scholarly journals A Novel Group Paging Control Method for Massive MTC Accesses in LTE Networks

2020 ◽  
Author(s):  
Cong Wang ◽  
Chengqiang Wei ◽  
Ning Li ◽  
Wenfeng Ma ◽  
Hui Tian
Keyword(s):  
Control Method ◽  
Random Access ◽  
Collision Probability ◽  
Utilization Rate ◽  
Lte Networks ◽  
Fifth Generation ◽  
Shared Channel ◽  
A Cell ◽  
Novel Method ◽  
Group Paging

Abstract The fifth-generation (5G) systems have to deal with massive deployment of machine-type-communication (MTC) devices. System overload may occur during a random access (RA) procedure under a limited number of preamble resources and physical uplink shared channel (PUSCH) resources especially when there exist massive MTC devices in a cell. In order to resolve the system overload (caused by the massive MTC deployment), the 3GPP proposed the adopted a group paging (GP)-based uplink access technique. But its performances dramatically decrease as the number of MTC devices increases. In this paper we propose a novel method, named ACB-based group paging overload control method (AGO). To reduce the number of simultaneous access MTC devices, AGO first scatters the MTC devices over a GP interval, and then automatically adjusts ACB parameters according to the load conditions. By doing so, AGO achieves high-channel access probability for MTC devices. Simulation results show that this method is superior to the GP and Pre-backoff (PBO) mechanisms in terms of success and collision probability, average access latency and resource utilization rate.

scholarly journals A Novel Group Paging Control Method for Massive MTC Accesses in LTE Networks

2020 ◽  
Author(s):  
Cong Wang ◽  
Chengqiang Wei ◽  
Ning Li ◽  
Wenfeng Ma ◽  
Hui Tian
Keyword(s):  
Control Method ◽  
Random Access ◽  
Collision Probability ◽  
Utilization Rate ◽  
Lte Networks ◽  
Fifth Generation ◽  
Shared Channel ◽  
A Cell ◽  
Novel Method ◽  
Group Paging

Abstract The fifth-generation (5G) systems have to deal with massive deployment of machine-type-communication (MTC) devices. System overload may occur during a random access (RA) procedure under a limited number of preamble resources and physical uplink shared channel (PUSCH) resources especially when there exist massive MTC devices in a cell. In order to resolve the system overload (caused by the massive MTC deployment), the 3GPP proposed the adopted a group paging (GP)-based uplink access technique. But its performances dramatically decrease as the number of MTC devices increases. In this paper we propose a novel method, named ACB-based group paging overload control method (AGO). To reduce the number of simultaneous access MTC devices, AGO first scatters the MTC devices over a GP interval, and then automatically adjusts ACB parameters according to the load conditions. By doing so, AGO achieves high-channel access probability for MTC devices. Simulation results show that this method is superior to the GP and Pre-backoff (PBO) mechanisms in terms of success and collision probability, average access latency and resource utilization rate.

scholarly journals Adaptive Access Class Barring Method for Machine Generated Communications

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Jaesung Park ◽  
Yujin Lim
Keyword(s):  
Success Probability ◽  
Access Network ◽  
Random Access ◽  
Original Method ◽  
Collision Probability ◽  
Data Traffic ◽  
Coverage Area ◽  
Access Channel ◽  
Communication Devices ◽  
A Cell

Cellular network is provisioned to serve traffic demands generated by human being. The random access channel used for nodes to compete for a connection with an eNB is limited. Even though machines generate very small amount of data traffic, the signaling channel of a network becomes overloaded and collisions occur to fail the access if too many MTC (Machine Type Communication) devices attempt to access network. To tackle the issue, 3GPP specifies an access class barring but leaves a specific algorithm as an implementation issue. In this paper, we propose an adaptive access barring method. Generally, an eNB does not know the number of MTC devices in its coverage area. Thus, it is difficult to control the barring factor by predicting the number of MTC devices in a service area of a cell. On the contrary, we control the barring factor based on the prediction of access intensity which can be measured at an eNB. Simulation results show that since the proposed method can manipulate the barring factor autonomously according to the access intensity, it is superior to the original method in terms of the access success probability and the collision probability.

scholarly journals Energy-Constrained Design of Joint NOMA-Diversity Schemes with Imperfect Interference Cancellation

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4194
Author(s):  
Fulvio Babich ◽  
Giulia Buttazzoni ◽  
Francesca Vatta ◽  
Massimiliano Comisso
Keyword(s):  
Interference Cancellation ◽  
Energy Levels ◽  
Random Access ◽  
Actual Performance ◽  
Available Energy ◽  
Fifth Generation ◽  
Code Modulation ◽  
Energy Constrained ◽  
The Relationship ◽  
The Internet Of Things

This study proposes a set of novel random access protocols combining Packet Repetition (PR) schemes, such as Contention Resolution Diversity Slotted Aloha (CRDSA) and Irregular Repetition SA (IRSA), with Non Orthogonal Multiple Access (NOMA). Differently from previous NOMA/CRDSA and NOMA/IRSA proposals, this work analytically derives the energy levels considering two realistic elements: the residual interference due to imperfect Interference Cancellation (IC), and the presence of requirements on the power spent for the transmission. More precisely, the energy-limited scenario is based on the relationship between the average available energy and the selected code modulation pair, thus being of specific interest for the implementation of the Internet of Things (IoT) technology in forthcoming fifth-generation (5G) systems. Moreover, a theoretical model based on the density evolution method is developed and numerically validated by extensive simulations to evaluate the limiting throughput and to explore the actual performance of different NOMA/PR schemes in energy-constrained scenarios.

scholarly journals A novel method for processing adipose-derived stromal stem cells using a closed cell washing concentration device with a hollow fiber membrane module

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Shinji Hayashi ◽  
Rieko Yagi ◽  
Shuhei Taniguchi ◽  
Masami Uji ◽  
Hidaka Urano ◽  
...  
Keyword(s):  
Stem Cells ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Membrane Module ◽  
Fiber Membrane ◽  
Cell Processing ◽  
Closed Cell ◽  
A Cell ◽  
Novel Method ◽  
Stromal Stem Cells

AbstractCell-assisted lipotransfer (CAL) is an advanced lipoinjection method that uses autologous lipotransfer with addition of a stromal vascular fraction (SVF) containing adipose-derived stromal stem cells (ASCs). The CAL procedure of manual isolation of cells from fat requires cell processing to be performed in clean environment. To isolate cells from fat without the need for a cell processing center, such as in a procedure in an operation theater, we developed a novel method for processing SVF using a closed cell washing concentration device (CCD) with a hollow fiber membrane module. The CCD consists of a sterilized closed circuit, bags and hollow fiber, semi-automatic device and the device allows removal of >99.97% of collagenase from SVF while maintaining sterility. The number of nucleated cells, ASCs and viability in SVF processed by this method were equivalent to those in SVF processed using conventional manual isolation. Our results suggest that the CCD system is as reliable as manual isolation and may also be useful for CAL. This approach will help in the development of regenerative medicine at clinics without a cell processing center.

Dark-Field X-Ray Microscopy of Immunogold-Labeled Cells

1996 ◽  
Vol 2 (2) ◽  
pp. 53-62 ◽  
Author(s):  
Henry N. Chapman ◽  
Jenny Fu ◽  
Chris Jacobsen ◽  
Shawn Williams
Keyword(s):  
Colloidal Gold ◽  
Dark Field Image ◽  
Dark Field ◽  
X Rays ◽  
X Ray ◽  
Scanning Transmission ◽  
A Cell ◽  
Specific Antigens ◽  
Genetic Sequences ◽  
Novel Method

The methods of immunolabeling make visible the presence of specific antigens, proteins, genetic sequences, or functions of a cell. In this paper we present examples of imaging immunolabels in a scanning transmission x-ray microscope using the novel method of dark-field contrast. Colloidal gold, or silver-enhanced colloidal gold, is used as a label, which strongly scatters x-rays. This leads to a high-contrast dark-field image of the label and reduced radiation dose to the specimen. The x-ray images are compared with electron micrographs of the same labeled, unsectioned, whole cell. It is verified that the dark-field x-ray signal is primarily due to the label and the bright-field x-ray signal, showing absorption due to carbon, is largely unaffected by the label. The label can be well visualized even when it is embedded in or laying behind dense material, such as the cell nucleus. The resolution of the images is measured to be 60 nm, without the need for computer processing. This figure includes the x-ray microscope resolution and the accuracy of the label positioning. The technique should be particularly useful for the study of relatively thick (up to 10 μm), wet, or frozen hydrated specimens.

scholarly journals Thermal station modelling and optimal control based on deep learning

2021 ◽  
Vol 25 (4 Part B) ◽  
pp. 2965-2973
Author(s):  
Min Cao
Keyword(s):  
Deep Learning ◽  
Thermal Power Station ◽  
Control Method ◽  
Learning Algorithm ◽  
Thermal Power ◽  
Heating System ◽  
Utilization Rate ◽  
Power Station ◽  
Deep Learning Algorithm ◽  
Deterministic Strategy

To solve the mismatch between heating quantity and demand of thermal stations, an optimized control method based on depth deterministic strategy gradient was proposed in this paper. In this paper, long short-time memory deep learning algorithm is used to model the thermal power station, and then the depth deterministic strategy gradient control algorithm is used to solve the water supply flow sequence of the primary side of the thermal power station in combination with the operation mechanism of the central heating system. In this paper, a large number of historical working condition data of a thermal station are used to carry out simulation experiment, and the results show that the method is effective, which can realize the on-demand heating of the thermal station a certain extent and improve the utilization rate of heat.

scholarly journals Real-Time Anticipation and Prevention of Hot Spots by Monitoring the Dynamic Conductance of Photovoltaic Panels

2021 ◽  
Author(s):  
William Lamb ◽  
Dallon Asnes ◽  
Jonathan Kupfer ◽  
Emma Lickey ◽  
Jeremy Bakken ◽  
...  
Keyword(s):  
Real Time ◽  
Hot Spots ◽  
Structural Damage ◽  
Reverse Bias ◽  
Control Method ◽  
Physical Damage ◽  
Operating Current ◽  
A Cell ◽  
Real Time Simulations ◽  
Dynamic Conductance

<div>Hot spotting in photovoltaic (PV) panels causes physical damage, power loss, reduced lifetime reliability, and increased manufacturing costs. The problem arises routinely in defect-free standard panels; any string of cells that receives uneven illumination can develop hot spots, and the temperature rise often exceeds 100°C in conventional silicon panels despite on-panel bypass diodes, the standard mitigation technique. Bypass diodes limit the power dissipated in a cell subjected to reverse bias, but they do not prevent hot spots from forming. An alternative control method has been suggested by Kernahan [1] that senses in real time the dynamic conductance |dI/dV| of a string of cells and adjusts its operating current so that a partially shaded cell is never forced into reverse bias. We start by exploring the behavior of individual illuminated PV cells when externally forced into reverse bias. We observe that cells can suffer significant heating and structural damage, with desoldering of cell-tabbing and discolorations on the front cell surface. Then we test PV panels and confirm Kernahan’s proposed panel-level solution that anticipates and prevents hot spots in real time. Simulations of cells and panels confirm our experimental observations and provide insights into both the operation of Kernahan’s method and panel performance.</div>

scholarly journals A Novel Method for Designing Fifth-Generation District Heating and Cooling Systems

2021 ◽  
Vol 246 ◽  
pp. 09001
Author(s):  
Marwan Abugabbara ◽  
Jonas Lindhe
Keyword(s):  
Analytical Solution ◽  
District Heating ◽  
Innovative Technology ◽  
Complete Agreement ◽  
Fluid Temperature ◽  
Existing Buildings ◽  
Cooling Systems ◽  
Heating And Cooling ◽  
Fifth Generation ◽  
Novel Method

District heating and cooling systems have been undergoing continuous development and have now reached the fifth-generation. In this innovative technology, connected buildings share local excess energy that otherwise would be wasted, which consequently reduces primary energy demands and carbon emissions. To date, the issue of implementing fifth-generation district systems on existing buildings has received scant attention, and our research addresses this challenging gap by proposing a novel method for designing these systems. We first explain the possible thermal interactions between connected buildings, and then present an analytical solution for the network energy balance, pipe design, and the prediction of fluid temperature under a fixed temperature difference control strategy. The analytical solution was validated against numerical simulations performed on 11 existing buildings located in Lund, Sweden using Modelica models. A diversity index metric between heating and cooling demands was also included in these models to assess the efficiency of the district system in the building cluster. The results from the analytical and numerical solutions were in complete agreement since Modelica is an equation-based modelling language. The developed models pave the way towards future investigations of different temperature control strategies and new business models that arise from the shift to the fifth-generation.

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