Indoor Radio Measurement and Planning for UMTS/HSPDA with Antennas

Over the last decade, mobile communication networks have evolved tremendously with a key focus on providing high speed data services in addition to voice. The third generation of mobile networks in the form of Universal Mobile Telecommunications System (UMTS) is already offering revolutionary mobile broadband experience to its users by deploying High Speed Downlink Packet Access (HSDPA) as its packet-data technology. With data speeds up to 14.4 Mbps and ubiquitous mobility, HSDPA is anticipated to become a preferred broadband access medium for end-users via mobile phones, laptops etc. While majority of these end-users are located indoors most of the time, approximately 70-80% of the HSDPA traffic is estimated to originate from inside buildings. Thus for network operators, indoor coverage has become a necessity for technical and business reasons. Macro-cellular (outdoor) to indoor coverage is a natural inexpensive way of providing network coverage inside the buildings. However, it does not guarantee sufficient link quality required for optimal HSDPA operation. On the contrary, deploying a dedicated indoor system may be far too expensive from an operator\u27s point of view. In this thesis, the concept is laid for the understanding of indoor radio wave propagation in a campus building environment which could be used to plan and improve outdoor-to-indoor UMTS/HSDPA radio propagation performance. It will be shown that indoor range performance depends not only on the transmit power of an indoor antenna, but also on the product\u27s response to multipath and obstructions in the environment along the radio propagation path. An extensive measurement campaign will be executed in different indoor environments analogous to easy, medium and hard radio conditions. The effects of walls, ceilings, doors and other obstacles on measurement results would be observed. Chapter one gives a brief introduction to the evolution of UMTS and HSDPA. It goes on to talk about radio wave propagation and some important properties of antennas which must be considered when choosing an antenna for indoor radio propagation. The challenges of in-building network coverage and also the objectives of this thesis are also mentioned in this chapter. The evolution and standardization, network architecture, radio features and most importantly, the radio resource management features of UMTS/HSDPA are given in chapter two. In this chapter, the reason why Wideband Code Division Multiple Access (WCDMA) was specified and selected for 3G (UMTS) systems would be seen. The architecture of the radio access network, interfaces with the radio access network between base stations and radio network controllers (RNC), and the interface between the radio access network and the core network are also described in this chapter. The main features of HSDPA are mentioned at the end of the chapter. In chapter three the principles of the WCDMA air interface, including spreading, Rake reception, signal fading, power control and handovers are introduced. The different types and characteristics of the propagation environments and how they influence radio wave propagation are mentioned. UMTS transport, logical and physical channels are also mentioned, highlighting their significance and relationship in and with the network. Radio network planning for UMTS is discussed in chapter four. The outdoor planning process which includes dimensioning, detailed planning, optimization and monitoring is outlined. Indoor radio planning with distributed antenna systems (DAS), which is the idea and motivation behind this thesis work, is also discussed. The various antennas considered and the antenna that was selected for this thesis experiment was discussed in chapter five. The antenna radiation pattern, directivity, gain and input impedance were the properties of the antenna that were taken into consideration. The importance of the choice of the antenna for any particular type of indoor environment is also mentioned. In chapter six, the design and fabrication of the monopole antennas used for the experimental measurement is mentioned. The procedure for measurement and the equipment used are also discussed. The results gotten from the experiment are finally analyzed and discussed. In this chapter the effect of walls, floors, doors, ceilings and other obstacles on radio wave propagation will be seen. Finally, chapter seven concludes this thesis work and gives some directions for future work

Proceedings of the Fifth International Mobile Satellite Conference 1997

Satellite-based mobile communications systems provide voice and data communications to users over a vast geographic area. The users may communicate via mobile or hand-held terminals, which may also provide access to terrestrial communications services. While previous International Mobile Satellite Conferences have concentrated on technical advances and the increasing worldwide commercial activities, this conference focuses on the next generation of mobile satellite services. The approximately 80 papers included here cover sessions in the following areas: networking and protocols; code division multiple access technologies; demand, economics and technology issues; current and planned systems; propagation; terminal technology; modulation and coding advances; spacecraft technology; advanced systems; and applications and experiments

Electromagnetic model subdivision and iterative solvers for surface and volume double higher order numerical methods and applications

2019 Fall.Includes bibliographical references.Higher order methods have been established in the numerical analysis of electromagnetic structures decreasing the number of unknowns compared to the low order discretization. In order to decrease memory requirements even further, model subdivision in the computational analysis of electrically large structures has been used. The technique is based on clustering elements and solving/approximating subsystems separately, and it is often implemented in conjunction with iterative solvers. This thesis addresses unique theoretical and implementation details specific to model subdivision of the structures discretized by the Double Higher Order (DHO) elements analyzed by i) Finite Element Method - Mode Matching (FEM-MM) technique for closed-region (waveguide) structures and ii) Surface Integral Equation Method of Moments (SIE-MoM) in combination with (Multi-Level) Fast Multipole Method for open-region bodies. Besides standard application in decreasing the model size, DHO FEM-MM is applied to modeling communication system in tunnels by means of Standard Impedance Boundary Condition (SIBC), and excellent agreement is achieved with measurements performed in Massif Central tunnel. To increase accuracy of the SIE-MoM computation, novel method for numerical evaluation of the 2-D surface integrals in MoM matrix entries has been improved to achieve better accuracy than traditional method. To demonstrate its efficiency and practicality, SIE-MoM technique is applied to analysis of the rain event containing significant percentage of the oscillating drops recorded by 2D video disdrometer. An excellent agreement with previously-obtained radar measurements has been established providing the benefits of accurately modeling precipitation particles

Artificial neural networks for location estimation and co-cannel interference suppression in cellular networks

This thesis reports on the application of artificial neural networks to two important problems encountered in cellular communications, namely, location estimation and co-channel interference suppression. The prediction of a mobile location using propagation path loss (signal strength) is a very difficult and complex task. Several techniques have been proposed recently mostly based on linearized, geometrical and maximum likelihood methods. An alternative approach based on artificial neural networks is proposed in this thesis which offers the advantages of increased flexibility to adapt to different environments and high speed parallel processing. Location estimation provides users of cellular telephones with information about their location. Some of the existing location estimation techniques such as those used in GPS satellite navigation systems require non-standard features, either from the cellular phone or the cellular network. However, it is possible to use the existing GSM technology for location estimation by taking advantage of the signals transmitted between the phone and the network. This thesis proposes the application of neural networks to predict the location coordinates from signal strength data. New multi-layered perceptron and radial basis function based neural networks are employed for the prediction of mobile locations using signal strength measurements in a simulated COST-231 metropolitan environment. In addition, initial preliminary results using limited available real signal-strength measurements in a metropolitan environment are also reported comparing the performance of the neural predictors with a conventional linear technique. The results indicate that the neural predictors can be trained to provide a near perfect mapping using signal strength measurements from two or more base stations. The second application of neural networks addressed in this thesis, is concerned with adaptive equalization, which is known to be an important technique for combating distortion and Inter-Symbol Interference (ISI) in digital communication channels. However, many communication systems are also impaired by what is known as co-channel interference (CCI). Many digital communications systems such as digital cellular radio (DCR) and dual polarized micro-wave radio, for example, employ frequency re-usage and often exhibit performance limitation due to co-channel interference. The degradation in performance due to CCI is more severe than due to ISI. Therefore, simple and effective interference suppression techniques are required to mitigate the interference for a high-quality signal reception. The current work briefly reviews the application of neural network based non-linear adaptive equalizers to the problem of combating co-channel interference, without a priori knowledge of the channel or co-channel orders. A realistic co-channel system is used as a case study to demonstrate the superior equalization capability of the functional-link neural network based Decision Feedback Equalizer (DFE) compared to other conventional linear and neural network based non-linear adaptive equalizers.This project was funded by Solectron (Scotland) Ltd

Path Loss Predictions in the VHF and UHF Bands Within Urban Environments: Experimental Investigation of Empirical, Heuristics and Geospatial Models

(c) 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.[EN] Deep knowledge of how radio waves behave in a practical wireless channel is required for effective planning and deployment of radio access networks in urban environments. Empirical propagation models are popular for their simplicity, but they are prone to introduce high prediction errors. Different heuristic methods and geospatial approaches have been developed to further reduce path loss prediction error. However, the efficacy of these new techniques in built-up areas should be experimentally verified. In this paper, the efficiencies of empirical, heuristic, and geospatial methods for signal fading predictions in the very high frequency (VHF) and ultra-high frequency (UHF) bands in typical urban environments are evaluated and analyzed. Electromagnetic field strength measurements are performed at different test locations within four selected cities in Nigeria. The data collected are used to develop path loss models based on artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS), and Kriging techniques. The prediction results of the developed models are compared with those of selected empirical models and field measured data. Apart from Egli and ECC-33, the root mean squared error (RMSE) produced by all other models under investigation are considered acceptable. Specifically, the ANN and ANFIS models yielded the lowest prediction errors. However, the empirical models have the lowest standard deviation errors across all the bands. The findings of this study will help radio network engineers to achieve efficient radio coverage estimation; determine the optimal base station location; make a proper frequency allocation; select the most suitable antenna; and perform interference feasibility studies.This work was supported jointly by the funding received from IoT-Enabled Smart and Connected Communities (SmartCU) Research Cluster and the Center for Research, Innovation and Discovery (CUCRID) of Covenant University, Ota, Nigeria.Faruk, N.; Popoola, SI.; Surajudeen-Bakinde, NT.; Oloyede, AA.; Abdulkarim, A.; Olawoyin, LA.; Ali, M.... (2019). Path Loss Predictions in the VHF and UHF Bands Within Urban Environments: Experimental Investigation of Empirical, Heuristics and Geospatial Models. IEEE Access. 7:77293-77307. https://doi.org/10.1109/ACCESS.2019.2921411S7729377307

Quality of Service Differentiation in Heterogeneous CDMA Networks : A Mathematical Modelling Approach

Next-generation cellular networks are expected to enable the coexistence of macro and small cells, and to support differentiated quality-of-service (QoS) of mobile applications. Under such conditions in the cell, due to a wide range of supported services and high dependencies on efficient vertical and horizontal handovers, appropriate management of handover traffic is very crucial. Furthermore, new emerging technologies, such as cloud radio access networks (C-RAN) and self-organizing networks (SON), provide good implementation and deployment opportunities for novel functions and services. We design a multi-threshold teletraffic model for heterogeneous code division multiple access (CDMA) networks that enable QoS differentiation of handover traffic when elastic and adaptive services are present. Facilitated by this model, it is possible to calculate important performance metrics for handover and new calls, such as call blocking probabilities, throughput, and radio resource utilization. This can be achieved by modelling the cellular CDMA system as a continuous-time Markov chain. After that, the determination of state probabilities in the cellular system can be performed via a recursive and efficient formula. We present the applicability framework for our proposed approach, that takes into account advances in C-RAN and SON technologies. We also evaluate the accuracy of our model using simulations and find it very satisfactory. Furthermore, experiments on commodity hardware show algorithm running times in the order of few hundreds of milliseconds, which makes it highly applicable for accurate cellular network dimensioning and radio resource management

Towards Battery-Free Internet of Things (IoT) Sensors: Far-Field Wireless Power Transfer and Harmonic Backscattering

RÉSUMÉ Notre vie tend à être plus agréable, plus facile et plus efficace grâce à l'évolution rapide de la technologie de l'Internet des objets (IoT). La clef de voute de cette technologie repose essentiellement sur la quantité de capteurs IoT interconnectés, que l’on est en mesure de déployer dans notre environnement. Malheureusement, l’électronique conventionnelle fonctionnant sur piles ou relié au réseau électrique ne peut pas constituer une solution durable en raison des aspects de coût, de faisabilité et d'impact environnemental. Pendant ce temps, le changement climatique dû à la consommation excessive de combustibles fossiles continue de s'aggraver. Il devient donc urgent de trouver une solution pour l’alimentation électrique des capteurs IoT géographiquement répartis à grande échelle, afin de simultanément soutenir la mise en oeuvre de nombreux capteurs IoT tout en limitant leur poids environnemental. L'énergie radiofréquence (RF) ambiante, qui sert de support à l'information sans fil, est non seulement capitale pour notre société, mais aussi omniprésente dans les zones urbaines et suburbaines. Elle permet de réaliser des communications et des détections sans fil. Cependant, l'énergie RF ambiante est majoritairement « gaspillée » car seule une toute petite partie de la puissance transmise est effectivement reçu ou « consommée » par le destinataire. C'est pourquoi le recyclage de l'énergie RF ambiante est une solution prometteuse pour alimenter les capteurs IoT. Pour certains capteurs IoT consommant une puissance plus élevée, l’apport d'énergie sans fil pourra similairement se faire par des centrales électriques spécialisées, suivant le même schéma d’alimentation sans fil. Pour utiliser et récupérer cette énergie RF, cette thèse présente deux techniques principales : la récupération/réception de puissance sans fil en champ lointain (wireless power transfer: WPT) et la rétrodiffusion d'harmoniques. Le chapitre 2 aborde les différents mécanismes de conversion de fréquence entre le WPT en champ lointain et la rétrodiffusion d'harmoniques. La récupération de WPT en champ lointain consiste à convertir l'énergie RF en puissance continue. En revanche, la rétrodiffusion d'harmoniques a pour but de convertir l'énergie RF dans une autre fréquence, dans la plupart des cas, la composante harmonique de rang 2. A titre d'étape préliminaire de recherche et d'étude de faisabilité, une cartographie de la densité de l'énergie RF ambiante dans les zones centrales de l'île de Montréal est résumée au chapitre 3. Contrairement aux mesures traditionnelles précédentes effectuées à des endroits fixes, cette mesure dynamique a été réalisée le long des rues, des routes, des avenues et des autoroutes pour couvrir une large zone.----------ABSTRACT Our life is becoming more convenient, efficient, and intelligent with the aid of fast-evolving Internet of Things (IoT) technology. One essential foundation of IoT technology is the development of numerous interrelated IoT sensors that are distributed extensively in our environment. However, conventional batteries/cords-based powering solutions are certainly not an acceptable long-term solution, considering the incurred cost, feasibility, most of all, environmental impact. Meanwhile, climate change due to excessive consumption of fossil fuels is worsening day by day. Therefore, a transformative powering solution for such large-scale and geographically scattered IoT sensors is of extreme importance in support of such extensive IoT sensors implementation while simultaneously mitigating its environmental burden. Serving as a critical information carrier, ambient radiofrequency (RF) energy is pervasive in urban and suburban areas to realize wireless communication and sensing. However, part of ambient RF energy is dissipated due to path loss if not fully consumed by end-users. Hence, recycling the wasted ambient RF energy to power IoT sensors is a promising solution. The concept of harnessing wireless energy for powering IoT sensors requiring a higher power supply is also feasible through the dedicated wireless power delivery from specialized power stations, which can be an effective supplement. To realize the RF power scavenging, this thesis research introduces two mainstream techniques: far-field wireless power transfer (WPT) and harmonic backscattering. Chapter 2 discusses the different frequency conversion mechanisms applied for far-field or ambient WPT harvesting and harmonic backscattering. Far-field WPT harvesting converts RF energy into dc power (zeroth harmonic). In contrast, harmonic backscattering upconverts RF energy into its harmonics, in most cases, the second harmonic component. As a preliminary research step and a feasibility study, a survey of ambient RF energy density in the core areas on Montreal Island is summarized in Chapter 3. Different from the previously published traditional measurements at fixed locations, this dynamic measurement is carried out along streets, roads, avenues, and highways to cover a large area. Also, a stationary measurement in Downtown Montreal is to reveal whether human activities are able to bring visible change to ambient RF energy levels. This work demonstrates how much ambient RF energy is available in free space and acts as a significant reference for researchers and engineers designing ambient RF energy harvesting circuits/systems for practical applications

Economically sustainable public security and emergency network exploiting a broadband communications satellite

The research contributes to work in Rapid Deployment of a National Public Security and Emergency Communications Network using Communication Satellite Broadband. Although studies in Public Security Communication networks have examined the use of communications satellite as an integral part of the Communication Infrastructure, there has not been an in-depth design analysis of an optimized regional broadband-based communication satellite in relation to the envisaged service coverage area, with little or no terrestrial last-mile telecommunications infrastructure for delivery of satellite solutions, applications and services. As such, the research provides a case study of a Nigerian Public Safety Security Communications Pilot project deployed in regions of the African continent with inadequate terrestrial last mile infrastructure and thus requiring a robust regional Communications Satellite complemented with variants of terrestrial wireless technologies to bridge the digital hiatus as a short and medium term measure apart from other strategic needs. The research not only addresses the pivotal role of a secured integrated communications Public safety network for security agencies and emergency service organizations with its potential to foster efficient information symmetry amongst their operations including during emergency and crisis management in a timely manner but demonstrates a working model of how analogue spectrum meant for Push-to-Talk (PTT) services can be re-farmed and digitalized as a “dedicated” broadband-based public communications system. The network’s sustainability can be secured by using excess capacity for the strategic commercial telecommunication needs of the state and its citizens. Utilization of scarce spectrum has been deployed for Nigeria’s Cashless policy pilot project for financial and digital inclusion. This effectively drives the universal access goals, without exclusivity, in a continent, which still remains the least wired in the world