- Seminar, Dept. of Electrical and Computer Eng., University of California, Davis, CA, USA, May 14, 2004.
- Seminar, Dept. of Electrical and Systems Eng., Washington University in St. Louis, St. Louis, MO, USA, Dec. 3, 2004.
Optimal Preamble Design for Short Packet Circularly Pulse-Shaped OFDM Transmi...Yenming Huang
IEEE GLOBECOM 2020
SPC1: SIGNAL PROCESSING FOR OFDM AND VLC
Title: Optimal Preamble Design for Short Packet Circularly Pulse-Shaped OFDM Transmissions
Authors: Yenming Huang, Polin Huang, and Borching Su
Modeling, Analysis, and Design of Multi-tier and Cognitive Cellular Wireless ...indonesiabelajar
Abstract: Multi-tier architecture with small cells such as femtocells, picocells, macrocells, and metrocells, overlaid with traditional macrocells is considered as a promising option to improve the network coverage and capacity of the next generation cellular wireless networks. Also, in such multi-tier networks, cognitive radio concepts will likely to be used by these small cells to improve the radio spectrum utilization. In this context, modeling, analysis, and design of multi-tier and cognitive cellular networks is increasingly attracting the attention of the research community. Recently, stochastic geometry models have been shown to provide tractable yet accurate performance bounds for multi-tier and cognitive cellular wireless networks. Given the need for interference characterization in multi-tier cellular networks, stochastic geometry models provide high potential to simplify their modeling and provide insights into their design. In this seminar, I will present a review of the stochastic geometry models for single-tier as well as multi-tier and cognitive cellular wireless networks. I will also present a taxonomy based on the target network model, the point process used, and the performance evaluation technique. To this end, I will discuss the open research challenges and future research directions.
Prof Ekram Hossain
Optimal Preamble Design for Short Packet Circularly Pulse-Shaped OFDM Transmi...Yenming Huang
IEEE GLOBECOM 2020
SPC1: SIGNAL PROCESSING FOR OFDM AND VLC
Title: Optimal Preamble Design for Short Packet Circularly Pulse-Shaped OFDM Transmissions
Authors: Yenming Huang, Polin Huang, and Borching Su
Modeling, Analysis, and Design of Multi-tier and Cognitive Cellular Wireless ...indonesiabelajar
Abstract: Multi-tier architecture with small cells such as femtocells, picocells, macrocells, and metrocells, overlaid with traditional macrocells is considered as a promising option to improve the network coverage and capacity of the next generation cellular wireless networks. Also, in such multi-tier networks, cognitive radio concepts will likely to be used by these small cells to improve the radio spectrum utilization. In this context, modeling, analysis, and design of multi-tier and cognitive cellular networks is increasingly attracting the attention of the research community. Recently, stochastic geometry models have been shown to provide tractable yet accurate performance bounds for multi-tier and cognitive cellular wireless networks. Given the need for interference characterization in multi-tier cellular networks, stochastic geometry models provide high potential to simplify their modeling and provide insights into their design. In this seminar, I will present a review of the stochastic geometry models for single-tier as well as multi-tier and cognitive cellular wireless networks. I will also present a taxonomy based on the target network model, the point process used, and the performance evaluation technique. To this end, I will discuss the open research challenges and future research directions.
Prof Ekram Hossain
10-Gb/S Transmission of Wdm Pon for Man with 50km Reach Based On FtthIJERA Editor
The wavelength-division-multiplexed passive optical network (WDM-PON) is considered to be the next evolutionary solution for a simplified and future-proofed access system that can accommodate exponential traffic growth and bandwidth-hungry new applications. WDM-PON mitigates the complicated time-sharing and power budget issues in time division- multiplexed PON (TDM-PON) by providing virtual point-to-point optical connectivity to multiple end users through a dedicated pair of wavelengths. The objective of this paper is proposed a scheme for metropolitan area networks comprising optical components based on arrayed waveguide grating multiplexers, demultiplexers .The Arrayed waveguide gratings based multiplexers and demultiplexers for WDM applications prove to be capable of precise multiplexing and demultiplexing of a large number of channels with relatively low losses.
IoT Needs Good Neighbours - Cognitive Radio Turns Enemies into FriendsAMIHO Technology
With the internet of things the use of connected devices is predicted to be in many tens of billions. In this presentation, Steve Clarke discusses the use of various wireless technologies and techniques such as cognitive radio to allow these devices to co-exist in harmony with their (many) neighbours.
Steve Clarke, Technical Director of AMIHO, presented this paper at the prestigious Embedded World conference,Feb 2016.
Cognitive Radio definition and benefits Mustafa Sadiq
cognitive radio definition and its relationship to the software defined radio is explained in this presentation. The spectrum sense is also explained here as well
10-Gb/S Transmission of Wdm Pon for Man with 50km Reach Based On FtthIJERA Editor
The wavelength-division-multiplexed passive optical network (WDM-PON) is considered to be the next evolutionary solution for a simplified and future-proofed access system that can accommodate exponential traffic growth and bandwidth-hungry new applications. WDM-PON mitigates the complicated time-sharing and power budget issues in time division- multiplexed PON (TDM-PON) by providing virtual point-to-point optical connectivity to multiple end users through a dedicated pair of wavelengths. The objective of this paper is proposed a scheme for metropolitan area networks comprising optical components based on arrayed waveguide grating multiplexers, demultiplexers .The Arrayed waveguide gratings based multiplexers and demultiplexers for WDM applications prove to be capable of precise multiplexing and demultiplexing of a large number of channels with relatively low losses.
IoT Needs Good Neighbours - Cognitive Radio Turns Enemies into FriendsAMIHO Technology
With the internet of things the use of connected devices is predicted to be in many tens of billions. In this presentation, Steve Clarke discusses the use of various wireless technologies and techniques such as cognitive radio to allow these devices to co-exist in harmony with their (many) neighbours.
Steve Clarke, Technical Director of AMIHO, presented this paper at the prestigious Embedded World conference,Feb 2016.
Cognitive Radio definition and benefits Mustafa Sadiq
cognitive radio definition and its relationship to the software defined radio is explained in this presentation. The spectrum sense is also explained here as well
La participación ciudadana en la administración localIbiza Melián
El presente trabajo trata de demostrar la importancia de la participación ciudadana en el vigente ambiente de crisis económica, política y social. En el que se produce cada vez una mayor desafección y desinterés por las políticas públicas. Agrandándose la brecha entre administradores y administrados. Propugnando como antídoto ante este mal que arrecia en los albores del siglo XXI, pasar de una democracia representativa a otra participativa. Empezando por la Administración más cercana al ciudadano, los Ayuntamientos.
Why customer value propositions really matter - A focus on the telecom servic...Juan Carlos Sanchez
This strategic white paper, written in 2010, examines how the traditional business of communication service providers is under threat from innovative, Web-based services, delivered 'over-the-top' of Internet access.
To stay in the game, service providers and their ICT partners must find a way to deliver more effective customer value propositions, that offer top and bottom-line impact. This can be achieved by using a customer-focused, decision-driven approach to deliver the offers that users really want, quickly and effectively.
Negyedik rész: Új remény – A telefon visszatérRobert Pinter
Az NJSZT 6. Digitális Esélyegyenlőség konferenciáján elhangzott előadás diái. A téma, hogy vajon remény vagy illúzió, hogy az okostelefon csökkentheti a digitális szakadékot.
Paradojas que habitan las instituciones educativas en tiempo de fluidezPedro Roberto Casanova
Compiladores
Alejandra Taborda, Gladys Leoz y Gabriela Dueñas
Equipo de autores
Alejandra Taborda; Belén Piola; Gladys Leoz; Carolina Farconessi; Juan Vasen; Gabriela Dueñas; Adrian Grassi;Esteban Levin; María Cristina Rojas; Norma Filidoro; Graciela Paolicci;Lucia Abreu; Alicia Sabó; Mario Chades; Alicia Corvalán de Mezzano.
Universidad Nacional de San Luis
Travel2be - Resumen I Estudio de Satisfacción Usuarios de AerolíneasTravel2be
Resumen de los resultados obtenidos por Travel2be en el I estudio de satisfacción de usuarios de aerolíneas.
Para más información pueden contactarnos a través del e-mail indicado al final de la presentación.
Emprender en Murcia — «Quiero montar un negocio ¿qué me aconsejas?» es como «...Begoña Martínez
Conferencia en el curso de «Iniciativa emprendedora:
proceso de creación de empresas» de la Escuela de Organización Industrial y la Universidad de Murcia.
Kyeong Soo Kim, Academic Weeks Videoconference Session with Pakistan COMSATS Institute of Information Technology (CIIT), Swansea University, Swansea, Wales UK, Dec. 14, 2010.
International Journal of Engineering Research and Applications (IJERA) aims to cover the latest outstanding developments in the field of all Engineering Technologies & science.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
A Platform for Data Intensive Services Enabled by Next Generation Dynamic Opt...Tal Lavian Ph.D.
The new architecture is proposed for data intensive enabled by next generation dynamic optical networks
Offers a Lambda scheduling service over Lambda Grids
Supports both on-demand and scheduled data retrieval
Supports bulk data-transfer facilities using lambda-switched networks
Provides a generalized framework for high performance applications over next generation networks, not necessary optical end-to-end
Supports out-of-band tools for adaptive placement of data replicas
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
ASON – Automatically Switched Optical Networks
Dynamically switch the light path
Enabler for many applications
Controlled by UNI and NNI – Allow applications to set the light path
Allow to add the intelligence into the optical core
ASON:
The Automatic Switched Optical Network (ASON) is both a framework and a technology capability.
As a framework that describes a control and management architecture for an automatic switched optical transport network.
As a technology, it refers to routing and signalling protocols applied to an optical network which enable dynamic path setup.
Recently changed names to Automatic Switched Transport Network (G.ASTN)
Kyeong Soo Kim, "Theoretical and Practical Bounds on the Initial Value of Skew-Compensated Clock for Clock Skew Compensation Algorithm Immune to Floating-Point Precision Loss (Extended Version)," Special lecture, Department of Mathematics, Chungnam National University (CNU), Daejoen, Korea, January 25, 2023.
Kyeong Soo Kim, "Theoretical and practical bounds on the initial value of skew-compensated clock for clock skew compensation algorithm immune to floating-point precision loss," Invited talk, 2023 International Conference
for Mathematics and Its Applications, Chungnam National University (CNU), Daejoen, Korea, Jan. 16-18, 2023.
Kyeong Soo Kim, "Clock skew compensation algorithm immune to floating-point precision loss," Invited talk, to be delivered at 2022 International Workshop on Mathematics and Its Applications, Chungnam National University (CNU), Daejoen, Korea, August 4-5, 2022.
Kyeong Soo Kim, "Energy-efficient time synchronization in wireless sensor networks," Invited talk, 2019 Distinguished Lecture and International Interdisciplinary Workshop, Chungnam National University (CNU), Daejeon, Korea, August 5-9, 2019.
Kyeong Soo Kim, "Atomic scheduling of appliance energy consumption in residential smart grid," Invited talk, CNU International Workshop on Industrial Mathematics, Chungnam National University (CNU), Daejeon, Korea, Oct. 7, 2016.
Kyeong Soo Kim, Invited talk, 2016 International Conference on Internet of Things and 5G Mobile Technologies (2016 ICIOT-5GMT), Guangzhou University, Guangzhou, Nov. 27-28, 2016.
Kyeong Soo Kim, Centre for Smart Grid and Information Convergence (CeSGIC) 1st International Workshop on Smart Grid Technology and Data Processing
Xi'an Jiaotong-Liverpool University (XJTLU)
Suzhou, China
19 June 2015
Tutorial at IEEE 802 LMSC Plenary Session, Dallas, TX, USA, Nov. 13, 2006 (with W. Steven Conner, Intel Corp., Jan Kruys, Cisco Systems, and Juan Carlos Zuniga, InterDigital Comm. Corp.).
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
Connector Corner: Automate dynamic content and events by pushing a buttonDianaGray10
Here is something new! In our next Connector Corner webinar, we will demonstrate how you can use a single workflow to:
Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But there’s more:
In a second workflow supporting the same use case, you’ll see:
Your campaign sent to target colleagues for approval
If the “Approve” button is clicked, a Jira/Zendesk ticket is created for the marketing design team
But—if the “Reject” button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
And...
Speakers:
Akshay Agnihotri, Product Manager
Charlie Greenberg, Host
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
As AI technology is pushing into IT I was wondering myself, as an “infrastructure container kubernetes guy”, how get this fancy AI technology get managed from an infrastructure operational view? Is it possible to apply our lovely cloud native principals as well? What benefit’s both technologies could bring to each other?
Let me take this questions and provide you a short journey through existing deployment models and use cases for AI software. On practical examples, we discuss what cloud/on-premise strategy we may need for applying it to our own infrastructure to get it to work from an enterprise perspective. I want to give an overview about infrastructure requirements and technologies, what could be beneficial or limiting your AI use cases in an enterprise environment. An interactive Demo will give you some insides, what approaches I got already working for real.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
How world-class product teams are winning in the AI era by CEO and Founder, P...
Next-Generation Optical Access Architecture
1. On The Next-Generation
Optical Access Architecture
Joseph Kim
AST, STMicroelectronics
Washington University in St. Louis
Dec. 3, 2004
Outline
I. ST and SNRC Introduction
II. Paradigm Shift in Optical Networking
III. Next-Generation Optical Access Architecture
• Why Optical Access?
• TDM-PON: Current-Generation Optical Access
• Stanford University aCCESS (SUCCESS)
IV. Summary
2. I. ST and SNRC Introduction
Overview of STMicroelectronics
Overview of Stanford Networking Research
Center
3.
4. Advanced System Technology
Mission
• To provide the advanced system
knowledge able to establish ST as the
system on a chip leading company in the
market for the products of the next decade
Role
• To provide the Company with long-term core
business and leadership in key markets
5. SAN JOSE’
SAN DIEGO
CATANIAGRENOBLE
GENEVA
MILANO
AIX EN PROVENCE
BOSTON LECCE
HONG KONG
= large research lab
(>15 people)
NOIDA
BANGALORE
BRISTOL LUGANO
PORTLAND PARIS
AST - Global R&D Organization
AST - Optical Networking Activities
GIANT
Validation of GPON in
demonstrator
Integration of building blocks
Performance (efficiency, QoS)
testing
Service demonstration
GBRA
GXT0
CPA
GLTA Board GNTA Board
GBLA
LD+
AFE
PD+
AFE
WDM
GXTP
NT version
PD+
AFE
LD+
AFE
WDM
CDR
GXTP
LT
version
LD
Driver
ARM
Designed
by STM
Designed
by STM
Designed
by Intec
Designed
by IntecSystem Info control
PTSP OBC PTSP OBC
Designed
by ABell
Designed
by ABell
1.25 Gbps
622 MbpsGBRA
GXT0
CPA
GLTA Board GNTA Board
GBLA
LD+
AFE
PD+
AFE
WDM
GXTP
NT version
PD+
AFE
LD+
AFE
WDM
CDR
GXTP
LT
version
LD
Driver
ARM
Designed
by STM
Designed
by STM
Designed
by Intec
Designed
by IntecSystem Info control
PTSP OBC PTSP OBC
Designed
by ABell
Designed
by ABell
1.25 Gbps
622 Mbps
SYMPHATI
Symmetrical PON at high bit rate
Specify and design chipset for 1.25
Gbps upstream GPON - Class B
Lab demo at 622 Mb/s upstream
APON system
6. MEMS – free space
Bubble switch
ST Competences in Optics - 1
ST Competences in Optics – 2
7. Stanford Networking Research Center
- Overview
Established in 2000
• 5 Founding Members (ST,
3com, Bosch, Cisco, Sony)
• 5 Senior Members
• 13 Affiliates
3 Major Research Areas
• Wireless Access
• Internet Technologies
• Information Services
6 Projects
• ~ 20 faculty
• ~ 40 PhD students
Annual Budget
• $3.5M/year
For more information
• http://snrc.stanford.edu
SNRC - Current Projects (2003~2005)
Next Generation
Access Networks*
Robust & Adaptive Protocol Design
for Multimedia Wireless Networks
SupraNodes: Next Generation
Switching Network Elements
Novel Design, Analysis and
Monitoring Methods
for High-speed Networks
Collaborative Networks of
Imaging Sensors
Separating Syntax, Semantics, &
Patterns
in Web Service Composition
Optical Networking Area
8. SNRC - Opportunities
Ideal venue for collaborations
• Between Industry and Faculties/Students
• Between Industries
• Between Faculties/Students
Through
• Funded multi-PI research projects
• Fellow/Mentor/Advisor programs
• Researchers-in-Residence (R-i-Rs)
PNRL - Overview
Founded in 1990 and Headed by:
Professor Leonid G. Kazovsky
Group Members:
8 Ph.D. students,
2 visiting scholars,
1 Researcher-in-Residence,
1 consulting professor.
Equipment: ~ $5,000,000
Home Page: http://pnrl.stanford.edu
9. PNRL - Current Access Projects
Next-Generation Optical Access
-ST(@SNRC) with F/M/A
Advanced Access Networks Research
- KDDI, Japan
Next-Generation Burst-Mode Receiver
- ITRI, Taiwan
II. Paradigm Shift in Optical Networking
Overview
Traditional Way of Using Wavelengths
New Way of Using Wavelengths
Continuous-Mode vs. Burst-Mode
Communications
Examples
Enabling Technologies
10. Paradigm Shift in Optical Networking
Towards more Flexible, Dynamically-Reconfigurable
Optical Networks from Fixed, Static ones
Driving forces behind this shift
• Mismatch between service/usage model & network infrastructure
• Unbalance between backbone (waste of BW) and access (lack of
it)
• Rapid development in enabling technologies
! Tunable optical components
! Burst-mode communications
! Optical packet/burst/flow switching
Dynamically-reconfigurable networks
better meet varying user demands even
with fewer resources!
Traditional Way of Using Wavelengths
TX
TX
TX
TX
RX
RX
RX
RX
SW SW
11. Optical Network with
Passive/Semi-passive Nodes
New Way of Using Wavelengths
Tunable
TX
SW
Tunable
TX
SW
Tunable
TX
SW
Fixed
RX
SW
Fixed
RX
SW
Fixed
RX
SW
Continuous-Mode vs. Burst-Mode
Communications
TX RXSW SW
...010110100101110100101001001010101111101001010101…
SONET/SDH
Packet Packet Packet
RX SW
10011…0110
Packet Packet Packet
011…010 011…010
12. Examples
WAN
• TWIN, Lucent Bell Labs
MAN
• HORNET, PNRL/Stanford
• RINGO, Politechnico de Turin
Regional Access
• ONRAMP, Lincoln Lab/MIT
Access
• STARNET, DWA-PON & SUCCESS, PNRL/Stanford
• TOBASCO, Lucent
TWIN*: Network is a Giant Switch
TWIN cloud
DS-3
interface
Ethernet
interface
ATM
over OC-3
interface
Traffic destined to this node
should use purple wavelength
Network ~ Logical node
Core ~ Virtual back-plane
Edge node ~ Port
* Indra Widjaja et al., “Light core and intelligent edge for a flexible, thin-layered, and cost-effective optical
transport network,” IEEE Comm. Mag., vol. 41, no. 5, pp. 30 - 36, May 2003.
13. Tunable
Transmitter
!1
POP
Access Point
Access Point
Access Point
Access Point
Access Point
. . . . . .
Wireless
IP Cell
!"
Packet
Switch
Local
network
POP = Point of Presence
To long-haul network
!1
dropMAC
Packet
Receiver
HORNET*: Flexible, Multi Service Ring
* Ian White et al., "A summary of the HORNET project: A next-generation metropolitan
area network", IEEE JSAC, vol. 21, no. 9, pp. 1478-1494, Nov. 2003.
* N. M. Froberg, "The NGI ONRAMP Test Bed: Reconfigurable WDM Technology for Next
Generation Regional Access Networks," IEEE JLT, Dec. 1998. (Slide from Sarah Dubner)
ONRAMP*: Regional Access
14. DWA-PON*
* Y-L. Hsueh et al., “Success-DWA: A highly scalable and cost-effective optical access network”,
IEEE Comm. Mag., vol. 42, no. 8, pp. 24 - 30, Aug. 2004.
TL1
TL2
TL3
TL4
User 1
User16
…
User17
User32
User33
User48
User49
User64
AWG
Ch 1
Ch16
Ch 1
Ch16
Ch 1
Ch16
Ch 1
Ch16
………
…………
PON1
PON2
PON3
PON4
_
…
User Channel 1 User Channel 2 User Channel 16
AWG Channels
1 2 3 4 5 6 7 8 6
1
6
2
6
3
6
4
TL: Tunable Laser
Enabling Technologies
Common denominator in technologies enabling
flexible, dynamically-reconfigurable optical
networks
• CWDM
• Tunable Filters
• Tunable Lasers
• Burst-Mode Receivers (BMRs)
The paradigm shift pushes these technologies
towards the edge of the networks!
15. Coarse Wavelength Division Multiplexing
ITU-T Recommendation G.694.2
• 1270-1610 nm, 18 wavelengths, 13nm flat-top
• Permitting low-cost components
! Uncooled, unstabilized, direct-modulated transmitter
Migration path: CWDM to DWDM
• Iannone, “In-Service Upgrade of an Amplified 130-km Metro CWDM
Transmission System Using a Single LOA with 140-nm Bandwidth,” OFC ‘03
Tunable Filters – Promising
Technology for Access
Active thin film (Aegis Semiconductor)
"Integrated into semiconductors
"Small size & power
16. Tunable Lasers
Fast tuning time is critical
• State-of-the-art: ~5 ns over entire C-band
! Based on GCSR laser
! Digitally-controlled driver with overdriving pulse technique
* K. Shrikhande et al., "Performance Demonstration of a Fast-Tunable Transmitter and
Burst-Mode Packet Receiver for HORNET," OFC, ThG2-1, Mar., 2001.
Burst-Mode Receivers
Focus shifted from OLT to ONUs
One-chip solution preferred
• For mass deployment with ONUs
• Eventually, there will be no cost difference
between continuous-mode & burst-mode receivers
17. III. Next-Generation Optical Access
Architecture
Why Optical Access?
TDM-PON: Current-Generation Optical
Access
Stanford University aCCESS (SUCCESS)
Why Optical Access?
Advantages of fiber as a transmission
medium
• Greater capacity (100s of Tb/s*)
• Smaller size and light weight
• Immune to electromagnetic interference
Fiber penetration in the networks
• Already deployed in the backbone, the WANs, and
the MANs.
• Optical Ethernet is being introduced in LANs and
will spread to MANs and WANs.
* Mitra & Stark, Nature, vol 411, June 28, 2001.
18. TDM-PON Example - EPON
Proposed 1490nm downstream and
1310 nm upstream (1550 free for WDM
overlays)
Data is transmitted in variable-length
packets of up to 1,518 bytes (i.e.,
Ethernet frame)
Some packets may be intended for all
of the ONUs (broadcast packets) or a
particular group of ONUs (multicast
packets)
Upstream traffic is managed utilizing
TDM technology, in which transmission
time slots are dedicated to the ONUs
Time slots are synchronized so that
upstream packets from the ONUs do
not interfere with each other
The synchronization marker is a one-
byte code that is transmitted every 2
ms to synchronize the ONUs with the
OLT
* Source: Alloptic
TDM-PON Example
- APON (Lucent FTTB/H ONT)
Top View Rear View*
Front View Fiber
Cassette
* UNI cards are PCMCIA type.
19. Evolution of PONs
TDM-PONs
OLT
ONT
ONT
ONT
WDM-PONs
OLT
ONT
ONT
ONT
?
SUCCESS* - Overview
Sponsored by ST/SNRC
• Through F/M/A program
Next-generation optical access architecture based on
• Hybrid WDM/TDM-PONs
• Ring+Tree topology
• Fast Tunable Components
Starting point: How to efficiently/smoothly upgrade
TDM-PONs with those enabling technologies in the
future?
* F-T. An et al., “SUCCESS: A next-generation hybrid WDM/TDM optical access
network architecture,” IEEE/OSA JLT, vol. 22, no. 11, pp. 2557-2569, Nov. 2004.
20. SUCCESS – Major Objectives
Backward compatibility
• To guarantee the coexistence of current-generation (TDM-
PON) and next-generation (WDM-PON) optical access
systems in the same network
Easy upgradeability
• To provide smooth migration paths:
! TDM-PON # Hybrid WDM/TDM-PON # WDM-PON
Protection/restoration capability
• To support both residential/business users on the same
access infrastructure
SUCCESS – Features
Flexible Remote Nodes (RNs) with protection & restoration
capability
• Thin film filters as CWDM add/drop filters
• Passive splitter for TDM-PONs
• Athermal cyclic AWG for new WDM-PONs
Cost-effective ONUs for WDM-PON
• No local light source (for DWDM)
! Optical bursts provided by OLT for upstream transmission, are
modulated by SOA at ONU, and send back to OLT.
! New MAC protocols designed for efficient bidirectional transmission
Integrated OLT
• Based on tunable components
• Can support both TDM-PONs and WDM-PONs
21. Examples of Typical WDM-PONs
TX
RX
RX
ONUi
RX TX
ONUj
DEMUX MUX
RNk
… …
. . . . .
RXTX TX… …
MUX DEMUX
OLT
!
upstream downstream
2-fiber ring, 2 AWGs in 1 RN,
and 2 sets of wavelengths
RN
AWG
AWG
RX TX
…
TX RX
…
TX RX
OLT
ONUi ONUj
.....
:Passive splitter
C :CWDM, splitter
C
C
C
Single Fiber, bi-directional transmission
Network Migration Scenario under SUCCESS
CO
“Plain-old” PON
2$N
Flexible, protected, efficient
Access Networks.
Old ONUs and dist.
fibers are preserved.
W
W :DWDM, AWG
Co-Existing TDM/WDM-PONs
W
W
22. SUCCESS Architecture and Topology
Central
Office
RN
RN
RN
RN
!’
1, !2
!1
!2
!21
!22 !23
!’
1
!’
3, !4, …
!1, !2
!3, !4, …
!3
!’
3
!3
!31
!32
!33
TDM-PON ONU
RN TDM-PON RN
WDM-PON ONU
RN WDM-PON RN
Virtually only 2 sets
of OLT resides in CO
Protection & restoration is
possible by using different !s
on east- and west- bound.
Wavelength Assignment
Maintain backward compatibility for TDM-PON ONUs and allow
new WDM-PON ONUs to coexist
Little changes to current TDM-PON ONUs
! (nm)
O-Band E-Band S-Band C-Band L-Band
1260 1360 1460 1530 1565 1625
Upstream TDM traffic
Downstream TDM traffic
Downstream and Upstream WDM traffic,
one per ONU
CWDM Demux at OLT Tunable Lasers and
Filters at OLT
23. RN with Passive Splitter
2$N
Downstream:
1550.12nm
Upstream:
1310nm
RN
15dB
4~32 ONUs
N$N
RN
ring ringring ring
Other !s
Downstream:
1550.12nm
Upstream:
1310nm
Downstream:
1550.92nm
Upstream:
1290nm
Other !s
ONU group #2 ONU group #1
N-2N-2
For TDM-PONs
For WDM-PONs
Based on Athermal cyclic AWG
BW of the thin-film band splitter (for DWDM !s):
• Up/down-stream shares same !: (N-1)$%.
• Up/down-stream have different ! : (2$N-1)$ %.
RN with AWG
N-1 ONU N-1 ONU
AWG
.
.
.
.
.
.
!
ring ring
RN
Other !s
24. Semi-Passive RN for
Protection/Restoration
10/90
Elec.
Ctrl.
2$2
switch
N-1 N-1
Band splitters (A/D)
Passive splitter
or AWG
West East
Power from
one ONU
RN
ONU Structure for WDM-PON
SOA
distribution
fiber
Single port VCSOA
as modulator
SOA
2
3
1distribution
fiber
SOA may be used
as pre-amplifier
No local DWDM source for lowering cost
SOA as modulator and/or pre-amp
25. to the ring
WDM
coupler
CWDM
DWDM
Fast TLS
Pre-Amp
Post-Amp
Demux
TF
same
ISP
…
OLT Structure
Use tunable components to reduce transceiver counts and network
cost.
Each ISP can have TX/RX pair(s) to bundle/unbundle data in
optical domain.
The number of fast tunable laser sources depends on the number
of users, services, and the network load.
Scalability of SUCCESS - Wavelengths
Number of available wavelengths dictates number of users.
CWDM channels carry upstream data of TDM-PON, DWDM channels in
C/L band carry both downstream and upstream data of WDM-PON.
Factors influencing number of available wavelengths:
• Channel spacing of AWG, attenuation profile of optical fiber, and optical
amplifier gain bandwidth.
Number
of
Available
DWDM
Wave-
lengths
Fiber
Atten-
uation,
dB/km
AllWaveTM
CWDM
upstream
DWDM
26. Scalability of SUCCESS – Wavelengths (Continued)
Where
• !C: # of channels for CWDM TDM-based upstream traffic,
• !D: # of channels for DWDM ONUs,
• %!: Channel spacing of AWG is (in GHz);
Note that
• Total 18 CWDM wavelengths are available:
• With 20nm spacing and AllWaveTM fiber;
• Each nm corresponds to roughly 125GHz;
• For each !C corresponds to the number of 32$!C CWDM ONUs, and !D
means there are !D DWDM ONUs.
c
c
D !
!
!
! "
#
$"$
=
125)18(20
ONU1
ONU2
ONU3
SMF:2.2km SMF:15km SMF:5km
SMF:15kmSMF:2.2km
TLS:!2
TLS:!1
OBPF EDFA
thin-film A/D
circulator
passive splitter
OLT
ONU1, 2
SOA AM
75/25
Experimental Setup
RN
RN
RN
AWG
RN
PRBS
35km SMF Ring
1 OLT, 2 ONUs
27. 800 ps
800 ps
Experimental Results
Downstream Data Eye Diagram:
Upstream Data Eye Diagram:
2 ms
2 ms
leading edge of
CW burst on !1
leading edge of
upstream traffic on !1
2 ms
The timing diagram of packetized
transmission based on SUCCESS MAC:
Downstream
packets and CW
bursts on !1
Downstream
packets and CW
bursts on !2
Upstream
traffic monitored
at OLT
SUCCESS WDM-PON MAC Protocol
Design goal
• To provide efficient bidirectional transmission over
half-duplex physical channel.
Challenges
• Variable-length frames
• Time-sharing of the same channel for both up-
and downstream traffic
• No separate control channel/frame structure
• No delay equalization
! Need to reduce the impact of different RTTs.
28. SUCCESS WDM-PON Frame Formats
Delimiter Preamble
(01…01)
1-Bit
ID(=1)
Ethernet Frame
CW
or
16-Bit
Grant
Overhead (= 24 Bits)
For
Downstream
For
Upstream
Delimiter Preamble
(01…01)
Overhead
Ethernet Frame 16-Bit
Report
Ethernet Frame …
Delimiter Preamble
(01…01)
1-Bit
ID(=0)
Overhead
First Step - Sequential Scheduling
RX1
RX2
TX1
TX2
TX3
t0
RTT3
!1
!2
!4
G
!4!1
New transmission
scheduled!
t1
l1
RTT1
!2
!1
t
Example for 3 TXs, 2 RXs & 4 CHs
29. Sequential Scheduling – Pseudo Code
Begin
wait until a packet arrives;
set d = packet.destination, l = packet.length;
select i such that TX[i] <= TX[m] for all m = 1,…,M and m & i;
if packet is for upstream
select j such that RX[j] <=RX[n] for all n = 1,…,N and n & j;
set t = max(RX[j] + G – RTT[d], TX[i] + G, CH[d]);
set RX[j] = t + l + RTT[d]; /* update status variables */
schedule reception at time = t + RTT[d] with RX[j] via CH[d];
else /* packet is for downstream */
set t = max(TX[i] + G, CH[d]);
/* Common processing for both up- & downstream packet */
set CH[d] = t + l, TX[i] = t + l; /* update status variables */
schedule transmission at time = t with TX[i] via CH[d];
End
Simulation Environment
Based on OMNeT++:
• Object-oriented design
! C++ based
• Messaging classes
• Statistics collection
• WDM capability
! Supporting more than one links between nodes
• Optional graphic interface good for debugging
30. Simulator based on OMNeT++
Simulation - Setup
Network Configuration
• 16 ONUs divided into 4 groups (with 4 ONUs per
each) and placed from the OLT 5 km, 10 km, 15
km and 20 km, respectively.
MAC Parameters
• Line rate: 10 Gbps
• Maximum grant size: 2 Mbits
• ONU timeout: 2 ms
• Guard band: 50 ns
• ONU queue size: 10 MB
31. Simulation - Setup
Traffic
• Arrival Process: Poisson
• Packet size distribution: Based on measurement
trace from MCI-backbone OC-3 links
• Ratio of downstream to upstream traffic: 2:1
Performance measures
• Throughput
• Average end-to-end packet delay
Simulation Results – Throughput
Upstream Throughput
Downstream Throughput
32. Simulation Results - Delay
Upstream Delay
Downstream Delay
Next Step - Batch Scheduling*
Improvements over sequential scheduling
• Schedule over multiple frames in VOQs with the
earliest available TX and RX
! Room for optimization & priority queueing to minimize wasted
resources for higher throughput and better fairness
Implementation Options
• Adaptive Batch Size
! Varying upon queue length, packet dead line and so on
• Multiple sets of VOQs per ONU
! To provide multiple QoS classes and better fairness between
up- and downstream traffic through priority queueing
* K. S. Kim et al, “Batch scheduling algorithm for SUCCESS WDM-PON,”
Proc. of GLOBECOM 2004, Dallas, TX, USA, Nov. 2004.
33. Batch Scheduling – Timing Diagram
Arrival
Time
Scheduled
TX Time
Scheduling the 2nd batch
and remnants from the 1st
one.
Scheduling the 1st batch
1st batch 2nd batch 3rd batch
Batch Scheduling - OLT Structure
…Downstream
VOQs
…Upstream
VOQs Scheduler*
…Polling
VOQs
TX queue
(1 frame)
Tunable
Laser
TX1
Fiber
...
TX queue
(1 frame)
Tunable
Laser
TXM
Pointer to a frame to
be scheduled next
* Scheduler maintains a list of
scheduled transmissions and
receptions where transmission &
reception times, VOQ #, CH #, RX #
and TX # are stored.
Scheduled frames
To RXs (control signals)
34. Initial Results - Throughput
Upstream Throughput
Downstream Throughput
Summary
Mismatch between current service/usage model and
network infrastructure is a driving force behind the
paradigm shift in optical networking
• Towards flexible dynamically-reconfigurable optical networking
• Rapid developments in tunable optical components, CWDM, and
BMRs make such dynamically-reconfigurable optical networking
feasible.
• Advances in architectural study push those enabling technologies
towards the edge of the network.
SUCCESS is a joint research initiative for a next-
generation optical access architecture
• Exploiting the benefit of flexible, dynamically-reconfigurable
optical networking in access
• Guaranteeing smooth transition paths from current TDM-PONs to
future WDM-based optical access
35. Future Work
Subsystem and component level
• Fast tunable lasers and receivers at OLT
• Fast modulation technique for SOA at ONU
System level
• Efficient and fair scheduling algorithms
! Batch scheduling with adaptive batch period
! Theoretical scheduling algorithm and performance bounds
! Randomized version of batch scheduling algorithm
• Support of better QoS
! Hierarchical scheduling
• 2nd-generation testbed with MAC
! With upper layers for demonstration at application level
Thank You for Your Attendance!
For more information, please contact me
(kks@stanford.edu) or visit the following:
•Personal home page: http://www.stanford.edu/~kks
•PNRL: http://pnrl.stanford.edu
•SNRC: http://snrc.stanford.edu