Traffic-Driven Energy Efficient Operational Mechanisms in Cellular Access Networks

Recent explosive growth in mobile data traffic is increasing energy consumption in cellular networks at an incredible rate. Moreover, as a direct result of the conventional static network provisioning approach, a significant amount of electrical energy is being wasted in the existing networks. Therefore, in recent time, the issue of designing energy efficient cellular networks has drawn significant attention, which is also the foremost motivation behind this research. The proposed research is particularly focused on the design of self-organizing type traffic-sensitive dynamic network reconfiguring mechanisms for energy efficiency in cellular systems. Under the proposed techniques, radio access networks (RANs) are adaptively reconfigured using less equipment leading to reduced energy utilization. Several energy efficient cellular network frameworks by employing inter-base station (BS) cooperation in RANs are proposed. Under these frameworks, based on the instantaneous traffic demand, BSs are dynamically switched between active and sleep modes by redistributing traffic among them and thus, energy savings is achieved. The focus is then extended to exploiting the availability of multiple cellular networks for extracting energy savings through inter-RAN cooperation. Mathematical models for both of these single-RAN and multi-RAN cooperation mechanisms are also formulated. An alternative energy saving technique using dynamic sectorization (DS) under which some of the sectors in the underutilized BSs are turned into sleep mode is also proposed. Algorithms for both the distributed and the centralized implementations are developed. Finally, a two-dimensional energy efficient network provisioning mechanism is proposed by jointly applying both the DS and the dynamic BS switching. Extensive simulations are carried out, which demonstrate the capability of the proposed mechanisms in substantially enhancing the energy efficiency of cellular networks

A 5G beam-steering microstrip array antenna using both-sided microwave integrated circuit technology

In this paper a beam steering 2×2 microstrip array antenna is proposed and simulated for the 5G sub-6 GHz frequency band. The array antenna is designed at the resonant frequency of 3.5 GHz. The antenna has four patches excited by two microstrip lines. Microstrip lines on top of teflon substrate of 0.8 mm height and slot line in the ground plane makes a hybrid junction. The design uses both sided microwave integrated circuit (MIC) to feed signal to the patch elements. This designed array antenna has the beam steering capability of maximum -17º to +17º while keeping the side lobe gain below 10 dB. The simulation results show that the array antenna is designed through good input impedance matching. The antenna has a return loss of -43 dB at center frequency 3.5 GHz. The results also show that the array antenna has a high gain of 12.57 dBi and directivity of 25.11 dB. The maximum gain of this antenna is 24.1 dB at -17º and +17º. The proposed work is simulated on keysight technologies advanced designed system (ADS)

Design and characterization of a circularly polarized microstrip-line-fed slot array antenna for S-band applications

A 2×2 slot array antenna fed by microstrip line for circular polarization operated in the S band frequency range is designed in this paper. Single cross slot with single port feed as well as dual port feed is taken into consideration for realizing circular polarization and combining these two processes, the slot array is designed with single feed for circular polarization. The antennas are designed on a Teflon glass fiber substrate of thickness 0.8 mm. The slot array dimension is 120×142×1.636 mm3. Smith chart of single cross slot antenna with single feed as well as dual feed has a dip at 2.69 and 2.53 GHz respectively indicate the capability of realizing circular polarization in the S band frequency range. The return loss of the slot array antenna is -58 dB shows good input impedance matching of the antenna. A dip in the smith chart of the slot array shows circular polarization near 2.4 GHz ensuring wireless applications as well. Axial ratio is found to be less than 1 dB in the resonance frequency. The impedance bandwidth percentage of the slot array antenna is 12.24%. The simulation is done by using keysight advanced design system (ADS) software

Embracing collaborative protected area management for conservation: an analysis of the development of the forest policy of Bangladesh

With the history and experiences of more than one hundred years in formulation and revisions since the British colonial period, the forest policy of Bangladesh has turned away from a traditional production premises towards protection. Establishing protected areas for biodiversity conservation dates back to the 1960s. The strategy gained impetus with the passage of national legislation in 1973 that included the provision of declaring forests as national parks, wildlife sanctuaries and game reserves for the protection of the natural forest resources. Due to the absence of a clear demarcation between core areas and buffer zones and the absence of concern for the sustention of local communities' usufruct rights, degradation continued in the protected areas. Therefore, an alternative strategy of co-management involving local stakeholders and provision of incentives in terms of Alternative Income Generation (AIG) supports has been introduced by the government under a donor assisted project. This new policy is being implemented in five pilot sites. This co-management strategy has demonstrated positive impacts and, increasingly, is gaining recognition as appropriate for other protected areas. This paper reviews the evolutionary history of and periodical changes in the forest policy of Bangladesh - highlighting the conservation aspects, the development of protected areas and the gradual adoption of their collaborative management.ArticleINTERNATIONAL FORESTRY REVIEW. 11(3):359-374 (2009)journal articl

Global observation of EKC hypothesis for CO2, SOx and NOx emission: A policy understanding for climate change mitigation in Bangladesh

Environmental Kuznets Curve (EKC) hypothesis is critical to understanding the developmental path of a nation in relation to its environment. How the effects of economic development processes dictate environmental changes can be found through the study of EKC. To understand the EKC phenomena for climate change, this study was undertaken by reviewing the available literature. As CO2, SOx and NOx are the significant greenhouse gases (GHG) responsible for global warming, thus leading to climate change, the study focused on those GHGs for EKC consideration. With an understanding of the different EKC trajectories, an attempt was made to determine the implications for the economic development of Bangladesh in regards to the EKC. It was shown that EKC for CO2 was following a monotonous straight line in most cases. SOx were shown to follow the full trajectory of the EKC in most situations and NOx was shown the hope only for the developed countries getting the low-income turning point. The type of economic policy that Bangladesh should follow in regards to the discussed pollutants and sources is also revealed. From these discussions, contributions to policy stimulation in Bangladesh are likely to be made. (C) 2010 Elsevier Ltd. All rights reserved.ArticleENERGY POLICY. 38(8):4643-4651 (2010)journal articl

PV-Powered CoMP-Based Green Cellular Networks with a Standby Grid Supply

This paper proposes a novel framework for PV-powered cellular networks with a standby grid supply and an essential energy management technique for achieving envisaged green networks. The proposal considers an emerging cellular network architecture employing two types of coordinated multipoint (CoMP) transmission techniques for serving the subscribers. Under the proposed framework, each base station (BS) is powered by an individual PV solar energy module having an independent storage device. BSs are also connected to the conventional grid supply for meeting additional energy demand. We also propose a dynamic inter-BS solar energy sharing policy through a transmission line for further greening the proposed network by minimizing the consumption from the grid supply. An extensive simulation-based study in the downlink of a Long-Term Evolution (LTE) cellular system is carried out for evaluating the energy efficiency performance of the proposed framework. System performance is also investigated for identifying the impact of various system parameters including storage factor, storage capacity, solar generation capacity, transmission line loss, and different CoMP techniques.Comment: 14 pages, International Journal of Photoenergy, 6189468, 201

Assessing the effectiveness of landslide slope stability by analysing structural mitigation measures and community risk perception

Rainfall-induced landslides seriously threaten hilly environments, leading local authorities to implement various mitigation measures to decrease disaster risk. However, there is a significant gap in the current literature regarding evaluating their effectiveness and the associated community risk perception. To address this gap, we used an interdisciplinary and innovative approach to analyse the slope stability of landslides, evaluate the effectiveness of existing structural mitigation measures, and assess the risk perception of those living in danger zones. Our case study focused on the Kutupalong Rohingya Camp (KRC) in Cox’s Bazar, Bangladesh, which is home to over one million Rohingya refugees from Myanmar. Although various structural and non-structural countermeasures were implemented in the KRC to mitigate the impact of landslides, many of them failed to prevent landslides from occurring. We utilised a variety of methods from the physical sciences, including the infinite slope, limit equilibrium (LEM), and finite element (FEM) approaches, to calculate the factor of safety (FoS) for specific slopes. Additionally, in the social sciences domain, we conducted a questionnaire survey of approximately 400 Rohingya participants to assess the community’s perception of the interventions and the degree of disaster risk. Our findings indicated that slopes with a gradient greater than 40° were unstable (FoS < 1), which was present throughout the entire KRC area. The effectiveness of the LEM and FEM methods was evaluated for four dominant slope angles (40°, 45°, 50°, and 55°) under varying loads (0, 50, and 100 kN/m2). The slopes were found to be stable for lower slope angles but unstable for higher slope angles (> 50°) and increased overburden loads (50–100 kN/m2). Different mitigation measures were tested on the identified unstable slopes to assess their effectiveness, but the results showed that the countermeasures only provided marginal protection against landslides. Survey results revealed that at least 70% of respondents believed that concrete retaining walls are more effective in reducing landslide occurrence compared to other measures. Additionally, about 60% of the respondents questioned the reliability of the existing structural mitigation measures. The study also found that the cohesion and friction angle of lower sandstone and the cohesion of upper soil layers are important factors to consider when designing and implementing slope protection countermeasures in the KRC area

Modeling and Prediction of Water Quality: Evidence of Benarpota Station of Sundarbans Region

The Sundarbans contain the world's largest coastal mangrove forest, with an area of about 10,000 km2 (3,900 sq mi), of which about 6,000 km2 (2,300 sq mi) are located in Bangladesh and about 4,000 km2 (1,500 sq mi) in India. Salinity will be the major issue in the future which could destroy the natural ecological balance. The major salinity components are electric conductivity (EC) at low tide and high tide with the corresponding chloride in low tide and high tide. This study develops a SARMA (2, 0, 2) (2, 0, 0) [4] model as it provides the minimum value of model selection criterion (AIC, BIC, SIC, RMSE) compare to all other models. It was found that the bestfitted model for EC in a high tide of study area follows a seasonal autoregressive moving average model of order (2, 0, 2)(2, 0, 0) [4] and chloride in high tide follows SARMA (1, 0, 1) (2, 0, 2) [4]. After fitting the time series model and forecasting the fitted model, the study showed that in both electric conductivity (EC) and salinity (Chloride ppm) increasing in the last three decades. EC crosses the poor water quality level which is more than 4 ppt or 2560 ppm. Salinity also crosses the poor water quality level which is more than 5 ppt or 3200 ppm. The findings of this study would be a potential contribution to make a comprehensive management plan for the long-term conservation and protection of the cultural landscape and mangrove wetlands ecosystem in the Sundarbans region

Livelihood Pattern and Forest Dependence of the Major Tribes in Rangamati, Bangladesh

Indigenous people are of great interest and intense significance from forest perspective, as they inhabit for a very long time over the same region. In Bangladesh, tribal communities reside with close touch of forests and thus, quite dependent on it. That’s why, it of tremendous importance to study their Do’s and Don’ts in order to propose better forest and environmental management interventions considering options for enhancing livelihoods of the indigenous communities in Bangladesh. In this research, four major tribes of Rangamati in four sites have been purposively selected for questionnaire survey. Data has been taken into consideration from two vital viewpoint, livelihood pattern and forest dependence, assuming that all tribes are dependent on forest resources for their livelihood. And it is found that, Tanchangya and Chakma community are more economically well-off in terms of land ownership and income per capita respectively. Forestry practice provides little share in their total income though Tanchangya community has the highest land per capita in forestry sector as well as in agricultural sector. On the other hand, Marma community’s living standard is comparatively low as their income and land per capita is low, and they are more dependent on forest. Tripura community keeps the comparative middle status in almost every sector. A variety of other social and environmental factors were also collected and thoroughly analyzed here which can be very useful for further study.OtherShinshu University International Symposium 2010 : Sustainable Agriculture and Environment : Asian Networks II 　信州大学国際シンポジウム2010 : 持続的農業と環境 : アジアネットワークII ― アジアネットワークの発展をめざして―. 信州大学農学部, 2010, 45-58conference pape