216 research outputs found
Energy Efficient Altitude Optimization of an Aerial Access Point
In this paper, we propose an energy-efficient optimal altitude for an aerial
access point (AAP), which acts as a flying base station to serve a set of
ground user equipment (UE). Since the ratio of total energy consumed by the
aerial vehicle to the communication energy is very large, we include the aerial
vehicle's energy consumption in the problem formulation. After considering the
energy consumption model of the aerial vehicle, our objective is translated
into a non-convex optimization problem of maximizing the global energy
efficiency (GEE) of the aerial communication system, subject to altitude and
minimum individual data rate constraints. At first, the non-convex fractional
objective function is solved by using sequential convex programming (SCP)
optimization technique. To compare the result of SCP with the global optimum of
the problem, we reformulate the initial problem as a monotonic fractional
optimization problem (MFP) and solve it using the polyblock outer approximation
(PA) algorithm. Numerical results show that the candidate solution obtained
from SCP is the same as the global optimum found using the monotonic fractional
programming technique. Furthermore, the impact of the aerial vehicle's energy
consumption on the optimal altitude determination is also studied.Comment: This version of the work has been accepted for publication in the
IEEE 31st PIMRC 2020 - Workshop on UAV Communications for 5G and Beyond; 7
pages; 5 figure
High quality draft genome sequence of Olivibacter sitiensis type strain (AW-6T), a diphenol degrader with genes involved in the catechol pathway
Olivibacter sitiensis Ntougias et al. 2007 is a member of the family Sphingobacteriaceae, phylum Bacteroidetes. Members of the genus Olivibacter are phylogenetically diverse and of significant interest. They occur in diverse habitats, such as rhizosphere and contaminated soils, viscous wastes, composts, biofilter clean-up facilities on contaminated sites and cave environments, and they are involved in the degradation of complex and toxic compounds. Here we describe the features of O. sitiensis AW-6(T), together with the permanent-draft genome sequence and annotation. The organism was sequenced under the Genomic Encyclopedia for Bacteria and Archaea (GEBA) project at the DOE Joint Genome Institute and is the first genome sequence of a species within the genus Olivibacter. The genome is 5,053,571 bp long and is comprised of 110 scaffolds with an average GC content of 44.61%. Of the 4,565 genes predicted, 4,501 were protein-coding genes and 64 were RNA genes. Most protein-coding genes (68.52%) were assigned to a putative function. The identification of 2-keto-4-pentenoate hydratase/2-oxohepta-3-ene-1,7-dioic acid hydratase-coding genes indicates involvement of this organism in the catechol catabolic pathway. In addition, genes encoding for β-1,4-xylanases and β-1,4-xylosidases reveal the xylanolytic action of O. sitiensis
High-quality permanent draft genome sequence of the extremely osmotolerant diphenol degrading bacterium Halotalea alkalilenta AW-7T, and emended description of the genus Halotalea
Members of the genus Halotalea (family Halomonadaceae) are of high significance since they can tolerate the greatest glucose and maltose concentrations ever reported for known bacteria and are involved in the degradation of industrial effluents. Here, the characteristics and the permanent-draft genome sequence and annotation of Halotalea alkalilenta AW-7(T) are described. The microorganism was sequenced as a part of the Genomic Encyclopedia of Type Strains, Phase I: the one thousand microbial genomes (KMG) project at the DOE Joint Genome Institute, and it is the only strain within the genus Halotalea having its genome sequenced. The genome is 4,467,826 bp long and consists of 40 scaffolds with 64.62 % average GC content. A total of 4,104 genes were predicted, comprising of 4,028 protein-coding and 76 RNA genes. Most protein-coding genes (87.79 %) were assigned to a putative function. Halotalea alkalilenta AW-7(T) encodes the catechol and protocatechuate degradation to β-ketoadipate via the β-ketoadipate and protocatechuate ortho-cleavage degradation pathway, and it possesses the genetic ability to detoxify fluoroacetate, cyanate and acrylonitrile. An emended description of the genus Halotalea Ntougias et al. 2007 is also provided in order to describe the delayed fermentation ability of the type strain
Shared Access Satellite-Terrestrial Reconfigurable Backhaul Network Enabled by Smart Antennas at MmWave Band
5G traffic expectations require not only the appropriate access infrastructure, but also the corresponding backhaul infrastructure to ensure well-balanced network scaling. Optical fiber and terrestrial wireless backhaul will hardly meet 100 percent coverage, and satellite must be considered within the 5G infrastructure to boost ubiquitous and reliable network utilization. This work presents the main outcomes of the SANSA project, which proposes a novel solution that overcomes the limitations of the traditional fixed backhaul. It is based on a dynamic integrated satellite- terrestrial backhaul network operating on the mmWave band. Its key principles are seamless integration of the satellite segment into terrestrial backhaul networks, a terrestrial wireless network capable of reconfiguring its topology according to traffic demands, and aggressive frequency reuse within the terrestrial segment and between terrestrial and satellite segments. The two technological enablers of SANSA are smart antenna techniques at mmWave and software defined intelligent hybrid network management. This article introduces these 5G enablers, which permit satellite communications to play a key role in different 5G use cases, from the early deployment of 5G services in sparse scenarios to enhanced mobile broadband in denser scenarios
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