scholarly journals The Hybrid Traffic Offloading Mode for Disaster-Resilient Communication Networks Based on User Mobility

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Ang-Hsun Tsai ◽  
Chung-Hsien Tsai
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Spectrum Efficiency ◽  
System Capacity ◽  
Traffic Information ◽  
Core Network ◽  
Emergency Relief ◽  
The Core ◽  
Traffic Offloading ◽  
Safety Research

Emergency communication systems play a major role in disaster-relief environments. In terms of the public safety research, the emergency relief communication system can provide a high system capacity for networks based on the development of Long-Term Evolution. However, in the event of a disaster, mass traffic information can cause congestion in the core network, and communications between relief workers may be limited. Consequently, spectrum efficiency can be very weak. This paper provides a hybrid traffic offloading mechanism combining Device-to-Device (D2D) and Local IP Access (LIPA) modes for the disaster-resilient network. With receiving power, the distance between relief workers and the distance between relief workers and the vehicular eNodeB (VeNB) as the LIPA/D2D switching criteria, the network can select an appropriate mode to prevent core network congestion. This paper also considers the effects of the mobility models (i.e., random walk and random direction) on the spectrum efficiency of the disaster-resilient communication system. The proposed hybrid LIPA/D2D traffic offloading mechanism can prevent the local communication traffic from flowing into the core network and significantly improve the system spectrum efficiency when the core network is under congestion. Therefore, the proposed mechanism can effectively improve the quality of the communication between relief workers served by the same VeNB for performing rescue operations. Moreover, the hybrid LIPA/D2D traffic offloading mechanism can be applied to the smart city and smart home in the future.

Radio communication systems high-speed railway transport

2017 ◽  
pp. 57-68
Author(s):  
Dmitriy Royenkov ◽  
Pavel Plekhanov ◽  
Vladimir Shmatchenko
Keyword(s):  
Life Cycle ◽  
Communication System ◽  
Communication Systems ◽  
High Speed ◽  
Digital Systems ◽  
System Capacity ◽  
Railway Transport ◽  
Radio Communication ◽  
Railroad Transport ◽  
The Given

Objective: To study the main approaches to organization of radio communication on high-speed railroad transport, to determine the requirements for functional capabilities and the structure of radio communication systems. Methods: The analysis of modern international and home practice in the sphere of radio telecommunication systems was applied for railway transport, on the basis of application strategy of interconnected indices’ complex, including reliability, availability, maintainability and safety (Reliability, Availability, Maintainability and Safety – RAMS) and cost (Life Cycle Cost – LCC) at all stages of transportation systems’ life cycle. Results: GSM-R standard was chosen as the basic one for organization of digital systems of engineering radio communication for high-speed mainlines. The choice was conditioned by the fact that the standard in question was developed for the purposes of railroad transport and is the basis for constructing European integrated railway radio enhanced network EIRENE (European Integrated Railway Radio Enhanced Network). Moreover, it was established that the most promising standard of radio communication for railway transport might be LTE (LTE-R) standard. Communication system capacity of the given standard, its applicability for the solution of the extensive range of railway radio communication tasks (including the task of providing customer radio communication) will make it possible to replace several different radio communication systems, solving specific functional tasks, by one which is more convenient and reliable. However, global and domestic experience of the standard in question application on railroad transport (including high-speed mainlines) has yet been insufficient, while the cost of LTE equipment is significantly higher compared to GSM-R standard. Practical importance: The requirements for functionality and structure of radio communication systems for high-speed networks were stated, including the requirements for digital systems of engineering radio communication (basic and reserved), the system of engineering on-line repair radio communication and digital wireless data communication system. Certain standards of radio communication allow for the realization of the given requirements.

Performance analysis of various massive MIMO detection algorithms in 5G Wireless technologies

2019 ◽  
Vol 10 ◽  
Author(s):  
Shihab Jimaa ◽  
Jawahir Al-Ali
Keyword(s):  
Massive Mimo ◽  
Spectrum Efficiency ◽  
System Capacity ◽  
Network Coverage ◽  
Mimo Detection ◽  
Infinity Norm ◽  
Detection Algorithms ◽  
Alternating Direction ◽  
5G Systems ◽  
Efficient Power

Background: The 5G will lead to a great transformation in the mobile telecommunications sector. Objective: The huge challenges being faced by wireless communications such as the increased number of users have given a chance for 5G systems to be developed and considered as an alternative solution. The 5G technology will provide a higher data rate, reduced latency, more efficient power than the previous generations, higher system capacity, and more connected devices. Method: It will offer new different technologies and enhanced versions of the existing ones, as well as new features. 5G systems are going to use massive MIMO (mMIMO), which is a promising technology in the development of these systems. Furthermore, mMIMO will increase the wireless spectrum efficiency and improve the network coverage. Result: In this paper we present a brief survey on 5G and its technologies, discuss the mMIMO technology with its features and advantages, review the mMIMO capacity and energy efficiency and also presents the recent beamforming techniques. Conclusion: Finally, simulation of adopting different mMIMO detection algorithms are presented, which shows the alternating direction method of multipliers (ADMM)-based infinity-norm (ADMIN) detector has the best performance.

Fault Tree Analysis for a Modern Communication System

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Kamal Hamid ◽  
Nadim Chahine
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Theory And Practice ◽  
Tree Analysis ◽  
Satisfactory Performance ◽  
System Components ◽  
Link Budget ◽  
Simulation Results

Wireless communications became one of the most widespread means for transferring information. Speed and reliability in transferring the piece of information are considered one of the most important requirements in communication systems in general. Moreover, Quality and reliability in any system are considered the most important criterion of the efficiency of this system in doing the task it is designed to do and its ability for satisfactory performance for a certain period of time, Therefore, we need fault tree analysis in these systems in order to determine how to detect an error or defect when happening in communication system and what are the possibilities that make this error happens. This research deals with studying TETRA system components, studying the physical layer in theory and practice, as well as studying fault tree analysis in this system, and later benefit from this study in proposing improvements to the structure of the system, which led to improve gain in Link Budget. A simulation and test have been done using MATLAB, where simulation results have shown that the built fault tree is able to detect the system’s work by 82.4%.

scholarly journals Peptide signaling without feedback in signal production operates as a true quorum sensing communication system in Bacillus subtilis

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Iztok Dogsa ◽  
Mihael Spacapan ◽  
Anna Dragoš ◽  
Tjaša Danevčič ◽  
Žiga Pandur ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bacillus Subtilis ◽  
Quorum Sensing ◽  
Cell Density ◽  
Communication System ◽  
Communication Systems ◽  
Feedback Loop ◽  
Signal Molecules ◽  
Specific Cell ◽  
Sharp Transition

AbstractBacterial quorum sensing (QS) is based on signal molecules (SM), which increase in concentration with cell density. At critical SM concentration, a variety of adaptive genes sharply change their expression from basic level to maximum level. In general, this sharp transition, a hallmark of true QS, requires an SM dependent positive feedback loop, where SM enhances its own production. Some communication systems, like the peptide SM-based ComQXPA communication system of Bacillus subtilis, do not have this feedback loop and we do not understand how and if the sharp transition in gene expression is achieved. Based on experiments and mathematical modeling, we observed that the SM peptide ComX encodes the information about cell density, specific cell growth rate, and even oxygen concentration, which ensure power-law increase in SM production. This enables together with the cooperative response to SM (ComX) a sharp transition in gene expression level and this without the SM dependent feedback loop. Due to its ultra-sensitive nature, the ComQXPA can operate at SM concentrations that are 100–1000 times lower than typically found in other QS systems, thereby substantially reducing the total metabolic cost of otherwise expensive ComX peptide.

scholarly journals Scaling capacity of fiber-optic transmission systems via silicon photonics

Nanophotonics ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Wei Shi ◽  
Ye Tian ◽  
Antoine Gervais
Keyword(s):  
Silicon Photonics ◽  
Communication Systems ◽  
Large Scale ◽  
Recent Progress ◽  
Fiber Optic ◽  
Rapid Evolution ◽  
System Capacity ◽  
Disruptive Technology ◽  
System Perspective ◽  
Silicon Photonic

AbstractThe tremendous growth of data traffic has spurred a rapid evolution of optical communications for a higher data transmission capacity. Next-generation fiber-optic communication systems will require dramatically increased complexity that cannot be obtained using discrete components. In this context, silicon photonics is quickly maturing. Capable of manipulating electrons and photons on the same platform, this disruptive technology promises to cram more complexity on a single chip, leading to orders-of-magnitude reduction of integrated photonic systems in size, energy, and cost. This paper provides a system perspective and reviews recent progress in silicon photonics probing all dimensions of light to scale the capacity of fiber-optic networks toward terabits-per-second per optical interface and petabits-per-second per transmission link. Firstly, we overview fundamentals and the evolving trends of silicon photonic fabrication process. Then, we focus on recent progress in silicon coherent optical transceivers. Further scaling the system capacity requires multiplexing techniques in all the dimensions of light: wavelength, polarization, and space, for which we have seen impressive demonstrations of on-chip functionalities such as polarization diversity circuits and wavelength- and space-division multiplexers. Despite these advances, large-scale silicon photonic integrated circuits incorporating a variety of active and passive functionalities still face considerable challenges, many of which will eventually be addressed as the technology continues evolving with the entire ecosystem at a fast pace.

scholarly journals Design Methodology of Passive In-Line Relays for Molecular Communication in Flow-Induced Microfluidic Channel

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 65
Author(s):  
Puneet Manocha ◽  
Gitanjali Chandwani
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Microfluidic Channel ◽  
Microfluidic Channels ◽  
Molecular Communication ◽  
External Energy ◽  
Lab On Chip ◽  
Molecular Communication Systems ◽  
Macro Scale ◽  
On Chip

Molecular communication is a bioinspired communication that enables macro-scale, micro-scale and nano-scale devices to communicate with each other. The molecular communication system is prone to severe signal attenuation, dispersion and delay, which leads to performance degradation as the distance between two communicating devices increases. To mitigate these challenges, relays are used to establish reliable communication in microfluidic channels. Relay assisted molecular communication systems can also enable interconnection among various entities of the lab-on-chip for sharing information. Various relaying schemes have been proposed for reliable molecular communication systems, most of which lack practical feasibility. Thus, it is essential to design and develop relays that can be practically incorporated into the microfluidic channel. This paper presents a novel design of passive in-line relay for molecular communication system that can be easily embedded in the microfluidic channel and operate without external energy. Results show that geometric modification in the microfluidic channel can act as a relay and restore the degraded signal up-to 28%.

A controlled deflection routing and wavelength assignment based scheme in Optical Burst Switched (OBS) networks

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Bakhe Nleya ◽  
Philani Khumalo ◽  
Andrew Mutsvangwa
Keyword(s):  
Wavelength Conversion ◽  
Wavelength Assignment ◽  
Wavelength Converters ◽  
Core Network ◽  
Least Cost Path ◽  
Deflection Routing ◽  
Backbone Networks ◽  
The Core ◽  
Optical Burst

AbstractHeterogeneous IoT-enabled networks generally accommodate both jitter tolerant and intolerant traffic. Optical Burst Switched (OBS) backbone networks handle the resultant volumes of such traffic by transmitting it in huge size chunks called bursts. Because of the lack of or limited buffering capabilities within the core network, burst contentions may frequently occur and thus affect overall supportable quality of service (QoS). Burst contention(s) in the core network is generally characterized by frequent burst losses as well as differential delays especially when traffic levels surge. Burst contention can be resolved in the core network by way of partial buffering using fiber delay lines (FDLs), wavelength conversion using wavelength converters (WCs) or deflection routing. In this paper, we assume that burst contention is resolved by way of deflecting contending bursts to other less congested paths even though this may lead to differential delays incurred by bursts as they traverse the network. This will contribute to undesirable jitter that may ultimately compromise overall QoS. Noting that jitter is mostly caused by deflection routing which itself is a result of poor wavelength and routing assigning, the paper proposes a controlled deflection routing (CDR) and wavelength assignment based scheme that allows the deflection of bursts to alternate paths only after controller buffer preset thresholds are surpassed. In this way, bursts (or burst fragments) intended for a common destination are always most likely to be routed on the same or least cost path end-to-end. We describe the scheme as well as compare its performance to other existing approaches. Overall, both analytical and simulation results show that the proposed scheme does lower both congestion (on deflection routes) as well as jitter, thus also improving throughput as well as avoiding congestion on deflection paths.

scholarly journals Periinfarct rewiring supports recovery after primary motor cortex stroke

2021 ◽  
pp. 0271678X2110029
Author(s):  
Mitsouko van Assche ◽  
Elisabeth Dirren ◽  
Alexia Bourgeois ◽  
Andreas Kleinschmidt ◽  
Jonas Richiardi ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Spatial Scales ◽  
Premotor Cortex ◽  
Core Network ◽  
Small Spatial Scale ◽  
The Core ◽  
Hand Dexterity ◽  
Motor Network ◽  
Motor Improvement

After stroke restricted to the primary motor cortex (M1), it is uncertain whether network reorganization associated with recovery involves the periinfarct or more remote regions. We studied 16 patients with focal M1 stroke and hand paresis. Motor function and resting-state MRI functional connectivity (FC) were assessed at three time points: acute (<10 days), early subacute (3 weeks), and late subacute (3 months). FC correlates of recovery were investigated at three spatial scales, (i) ipsilesional non-infarcted M1, (ii) core motor network (M1, premotor cortex (PMC), supplementary motor area (SMA), and primary somatosensory cortex), and (iii) extended motor network including all regions structurally connected to the upper limb representation of M1. Hand dexterity was impaired only in the acute phase ( P = 0.036). At a small spatial scale, clinical recovery was more frequently associated with connections involving ipsilesional non-infarcted M1 (Odds Ratio = 6.29; P = 0.036). At a larger scale, recovery correlated with increased FC strength in the core network compared to the extended motor network (rho = 0.71; P = 0.006). These results suggest that FC changes associated with motor improvement involve the perilesional M1 and do not extend beyond the core motor network. Core motor regions, and more specifically ipsilesional non-infarcted M1, could hence become primary targets for restorative therapies.

scholarly journals Implementation of conventional communication system in deep learning

2017 ◽  
Vol 7 (1.1) ◽  
pp. 696
Author(s):  
Satyanarayana P ◽  
Charishma Devi. V ◽  
Sowjanya P ◽  
Satish Babu ◽  
N Syam Kumar ◽  
...  
Keyword(s):  
Machine Learning ◽  
Computer Vision ◽  
Communication Network ◽  
Deep Learning ◽  
Communication System ◽  
Communication Systems ◽  
Physical Layer ◽  
Learning Capacity ◽  
Constrained Learning ◽  
Complex Channel

Machine learning (ML) has been broadly connected to the upper layers of communication systems for different purposes, for example, arrangement of cognitive radio and communication network. Nevertheless, its application to the physical layer is hindered by complex channel conditions and constrained learning capacity of regular ML algorithms. Deep learning (DL) has been as of late connected for some fields, for example, computer vision and normal dialect preparing, given its expressive limit and advantageous enhancement ability. This paper describes about a novel use of DL for the physical layer. By deciphering a communication system as an auto encoder, we build up an essential better approach to consider communication system outline as a conclusion to-end reproduction undertaking that tries to together enhance transmitter and receiver in a solitary procedure. This DL based technique demonstrates promising execution change than traditional communication system.  

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