85 research outputs found
Indoor Wireless Communications using Slotted ISMA protocols
No full textThe performance of the Slotted ISMA protocols in Rician fading channel for Indoor Wireless communications considering Pico Cellular systems have been analyzed in this thesis. The throughput of Slotted nonpersistant Inhibit Sense Multiple Access (np-ISMA), Slotted 1-persistent ISMA (1p-ISMA) and Slotted np-ISMA\CD (Collision Detection) is investigated in the presence of n-interfering signals whose random amplitudes are considered as Rician distributed. Numerical results are presented, indicating the effect of propagation impairments on channel capacity. The results are of importance for mobile networks and indoor wireless office communications.Electrical Engineering, Mathematics and Computer ScienceTelecommunicatie- en Verkeersbegeleidingssysteme
Unslotted Hybrid CDMA/ISMA Protocol for Indoor Wireless Computer Communications
No full textA hybrid Code Division Multiple Access / Inhibit Sense Multiple Access (CDMA/ISMA) protocol has been proposed as an effective multiple access scheme for Indoor Wireless Computer Communications. This new protocol combines the advantages of both CDMA and ISMA into one protocol. On the one hand the ISMA protocol introduces a limitation to the number of simultaneous accesses to the transmission channel. On the other hand the CDMA protocol introduces an improvement to the packet survival chance. It is shown that the performance of the hybrid protocol is indeed better than CDMA only. In addition, code sharing can be applied to reduce hardware cost. The slotted hybrid CDMA/ISMA protocol using the p-persistent ISMA scheme has already been analysed. In this report, we investigate the hybrid protocol using the unslotted non-persistent ISMA scheme. The analysis is done for a star-connected multiple access wireless computer network. The performance comparison between the slotted and unslotted hybrid CDMA/ISMA protocol is evaluated in terms of throughput and delay using computer simulation and mathematical analysis.Electrical Engineering, Mathematics and Computer ScienceTelecommunicatie- en Verkeersbegeleidingssysteme
Performance Analysis of Slotted ISMA Protocols for Mobile Communications on a Three Lane Motorway
No full textA slotted ISMA protocol has been proposed for using with the communication channel from vehicles to a base station near the motorway. In this report the performance of this channel using the proposed protocol is analysed. Three slotted ISMA protocols can be distinguished, namely: • p-persistent slotted ISMA; • 1-persistent slotted ISMA; • non-persistent slotted ISMA. The performance of the protocol has been measured in terms of the throughput and the packet delay of the communication channel. The system has been modelled by assuming a capture receiver at the base station. The vehicles are assumed to maintain constant velocities while moving in one direction inside a cell of 200 metres on a three-lane motorway. The distribution of the vehicle positions on the motorway has been considered. Also the influence of the packet length and collision detection ratio will be examined. Furthermore the integration of DECT with the designed system is investigated. The performance of the system has been investigated for three traffic types: light traffic, heavy traffic and queuing traffic.Applied SciencesElectrical EngineeringTelecommunications and Traffic-Control Systems Grou
Performance Analysis of a Hybrid ISMA/CDMA Protocol for Indoor Wireless Communication
No full textThe hostile transmission medium encountered in Indoor: Wireless Communications (IWC) requires the use of special communication protocols. In this report we investigate a combination of the Inhibit Sense Multiple Access (ISMA) and Code Division Multiple Access (CDMA) protocols. The ISMA protocol limits the number of simultaneous accesses to the transmission channel and the CDMA protocol improves the packet survival chance. With CDMA each bit is transmitted using several code bits, giving each signal has its own, easy to recognize, signature. Coding spreads the signal over a large transmission bandwidth, which makes it particularly resistant to fading and multipath propagation, two key factors which degrade network performance…Applied SciencesElectrical EngineeringTelecommunications and Traffic Control Systems Grou
Hybrid CDMA / ISMA Protocol in Rician Fading Channel in Indoor Wireles Data Communications
No full textThis thesis describes the performance analysis of a star-connected, indoor wireless computer data communication system using direct-sequence code division multiple access (DS-CDMA) and Hybrid CDMA / Inhibit Sense Multiple Access (ISMA) protocol. The channel performance is investigated in terms of bit error rate (BER) and the protocol performance is investigated in terms of traffic-throughput and throughput-delay characteristics. To enhance the performance, a diversity technique using Maximum Ratio Combining (MRC) is used. Comparison of the simulation results with the analytical results is also performed.Applied SciencesElectrical EngineeringTelecommunications and Traffic Control Systems Grou
Throughput analysis of some mobile packet radio protocols in Rician fading Channels
No full textThe throughput of packet radio channels is investigated theoretically using the interference model in Rician fading environment. Three types of packet protocols are considered, namely: i) slotted ALOHA, ii) unslotted nonpersistent ISMA, and iii) slotted nonpersistent ISMA. Numerical results are presented, indicating the effect of propagation impairments on channel capacity. The results are of importance for mobile data networks, wireless office communications and other packet systems with contention-limited performance.Electrical Engineering, Mathematics and Computer ScienceTelecommunicatie- en Verkeersbegeleidingssysteme
Spatial econometric model of the spillover effects of financial development on carbon emissions: A global analysis
No full textThis study investigates the impact of financial development (FD) on CO2 emissions in the presence of economic growth, industrial growth, and renewable energy consumption. The sample size consists of panel of 89 countries for the period 1992-2014. The empirical analysis has been done by applying spatial econometrics techniques for exploring the spillover effects from the neighboring countries. The results demonstrate that spatial dependency exists among the sample economies. The spatial segregation analysis reveals that both local (direct) and spillover (indirect) financial development effects significantly lower local carbon emissions. Furthermore, the results demonstrate that in developed countries FD lowers the CO2 emissions whereas in developing countries FD increases the carbon emissions. The findings are useful for economic policy makers for devising economic and environment related policies by considering the intensity of FD spatial effects in the local economy's pollution level. The findings of this study are also useful for highlighting the fact that whether local economy's environment improved (or deteriorated) because of its own initiatives (pressure) for (on) environment or due to other country's initiatives (pressure) regarding FD
Spatial Econometric Model of the Spillover Effects of Financial Development on Carbon Emissions: A Global Analysis
No full textThis study investigates the impact of financial development (FD) on CO2 emissions in the presence of economic growth, industrial growth, and renewable energy consumption. The sample size consists of panel of 89 countries for the period 1992-2014. The empirical analysis has been done by applying spatial econometrics techniques for exploring the spillover effects from the neighboring countries. The results demonstrate that spatial dependency exists among the sample economies. The spatial segregation analysis reveals that both local (direct) and spillover (indirect) financial development effects significantly lower local carbon emissions. Furthermore, the results demonstrate that in developed countries FD lowers the CO2 emissions whereas in developing countries FD increases the carbon emissions. The findings are useful for economic policy makers for devising economic and environment related policies by considering the intensity of FD spatial effects in the local economy’s pollution level. The findings of this study are also useful for highlighting the fact that whether local economy’s environment improved (or deteriorated) because of its own initiatives (pressure) for (on) environment or due to other country’s initiatives (pressure) regarding FD.
Financial globalization: a description from the standpoint of a process approach = Фінансова глобалізація: характеристика з позицій процесного підходу
No full textOnyshchenko S.V. Financial globalization: a description from the standpoint of a process approach // Information Technologies and Management 2017 : theses of the 15th International Scientific Conference, April 27-28. – Riga : ISMA University, 2017. – P. 140-141.The complexity of the financial globalization process is caused not only by the presence of a significant number of subprocesses, their scale, and depth of consequences but also common consequences of these subprocesses, for which a synergistic effect is observed. Author proved that manifestation of financial globalization caused by the growth of financial markets and the priority development of the international financial sector in comparison with the real sector of the world economy.
The descriptive model of financial globalization from the position of process approach is proposed, taking into account the subjects and objects of financial globalization.Складність процесу фінансової глобалізації зумовлена не лише наявністю значної кількості підпроцесів, їх масштаб і глибину наслідків, а також спільні наслідки цих підпроцесів, для яких спостерігається синергетичний ефект.
Автором доведено, що прояв фінансової глобалізації зумовлений зростанням фінансових ринків та пріоритетним розвитком
міжнародний фінансовий сектор у порівнянні з реальним сектором світової економіки.
Запропоновано описову модель фінансової глобалізації з позиції процесного підходу з урахуванням суб’єктів та об’єктів фінансової глобалізації
Environmental sustainability in technologically advanced economies: The role of eco-digitalization, green finance, and green technology
No full textThis study investigates the effects of eco-digitalization, green technology, and green finance on environmental sustainability in the presence of affluence and population. The sample size consists of a panel of 19 technologically advanced economies covering the time span from 1980 to 2023. The econometric model is designed using the STIRPAT framework. The empirical results are based on panel time series analysis. The panel unit root tests illustrate that variables are stationary at the first difference and follow the I (1) order of integration. The panel cointegration test confirms the presence of long-run relationships between the variables. The empirical findings reveal that eco-digitalization, green technology, and green finance help to boost environmental sustainability by reducing carbon emissions and ecological footprints in technologically advanced economies. Furthermore, the empirical investigation proceeds using two major technological phases in the sampled economies. The results reveal heterogeneous effects of technological innovations and population growth on environmental quality across the phases of technological advancement. Our findings are helpful for policymakers, environmentalists, and development practitioners in designing and implementing policies that help mitigate carbon emissions and achieve environmental sustainability
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