Auto-tuning of RRM parameters in UMTS networks. Feasibility study.

Due to the intrinsic characteristics of WCDMA and the great number of services offered by UMTS, its radio channel is much more dynamic compared with GERAN systems. The traffic fluctuations and users mobility can cause the impairment of the network performance and of the quality of service (QoS) in certain cells. In the worst case a significant degradation of the QoS may be observed and as a result the operator defined targets are not met. Nowadays UMTS operators have fixed, and usually uniform, settings for their network parameters. This static configuration is not able to adapt automatically to the changes that occur in the network. A fixed parameter setting then gives a non optimal solution for the network optimization process and thus the utilization of the radio interface is not maximized. The goal of the automated tuning is to adjust dynamically these parameters in a continuous way without human intervention, which is only required in definition of the reference QoS. The current PFC aims at validating the feasibility of automated optimization of certain UMTS RRM parameters. The main tasks to be developed by the students are: - Simulator developement (Matlab programmed). A basic static Montecarlo simulator is available as a reference. - Study of UMTS handover algorithm and study of potential parameters to be automatically tuned. - Proposal of algorithm to tune the previously selected parameters, and evaluation of achieved gains. - Study of UMTS CAC algorithm and study of potential parameters to be automatically tuned. Development of first and basic ideas to propose tuning algorithm.The present PFC is located inside the framework of the UMTS networks, and more specifically in the development of new Radio Resource Management (RRM) algorithms capable to maximize the capacity and the performance of the network. In this sense a powerful simulation tool capable to analyze in depth the behavior of the UMTS network under different simulation scenarios has been developed. It has been focused in the study of the main algorithms that manage the allocation of radio resources in UMTS networks: Power Control (PC), Admission Control (AC) and Soft/Softer Handover (SHO). The problem observed in classical SHO strategies is the rigidity of the mechanism, which cannot adapt to variations in the traffic patterns. The improvements on SHO procedures are based on dynamic automated tuning of SHO parameters. A three blocks based functional architecture is described to adapt parameters to service mix dynamics and overcome capacity problems. Several tests have been done over different traffic situations in order to demonstrate the feasibility of the Auto-Tuning System (ATS). The results obtained show a considerable increment in the network capacity. In this sense ATS is considered as an effective pre-congestion-control strategy. Referring now to AC strategies, it is necessary to underline that three new AC algorithms have been implemented: Dynamic AC, Complete Partitioning AC (CP-AC) and Complete Sharing AC (CS-AC) strategies have been developed with the same goal, enhance the capacity of the network. Dynamic AC was proposed to provide flexibility to the current AC algorithm. This strategy is based on the ATS philosophy where a dynamic AC threshold is fixed to the optimum threshold in real time according to the current service mix. On the other hand, CS-AC and CP-AC are complex strategies based on static algorithms where fixed thresholds or load margins were applied in order to note their advantages and drawbacks depending on the users distribution, uniform or mostly close to the cell edge. As a result of this project a scientific publication inside the context of COST european projects has been carried out. In special, is about the COST 2100 ”Pervasive Mobile & Ambient Wireless Communications” and the title of the publication is ”Automatic Tuning of Soft Handover Parameters in UMTS Networks”. The paper was presented in the meeting number 3, held in Duisburg (Germany) between 10th and 12th of September 2007

Ground plane booster antenna technology for wireless handheld devices

This thesis is framed in the field of mobile communications and more particularly in handset antennas. The wireless industry is constantly growing, which entails challenging handset antenna specifications. Handset antennas not only have to be multi-band for satisfying the great number of communication services, but also sufficiently small as for fitting in the reduced space imposed by the handset platforms. The appearance of the MIMO (Multiple Input Multiple Output) technology, further exacerbates these challenges. In order to satisfy these requirements, this thesis proposes the use of the ground plane, inherently present in any handset platform, as the main radiator. Electrically small nonresonant elements, called along this thesis as ground plane boosters, are used to transfer energy to this ground plane. The solution removes the need of including a dedicated antenna featured by considerable dimensions, thus releasing space to integrate other antennas, as well as, other handset components, services and functionalities.Postprint (published version

Ground plane booster antenna technology for wireless handheld devices

This thesis is framed in the field of mobile communications and more particularly in handset antennas. The wireless industry is constantly growing, which entails challenging handset antenna specifications. Handset antennas not only have to be multi-band for satisfying the great number of communication services, but also sufficiently small as for fitting in the reduced space imposed by the handset platforms. The appearance of the MIMO (Multiple Input Multiple Output) technology, further exacerbates these challenges. In order to satisfy these requirements, this thesis proposes the use of the ground plane, inherently present in any handset platform, as the main radiator. Electrically small nonresonant elements, called along this thesis as ground plane boosters, are used to transfer energy to this ground plane. The solution removes the need of including a dedicated antenna featured by considerable dimensions, thus releasing space to integrate other antennas, as well as, other handset components, services and functionalities

Análisis y diseño de monopolos acoplados para dispositivos móviles multibanda

A novel low profile planar antenna is proposed. The antenna presented is a coupled monopole antenna, comprising at least a driven element coupled with one or more parasitic elements. The design proposed is suitable to be used into a handheld device. The dimensions of the antenna are 33x15x1 mm 3 . In order to facilitate the integration of other components, such cameras or speakers, a ground plane area at the right side of the antenna is provided. The study carried out reveals the relevance of the arms location over the performance of the antenna. The theoretic base is reinforced by a network model and a parametrical study. The coupling between elements controls the behaviour of the antenna. In this sense, a weak coupling between the driven element and at least one parasitic element enhances the bandwidth, whereas a multiband behaviour is achieved by a strong coupling. Finally, the PCB (Printed Circuit Board) influence has also been analyzedPeer ReviewedPostprint (published version

Frequency Beam Steering Antenna for Millimeter Wave Checkpoint Scanners

Millimeter wave scanners are the most prevalent nearfield imaging passenger security systems. The paper describes a planar antenna to replace multiple antennas used in millimeter wave security checkpoints. The antenna is compact in size and capable of frequency scanning over an angle of -50 o to 15o. It operates across FCC’s frequency range of 24.25 GHz to 30 GHz for full-body airport scanners. The antenna structure, which is based on cheap microstrip technology, is simple to design and fabricate. The proposed antenna consists of a linear array of 1×4 radiating elements. The measured results conforms the antenna exhibits a maximum gain and radiation efficiency measured are 6.75 dBi and 82.34%, respectively, at 27.5 GHz

The Hilbert monopole revisited

A comparison between the resonant performance of the third iteration Hilbert monopole and a spiral shaped one of the same size and resonant frequency is presented. Quality factor, bandwidth, efficiency and radiation patterns are investigated. Although the Hilbert monopole total wire length is longer, it shows nearly the same radiation efficiency yet a lower quality factor. Hence the higher compression efficiency of the spiral shaped monopole does not provide any advantage in the antenna electromagnetic performance. Differences in radiation pattern are also observed. It is demonstrated that antenna resonance performance depends on its geometry, and not only on its size or wire length.Peer ReviewedPostprint (published version

Analysis of the specific absorption rate in handset antennas with slotted ground planes

The study of the interaction between human head and handset antennas should be taken into account since all the mobile phones have to guarantee a biological compatibility. This research analyzes several antennas with different slotted ground planes in terms of free space and also in terms of human head interaction. The main objective is to compare the measured bandwidth and efficiency in free space and the impact on measured SAR (Specific Absorption Rate) of such antennas as a function of the slot configuration and the antenna/slot location. Results show that slots may be useful to increase bandwidth and efficiency while keeping a similar SAR compared to the non-slotted ground plane. Changing the antenna and the slot location is a good way to achieve a significant SAR reduction.Peer ReviewedPostprint (published version

Conformación del diagrama de radiación de un monopolo en L

The typical radiation pattern of an L-monopole antenna can be easily modified by changing the geometrical characteristics of the structure. To shape a specific radiation pattern through a basic structure becomes an interesting freedom degree in order to better adapt the behaviour of the antenna to the design specifications. Thus, to solve the question,an accurate analysis following the radiated field basic equations has been carried out. The theoretical study is validated through a simulation and experimental process. The results depict three main regions, delimited by geometrical boundaries, where the Lshaped wire antenna present three specific radiation pattern types, a monopole-type, a half isotropic type or even, a patchtype radiation pattern. Consequently, the method described herein demonstrates that simple modifications applied to the geometry of a basic structure, allow obtaining radiation properties associated to more complex structures.Peer ReviewedPostprint (published version

Emotional health assessment related to COVID-19 in older people: A cross-sectional study

Background: The aim of this study was to assess the presence of anxiety, fear and psychological distress in the population of people over 65 years of age and to study possible differences with a sample of subjects aged between 60 and 65 years. Methods: A descriptive and psychometric cross-sectional study. The total sample used consisted of 1112 subjects from university training programmes for the old people from all over Spain. Anxiety and fear of COVID-19 were measured using the AMICO scale and psychological distress using the GHQ-12 instrument. Results: Significant differences were found in the AMICO (p = 0.006) and GHQ-12 (p = 0.03) measures between age subgroups, with lower values in older age groups. Contrast statistics showed significant differences on both measures (AMICO and GHQ) in women, single or widowed subjects, and those who had not been infected by the SARS-CoV-2 virus. Limitations: It would be desirable to increase the sample size, especially in the lower age group (<65). The establishment of the age limit between the two groups could be located at 60 years of age. The use of new technologies to get information should be considered. Conclusions: Overall, moderate levels of fear and anxiety of COVID-19 were present. Women tended to have higher levels of both general psychological distress and fear and anxiety of COVID-19. Especially in those over 65, higher levels of distress and fear/anxiety of COVID-19 were associated with being widowed or single, and not having been infected before with SARS-CoV-2.FUNDING FOR OPEN ACCESS CHARGE: Universidad de Huelva / CBUA