GSM Standards Research Articles

A Feasibility Inquiry to the Sustainable Utilization of Few Invasive Flora

Objectives: The study focuses on utilising invasive flora affecting the indigenous plants and thereby bring about monetary benefits to the local people by means of handmade papers from the invasive weeds. Methods: Handmade paper from five invasive plants namely, Eichhornia crassipes, Eupatorium odorata, Combretum indicum, Lantana camara and Hyptis capitata was attempted. These plants after collection from Nilambur, Kerala were subjected to treatment with washing soda, blending, vat preparation, moulding and drying. This is followed by checking the paper quality parameters viz., Productivity, Clarity/opacity/transparency, Strength, Grammage, Paper grain, Ageing of paper and Moisture content. Findings: Out of the five invasive plants tested, the fibre yield was maximum for Eichhornia, but the productivity rate was less compared to other samples. Lantana and Hyptis yielded maximum productivity even though the fibre yield from these plants was less. The fibre uniformity of paper developed was positively detected for all the 4 plants except Eichhornia thereby proving the feasibility for paper manufacture. All sample paper allows the light; so, all are translucent in nature. Integrity of paper samples was retained in the paint test. The age test also yielded positive results. The gsm test showed lowest for Eichhornia as 98.12g/m2; Lantana 111.87g/m2; Combretum 131.87g/m2; Hyptis 163.75g/m2; Eupatorium is 255g/m2. Even though the gsm of Eichhornia is the best for paper manufacture according to gsm standards, the lack of fibre uniformity is a withdrawing feature for feasibility. The moisture content appeared high for Eichhornia and lowest for Combretum. Novelty: To date, studies on invasive plant utilisation done individually; no comparative study on productivity done. Current study can be further refined for environmental sustenance along with livelihood for local people. Keywords: Invasive Flora, Paper manufacture, Grammage test, Productivity, Ecological sustainability

Detection of unauthorized cell phone use during exam

In this article algorithm for detecting and determining the position of signal source produced by an active subscriber terminal of a cellular communication system GSM standard is introduced. Also there are presented results of simulation of the detection system operation and results of experiments on monitoring the signal spectrum of an active subscriber GSM cellular communication system.

SISTEM DE COMUNICAȚIE MOBIL, GSM-WIFI, PENTRU VEHICULELE AGRICOLE

The research carried out in this paper aimed to create a communication network for a fleet of agricultural vehicles by means of which to transmit and receive information on the status of work, working time, processed areas, number of machines used and much more necessary information. Communication is based on GSM and WiFi standards, which bring the most secure security standards in data protection to this network. The major advantage of the solution presented is that all the important information is concentrated in one place. The proposed communication system consists of a mobile device that routes the WiFi network on a GSM network that has a minimum 3G standard but also works with 5G, depending on the GSM operator and the devices that are mounted on vehicles, which communicate over the WiFi network. The communication device was mounted on an electric tractor, where it was powered by the tractor's power source. In this communication architecture, the vehicle transmitted information to a control centre and also to other vehicles in the vicinity. The system was able to receive data from other devices, authorized in the system, which could be fixed in the field. The collected data were transmitted to a server in a remote location. The obtained results showed a decrease of signal strength while getting further away from the tractor, with good results up to 100 m radius.

Development of Wireless Network Indoor Coverage System Based on Optical Fiber Distribution System.

With the continuous development of network communication technology, the domestic network has covered the homes of ordinary people, but the indoor coverage system of the network cable network needs to be further improved. The optical fiber distribution system is a signal coverage system integrating GSM, TD-SCDMA, and other standards. It is mainly composed of system access unit, system expansion unit, and system remote unit. Wireless network is an important communication technology, which is easy to use and can be connected wirelessly over long distances. The purpose of this paper is to study an optical fiber distribution system for indoor coverage design of wireless networks, so as to achieve faster and more efficient coverage. In this paper, a wireless network signal processing algorithm is proposed, and a systematic method for designing the wireless network indoor coverage of the optical fiber distribution system is proposed, and the algorithms are compared and tested. The test results in this paper show that the signal strength obtained by the algorithm in this paper is −54.83 dB, while the traditional artificial design algorithm is only −45.97 dB. In addition, the wireless network base point of the algorithm in this paper is also 3 lower than the traditional one. Moreover, the coverage rate achieved by the algorithm in this paper is 3.17% higher than that of the network cable network base point layout given by the genetic algorithm, and the average received signal strength is 3.34 dB higher. In addition, the algorithm in this paper takes 9.1 s, 11.2 s, and 5.3 s for the three scenarios of underground parking lot, large shopping mall, and residential residential area, while the traditional manual design algorithm takes 87.9 s, 108.8 s, and 51.7 s, respectively. The algorithm in this paper is only about 1/10 of the traditional artificial design algorithm. Therefore, it can be concluded that the coverage effect of the wireless network indoor coverage system of the optical fiber distribution system designed in this paper is significantly improved.

Why are smart cities proving to be so hard to deliver?

Why are smart cities proving to be so hard to deliver?

A Fast Settling Multi-Standard CMOS Fractional-N Frequency Synthesizer for DECT/GSM/ CDMA &/NADC Wireless Communication Standards

A fast settling multi-standard CMOS fractional-N frequency synthesizer for DECT, GSM, CDMA and NADC wireless communication standards is proposed. This frequency synthesizer was simulated with ADS2008 in TSMC RF CMOS 0.18 µm. Frequency range is 824-1900 MHz, a switched capacitor LC-VCO was used in order to produce this frequency range. Frequency synthesizers have three main specifications of phase noise, settling time and power consumption. A new channel select circuit was designed instead of ∑∆ modulator to locate spur tones far from center frequency. A high reference frequency was used in order to reduce the VCO phase noise and locate the spur tones far from center frequency; these tones are produced by charge pump (reference spur) and N/N+1 divider (fractional spur). Two ways were used for phase noise optimization; in the first way phase noise was reduced by a low pass filter and a bypass capacitor (CT) that eliminate thermal noise and 2ω0 harmonics of tail current source; in the second way with biasing of VCO transistors only in saturation region preventing reduction of quality factor(Q) in tank circuit. These two ways in VCO of DECT were used, consequently the phase noise at 1875MHz center frequency was improved from -119.4 dBc/Hz at 3.4 MHz offset frequency to -144.3 dBc/Hz at 3.4 MHz offset frequency. The settling time for all standards was achieved less than almost 1 μs over the entire frequency range. For DECT synthesizer phase noise of -116.37 dBc/Hz at 3 MHz offset frequency was obtained, the first spur tone was located in 7.35 MHz offset from center frequency, also settling time of 350ns was obtained. The whole frequency synthesizer in loop1 (for DECT) draws 13 mA and in loop2 (for GSM900, CDMA & NADC) draws 13.67 mA from a 1.8 V voltage supply.

Tunable dual-band bandpass filter for multi-standard applications

A new tunable dual-mode dual bandpass filter (DBPF) is presented based on coupled-line resonators structure. The center frequency and bandwidth can be individually tuned in each band with varactors, which are loaded at the end and middle of the coupled resonators. Varactor diodes can adjust the lower band from GPS to GSM standards (from 1.57 to 1.85 GHz), and the higher band for GSM, UMTS, WiFi and WiMAX applications (from 1.85 to 2.5 GHz). The LC equivalent model of the proposed filter is presented to analyze the resonator at odd- and even-mode frequencies to prove the favorable role of each varactor in tuning the center frequency and bandwidth. To validate the simulation results, the proposed filter is fabricated and measured. Measurement results are in good agreement with LC equivalent model and simulation results.

A dual‐mode tunable bandpass filter for GSM, UMTS, WiFi, and WiMAX standards applications

SummaryThis paper presents a dual‐mode tunable bandpass filter (BPF) for global system for mobile communication, universal mobile telecommunications system, wireless fidelity, and worldwide interoperability for microwave access standard applications. The proposed filter consists of a stepped‐impedance resonator, single resonator, and coupled line, which are loaded with varactors. The center frequency and bandwidth of the proposed filter can be tuned with tuning varactors. Furthermore, the measurement results show that the BPF can be tuned over the frequency range of 1.8 to 2.5 GHz. Moreover, the bandwidth can be changed at each certain frequency. Furthermore, using PIN diodes, a bandstop filter is added to the tunable BPF to reduce the out‐of‐band frequencies around the desired frequencies. The values of LC equivalent circuits are calculated, and the results are compared with those obtained from the layout of the proposed structure. Finally, the measurement results justify the simulation results.

Design of a reconfigurable front‐end for a multistandard receiver for the frequency range of 800 MHz to 2.5 GHz

SummaryIn this paper, a reconfigurable receiver front‐end for the frequency range of 800 MHz to 2.5 GHz is presented. The radio frequency front‐end is realized in wideband form with reconfigurable baseband filter. The proposed front‐end targets the GSM, WLAN, WCDMA, and GPS standards residing in the aimed frequency range. The necessary specifications for each individual standard have been revisited and recalculated. The interaction of the different standards and their interoperability has been thoroughly investigated and extra specifications derived for the multistandard receiver. The multistandard receiver has been designed, layouted, and simulated in RFCMOS 0.18‐μm process.

A Survey on Transferring Standards of GSM-R in Railway Sector

GSM-Railways (GSM-R), which is evolutionary railway mobile communication technology, are gradually replacing analogue radio systems. Although GSM-R is an impossible achievement in terms of European railway interoperability, from a telecommunication point of view, it is successive technology. This study present the transfer of a telecommunication standard to another railways and it studies whether the adoption of an upgraded version of the GSM standard (GSM‐R) turned out to be an efficient choice. The transfer and deployment of GSM‐R is technically importance to the success of another European railway project. The introduction of the new signaling system rests on achieving interoperability in radio‐communication.The study will focus on the GSM-R part of the ERTMS system and its interworking with ETCS.

A self-control technique for high efficiency class-E CMOS power amplifier

In this paper, a self-control (SC) technique for high efficiency class-E CMOS power amplifier is presented for GSM standard. Cascode topology due to high sustainability of voltage stress is mostly considered in CMOS PAs, but slow transition of common-gate device from triode to cut-off region is the most problematic issue of cascode configuration and the main source of power loss. In order to minimize its power loss a positive feedback technique is used. The proposed technique speeds up on-to-off and off-to-on transition time and lower the on and off drain׳s voltage of the common-gate device. Therefore, the common-gate device turns off and on instantly after common-source device in lower drain voltage and consequently the technique shows an improvement in the overall performance of the PA. To demonstrate its performance a self-control class-E CMOS PA has been designed, simulate, and compared to conventional class-E CMOS PA. It has shown that more than 2% improvement is achieved in power-added efficiency (PAE). Under a 3.3V power supply, the proposed CMOS PA in 0.18um CMOS process at 1.8GHz gives 29.6dBm output power.

Electromagnetic radiation security estimation on the residential building roof for cellular antenna

The work objective is to estimate the electromagnetic environment on the roof where a mobile system base station aerial is installed. The problem arises during maintenance, repair, and assembly operations for antenna-feeder devices. The evaluation problem for ecological assessment of the electromagnetic environment at a standard height of two meters above the roof is solved with the computational prediction method. Two strict models are used for electrodynamic simulation of energy flux density, i.e. a two ray model which describes the plane electromagnetic wave diffraction on the flat perfectly conducting roof surface, and finite models of the roof are described with the canonical problem on a wedge of infinite extent. The difference between the developed model and the known ones lies within the research possibility not only in the computational points but within a whole computational plane. In the simulation process, antenna emission characteristics can be set in a number of ways including those obtained from the radiation object specifications, as it is proposed in a well-known technique. The simulation results for energy flux density distribution in a horizontal plane within the roof space are given. Computational points are placed at the square grid nodes with the period of a quarter wavelength of the transmitter. A physical interpretation of the obtained results is given. A safety conclusion on the human presence on the roof with operating directional cel lular antenna of GSM standard is formulated.

Lossless Compression for Transmitting ECG in SMS with High Quality for Mobile Telecardiology Systems

This paper presents a novel lossless compression for 'ECG in SMS' (LCES) deployable on resource-constrained devices like mobile phones for efficient use in remote health monitoring systems. Even losslessly compressed ECG suffers transmission loss in GSM networks due to use of special character set stated by the GSM standards. The LCES overcomes these challenges by adopting the ETSI GSM 03.38 character set in the symbol substitution phase to abstain loss in ECG transmission. The LCES was implemented and tested as an Android App using MIT-BIH Arrhythmia and Compression Test Databases. An average compression-ratio of 7.03 and percentage-root-mean-square-distortion as low as 0.022 proving superior compression performance and quality for real-time mobile-based remote health monitoring systems were obtained.

A phase-noise reduction technique for RF CMOS voltage-controlled oscillator with a series LC resonator

This paper proposes a novel phase-noise reduction technique for high performance voltage-controlled oscillator (VCO) using a cross-coupled series LC resonator, rather than parallel LC resonator. The proposed technique makes a time difference between the zero crossing point of the drain node voltages and that of the gate node voltages of the switching pair. By adding cross coupled PMOS loading, the drain voltages are made close to a rectangular shape, which makes an ideal on–off switching of the VCO. Since the current source contributes large portion of noise to the output, it is removed in the proposed VCO to further improve the noise performance. While the series connected inductor and capacitor enhances the fundamental frequency swing at the LC connection node, it gives a cleaner spectral purity output and suppresses the overall noise at the drain node of the cross-coupled switching cell.The proposed technique is verified using a 65nm CMOS process with the VCO operating at around 3.6GHz frequency range. The post-layout phase noise of the VCO is −123dBc/Hz, −126dBc/Hz, and −137dBc/Hz at 600kHz, 800kHz, and 3MHz offset frequencies, respectively, which satisfy the stringent phase noise requirements such as GSM standards operating at 900-MHz, 1800-MHz and 1900-MHz band. The proposed VCO consumes 5.6mW dc power from a 1-V supply. The proposed VCO achieves the calculated figure-of-merit (FOM) of −201dBc/Hz at 3MHz offset.

The creation of standards for global mobile communication: GSM and UMTS standardization from 1982 to 2000

GSM and UMTS are the leading standards for digital mobile communications with 5.4 billion users and nearly 90 percent world market share. Success factors for this development were the advanced and timely available system standards developed until the end of the 1990s in Europe. In the pioneer period (1982 to 1992) Phase 1 of the digital GSM standard was developed for the first GSM networks. GSM Phase 2 completed in 1995 provided a platform for an unlimited feature evolution. The GSM Phase 2+ program (1993 to 2000) provided new services, better speech quality and enhanced data services and made GSM a system of generation 2.5. An evolution to the Third Generation based on the GSM core network evolution and a new radio subsystem was conceived in the period from 1996 to 2000. A consensus between Europe, Japan and the North American GSM community on this concept was achieved. The standardization work required an effective global working structure. This was also necessary for the GSM work. To cover these needs, the Third Generation Partnership Project (3GPP) was created to develop globally applicable technical specifications. 3GPP exists since the end of 1998 and has developed a series of specification releases for 3G and a new 4G system (LTE).

Research of GMR-1 in GEO Satellite Mobile Communications

At present, technology related to GEO is wide used in the civil and military fields. In this paper, firstly, the generation of GMR-1 was introduced and then a detail illustration of how to comprehend the GMR-1 system and its structure was made by comparison between GMR-1 specifications and GSM standard. These two specifications were compared in terms of the physical channel, logical channel, bursts, mapping and so on. The analysis indicates that GMR-1 modified the lower layers for the satellite channel. In the end, we are looking ahead to the future of the GMR-1.

Tunable wideband SAW-less receiver front-end in 65 nm CMOS

A surface acoustic wave-less receiver front-end for GSM, TD-LTE and TD-SCDMA standards featuring a novel low noise amplifier (LNA) architecture and harmonic rejection technique is presented. The tw...

Behavioral Modeling and Simulation of Cascade Multibit ΣΔ Modulator for Multistandard Radio Receiver

In this paper, a cascade Sigma-Delta (ΣΔ) Analog to Digital Converter (ADC) for multistandard radio receiver was presented. This converter is supposed to be able to support GSM, UMTS, Wifi and WiMAX communication standards. The Sigma-Delta modulator makes use of 4 bit quantizer and Data-Weighted-Averaging (DWA) technique to attain high linearity over a wide bandwidth. A top-down design methodology was adopted to provide a reliable tool for the design of reconfigurable high-speed ΣΔMs. VHDL-AMS language was used to model the analog and mixed parts of the selected 2-1-1 cascade ΣΔ converter and to verify their reconfiguration parameters based on behavioural simulation. This multistandard architecture was high level sized to adapt the modulator performance to the different standards requirements. The effects of circuit non-idealities on the modulator performance were modeled and analyzed in VHDLAMS to extract the required circuit parameters.

Feasibility Study of 4G Cellular Antennas for Eyewear Communicating Devices

A feasibility study of 4G cellular antennas operating in the LTE, GSM, DCS, PCS, and WLAN2400 standards for wirelessly connected eyewear is presented. The target bands are 700-960 MHz and 1.7-2.7 GHz. The antenna designs are capacitive coupling element types, with simple layout printed on one side of the printed circuit board (PCB) substrate. Three different antennas are examined in terms of obtainable bandwidth potential, reflection coefficient, and specific absorption rate (SAR) values considering two human-head models (SAM and Visible Human). The best antenna is -6 dB matched and has radiation efficiencies around 14% and 36% in respectively low and high frequency bands. Based on simulation data, SAR values could be above the 1-g standards.

A Collective Statistical Analysis of Outdoor Path Loss Models

This study encompasses nine path loss models (Erceg-Greenstein, Green-Obaidat, COST Hata, Hata Urban, Hata Rural, Hata Suburban, SUI, Egli and ECC-33) which were programmed on Python and studied for their results in an urban architecture (translated by higher attenuation variables) at 950 MHz and 1800 MHz. The results obtained showed that increasing the transmission antenna height with the increasing distance not only lowers down the path loss readings, but also shows that the standard deviation between the results of studied path loss models increases with the increasing transmission antenna height and increasing distance at both 950 MHz and 1800 MHz systems, especially when transmission antenna height crosses the GSM standard of 40 meters and cell-radius exceeds the limit of 20 kilometers. Moreover, it is also observed that at both 950 MHz and 1800 MHz, the path loss readings of all the models disperse from their collective mean between 1 and 10 Km, but tend converge afterwards (i.e. from 10 to 40 Km and onwards) towards their mean, which indicates that path loss readings of the urban models tend to follow either a single convergence point on large distances or reach their maximum threshold level (a level from which their readings cannot exceed or differ from each other significantly).