scholarly journals A Bursts Contention Avoidance Scheme Based on Streamline Effect Awareness and Limited Intermediate Node Buffering in the Core Network

2020 ◽  
Vol 9 (6) ◽  
pp. 124-134
Keyword(s):  
Performance Comparison ◽  
Core Network ◽  
Network Resources ◽  
Intermediate Node ◽  
Control Packet ◽  
Data Packets ◽  
Acceptable Quality ◽  
Offset Time ◽  
Data Burst

In an Optical Burst Switched (OBS) network, data packets sourced from peripheral networks are assembled into huge sized data bursts. For each assembled data burst, an associated control signal in the form of a burst control packet is (BCP) is generated and scheduled at an offset time ahead of the data burst. The offset timing is to allow for the pre-configuration of required resources at all subsequent intermediate nodes prior to the actual data burst’s arrival. In that way, the data burst will fly-by each node and hence no requirement for temporary buffering at all intermediate nodes. An operational requirement of an OBS network is that it be loss-less as in that way a consistent as well as acceptable quality of service (QoS) for all applications and services it serves as a platform can be guaranteed. Losses in such a network are mainly caused by improper provisioning as well as dimensioning of resources thus leading to contentions among bursts and consequently discarding of some of the contending data bursts. Key to both provisioning as well as proper dimensioning of the available resources in an optimized way is the implementation of effective routing and wavelength (RWA) that will seclude any data losses due to contention occurrences. On the basis of the effects of the streamline effect (SLE), that is, effectively secluding primary contention among flows (streams) in the network, we propose in this paper a limited intermediate buffering that couples with SLE aware prioritized RWA (LIB-PRWA) scheme that combats secondary contention as well. The scheme makes routing decisions such as selection of primary and deflection routes based on current resources states in the candidate paths. A performance comparison of the proposed scheme is carried out and simulation results demonstrate its comparative abilities to effectively reduce losses as well as maintaining both high network resources utilization as well as QoS.

scholarly journals Performability Evaluation of Voice Services in Converged Networks

2020 ◽  
Vol 27 (4) ◽  
pp. 11-19
Author(s):  
Almir Pereira Guimarães ◽  
Dênis Da Silva Rodrigues ◽  
Bruno Costa e Silva Nogueira
Keyword(s):  
Block Diagram ◽  
Discrete Event ◽  
Stochastic Petri Nets ◽  
Data Traffic ◽  
Network Resources ◽  
Acceptable Quality ◽  
Quality Of Voice ◽  
Warm Standby ◽  
Higher Sensitivity

In the last years, the transmission of voice services in converged networks has experienced a huge growth. However, there are still some questions considering the ability of these networks to deliver voice services with acceptable quality. In this paper, we applied analytical modeling and simulation to analyze the quality of voice services using a new index, called MOS a , which considers jointly the MOS index and the availability of the subjacent infrastructure. We consider the influence of different CODECs (G.711 and G.729), queuing policies (Priority Queuing and Custom Queuing), and the warm standby redundancy mechanism. Our goal is to analyze the quality of these services by taking into account overloading conditions in different  architectures/scenarios. These scenarios were constructed using the modeling mechanisms Reliability Block Diagram and Stochastic Petri Nets in addition to a discrete event simulator. Experimental results indicate that the G.711 CODEC has a higher sensitivity both in terms of data traffic volume and allocated network resources in relation to the G.729 CODEC.

scholarly journals A Node-Regulated Deflection Routing Framework for Contention Minimization

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Bakhe Nleya ◽  
Andrew Mutsvangwa
Keyword(s):  
Wavelength Division Multiplexing ◽  
Network Performance ◽  
Cost Effective ◽  
Core Network ◽  
Network Resources ◽  
Deflection Routing ◽  
Wavelength Division ◽  
Backbone Networks ◽  
Candidate Solution ◽  
Data Burst

Optical Burst Switching (OBS) paradigm coupled with Dense Wavelength Division Multiplexing (DWDM) has become a practical candidate solution for the next-generation optical backbone networks. In its practical deployment only the edge nodes are provisioned with buffering capabilities, whereas all interior (core) nodes remain buffer-less. In that way the implementation becomes quite simple as well as cost effective as there will be no need for optical buffers in the interior. However, the buffer-less nature of the interior nodes makes such networks prone to data burst contention occurrences that lead to a degradation in overall network performance as a result of sporadic heavy burst losses. Such drawbacks can be partly countered by appropriately dimensioning available network resources and reactively by way of deflecting excess as well as contending data bursts to available least-cost alternate paths. However, the deflected data bursts (traffic) must not cause network performance degradations in the deflection routes. Because minimizing contention occurrences is key to provisioning a consistent Quality of Service (QoS), we therefore in this paper propose and analyze a framework (scheme) that seeks to intelligently deflect traffic in the core network such that QoS degradations caused by contention occurrences are minimized. This is by way of regulated deflection routing (rDr) in which neural network agents are utilized in reinforcing the deflection route choices at core nodes. The framework primarily relies on both reactive and proactive regulated deflection routing approaches in order to prevent or resolve data burst contentions. Simulation results show that the scheme does effectively improve overall network performance when compared with existing contention resolution approaches. Notably, the scheme minimizes burst losses, end-to-end delays, frequency of contention occurrences, and burst deflections.

Introduction

2010 ◽  
pp. 1-13 ◽  
Author(s):  
Sasan Adibi ◽  
Raj Jain ◽  
Shyam Parekh ◽  
Bell Labs
Keyword(s):  
Wireless Networks ◽  
Quality Of Service ◽  
User Experience ◽  
Quality Of Experience ◽  
Mobile Services ◽  
Network Resources ◽  
Acceptable Quality ◽  
New Challenges

Emergence of all IP based wired and wireless networks for mobile services, calls for new innovations and architectural approaches. Coexistence of legacy and emerging networks such as different generations of networks based on 3GPP and 3GPP2 specifications, Wi-Fi and WiMAX, have posed new challenges to guarantee acceptable Quality of Experience (QoE) to the users. Different user environments such as fixed, nomadic, and vehicular have brought about new Quality of Service (QoS) practices and have introduced policies to best optimize the network resources and enhance user experience.

Simulation modeling of packet switching network segment functioning

2019 ◽  
pp. 75-82
Author(s):  
D. V. Shelkovoy ◽  
A. A. Chernikov
Keyword(s):  
Quality Of Service ◽  
Communication Networks ◽  
Simulation Modeling ◽  
Data Stream ◽  
Switching Network ◽  
Data Packets ◽  
Channel Resource ◽  
Switching Node ◽  
Joint Examination

The testing results of required channel resource mathematical estimating models for the for serving the proposed multimedia load in packet-switched communication networks are presented in the article. The assessment of the attainable level of quality of service at the level of data packet transportation was carried out by means of simulation modeling of the functioning of a switching node of a communication network. The developed modeling algorithm differs from the existing ones by taking into account the introduced delay for processing each data stream packet arriving at the switching node, depending on the size of the reserved buffer and the channel resource for its maintenance. A joint examination of the probability of packet loss and the introduced delay in the processing of data packets in the border router allows a comprehensive assessment of the quality of service «end to end», which in turn allows you to get more accurate values of the effective data transmitted rate by aggregating flows at the entrance to the transport network.

scholarly journals Nodule Detection with Convolutional Neural Network Using Apache Spark and GPU Frameworks

2021 ◽  
Vol 11 (6) ◽  
pp. 2838
Author(s):  
Nikitha Johnsirani Venkatesan ◽  
Dong Ryeol Shin ◽  
Choon Sung Nam
Keyword(s):  
Neural Network ◽  
Radiation Dose ◽  
Convolutional Neural Network ◽  
Model Performance ◽  
Performance Comparison ◽  
Apache Spark ◽  
Training Time ◽  
Learning Framework ◽  
Proposed Model

In the pharmaceutical field, early detection of lung nodules is indispensable for increasing patient survival. We can enhance the quality of the medical images by intensifying the radiation dose. High radiation dose provokes cancer, which forces experts to use limited radiation. Using abrupt radiation generates noise in CT scans. We propose an optimal Convolutional Neural Network model in which Gaussian noise is removed for better classification and increased training accuracy. Experimental demonstration on the LUNA16 dataset of size 160 GB shows that our proposed method exhibit superior results. Classification accuracy, specificity, sensitivity, Precision, Recall, F1 measurement, and area under the ROC curve (AUC) of the model performance are taken as evaluation metrics. We conducted a performance comparison of our proposed model on numerous platforms, like Apache Spark, GPU, and CPU, to depreciate the training time without compromising the accuracy percentage. Our results show that Apache Spark, integrated with a deep learning framework, is suitable for parallel training computation with high accuracy.

scholarly journals Manufacturing and development of a bolted GFRP flange joint for oil and gas applications

2021 ◽  
pp. 095440542198951
Author(s):  
Muhsin Aljuboury ◽  
Md Jahir Rizvi ◽  
Stephen Grove ◽  
Richard Cullen
Keyword(s):  
Pressure Vessel ◽  
Oil And Gas ◽  
Polyester Resin ◽  
High Strength ◽  
Adhesively Bonded ◽  
Acceptable Quality ◽  
Composite Pipe ◽  
And Performance ◽  
Composite Pipes

The goal of this experimental study is to manufacture a bolted GFRP flange connection for composite pipes with high strength and performance. A mould was designed and manufactured, which ensures the quality of the composite materials and controls its surface grade. Based on the ASME Boiler and Pressure Vessel Code, Section X, this GFRP flange was fabricated using biaxial glass fibre braid and polyester resin in a vacuum infusion process. In addition, many experiments were carried out using another mould made of glass to solve process-related issues. Moreover, an investigation was conducted to compare the drilling of the GFRP flange using two types of tools; an Erbauer diamond tile drill bit and a Brad & Spur K10 drill. Six GFRP flanges were manufactured to reach the final product with acceptable quality and performance. The flange was adhesively bonded to a composite pipe after chamfering the end of the pipe. Another type of commercially-available composite flange was used to close the other end of the pipe. Finally, blind flanges were used to close both ends, making the pressure vessel that will be tested under the range of the bolt load and internal pressure.

scholarly journals A Highly Effective Route for Real-Time Traffic Using an IoT Smart Algorithm for Tele-Surgery Using 5G Networks

2021 ◽  
Vol 10 (2) ◽  
pp. 30
Author(s):  
Radwan S. Abujassar ◽  
Husam Yaseen ◽  
Ahmad Samed Al-Adwan
Keyword(s):  
Live Streaming ◽  
Data Traffic ◽  
Data Packets ◽  
Real Time Traffic ◽  
Medical Quality ◽  
Optimal Smoothing ◽  
Patient Will ◽  
Three Stages ◽  
Exchange Data

Nowadays, networks use many different paths to exchange data. However, our research will construct a reliable path in the networks among a huge number of nodes for use in tele-surgery using medical applications such as healthcare tracking applications, including tele-surgery which lead to optimizing medical quality of service (m-QoS) during the COVID-19 situation. Many people could not travel due to the current issues, for fear of spreading the covid-19 virus. Therefore, our paper will provide a very trusted and reliable method of communication between a doctor and his patient so that the latter can do his operation even from a far distance. The communication between the doctor and his/her patient will be monitored by our proposed algorithm to make sure that the data will be received without delay. We test how we can invest buffer space that can be used efficiently to reduce delays between source and destination, avoiding loss of high-priority data packets. The results are presented in three stages. First, we show how to obtain the greatest possible reduction in rate variability when the surgeon begins an operation using live streaming. Second, the proposed algorithm reduces congestion on the determined path used for the online surgery. Third, we have evaluated the affection of optimal smoothing algorithm on the network parameters such as peak-to-mean ratio and delay to optimize m-QoS. We propose a new Smart-Rout Control algorithm (s-RCA) for creating a virtual smart path between source and destination to transfer the required data traffic between them, considering the number of hops and link delay. This provides a reliable connection that can be used in healthcare surgery to guarantee that all instructions are received without any delay, to be executed instantly. This idea can improve m-QoS in distance surgery, with trusted paths. The new s-RCA can be adapted with an existing routing protocol to track the primary path and monitor emergency packets received in node buffers, for direct forwarding via the demand path, with extended features.

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 Void Avoidance Opportunistic Routing Protocol for Underwater Wireless Sensor Networks

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 1942
Author(s):  
Rogaia Mhemed ◽  
Frank Comeau ◽  
William Phillips ◽  
Nauman Aslam
Keyword(s):  
Sensor Networks ◽  
Routing Protocol ◽  
Opportunistic Routing ◽  
Packet Delivery Ratio ◽  
Delivery Ratio ◽  
Underwater Sensor Networks ◽  
Network Resources ◽  
Hop Count ◽  
Intermediate Node ◽  
Packet Delivery

Much attention has been focused lately on the Opportunistic Routing technique (OR) that can overcome the restrictions of the harsh underwater environment and the unique structures of the Underwater Sensor Networks (UWSNs). OR enhances the performance of the UWSNs in both packet delivery ratio and energy saving. In our work; we propose a new routing protocol; called Energy Efficient Depth-based Opportunistic Routing with Void Avoidance for UWSNs (EEDOR-VA), to address the void area problem. EEDOR-VA is a reactive OR protocol that uses a hop count discovery procedure to update the hop count of the intermediate nodes between the source and the destination to form forwarding sets. EEDOR-VA forwarding sets can be selected with less or greater depth than the packet holder (i.e., source or intermediate node). It efficiently prevents all void/trapped nodes from being part of the forwarding sets and data transmission procedure; thereby saving network resources and delivering data packets at the lowest possible cost. The results of our extensive simulation study indicate that the EEDOR-VA protocol outperforms other protocols in terms of packet delivery ratio and energy consumption

scholarly journals Adaptive Reservation of Network Resources According to Video Classification Scenes

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 1949
Author(s):  
Lukas Sevcik ◽  
Miroslav Voznak
Keyword(s):  
User Satisfaction ◽  
Quality Evaluation ◽  
Spatial Information ◽  
Service Providers ◽  
Video Quality ◽  
Subjective Assessment ◽  
Video Sequences ◽  
Network Resources ◽  
Proposed Model

Video quality evaluation needs a combined approach that includes subjective and objective metrics, testing, and monitoring of the network. This paper deals with the novel approach of mapping quality of service (QoS) to quality of experience (QoE) using QoE metrics to determine user satisfaction limits, and applying QoS tools to provide the minimum QoE expected by users. Our aim was to connect objective estimations of video quality with the subjective estimations. A comprehensive tool for the estimation of the subjective evaluation is proposed. This new idea is based on the evaluation and marking of video sequences using the sentinel flag derived from spatial information (SI) and temporal information (TI) in individual video frames. The authors of this paper created a video database for quality evaluation, and derived SI and TI from each video sequence for classifying the scenes. Video scenes from the database were evaluated by objective and subjective assessment. Based on the results, a new model for prediction of subjective quality is defined and presented in this paper. This quality is predicted using an artificial neural network based on the objective evaluation and the type of video sequences defined by qualitative parameters such as resolution, compression standard, and bitstream. Furthermore, the authors created an optimum mapping function to define the threshold for the variable bitrate setting based on the flag in the video, determining the type of scene in the proposed model. This function allows one to allocate a bitrate dynamically for a particular segment of the scene and maintains the desired quality. Our proposed model can help video service providers with the increasing the comfort of the end users. The variable bitstream ensures consistent video quality and customer satisfaction, while network resources are used effectively. The proposed model can also predict the appropriate bitrate based on the required quality of video sequences, defined using either objective or subjective assessment.

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