propagation mechanisms, (ii): identify the main channel characteristics, and (iii): construct off-line the RSS-based fingerprint database. To validate this approach, the RT simulated RSS fingerprints are compared to ones measured in an indoor office environment where 3 Bluetooth Low Energy (BLE) beacons are distributed. Our results show good agreement, especially when a strong line-of-sight (LOS) dominates the radio wave propagation. The susceptibility of BLE to fast fading and the impact of human shadowing on RSS fingerprints are also demonstrated, and a pathloss model is proposed to describe the fluctuations of the RSS fingerprints in the environment. These preliminary results encourage further development in order to reduce the complexity of the RT simulation tool while keeping satisfactory prediction accuracy for the RSS fingerprints.
||DWG1,Localisation and Tracking
||Energy-Efficiency vs. Performance Optimization in Low-Power Wireless Transmission
||In this paper we analyze energy-efficiency vs. performance trade-off in low power wireless communications at component level and check hypothesis that the trade-off can be improved by introducing power supply voltage as design variable compared to the case when power supply voltage is fixed. We set two testing formulations and analysis based on SI4455 transceiver show that the hypothesis holds true for both. Moreover, we show that almost 130% less power can be consumed when optimal setting is used in SI4455 transceiver, compared to the case when very low output power is produced under the high power supply voltage.
||Radio propagation model for mixed paths in Amazon environments for UHF band
||Leslye Castro Eras, Luís M. de J. S. Correia, Diego K. N. da Silva, Gervásio P. S. Cavalcante, Fabrício J. B. Barros
||This paper presents a radio propagation model for UHF band. It is designed for a scenario in the Amazon Region of Brazil, so it is formed for a suburban area, river and forest. The model is designed for the service of Mobile Digital Television (M-DTV) and Home Digital Television (H-DTV). The electric field propagation over the city, over the river and through the forest for M- DTV is calculated. For H-DTV is considered a fixed antenna on the roof of the houses. This two kinds of services were considered because of the traffic over the river and people who live on the border of the islands. The techniques used to this model are based on Geometrical Optics (GO) and the Uniform Theory of Diffraction (UTD). Then, the electrical parameters, the height of the constructions, antennas, and elevation of terrain are considered. Comparing the electric field of M-DTV and H-DTV at the distance of 1.6 km, presents a difference of 30 dB in the first path, for the second path (City-River) is 5 dB and for the third path is 1 dB.
||A Heterogeneous IoT-based Architecture for Remote Monitoring of Physiological and Environmental Parameters
||Gordana Gardašević, Hossein Fotouhi, Ivan Tomasic, Maryam Vahabi, Mats Bjorkman, and Maria Linden
||In this paper, we propose a heterogeneous Internet of Things (IoT) architecture for remote health monitoring (RHM) by employing Bluetooth and IEEE 802.15.4 wireless connectivity. The RHM system encompasses Shimmer physiological sensors with Bluetooth radio, and OpenMote environmental sensors with IEEE 802.15.4 radio. This system architecture collects measurements in a relational database in a local server to implement a Fog node for fast data analysis as well as in a remote server in the Cloud.
||Bode-Fano-based Approach for Analyzing Capabilities of Low Cost HF RFID Card Designs
||Shrief Rizkalla, Ralph Prestros and Christoph Mecklenbräuker
||Novel designs for HF RFID cards comprise an intermediate circuit between the main coil and chip, such that the chip is not physically connected to the coil on card which reduces costs of production, enhances card’s robustness against mechanical stress and improves communication capabilities. Based on the Bode-Fano limit, we carry out a theoretical analysis on the bandwidth capabilities of such type of cards and their derivatives. We verify these results through simulations and measurements of our own design, denoted as booster-based cards. Measurements on three booster-based card prototypes are carried out showing the various bandwidth and power capabilities of the cards. Additionally, a comparison between the performance of such type of cards with respect to the conventional ones is presented.
||Achievable Rates of Hierarchical Bit-Wise Network Coding Maps for Higher-Order Constellations in H-MAC Channel with Relative Fading
||The paper addresses Wireless Physical Layer Network Coding with Hierarchical Decode and Forward strategy. We analyze achievable hierarchical rates in one stage hierarchical MAC channel for higher order component constellations with bit-wise Hierarchical Network Code (HNC) maps. This is motivated by a possible application of state-of-the-art binary (e.g. LDPC) codes over higher order constellations. We show that the bit-mapped binary codes do not have the same achievable rates as direct higher-order codes. On top of this, the individual bits in the HNC map might provide very uneven performance and it strongly depends on the combination of component alphabets.
||Comparing Radio Propagation Channels Between 28 and 140 GHz Bands in a Shopping Mall
||Sinh L. H. Nguyen, Jan Jarvelainen, Aki Karttunen, Katsuyuki Haneda, and Jyri Putkonen
||In this document, we compare the radio propagation channels characteristics between 28 and 140 GHz bands based on wideband (several GHz) and directional channel sounding in a shopping mall environment. The measurements and data processing are conducted in such a way to meet requirements for a fair comparison of large- and small- scale channel parameters between the two bands. Our results reveal that there are high spatial-temporal correlation between 28 and 140 GHz channels, similar numbers of strong multipath components, and only small variations in the large-scale parameters between the two bands. Furthermore, when including the weak paths there are higher total numbers of clusters and paths in 28 GHz as compared to those in 140 GHz bands. Finally, our results demonstrate that the propagation channel in 140 GHz band could be exploited for future mobile radio communications.
||Real-Time Implementation and Validation of a Geometry-Based Stochastic Channel Model
||Markus Hofer, Zhinan Xu, Dimitrios Vlastaras, Bernhard Schrenk, David Löschenbrand, Fredrik Tufvesson, Thomas Zemen
||The performance of wireless communication systems is fundamentally determined by wireless communication channel properties. Wireless vehicular communication channels exhibit multipath propagation and non-stationary channel statistics. Methods and tools for the repeatable test of wireless communication systems and signal processing algorithms in such environments are urgently needed to enable the development of reliable communication links with low-latency. In this paper we present the measurement and validation of a real time channel emulation method for non-stationary scenarios based on a geometry-based stochastic channel model.
||Performance Analysis of a Generic Cooperative HARQ Algorithm over Rayleigh Faded Channels
||Agota Antal, Vasile Bota
||The relay-assisted Hybrid ARQ technique is regarded as a mean of further improving the coverage and reliability performance of future wireless networks. This paper studies the reliability, spectral efficiency and delay performance of a Repetition Redundancy cooperative HARQ (CHARQ) algorithm that uses both the direct source-destination link and the source-relay-destination path, and operates under a delay constraint. The analysis is made using practical modulation and channel code over block-faded Rayleigh channels. Its performance is compared to the performance provided by a generic relay-assisted HARQ (RHARQ) algorithm that does not use the source-destination link and by an HARQ algorithm using only the source-destination link. The results show that the CHARQ algorithm provides smaller block-error rate (BLER) and ensures target BLER and smaller delay at lower signal-to-noise ratios (SNR) than the other two studied algorithms, at the expense of smaller spectral efficiency than the HARQ algorithm. The paper also presents some preliminary considerations regarding the adaptive use of the three algorithms under maximum delay and BLER constraints, so that a maximum possible spectral efficiency would be obtained.
||An Angular Model for the Spatial User Distribution inside a Cell
||Per Hj. Lehne, Andrés A. Glazunov
||It is believed that the smart phone users’ relative position in the cells are of interest in order to optimize the network topology and tuning. Measurements done using an app installed on smart phones in regular use, shows that the distribution of positions is not uniform within sectorized cells. The angular statistics of the measurement data have been analyzed and the von Mises angular distribution has been suggested as a model. Key parameters for the distribution have been estimated to fit the data sets. Visually inspecting the cumulative distribution function and quantile-quantile (Q-Q) plots shows fairly good fit, however the data sets obtained are probably too sparse in order to draw a firm conclusion.
||A Scattering Model for 5G Networks
||Lawrence Sayer, Alberto Loaiza Freire
||Modelling tools that include diffuse scatter are essential for planning 5G networks that include millimetre wavelength wireless links. A Kirchhoff model is shown to be in good agreement with real world measurements of diffuse scatter from a rough wall at 60GHz. This work explores the validity of the Kirchhoff model where significant surface shadowing maybe present, which is a condition which theoretically renders the approximation invalid, but it is shown that in practice satisfactory results are obtained. A sensitivity analysis shows that the model will produce sensible results given a certain level of uncertainty in input parameters.
||Spatial Correlation for Distributed Massive MIMO in Indoor Scenarios
||David Löschenbrand, Markus Hofer, Thomas Zemen
||In massive MIMO systems, separation of mobile stations is fundamentally limited by their respective channel correlation. For Industry 4.0 use cases, where low-latency and ultra-reliable communication with numerous sensors is a key requirement, channel correlation significantly degrades performance. In this contribution, we investigate spatial channel correlation for collocated and distributed massive MIMO systems by means of the space collinearity function (SCF) in an indoor environment. Ray-tracing simulations are compared to measurements with a software-defined radio (SDR) testbed in combination with an xy-positioning system. We show the positive effect of distributed antennas on the spatial correlation and evaluate performance and limitations of ray-tracing analysis for massive MIMO systems.
||Spectrum sharing between LTE-TDD and VSAT DVB-S in C-band: experimental campaign on consumer VSAT receivers
||Claudia Carciofi, Paolo Grazioso, Doriana Guiducci, Valeria Petrini, Eva Spina, Giuseppe Di Sipio, Domenico Massimi, Enrico Scognamiglio, Vincenzo Sorrentino, Alessandro Casagni, Li Guoyue, Zhenbo Lai, Richard Rudd
||Owing to the ever increasing demand for mobile broadband connectivity, the mobile community is asking regulators to open new portions of radio spectrum for 5G services. One of the pioneer bands identified in Europe for the early deployment of 5G systems is the 3400-3800 MHz (C-band). This band is already used throughout Europe (and elsewhere) for both fixed service (i.e. radio relays) and fixed satellite service, mainly Earth stations. Coexistence with broadband mobile services should be investigated to properly identify sharing conditions in real environments. Studies on interference from C-band mobile broadband services to satellite Earth station receivers have been considered in ECC Reports 100, 203 & 254 and ITU-R Recommendation M.2109. However, measurements in literature are lacking for ‘Very Small Aperture Terminal’ (VSAT), whose location may not be known and that represents an important class of FSS terminal worldwide. This contribution gives an account of an experimental campaign aimed at determining the conditions of co-channel and adjacent-channel coexistence between LTE transmission and satellite reception by means of a consumer-grade VSAT receiver. The experimental campaign comprised on-air measurements implemented at the Ministry of Economic Development (MISE) premises of the National Radio-electrical Emissions Centre (Centro Nazionale Controllo Emissioni Radioelettriche – CNCER) in Rome, complemented by tests performed with Plum Consulting and Huawei in their laboratory near Milan. Results show that coexistence may be possible provided that, under the circumstances given, proper separation distances for co-frequency sharing are determined while adjacent channel sharing is less critical. The characteristics of VSAT equipment studied by laboratory measurements, show a relatively small variation in selectivity between different receivers.
||Efficient implementation of a spectrum scanner on a software-defined radio platform
||Riccardo Pace, Wim Aerts, Francois Quitin
||One of the important tasks of national regulators is to detect abusive usage of the radio-frequency (RF) spectrum. This document presents the implementation of an opportunistic spectrum scanner on a software-defined radio platform, whose aim is to continuously scan the RF spectrum and to detect whether any signals are present. The implementation is done on a USRP-N210 software-defined radio, a popular and cheap model. One major bottleneck of USRP-based implementations is the limited CPU computation power, which does not allow to process RF signals at high sample rates continuously. In the proposed implementation, most computation is done on the USRP FPGA, such that the host CPU is relieved and is only used to store data and coordinate the scanning. We present the details of the FPGA and the software architecture, as well as some experimental results that show the efficiency of the proposed spectrum scanner.
||Coding for Packet Losses in a Broadcast Channel with Side Information
||In a broadcast channel with one transmitter and several receivers, where receivers possess some partial data, the information rate can be increased by using coding techniques. This problem is known in the literature as index coding with side information. If some data packets are lost in the course of transmission, then properly designed coding scheme could be useful in increasing reliability of the system and decreasing the latency. In this work, the efficiency of coding in such systems is studied.
||A Study on mm-Wave Multi-User Indoor Beamforming
||F.Fuschini, M.Zoli, E.M.Vitucci, M.Barbiroli, V.Degli-Esposti
||This study is about mm-Wave Beamforming techniques in a Multi-User Indoor environment. Directional mm-Wave measurement data are used as reliable radio channel chracterization tool for the simulation study and, furthermore, are compared to Ray Tracing simulations. The main goal is to assess the quality of Spatial Division Multiple Access using three different Beamforming schemes in order to maximize network throughput in a simple and efficient way
||A Method for the Electromagnetic Characterization of Construction Materials based on Fabry-Pérot Resonance
||V. Degli-Esposti, M. Zoli, E. M. Vitucci, F.Fuschini, M. Barbiroli, J Chen
||The determination of the complex permittivity of low-loss construction materials at frequency bands above 6 GHz that are being proposed to allocate forthcoming mobile radio services is of critical importance for the design and deployment of future wireless systems. In this work a simple free-space method for the electromagnetic characterization of construction materials that doesn’t require multiple reflection or transmission coefficient measurements at different incidence angles is proposed and tested. The method is shown to yield permittivity and conductivity values in agreement with the literature for some common-use materials using a relatively simple measurement setup and procedure
||A Novel Airborne Self-Organising Architecture for 5G+ Networks
||Hamed Ahmadi, Konstantinos Katzis and Muhammad Zeeshan Shakir
||Network Flying Platforms (NFPs) such as unmanned aerial vehicles, unmanned balloons or drones flying at low/medium/high altitude can be employed to enhance network coverage and capacity by deploying a swarm of flying platforms that implement novel radio resource management techniques. In this paper, we propose a novel layered architecture where NFPs, of various types and flying at low/medium/high layers in a swarm of flying platforms, are considered as an integrated part of the future cellular networks to inject additional capacity and expand the coverage for exceptional scenarios (sports events, concerts, etc.) and hard-to-reach areas (rural or sparsely populated areas). Successful roll-out of the proposed architecture depends on several factors including, but are not limited to: network optimisation for NFP placement and association, safety operations of NFP for network/equipment security, and reliability for NFP transport and control/signaling mechanisms. In this work, we formulate the optimum placement of NFP at a Lower Layer (LL) by exploiting the airborne Self-organising Network (SON) features. Our initial simulations show the NFP-LL can serve more User Equipment (UE)s using this placement technique.
||An Environment-Driven, fully Discrete, Parallelized Ray-Launching Field Prediction Algorithm
||V. Degli-Esposti, J. S. Lu, E. M. Vitucci, F. Fuschini, M. Barbiroli, J. Blaha, H. L. Bertoni
||A novel environment-driven, fully discrete Ray Launching field prediction algorithm that takes advantage of environment visibility preprocessing for both diffuse and specular interactions is presented. The algorithm, being discrete, has been parallelized in a straightforward way on NVIDIA-compatible Graphical Processing Units. These innovative features combined allow to achieve a computation speed-up of up to three orders of magnitude compared to conventional algorithms, while retaining the same accuracy level
||Study of channel assigning methods impact on paths selection in CR-MANET
||M. MATIS, D. HRABČÁK, Ľ. DOBOŠ, D. NEZNÍK, J. PAPAJ
||Today, the performance of the wireless network is limited due to the traffic congestion and limited available spectrum. Cognitive radio (CR) technology can be seen as a promising technology to deals with the inefficiency in the spectrum usage by exploiting the existing wireless spectrum opportunistically. In cognitive radio ad hoc networks (CR MANET), all these problems need to be solved by taking facts like high fluctuation in the available spectrum as well as diverse quality-of-service (QoS) requirements into consideration. The main idea of CR networks is to share licensed spectrum used by primary users (PUs) with secondary users (SUs). The article provides guidelines for spectrum handoff methods impact on the CR MANET path selection based on IEEE 802.11x or other telecommunications access to sending data between devices in networks. For simplicity, the simulations of the problem were performed in WiFi 802.11x environment in order to point out possible usage of parameters from WiFi signalisation. The simulated approach is also possible to use for optimisation of channel selection for WiFi AP or WiFi routers. Simulations were focused on the influence of primary user (PU) on communication in single and multichannel environments with efficient channel assignment using different methods. The study, therefore, compares non-intelligent and intelligent methods of channel assignment and theirs influence on optimal path selection in process of message delivery from source to the destination of the message. All simulations and results were performed in Matlab environment.
||Point Clouds: some results of simple scattering and diffraction models at V/UHF in CH
||High capacity wireless communications for long range mobile networking at VHF and UHF imposes new challenges for mission critical applications. One of these challenges is to find a suitable propagation model able to predict as accurately as possible the propagation channel to assess the performance of narrow to wide-band wireless systems. The propagation channel is described by its impulse response, i.e., a set of multi-path components due to radio propagation along the direct and reflected or scattered paths. An investigation of so-called “point cloud” propagation models based on the detailed topographical data available in Switzerland is conducted. The results of the “point cloud” predictions are compared to wide band impulse response measurements. A challenge is to predict long delay multi paths with delay in the ranges up to hundreds of microseconds. The preliminary results aim to illustrate objectively the potential and limitations of “point cloud” propagation models using simple scattering and diffraction models.
||Models for Massive MIMO Mobility Scenarios
||Henry Brice, Evangelos Mellios, Mark Beach
||The demand for capacity within existing mobile networks continues to increase as more subscribers and more devices communicate in unison with the growth of data-rich applications. The evolving 5G telecommunications standards aim to respond to such demand. A promising approach to increasing capacity and reliability within the context of 5G is Massive Multiple-Input Multiple-Output (MIMO). Here many transmit antennas are used relative to the number of users, thus providing a greater opportunity to use the spatial characteristics of the channel for spatial diversity and multiplexing. The performance and modelling of Massive MIMO scenarios with mobile users is of great importance and this paper presents results from both simulated and practical mobility campaigns with multiple-users and large base station antenna arrays. The evolution of the Condition Number in time for the simulated and practical scenarios is examined as a way of quantifying the mutlipath richness of the channel and the rank deficiency of the channel correlation matrix. This is important as a full rank correlation matrix represents the ideal scenario for Massive MIMO based spatial multiplexing, within an operational scenario. The characteristics of the time evolution series for both measured and simulated data are compared and the correlation functions of the series investigated in order to consider the possibility of modelling the evolution of the channel stochastically using Auto-Regressive Integrated Moving-Average Processes. Some initial suggestions for the processes are presented and certain features of the time evolution of the channel are shown to be present in both the practical and simulated data.
||Clutter loss measurements in suburban environment at 26 GHz and 40 GHz
||Montenegro-Villacieros B., Chareau J.M., Bishop J., Viaud P., Pinato T., Basso M.
||Last World Radiocommunication Conference in 2015 (WRC-15), identified several frequency bands between 24.25 GHz and 86 GHz as possible candidates for the deployment of future terrestrial 5G systems. Agenda item 1.13 of next WRC-19, invites ITU-R to conduct and complete sharing and compatibility studies, taking into account the protection of services to which the band is allocated on a primary basis for the identified frequency bands. One of the steps to conduct these sharing studies, is to calculate the interference signal at the receiver by using the appropriate propagation model. In sharing scenarios between terrestrial-5G and satellite services, clutter los model is needed. The Recommendation ITU-R 2108 define a statistical clutter loss model for earth-space and aeronautical based on theoretical equations. In order to validate this model, the Joint Research Centre has conducted a first measurement campaign to characterize clutter loss in suburban environment at 26 GHz and 40 GHz. This document describes the scenario, the measurement setup and shows the initial results.
||An Architecture for QoS-aware Service Deployment in Software-Defined IoT Networks
||Slavica Tomovic, Walter Cerroni, Franco Callegati, Roberto Verdone, Igor Radusinovic, Milica Pejanovic, Chiara Buratti
||One of the major challenges in Internet of Things will be management and orchestration of multitechnology/multi-vendor network environments. According to many stakeholders, the adoption of software defined networking (SDN) principles in 5G (5-th Generation) wireless networks will simplify integration of mobile radio access with the IoT paradigm and make it possible to manage billions of connected smart objects through intelligent orchestration and provisioning systems. The special value of SDN lies its ability to support network virtualization and to automate deployment of new services on top of the virtualized network infrastructure. To pave the way towards this novel approach, we present a SDN-based architecture for virtualization of IoT networks, including an intent-based north-bound interface and a virtualized infrastructure manager, allowing virtualization of IoT resources. The architecture exploits SDN controller to program different IoT networks with the aim of providing to users the intended service at the requested level of quality. A prototype of the architecture is presented and numerical results related to round trip time, measured at the different levels of the architecture, are reported.
||Coexistence studies between LTE and narrowban mobile radio technologies in the 850MHz band for Colombia
||Andres Navarro Cadavid, Narcis Cardona and Gerardo Martinez
||Colombian administration, as well as other spectrum regulators is analizing the coexistence aspects in the 850MHz bands for LTE and Public safety technologies (PPDR). We made different analysis, based in the european experience and using laboratory tests as well as SEAMCAT simulations, in order to verify yhe conditions for the coexistence between LTE, P25 and PPDR-LTE (a proprietary public safety technology based in 1.4MHz LTE). IN this paper, we show the results of the analysis and the reccomendationd made to the Colombian regulator (ANE).
||Performance Limits of V2I Ranging Localization with LTE Networks
||José A. del Peral-Rosado, M. Angélica Barreto-Arboleda, Francesca Zanier, Gonzalo Seco-Granados, and José A. López-Salcedo
||Vehicle-to-infrastructure (V2I) communications are expected to be also exploited for positioning, in order to fulfil localization requirements posed by autonomous and assisted driving applications. This work assesses the ultimate capabilities of fourth generation (4G) cellular technologies for vehicular navigation, so it can be applicable for current Long Term Evolution (LTE) deployments as predecessor of fifth generation (5G) technologies. Our results show the performance limits of V2I ranging localization with the current 4G technology in highway scenarios. There is the need to use a maximum LTE bandwidth of 100 MHz, in order to ensure target position accuracies below 1 meter.
||Localisation and Tracking
||Ka Band Ray-Tracing Pathloss Prediction in Urban Scenarios
||Francesco Mani, Enrico Maria Vitucci, Marina Barbiroli, Franco Fuschini, Vittorio degli Esposti, Mingming Gan, Chao Li, Zhimeng Zhong, Jianyao Zhao
||This paper studies the performances of an outdoor ray-tracing model at mmWave frequencies between 26GHz and 38GHz. The channel metric used to assess the prediction capabilities of the tool is pathloss. The impact of advanced implementations such as diffuse scattering and vegetation contribution is verified with measurements in two urban scenarios. The results show that, in non-line-of-sight conditions, the contribution from non-specular components, even at these frequencies, is determinant to have a good prediction accuracy. Despite some deficiencies in the input database knowledge, the prediction errors are sufficiently good and the simulations are generally able to track the measurements behavior.
||Location-aware Enhanced Self-healing in Femtocell Networks
||S. Fortes, A. Aguilar-Garcia, E. Baena, Mariano Molina-García, Jaime Calle-Sánchez, José I. Alonso, Aaron Garrido Alfonso Fernández-Durán, R. Barco
||Given the increasing complexity and service requirements of cellular networks, their operation administration and management has become increasingly unmanageable solely by human operators’ analysis. This is particularly the case for those activities associated with the troubleshooting of network failures, such as the detection of problems and diagnosis of network faults. Under the Self-Organizing Networks paradigm, self-healing capabilities have been defined to overcome this complexity, automating the failure management. Classic self-healing approaches are based solely on the analysis of network-based metrics. However, small cell indoor environments, with the very variable nature of their demand and high base station density imply deep limitations to those approaches. To correct this, the increasing availability of indoor localization systems will provide an additional source of information to support self-healing in such environments. In this way, the present paper proposes a location-aware detection and diagnosis mechanism for femtocells scenarios. The approach is then evaluated in a testbed environment equipped with a real cellular-based localization system
||DWG3, Localisation and Tracking
||Availability optimization in a ring-based network topology
||Philippe Ezran, Yoram Haddad, Merouane Debbah
||Cellular networks are nowadays considered as a major critical infrastructure. Resiliency to failure due to disasters, weather based disruptions or malicious activities is essential. In the case of ring topology, because of delay and availability requirements, a wireless network connected to an aggregation node must sometimes be split into several rings. In this paper, we study the availability optimization in a ring- based network topology for a given number of cellular sites and a given size of rings. We prove that if each ring includes 3 nodes, the problem can be solved in a polynomial time, while for bigger rings, the problem is NP-hard. In this latter case, we provide approximation methods based on linear programming in order to converge to the solution.
||A Channel Model for Off-Body Communications with Dynamic Users
||Kenan Turbic, Luis M. Correia, Marko Beko
||This paper presents a dynamic off-body channel model, based on previously developed propagation model for static user and wearable antenna mobility model for user walking and running motions. The propagation model is based on geometrical optics and uniform theory of diffraction, while the mobility model represents position and orientation of the antenna using Fourier series whose parameters are estimated from motion capture data. Three scenarios with a dynamic user are simulated in order to compare the developed mobility model with the common alternative approaches, and analyse the influence of user’s motion on the channel. The results show that the proposed mobility model yields similar obtained received power as the skeleton-based model with motion capture data, where the average difference is below 0.5 dB. A significant influence of the user’s motion on the channel is observed for both free-space and multipath propagation, yielding received power variations of up to 35 dB in the considered scenarios.