UMTS Research Articles

Sequence-based detection of sleeping cell failures in mobile networks

This article presents an automatic malfunction detection framework based on data mining approach to analysis of network event sequences. The considered environment is long term evolution (LTE) of Universal Mobile Telecommunications System with sleeping cell caused by random access channel failure. Sleeping cell problem means unavailability of network service without triggered alarm. The proposed detection framework uses N-gram analysis for identification of abnormal behavior in sequences of network events. These events are collected with minimization of drive tests functionality standardized in LTE. Further processing applies dimensionality reduction, anomaly detection with K-Nearest Neighbors, cross-validation, postprocessing techniques and efficiency evaluation. Different anomaly detection approaches proposed in this paper are compared against each other with both classic data mining metrics, such as F-score and receiver operating characteristic curves, and a newly proposed heuristic approach. Achieved results demonstrate that the suggested method can be used in modern performance monitoring systems for reliable, timely and automatic detection of random access channel sleeping cells.

Enhancing RFID indoor localization with cellular technologies

Indoor localization, this means solutions providing the position of mobile objects/persons in indoor environments (e.g., hospitals, malls, etc.), is one of the most cutting-edge services with growing demand in smart applications such as robotics for care, pedestrian navigations, etc. With the objective of providing indoor localization, this paper presents the experimental analysis of simultaneous radio frequency measurements from two different radio frequency systems: Ultra High Frequency Radio Frequency IDentification (UHF RFID) and macrocellular networks. Extensively deployed cellular technologies (Global System for Mobile communications (GSM) and Universal Mobile Telecommunications System (UMTS)) are here evaluated with the purpose of enhancing pre-existent RFID-based localization systems at reduced costs. Temporal and statistical analysis of the measurements gathered from each technology is performed, and its applicability for localization is assessed. Based on this analysis, a RFID localization mechanism that is able to integrate macrocellular technologies information is proposed, showing improved results in terms of accuracy.

Effects of concurrent caffeine and mobile phone exposure on local target probability processing in the human brain.

Millions of people use mobile phones (MP) while drinking coffee or other caffeine containing beverages. Little is known about the potential combined effects of MP irradiation and caffeine on cognitive functions. Here we investigated whether caffeine intake and concurrent exposure to Universal Mobile Telecommunications System (UMTS) MP-like irradiation may interactively influence neuro-cognitive function in an active visual oddball paradigm. In a full factorial experimental design, 25 participants performed a simple visual target detection task while reaction time (RT) and electroencephalogram (EEG) was recorded. Target trials were divided into Low and High probability sets based on target-to-target distance. We analyzed single trial RT and alpha-band power (amplitude) in the pre-target interval. We found that RT was shorter in High vs. Low local probability trials, and caffeine further shortened RT in High probability trials relative to the baseline condition suggesting that caffeine improves the efficiency of implicit short-term memory. Caffeine also decreased pre-target alpha amplitude resulting in higher arousal level. Furthermore, pre-target gamma power positively correlated with RT, which may have facilitated target detection. However, in the present pharmacologically validated study UMTS exposure either alone or in combination with caffeine did not alter RT or pre-stimulus oscillatory brain activity.

Dual-band LTCC antenna based on 0.95Zn2SiO4-0.05CaTiO3 ceramics for GPS/UMTS applications**Project supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20133718120009), the Natural Science Foundation of Shandong Provence, China (Grant Nos. ZR2013FQ002 and ZR2014FQ006), the China Postdoctoral Science Foundation (Grant No. 2014M551935), the Qingdao Municipality Postdoctoral Science Foundation, China, and the Scientific Research

In this paper, we present a compact low-temperature co-fired ceramic (LTCC) dual-band antenna by using the electromagnetic coupling effect concept for global positioning system (GPS) and universal mobile telecommunication system (UMTS) applications. The overall dimension of the antenna is 8.6 mm × 13.0 mm × 1.1 mm. It consists of double meander lines and a via hole line. The top meander line operates at the upper band, and the bottom radiating patch is designed for the lower band. The via-hole line is employed to connect the double meander lines. Because of the effect of the coupled line, total dimension of the proposed antenna is greatly reduced. With the 2.5: voltage standing wave ratio (VSWR) impedance bandwidth definition, the lower and upper bands have the bandwidths of 110 MHz and 150 MHz, respectively. The proposed antenna is successfully designed, simulated, and analyzed by a high frequency structure simulator (HFSS). And the antenna is manufactured by using the 0.95Zn2SiO4-0.05CaTiO3 ceramics (εr = 7.1, tanδ = 0.00038) that is prepared by ourselves. The results show that the antenna is compact, efficient, and of near omnidirectional radiation pattern.

In-vitro assessment of Jurkat T-cells response to 1966 MHz electromagnetic fields in a GTEM cell.

This paper presents the experimental configuration and procedure as well as the in-vitro assessment of Jurkat T-cells response to 1966 MHz exposure of modulated and unmodulated electromagnetic signals within a Gigahertz Transverse Electro-Magnetic (GTEM) cell. Different combinations of electric field intensity, exposure duration and modulation schemes were applied. Exposures at continuous wave (CW) signal at low intensity levels (3 V/m) did not induce any significant DNA damage, but a slight increase was observed for extreme stress levels (76.4 V/m). On the other hand, the results indicate that, at both, low and high electric field intensity UMTS (Universal Mobile Telecommunications System) signal could be statistically related to DNA damage in-vitro. Nevertheless, further experiments are required, increasing the statistical number of samples and recruiting more DNA damage endpoints before conclusive statements are drawn.

Efficient Vertical Handoff in HeterogeneousWireless Network

Integration of heterogeneous wireless technologies is cardinal area of research for next generation mobile networks. Considering the heterogeneous environment, Universal Mobile Telecommunication System (UMTS) of cellular technology and Wireless Local Area Networks (WLAN) (over IEEE 802.11) are the most promising networks which can be integrated to facilitate the seamless communication. However, integration of UMTS and WLAN involves some challenging issues such as mobility management and handoff decision making. Handoff decision making depends on various metrics such as available bandwidth, jitter, delay, energy, cost, etc. Moreover, handoffs need to have seamless connectivity while maintaining the acceptable quality of service in heterogeneous network. Various approaches have been proposed to address handoff decision making problem. This paper proposes a novel fuzzy rule based handoff decision making algorithm for meeting the requirements of heterogeneous networks. It considers WLAN and UMTS as two integrated network entities. The algorithm allows the Mobile Terminal (MT) to always get connected to the most energy efficient and cost-effective network evaluated on the basis of various handoff metrics such as energy, traffic and cost.

Compact asymmetric coplanar strip fed Sinc shaped monopole antenna for multiband applications

A compact asymmetric coplanar strip fed Sinc shaped monopole antenna suitable for multifrequency operations is proposed for portable wireless devices. The proposed Sinc shaped monopole antenna with truncated half ground plane operates at three frequency bands, 2110–2380, 4180–4600, and 5200–5678 MHz, showing fractional impedance bandwidths of 12, 9, and 8.8%, respectively, suitable for Universal Mobile Telecommunications System, Long Term Evolution handheld devices, Worldwide Interoperability for Microwave Access, Wireless Local Area Network, Hyperlan-2, and aeronautical navigation applications. Proposed antenna shows a dual mode of polarization. Finally a prototype model is developed for a typical configuration and the simulated results are validated experimentally.

Modelling of the access part of a multi-service mobile network with service priorities

This paper presents a methodology for the modelling and optimization of multi-service radio access for universal mobile telecommunications system (UMTS) networks. The paper provides a description of the basis for modelling of a tandem pair: a wideband code division multiple access (WCDMA) interface and a Iub interface. The models involved in the study take into consideration a possibility of setting priorities to a number of selected traffic classes. Particular attention is given to the development of simple computational algorithms that would make it possible to determine the blocking probability for call streams with different priorities. The results of the analytical calculations are then compared with the results of simulation experiments, which confirms the high accuracy of the proposed analytical solutions.

Seamless LTE connectivity in high‐speed trains

AbstractHigh‐speed train (HST) is revitalizing the train as a preferred mid‐range transportation system. The provision of broadband Internet connectivity onboard trains is one of the key challenges in the competition among train operators. Unprecedented spectral efficiency and data rates (up to 100Mbps in high mobility) of the Universal Mobile Telecommunications System long‐term evolution (LTE) are expected to offer the solution for high‐speed Internet access onboard in HSTs. Massive wireless access and frequent handovers (HOs) of a large number of users might potentially cause service interruptions, and this, in turn, degrades intolerably the quality of experience (QoE) of users' onboard Internet access. In this paper, we propose a solution based on distributed antenna system that combines directional and omni‐directional antennas as train‐to‐ground radio‐access terminals (T‐RATs) and LTE femtocells in each carriage. Directional antennas are deployed at both ends of the HST to provide multi‐cell access by diversifying the HOs over multiple LTE cells. This mechanism virtually elongates the train size by connecting the front and rear carriages' T‐RATs to the faraway eNodeBs and augmenting the number of cells the HST can be simultaneously connected to. An ad hoc distributed load‐balancing mechanism that consists in offloading backlogged packets to the on‐service T‐RATs is mandatorily paired with multi‐cell access scheme to tie up with the request of seamless onboard Internet service at high QoE level. Copyright © 2015 John Wiley & Sons, Ltd.

Design of a Novel Architecture Signaling Network to Provide Internet Multimedia Subsystem Services through Aeronautical Passenger Communication

This article describes a novel architecture signaling network so that an IP Multimedia Subsystem (IMS) user, flying in an aircraft, be able to register with his IMS network of origin and have access to personal services and multimedia, through a Wide-Band Code Division Multiple Access (W-CDMA) link. The proposed architecture integrates the Session Initialization Protocol (SIP), the Network Mobility Basic Support (NEMO BS) protocol and the Mobile Internet Protocol (MIPv6) to enable the usage of IMS services by passenger on board an aircraft, as a type of Aeronautical Passenger Communication (APC) services. In this novel architecture, NEMO and MIPv6 protocols are responsible for the mobility management of smartphones and user notebook and the SIP protocol is responsible for the register and the management of sessions of an IMS user. This novel architecture enables an Air Communication Service Provider (ACSP) be able to supply to an on-board passenger (The IMS user) some APC services through an Universal Mobile Telecommunication System (UMTS). The simulation results indicate the accuracy of the proposed architecture into aeronautical scenarios.

A Comparative Study of Prioritized Handoff Schemes with Guard Channels in Wireless Cellular Networks

Mobility management has always been the main challenge in most mobile systems. It involves the management of network radio channel resource capacity for the purpose of achieving optimum quality of service (QoS) standard. In this era of wireless Personal Communication Networks such as Global System for Mobile Communication (GSM), Wireless Asynchronous Transfer Mode (WATM), Universal Mobile Telecommunication System (UMTS), there is a continuous increase in demand for network capacity. In order to accommodate the increased demand for network capacity (radio resource) over the wireless medium, cell sizes are reduced. As a result of such reduction in cell sizes, handoffs occur more frequently, and thereby result in increased volume of handoff related signaling. Therefore, a handoff scheme that can handle the increased signaling load while sustaining the standard QoS parameters is required.This work presents a comparative analysis of four popular developed handoff schemes. New call blocking probability, forced termination probability and throughput are the QoS parameters employed in comparing the four schemes. The four schemes are:RCS-GC,MRCS-GC, NCBS-GC, and APS-GC. NCBS-GChas the leased new call blocking probability while APS-GC has the worst. In terms of forced termination probability, MRCS-GC has the best result, whileRCS-GChas the worst scheme.MRCS-GC delivers the highest number of packets per second while APS-GC delivers the least. These performance metrics are computed by using the analytical expressions developed for these metrics in the considered models in a Microsoft Excel spreadsheet environment. http://dx.doi.org/10.4314/njt.v34i3.24

Advanced Train Location Simulator (ATLAS) for developing, testing and validating on-board railway location systems

This article focuses on a novel Advanced Train LocAtion Simulator (ATLAS) for on-board railway location using wireless communication technologies, such as satellite navigation and location based systems. ATLAS allows the creation of multiple simulation environments providing a versatile tool for testing and assessing new train location services. This enhancement reduces the number of tests performed in real scenarios and trains, reducing the cost and development time of new location systems as well as assessing the performance level for given tracks. The simulation platform is based on modular blocks, where each block can be replaced or improved. The platform uses Monte Carlo Simulation to generate results with statistical significance. This implementation allows the modification of the development platform to cover multiple requirements, such as, ranging errors in the input parameters or including other positioning technologies. In this paper, the generated input parameter errors have been taken from the results of the field tests realized by the 3GPP ensuring the validity of the used parameter errors. However, these could be easily adapted by the user to particular characterized environments. Case studies for the validation of ATLAS will be also introduced, including preliminary results related to the use of Global System for Mobile communications in Railway (GSM-R) and Universal Mobile Telecommunications System (UMTS) technologies for positioning. The validation stage provides a way to test the platform functionalities and verify its flexibility. The versatility of the platform to perform simulations using same configuration parameters for different case studies can be highlighted. Furthermore, first conclusions are drawn from the obtained results. The characterization of the infrastructure for the simulation and the performance improvement of the location systems in the tunnels (e.g., by including Inertial Measurement Unit (IMU)) are necessary to achieve accuracy levels that can be valid for ETCS level 3.

Exploiting Coexistence Between UMTS and LTE for Greener Cellular Networks with Particle Swarm Optimization

Switching base stations (BSs) off is considered an effective method for improving energy efficiency. This switch-off approach is a system-level approach that can be applied to an area covered by multiple cells, even if those cells use different radio access technologies. This study focuses on exploiting the coexistence of universal mobile telecommunications system and long-term evolution to achieve a balance between network performance (meeting the demands for high data rates at peak traffic hours) and energy efficiency based on traffic load variations while guaranteeing maximum coverage for the region. Particle swarm optimization has been adopted to maximize the cells' coverage area during a switch-off session with constraints for the transmission power of the BS (Ptx), the total antenna gain (G), the signal-to-interference-plus-noise ratio, and shadow fading (?). Moreover, the modulation and coding scheme and data rate are considered in this study. The results show that daily energy savings of up to 27.86 % can be achieved while guaranteeing cell coverage.

A Multiband Power Amplifier With a Reconfigurable Output-Matching Network for 10-MHz BW LTE Mobile Phone Applications

A single-chip power amplifier (PA) with a reconfigurable output-matching network is presented for fourth-generation multiband mobile phone applications. The multiband PA (MBPA) consists of an amplifier and a reconfigurable output-matching network [a band selection circuit (BSC) and a tunable transmission line (TTL)]. Multiband load-impedance modulation is done by controlling a p-i-n switch of the BSC and varactor diodes of the TTL in the reconfigurable output-matching network. This MBPA delivered a gain of more than 11 dB, an adjacent channel leakage ratio of the Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (E-UTRA) smaller than −32 dBc, and a power-added efficiency larger than 29% at the output power of 26 dBm for high and low frequency bands with a 10-MHz 16-quadrature amplitude modulation Long-Term Evolution signal.

Downlink Scheduling in Long Term Evolution

This is an investigated research article on resource block scheduling of Long Term Evolution (LTE). LTE is one of the evolutions of the Universal Mobile Telecommunication System (UMTS). It provides internet access to mobile users through smart phone, laptop and other android devices. LTE offers a high speed data and multimedia services. It supports data rates up to 100 Mbps in the downlink and 50 Mbps in the uplink transmission. Our research investigation was aim to the downlink scheduling. We have considered The Best CQI scheduling algorithm and the Round Robin scheduling algorithm. The implementation, analysis and comparison of these scheduling algorithms have been performed through MATLAB simulator. We have analyzed the impact of the scheduling schemes on the throughput and the fairness of both scheduling schemes. Here we have proposed a new scheduling algorithm that achieves a compromise between the throughput and the fairness. Orthogonal Frequency Division Multiplexing (OFDM) has been adopted as the downlink transmission scheme. We have considered the impact of the channel delay on the throughput. In addition, MIMO transceiver systems have been implemented to increase the throughput.

A Multi-Band Stacked RF Energy Harvester With RF-to-DC Efficiency Up to 84%

The aim of this paper is to show the possibility to harvest RF energy to supply wireless sensor networks in an outdoor environment. In those conditions, the number of existing RF bands is unpredictable. The RF circuit has to harvest all the potential RF energy present and cannot be designed for a single RF tone. In this paper, the designed RF harvester adds powers coming from an unlimited number of sub-frequency bands. The harvester's output voltage ratios increase with the number of RF bands. As an application example, a 4-RF band rectenna is designed. The system harvests energy from GSM900 (Global System for Mobile Communications), GSM1800, UMTS (Universal Mobile Telecommunications System) and WiFi bands simultaneously. RF-to-dc conversion efficiency is measured at 62% for a cumulative -10-dBm input power homogeneously widespread over the four RF bands and reaches 84% at 5.8 dBm. The relative error between the measured dc output power with all four RF bands on and the ideal sum of each of the four RF bands power contribution is less than 3%. It is shown that the RF-to-dc conversion efficiency is more than doubled compared to that measured with a single RF source, thanks to the proposed rectifier architecture.

ES-AKA: An Efficient and Secure Authentication and Key Agreement Protocol for UMTS Networks

The authentication and key agreement (AKA) protocol of the Universal Mobile Telecommunication System (UMTS) was proposed to solve the vulnerabilities found in the Global System for Mobile Communications (GSM) systems. The UMTS-AKA provides mutual authentication, but is still vulnerable to redirection attack, denial of service attack, and man-in-the-middle attack. Apart from various attacks possibilities, the UMTS-AKA has a problem of counter synchronization, generates huge overhead, and utilizes more bandwidth and message exchanges during the authentication. An intruder may apply these attacks to impersonate the network or mischarge the mobile users. In this paper, we propose an efficient and secure AKA protocol namely ES-AKA to prevent the UMTS network against these problems and attacks. This protocol also solves the synchronization problem occurred between a mobile station MS and its home network HLR. The ES-AKA protocol generates lesser communication overhead as compared to UMTS-AKA, EXT-AKA, COCKTAIL-AKA, SKA-AKA, AP-AKA, X-AKA, EURASIP-AKA, Full-AKA, and U-AKA protocols. In addition, it also generates less computation overhead than the UMTS-AKA, EXT-AKA, COCKTAIL-AKA, S-AKA, Full-AKA, and U-AKA protocols. On an average, the ES-AKA protocol reduces 62 % of the bandwidth, which is the maximum reduction of the bandwidth by any AKA protocol referred in the paper. This protocol is also able to reduce 6 % of the messages exchanged (in terms of computations) during the authentication in comparison to UMTS-AKA.

Mobile Banking

Purpose – Though Mobile Banking has raised high expectations in research and practice, it neither experienced broad adoption nor allows it banks to realize additional earnings yet. By analyzing the discourse in form of publications in research and practice as a proxy for the subsequent actual adoption, the purpose of this paper is to examine whether Mobile Banking is just a fashionable concept and whether academics or practitioners are leading the debate on Mobile Banking. Design/methodology/approach – On the basis of academic and practical Mobile Banking publications from the last 13 years, discourse analysis was applied to examine patterns in the Mobile Banking literature and thus debate in research and practice. Previous patterns have been extended to examine whether the Mobile Banking discourse has fashionable aspects indicating a transient hype or whether it indicates long-term institutionalization. By differentiating between academic and practical publications, the different roles have been analyzed. Findings – Mobile Banking discourse shows a positive trend indicating a broader adoption in nearer future which should encourage both researchers and practitioners to stay involved in the topic. Temporary developments and the emergence of technological innovations (e.g. Universal Mobile Telecommunications System, iPhone) created a fashionable hype around Mobile Banking showing that the acceptance is probably linked to developments like convenience, usefulness or availability. New phenomenon like social networks thus should be integrated in future considerations regarding Mobile Banking. Originality/value – First study about the fashionable aspect in Mobile Banking literature discourse. Combination of conceptual work, literature review and methodological approach in form of regression and pattern analysis. Applies the method of a former work and extends the methodology by the characteristics of fashionable innovations.

A possibilistic approach to UMTS base-station location problem

In this paper, we address the problem of planning the universal mobile telecommunication system base stations location for uplink direction. The objective is to maximize the total traffic covered and minimize the total installation cost based on data involving fuzziness. To define the cost, researchers used the current period market prices as constants. However prices may change over time. Our aim here is to deal with the imprecise and uncertain information of prices. For this we introduce a model of problem where each cost is a fuzzy variable, and then we present a decision-making model based on possibility theory. To solve the problem we propose a search algorithm based on the hybridization of genetic algorithm and local search method. To validate the proposed method some numerical examples are given.

Adaptive Modulation and Coding for LTE Wireless Communication

Long Term Evolution (LTE) is the new upgrade path for carrier with both GSM/UMTS networks and CDMA2000 networks. The LTE is targeting to become the first global mobile phone standard regardless of the different LTE frequencies and bands use in other countries barrier. Adaptive Modulation and Coding (AMC) is used to increase the network capacity or downlink data rates. Various modulation types are discussed such as Quadrature Phase Shift Keying (QPSK), Quadrature Amplitude Modulation (QAM). Spatial multiplexing techniques for 4×4 MIMO antenna configuration is studied. With channel station information feedback from the mobile receiver to the base station transmitter, adaptive modulation and coding can be applied to adapt to the mobile wireless channels condition to increase spectral efficiencies without increasing bit error rate in noisy channels. In High-Speed Downlink Packet Access (HSDPA) in Universal Mobile Telecommunications System (UMTS), AMC can be used to choose modulation types and forward error correction (FEC) coding rate.