scholarly journals Deterministic lightpath scheduling and routing in elastic optical networks

2021 ◽  
Author(s):  
Upama Vyas
Keyword(s):  
Optical Networks ◽  
Poor Performance ◽  
Heterogeneous Traffic ◽  
Support Network ◽  
Network Resources ◽  
Resource Conflict ◽  
Internet Backbone ◽  
Routing And Spectrum Assignment ◽  
Lightpath Scheduling

Abstract A huge torrent of information being generated from various heterogeneous applications and services is passing to and from the Internet backbone. Accommodating such heterogeneity and preserving the quality of service (QoS) of each traffic profile is a challenging task for operators. The heterogeneous traffic profile (HTP) considered in this work includes permanent lightpath demands (PLDs) and scheduled lightpath demands (SLDs). We propose various distance adaptive routing and spectrum assignment (DA-RSA) heuristics to resolve resource conflict among these two traffic profiles in elastic optical networks (EONs) under a full sharing environment. Conventionally, preemption was the only technique to resolve such conflict and ensure QoS for HTPs. Since excessive preemption leads to poor performance and lowers the degree of customer satisfaction, this work aims at reducing the preemption of demands. In order to do this, we propose to utilize bandwidth splitting as an alternative solution in such situations. Moreover, an integrated solution consisting of splitting and preemption is also proposed. We call this new integration as flow-based preemption. The simulation results demonstrate that utilizing splitting in place of preemption yields significant improvement in terms of all metrics of interest. Moreover, flow-based preemption is proved to be superior in performance than the only splitting-based solution. To the best of our knowledge, this is the first work addressing resource conflicts under a full-sharing environment by focusing on resource utilization at the link and node level. We believe that proposed heuristics support network operators to smoothly orchestrate network resources in the presence of such HTPs.

Cloud-Based Service Delivery Architecture with Service-Populating and Mobility-Aware Mechanisms

2014 ◽  
pp. 183-199
Author(s):  
Fragkiskos Sardis ◽  
Glenford Mapp ◽  
Jonathan Loo
Keyword(s):  
Service Delivery ◽  
Mobile Devices ◽  
Cloud Services ◽  
Network Resources ◽  
Internet Backbone ◽  
High Bandwidth ◽  
Processing And Storage ◽  
Cloud Technologies ◽  
And Storage

Advances in Mobile and Cloud technologies have redefined the way we perceive and use computers. Mobile devices now rely on Cloud technology for storage and applications. Furthermore, recent advances in network technology ensure that mobile devices in the future will have high-bandwidth connectivity at all times. This drives the incentive of doing all the processing and storage in the Cloud and using mobile devices to access the services. In this chapter, the authors argue that always-on connectivity along with increased demand of Cloud services will contest the Internet backbone and create problems in the management of Cloud resources. Client mobility is also a factor that should be taken into account when providing Cloud services to mobile devices. The authors therefore propose a new service delivery architecture that takes into account client mobility as well as the distance between clients and services in order to manage Cloud and network resources more efficiently and provide a better Quality of Experience for the user.

scholarly journals Spectrum Fragmentation-Aware Strategies for Deadline-Driven Dynamic Multicast Scheduling Problem in EON

2017 ◽  
Vol 22 (1) ◽  
pp. 5-12
Author(s):  
Marcin Markowski
Keyword(s):  
Optical Networks ◽  
Multicast Routing ◽  
Blocking Probability ◽  
Spectrum Utilization ◽  
Elastic Network ◽  
The Third ◽  
Dynamic Multicast ◽  
Routing And Spectrum Assignment ◽  
Multicast Scheduling

Abstract Since the spectrum fragmentation is an important issue for the dynamic demands allocation in the Elastic Optical Networks, minimization of it improves the spectrum utilization and decreases the blocking probability. In the paper, the dynamic deadline-driven multicast routing and spectrum assignment problem in the elastic network is considered. Three spectrum fragmentation-aware algorithms were proposed and evaluated. Two of proposed algorithms use the well-known fragmentation metrics, while the third one utilizes a new original fragmentation increase estimator. The results of the experiments validating the quality of proposed methods and algorithms were reported and analyzed.

A Novel Weighted Energy Efficient Routing and Spectrum Assignment Algorithm in Flexible Optical Networks

2015 ◽  
Vol 36 (3) ◽  
Author(s):  
Jijun Zhao ◽  
Qiuyan Yao ◽  
Danping Ren ◽  
Wei Li ◽  
Nawa Zhang
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Optical Networks ◽  
Energy Efficient ◽  
Utilization Efficiency ◽  
Energy Efficient Routing ◽  
Spectrum Assignment ◽  
Weighted Energy ◽  
Routing And Spectrum Assignment

AbstractThe network resource utilization efficiency is limited by the rigid nature of the current wavelength-routed optical networks. The recently proposed flexible optical network can allocate the spectral resources adaptively according to the traffic demand. Meanwhile, the transmission quality has always been a main objective during the routing process in optical networks. Recently, the energy efficiency has also been a hot topic because of the energy consumption problem. In this paper, we propose a novel weighted energy efficient routing and spectrum assignment scheme based on the designed quality of transmission (QoT)-energy estimation model in which the physical impairments and energy consumption are given consideration to two or more things. The simulation results demonstrate that the proposed algorithm can make a better balance between the quality of service (QoS) and energy efficiency.

Improvement in Gate Dielectric Quality of Ultra Thin a: SiN:H MNS Capacitor by Hydrogen Etching of the Substrate

2002 ◽  
Vol 716 ◽  
Author(s):  
Parag C. Waghmare ◽  
Samadhan B. Patil ◽  
Rajiv O. Dusane ◽  
V.Ramgopal Rao
Keyword(s):  
Silicon Nitride ◽  
Gate Dielectric ◽  
Substrate Surface ◽  
Scaling Limit ◽  
Tunneling Current ◽  
Chemical Vapor ◽  
Poor Performance ◽  
State Density ◽  
Direct Tunneling Current

AbstractTo extend the scaling limit of thermal SiO2, in the ultra thin regime when the direct tunneling current becomes significant, members of our group embarked on a program to explore the potential of silicon nitride as an alternative gate dielectric. Silicon nitride can be deposited using several CVD methods and its properties significantly depend on the method of deposition. Although these CVD methods can give good physical properties, the electrical properties of devices made with CVD silicon nitride show very poor performance related to very poor interface, poor stability, presence of large quantity of bulk traps and high gate leakage current. We have employed the rather newly developed Hot Wire Chemical Vapor Deposition (HWCVD) technique to develop the a:SiN:H material. From the results of large number of optimization experiments we propose the atomic hydrogen of the substrate surface prior to deposition to improve the quality of gate dielectric. Our preliminary results of these efforts show a five times improvement in the fixed charges and interface state density.

Effect of Resource Factors and Quality of Instruction on Performance in Mathematics of Nigeria Secondary School Students

2020 ◽  
Vol 5 (1) ◽  
pp. 61-69
Author(s):  
Umar Abdullahi ◽  
Musa Sirajo
Keyword(s):  
Secondary School ◽  
Secondary School Students ◽  
Poor Performance ◽  
Secondary School Student ◽  
Teaching Staff ◽  
Ministry Of Education ◽  
School Students ◽  
Quality Of Instruction ◽  
The Public

It seems that educational system in Nigeria has undergone only quantitative improvement in terms of number of schools and students’ enrolment. However, there has been little effort in respect to the capacity to manage them through provisions of adequate financial, human, material and physical resources. Physical and material resources in secondary schools were discovered to be inadequate and poorly equipped. Some of the secondary school buildings were dilapidated, also the allocated financial resource, teaching and non-teaching staff are grossly inadequate compared with the students’ enrolment. The public, the Ministry of Education and other stakeholders in education are expressing serious concern about the consistency of the poor performance of secondary school students especially in mathematics. Increase in population and the government’s free education programs make people want to take advantage of the education provided. Provision of both professionally qualified and non-qualified teachers by government and non-state providers of education also appear not to ameliorate the problem of declining performances in mathematics. The effect of all these on the public secondary school student academic performance in mathematics concern the researchers of this study. It is against this background that the study sought to empirically investigates effect of resource factors and quality of instruction on performance in mathematics of Nigeria secondary school students.

scholarly journals Impact of Pediatric COVID-19 on Family Health-Related Quality of Life: A Qualitative Study from Latvia

2021 ◽  
Vol 8 ◽  
pp. 2333794X2110123
Author(s):  
Inese Stars ◽  
Liene Smane ◽  
Zanda Pucuka ◽  
Ieva Roge ◽  
Jana Pavare
Keyword(s):  
Quality Of Life ◽  
Qualitative Study ◽  
Family Relationships ◽  
Family Health ◽  
Support Network ◽  
Health Related Quality ◽  
Related Quality ◽  
Health Related ◽  
The Impact

Information on family health-related quality of life (FHRQoL) among families of children with the coronavirus disease 2019 (COVID-19) is limited. This qualitative study explores the impact of pediatric COVID-19 on FHRQoL from the parents’ perspective. Semi-structured interviews were conducted with parents (n = 20) whose children had tested positive for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Inductive thematic analysis revealed the following 10 themes that represented parents’ perception of FHRQoL while taking care of a child with COVID-19: pediatric COVID-19 as a disease with many unknowns; emotional saturation; internal family relationships in the context of “a new experience”; routine household activities and daily regimen while family is in lockdown; plenty of free time; a wide social support network; social stigma associated with COVID-19; different options for work; savings and debts; challenges with family housing and transport availability. Our results show that parents experience multiple effects of pediatric COVID-19 with regard to FHRQoL.

scholarly journals Providing deterministic quality of service in slotted optical networks

2006 ◽  
Vol 14 (26) ◽  
pp. 12679 ◽  
Author(s):  
Chee Kheong Siew ◽  
Daojun Xue ◽  
Yang Qin ◽  
Jens Schmitt
Keyword(s):  
Quality Of Service ◽  
Optical Networks

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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