Telecommunication Base Stations Research Articles

Active Phase Change Material Cold Storage in Off-Grid Telecommunication Base Stations: Potential Assessment of Primary Energy Savings

The global demand for wireless, mobile communication, and data services has grown significantly in the recent years. Consequently, electrical energy consumption to provide these services has increased. The principal contributors to this electricity demand are approximately 7 million telecommunication base stations (TBS) worldwide. They act as access points for mobile networks and have typical electrical loads of 2–3 kW. Whereas for most of the TBS, the electricity is supplied by the grid, approximately 15% are located in remote areas or regions with poor grid accessibility, where diesel generators (DG) supply the required electricity. Based on a dynamic simulation model the application of a latent heat storage (LHS) using phase change material (PCM) in existing off-grid TBS has been analyzed. The LHS unit has been modeled as an air-based storage with phase change temperatures between 20 °C and 30 °C with the PCM being macro-encapsulated in slabs. This paper demonstrates the potential to reduce the primary energy consumption in off-grid TBS through the following methods: optimization of the DG operating point, of the air conditioning unit operation schedule and the utilization of photovoltaic (PV) energy.

The criteria for evaluating method and evidence on radiation health effects in epidemiological study: a review

This paper purpose is to assess whether the distance of base station plays a causal role leading to health problem. This research mostly focuses on participants around telecommunication base stations by assessing their symptoms and level of the incident of occurrence of pains and discomfort. It is important to rule out all the criteria and causality from cause and outcome in radiation health effects through epidemiological study. The major causal criteria to follow are criteria of biological plausibility, consistency, temporality and specificity of alternative explanations. True EMR value also should be determined to support the survey collection. Previous studies mostly have been performed were limited to the questionnaire survey and often burdened by the subjectivism-related error. The evidence for public health intervention must be sufficiently comprehensive to cover the complexity in epidemiological studies.

The perceptions of residents toward safeness of living vicinity of telecommunication base station

The perceptions of residents toward safeness of living vicinity of telecommunication base station

The effect of living nearby telecommunication base station: From the residents’ feeling

The effect of living nearby telecommunication base station: From the residents’ feeling

Experimental study on operation characteristics of a novel refrigeration system using phase change material

A refrigeration system using phase change material (PCM) with six operating modes is proposed to reduce the cooling energy use of energy-demanding spaces such as data centers and telecommunication base stations. PCM is used to store the cold of outdoor air (OA) and/or that produced by vapor compression refrigeration (VCR) at night, and to release the stored energy for indoor cooling during the daytime. Real-time space cooling and cold charging by VCR can be accomplished simultaneously. Free cooling from OA can provide significant energy saving for space conditioning. A prototype system using a commercially available PCM was developed and tested to investigate the system performance and operation characteristics. The temperatures of air, water and refrigerant were measured along with the refrigerant pressure. The study calculates and analyzes the refrigerating capacity, cooling capacity, cold storage rate, supplied cold, stored cold, and the coefficient of performance (COP) upon the measurements. Experimental results indicate that the proposed refrigeration system can perform the requested tasks in a stable manner. The paper further compares the operating performances with the cold from OA and from VCR. It is found that under the outdoor temperature of 15°C, OA appears to be more energy-efficient than VCR when the stored cold is less than 5.8MJ, but it takes more time to charge the cold.

Climate change and next generation cellular systems

As climate change could affect energy production, it can also undermine telecommunications development which requires increased energy consumption to drive improvement in network penetration, coverage and capacity. Employing secondary data analysis and simulation, this paper presents a study on climate change effect on energy consumption of telecommunication base stations. The impact of climate change on energy consumption was examined by introducing a climate factor,, into validated Base Transceivers Stations (BTS) power consumption models. The BTS energy demand was found to increase with increase in temperature due to cooling requirement. The result shows that, with 1 o C increase in outdoor temperature, heat flow through BTS shelter increases by 6.25%. This increase effect, manifests on cooling system with above 1 kW power. The result presented shows the importance of taking climate change variables into consideration when planning next generation cellular networks for sustainable deployment. Key Words: Climate change, renewable energy, cellular systems, base stations, mmWave communication, sustainability

Entropy Generation Rate Analysis of a Thermosyphon Heat Exchanger for Cooling a Telecommunication Base Station

Energy consumption can be reduced effectively if ambient energy is used to cool the telecommunication base station. A thermosyphon heat exchanger was adopted as a promising technique to utilise ambient energy. A prototype was developed, and the experimental system was constructed. Relations between dimensionless entropy generation rate, heat transfer rate and energy efficiency ratio of the thermosyphon heat exchanger were discussed theoretically and experimentally. Ambient temperature and facing air velocity were also examined. Results indicated that dimensionless entropy generation rate decreased by 8-9% when temperature difference increased by 3°C and increased by 8% when the ambient temperature increased by 3°C. The errors were in the range of 5.7-14.2%. When the facing air velocity increased from 2 m/s to 3.5 m/s, the test dimensionless entropy generation rate increased from 0.4 to 0.53 and the errors were 0.53-9.56%. Simulation and test results showed similar trends under different working conditions.

Entropy generation rate analysis of a thermosyphon heat exchanger for cooling a telecommunication base station

Entropy generation rate analysis of a thermosyphon heat exchanger for cooling a telecommunication base station

Hybrid Off-Grid SPV/WTG Power System for Remote Cellular Base Stations Towards Green and Sustainable Cellular Networks in South Korea

This paper aims to address the sustainability of power resources and environmental conditions for telecommunication base stations (BSs) at off-grid sites. Accordingly, this study examined the feasibility of using a hybrid solar photovoltaic (SPV)/wind turbine generator (WTG) system to feed the remote Long Term Evolution-macro base stations at off-grid sites of South Korea the energy necessary to minimise both the operational expenditure and greenhouse gas emissions. Three key aspects have been discussed: (i) optimal system architecture; (ii) energy yield analysis; and (iii) economic analysis. In addition, this study compares the feasibility of using a hybrid SPV/WTG system vs. a diesel generator. The simulation results show that by applying the proposed SPV/WTG system scheme to the cellular system, the total operational expenditure can be up to 48.52% more efficient and sustainability can be ensured with better planning by providing cleaner energy.

Optimal Solar Power System for Remote Telecommunication Base Stations: A Case Study Based on the Characteristics of South Korea’s Solar Radiation Exposure

This paper aims to address both the sustainability and environmental issues for cellular base stations in off-grid sites. For cellular network operators, decreasing the operational expenditures of the network and maintaining profitability are important issues. Hence, this study addresses the feasibility of a solar power system based on the characteristics of South Korean solar radiation exposure to supply the required energy to a remote cellular base station. The HOMER is used to determine the optimum size of the system components, to perform an energy production analysis, and to analyse the cost details of the project. The simulation results show that the proposed solar power system can achieve total operational expenditure savings of up to 48.6% by using sustainable and clean energy. This result means a significant long-term benefit can be achieved for cellular network operators.

An advanced control of hybrid cooling technology for telecommunication base stations

Inefficient cooling systems and rudimentary control methods are accountable for the significant cooling energy consumption in telecommunication base stations (TBSs). To address this issue, our study explores the performance of model predictive control (MPC) technology over a hybrid cooling system with ventilation and air-conditioning cooling. Specifically, a discrete particle swarm optimization (DPSO) algorithm is adopted in the MPC to handle the discontinuity and nonlinearity involved in the model built upon a state-space structure. Simulations are performed for a typical week during a cooling season. Moreover, we observe that a model mismatch could hinder the actual performance of MPC; thus, this study initiatively quantifies the impact of model mismatch by setting different coefficients of performance (COP) on the air-conditioner. The results show that the structured MPC has a better performance over conventional control methods, with an average reduction of 34% daily cooling energy consumption, while increasing the control accuracy in terms of maximum deviation from the desired temperature range. It is also found that a higher degree of model mismatch can lead to a higher performance degradation, either on the total energy consumption or on the room temperature deviation.

Comparative Study on Telecommunications Base Stations’ Power Supply Systems on Remote Sites in the Northern Part of Cameroon

Comparative Study on Telecommunications Base Stations’ Power Supply Systems on Remote Sites in the Northern Part of Cameroon

Power Consumption: Base Stations of Telecommunication in Sahel Zone of Cameroon: Typology Based on the Power Consumption—Model and Energy Savings

In this paper, the work consists of categorizing telecommunication base stations (BTS) for the Sahel area of Cameroon according to their power consumption per month. It consists also of proposing a model of a power consumption and finally proceeding to energy audits in each type of base station in order to outline the possibilities of realizing energy savings. Three types of telecommunication base stations (BTS) are found in the Sahel area of Cameroon. The energy model takes into account power consumption of all equipment located in base stations (BTS). The energy audits showed that mismanagement of lighting systems, and of air-conditioning systems, and the type of buildings increased the power consumption of the base station. By applying energy savings techniques proposed for base stations (BTS) in the Sahel zone, up to 17% of energy savings are realized in CRTV base stations, approximately 24.4% of energy are realized in the base station of Missinguileo, and approximately 14.5% of energy savings are realized in the base station of Maroua market.

How to assess and manage energy performance of numerous telecommunication base stations: Evidence in China

Existing calculated benchmarking methods and main energy performance assessment schemes often lack the practical ability to manage the energy performance of a vast number of widespread telecommunication base stations (TBSs). Therefore, on the basis of a TBS survey, this paper puts forward the dynamic simulation and sensitivity analysis method to allow the new rule “one energy benchmark for a group of similar TBSs” rather than the traditional rule “one benchmark for one assessed building”. The new method reasonably limits the number of benchmarks and a feasible benchmark system is established for managing numerous TBSs. The results indicate that, first, more than one million TBSs distributed in a large area of China can be divided into 448 typical scenarios. Second, the benchmarks for reasonable energy use of these scenarios can be organized into four simple benchmarking charts. Third, the attempt to establish further challenging energy benchmarks shows that the most energy-saving measure in TBSs, i.e., ventilation cooling, can fully eliminate the negative impact of poor configurations of envelops and cooling coefficients of performance (COP). Finally, establishing telecom industrial standards for locating the reasonable TBS energy consumption level even in giant countries appears feasible.

Optimization on Performance of the Latent Heat Storage Unit (LHSU) in Telecommunications Base Stations (TBSs) in China

Abstract A latent heat storage unit (LHSU) that combined with energy storage modules and an air cooler was investigated to save the space cooling energy consumption in telecommunications base stations in China. A mathematical model was employed to simulate the heat transfer processes within energy storage modules and air cooler. In addition, an experiment was carried out in an enthalpy difference laboratory. The relative errors of air and temperature difference between the simulation and experimental results were calculated for energy charging process and energy discharging process, respectively. It was shown that the relative error for the water circulation system was reported to 1.33% and 5.23% under the charging and discharging process and 7.27% and 8.00% for air circulation system. The annual energy saving ratio was presented as a function of PCM melting temperature for varied pump flow rates and fan flow rates. To obtain the maximum annual energy savings ratio, a genetic algorithm was developed, considering fan flow rate, pump flow rate and melting temperature of PCM. Annual energy savings ratios were improved by 6.48%, 4.39%, 3.48%, and 3.51%, in Shenyang, Zhengzhou, Changsha, and Kunming, respectively.

The Leading Practices of Green Mobile Telecommunication Base Station Design

The aim of this study is to identify the green mobile telecommunication base station design practices as adopted by leading cases, four cases were analyzed; Ericsson, ZTE, Huawei, and Bharti. The data were collected from the published data. This study reveals that; the design attributes could be classified to; primary and secondary design attributes. A lot of relationships are reported between the design attributes. This study helps the academics in understanding the relationship between design attributes and actions, so they can use the reported model of this study for teaching purposes or for further extended survey study. The base stations developer and mobile communication services providers have a good insight about the sustainable design alternatives. The green operations practices are still new and the research contribution is limited, the research contribution of green mobile telecommunication base station deign is very limited.

Nanostructured (Mg,M)2SiO4 As Cathode Material in Mg Ion Batteries

Rechargeable Li-ion batteries are already widely used, and the dominating solution for automotive as well as portable, high-power applications due to the superior power density. However, several challenges of Li-ion battery technology are yet to be overcome, e.g. with respect to cost, resource availability, safety issues related to risk of thermal runaway of batteries and the limited temperature window of Li-ion batteries due to electrolyte deterioration at low temperatures. Although expected to dominate the portable battery market in the foreseeable future, the above mentioned drawbacks of Li-based batteries mean they have limited suitability in several markets, including stationary energy storage systems and auxiliary power applications where low cost and high reliability under a wide temperature range are more important than low weight and high power density. There is therefore a need for development of new battery types, specifically aimed at low cost markets. Batteries based on magnesium and other divalent metal ions, with the option of transferring two electrons, compared to the one electron transferred in Li-ion batteries, were introduced around 2000 by Aurbach et al.[1] and represent a promising solution for future low cost, high energy density batteries. Rechargeable Mg-batteries are not yet commercially available, but have a theoretical energy density in the range of 100 Wh/kg[2] for Chevrel-phase cathodes and up to 500 Wh/kg for MgMnSiO4 cathodes[3]. Still, fundamental research is needed in order to produce high-performance batteries which are also stable and recyclable. In this aspect, an interdisciplinary approach covering modeling, innovative material synthesis routes and advanced experimental characterization techniques is a powerful combination which is herein proposed for the development of low cost novel Mg-ion batteries. Such developments will be beneficial for a wide range of applications, mainly stationary, that require use of batteries, such as for storage of renewable energy from intermittent energy sources (solar, wind and wave), stand-alone power systems, telecommunication base stations, auxiliary power, etc. In this work, selected (Mg,M)2SiO4 (M=Mn or Co) materials are synthesized through an advanced sol-gel route as well as flame spray pyrolysis, aiming to obtain enhanced electrical conductivity. The developed cathode materials are characterized electrochemically by using Mg alloys as the anode and a state-of-the art electrolyte. In-situ X-ray diffraction (XRD) is used to characterize phase evolution in the materials during cycling. The effect of different synthesis methods on morphology, phase purity, crystal structure and electrochemical properties will be presented. [1] D. Aurbach, Lu, Z., Schechter, A., Gofer, Y., Gizbar, H., Turgeman, R., Cohen, Y., Moshkovich, M., Levi, E., Nature 2000, 407, 724-727. [2] D. Aurbach, Y. Gofer, Z. Lu, A. Schechter, O. Chusid, H. Gizbar, Y. Cohen, V. Ashkenazi, M. Moshkovich, R. Turgeman, E. Levi, Journal of Power Sources 2001, 97-98, 28-32. [3] Z. Z. Feng, J. Yang, Y. Nuli, J. L. Wang, X. J. Wang, Z. X. Wang, Electrochemistry Communications 2008, 10, 1291-1294. Acknowledgements Financial support is gratefully acknowledged from the Research Council of Norway, grant number 221785/F20.

Performance of a free-air cooling system for telecommunications base stations using phase change materials (PCMs): In-situ tests

A free air cooling system that combines phase change material (PCM) with a natural cold source (i.e., cold air) was developed to reduce the space cooling energy consumption in telecommunications base stations (TBSs). Outside cold air, instead of air conditioning system was used to remove heat in the TBSs. In addition, a PCM technology was adopted to improve the mismatch between energy demand and supply on the electric grid. The proposed system was intended to operate in conjunction with existing air conditioning units within each TBS. Consequently, the running time the air conditioning units was reduced, resulting in energy and demand savings. A full scale prototype, herein referred to as latent heat storage unit (LHSU), was designed, built and tested in TBSs located in five different climatic regions in southwest and eastern China during different seasons. In addition, a mathematical model was developed to simulate the operation of the proposed LHSUs. Energy savings ratio (ESR) was used as the criterion to evaluate LHSU’s energy savings. The estimated average annual ESR in five climatic regions was approximately 50%, with a maximum value of 67%. The average percent running time in which the LHSU replaced the operation of conventional air conditioners was 82.6%, with values surpassing 75% in four of the five cities, and one city achieving a value of almost 100%.

Energy optimisation of hybrid off-grid system for remote telecommunication base station deployment in Malaysia

Cellular network operators are always seeking to increase the area of coverage of their networks, open up new markets and provide services to potential customers in remote rural areas. However, increased energy consumption, operator energy cost and the potential environmental impact of increased greenhouse gas emissions and the exhaustion of non-renewable energy resources (fossil fuel) pose major challenges to cellular network operators. The specific power supply needs for rural base stations (BSs) such as cost-effectiveness, efficiency, sustainability and reliability can be satisfied by taking advantage of the technological advances in renewable energy. This study investigates the possibility of decreasing both operational expenditure (OPEX) and greenhouse gas emissions with guaranteed sustainability and reliability for rural BSs using a solar photovoltaic/diesel generator hybrid power system. Three key aspects have been investigated: (i) energy yield, (ii) economic factors and (iii) greenhouse gas emissions. The results showed major benefits for mobile operators in terms of both environmental conservation and OPEX reduction, with an average annual OPEX savings of 43% to 47% based on the characteristics of solar radiation exposure in Malaysia. Finally, the paper compares the feasibility of using the proposed approach in a four-season country and compares the results against results obtained in Malaysia, which is a country with a tropical climate.

Effect of Radiofrequency Radiation from Telecommunication Base Stations on Microbial Diversity and Antibiotic Resistance

We aimed to investigate the effects of radiofrequency radiation from telecommunication on bacteria diversity and antibiotic sensitivity of surrounding bacteria micro-flora. In all cases of bacteria isolated, results indicated that radiation majorly influences and selected bacteria of specific morphology (rod-like, gram positive and spore formers) belonging to the genera Bacillus, Clostridium, Corynebacterium and Sporosarcina. Spore formation have been associated with prevention of DNA damage, this suggest that radiation may imposes stress detrimental to various non-spore forming, gram negative bacteria of nonrod morphology. The antibiotic resistance pattern indicated resistance above 50% in three of the ten common antibiotics tested with the highest of 96% recorded against zinnacef, followed by amoxicillin (70%) and ampiclox (56%). The highest resistance recorded was attributed to Bacillus spp while lowest resistance was recorded in Corynebacterium. The two largest groups of isolates; Bacillus and Clostridium have been reported as human pathogens and found to be multidrug resistant. © JASEM