This document provides an overview of dense wavelength division multiplexing (DWDM) technology. It discusses how the growing demand for bandwidth has overwhelmed existing telecommunications infrastructure. DWDM is presented as a solution that multiplies the capacity of existing fiber networks by transmitting multiple optical signals simultaneously on different wavelengths. The document provides background on the development of DWDM and its ability to significantly increase fiber capacity.
This document provides an overview of Dense Wavelength Division Multiplexing (DWDM) technology. It discusses key topics such as optical transmission, DWDM components like multiplexers/demultiplexers and amplifiers, DWDM networks and topologies, and transmission quality parameters. The presentation contains 32 slides and is intended to briefly explain DWDM as a means of achieving effective fiber-optic transmission and increasing bandwidth.
Microwave Links Correct Installation at Telecom Siteibrahimnabil17
- The document provides standards for installing microwave antennas, brackets, ODUs, IF cables, IDUs, APMs, and related equipment. Key requirements include properly matching antenna sizes to brackets, ensuring vertical poles and proper grounding, labeling all equipment clearly, arranging cables safely and with proper spacing, and configuring IDUs, power sources, and connections as specified. The goal is to perform all installations according to these standards to ensure safety, reliability, and manageability of the microwave network.
This document discusses next generation optical transport networks (OTN). It begins with an introduction to OTN switching and available options, including fixed and reconfigurable optical add-drop multiplexers with and without automatically switched optical network/generalized multi-protocol label switching control planes and OTN switching. It then discusses three capital expenditure components and recommends evaluating solutions based on total cost of ownership. The document concludes with recommending several options to consider and background on the author.
OTN networks provide transparent transport of client signals while protecting client management information and enabling low latency transport through enhanced fault detection and correction capabilities. Ciena enhances OTN with support for low-rate client interfaces, sub-wavelength grooming to improve efficiency, and intelligent control plane automation. The Optical Transport Network defined in ITU G.709 standards allows convergence of networks through transport of legacy and future client protocols with flexibility.
Submarine line termination equipment (SLTE) for open cablesADVA
Jörg-Peter Elbers’ NGON and DCI World presentation explored the specifics around open cables, technology developments and the implications for enhanced networking performance. The open cables concept for subsea transport was discussed as well as methods for the navigation and management of open cables and the key performance metrics for determining success.
This document provides an overview of optical DWDM fundamentals, including:
- Key terminology used in optical networks such as decibels, wavelength, frequency, and fiber impairments.
- Characteristics of optical fiber including different fiber types, fiber dimensions, and how light propagates through total internal reflection.
- Factors that reduce optical power over distance, specifically attenuation from absorption and scattering in the fiber material.
This document discusses trends, challenges, and solutions for mobile backhaul networks. It outlines the rapid bandwidth growth requirements for LTE, higher service demands including enterprise services and security, and increased O&M challenges. Huawei's LTEhaul 2.0 solution is presented as addressing these issues through features like proactive O&M, SDN virtualization, seamless multicast, and carrier-grade security. Specific technologies like eMBMS, small cell backhaul, Ethernet demarcation services, and IPSec solutions are also summarized.
OTN is an ITU standard that uses optical transport networking to transparently transport client signals such as Ethernet, SDH, and OTN itself over optical fiber. It combines the benefits of SONET/SDH for operations, administration, and management with the high bandwidth of DWDM. OTN aims to provide networking functionality, management capabilities, and performance monitoring for WDM networks using an optical channel data unit framework.
This document provides an overview of Dense Wavelength Division Multiplexing (DWDM) technology. It discusses key topics such as optical transmission, DWDM components like multiplexers/demultiplexers and amplifiers, DWDM networks and topologies, and transmission quality parameters. The presentation contains 32 slides and is intended to briefly explain DWDM as a means of achieving effective fiber-optic transmission and increasing bandwidth.
Microwave Links Correct Installation at Telecom Siteibrahimnabil17
- The document provides standards for installing microwave antennas, brackets, ODUs, IF cables, IDUs, APMs, and related equipment. Key requirements include properly matching antenna sizes to brackets, ensuring vertical poles and proper grounding, labeling all equipment clearly, arranging cables safely and with proper spacing, and configuring IDUs, power sources, and connections as specified. The goal is to perform all installations according to these standards to ensure safety, reliability, and manageability of the microwave network.
This document discusses next generation optical transport networks (OTN). It begins with an introduction to OTN switching and available options, including fixed and reconfigurable optical add-drop multiplexers with and without automatically switched optical network/generalized multi-protocol label switching control planes and OTN switching. It then discusses three capital expenditure components and recommends evaluating solutions based on total cost of ownership. The document concludes with recommending several options to consider and background on the author.
OTN networks provide transparent transport of client signals while protecting client management information and enabling low latency transport through enhanced fault detection and correction capabilities. Ciena enhances OTN with support for low-rate client interfaces, sub-wavelength grooming to improve efficiency, and intelligent control plane automation. The Optical Transport Network defined in ITU G.709 standards allows convergence of networks through transport of legacy and future client protocols with flexibility.
Submarine line termination equipment (SLTE) for open cablesADVA
Jörg-Peter Elbers’ NGON and DCI World presentation explored the specifics around open cables, technology developments and the implications for enhanced networking performance. The open cables concept for subsea transport was discussed as well as methods for the navigation and management of open cables and the key performance metrics for determining success.
This document provides an overview of optical DWDM fundamentals, including:
- Key terminology used in optical networks such as decibels, wavelength, frequency, and fiber impairments.
- Characteristics of optical fiber including different fiber types, fiber dimensions, and how light propagates through total internal reflection.
- Factors that reduce optical power over distance, specifically attenuation from absorption and scattering in the fiber material.
This document discusses trends, challenges, and solutions for mobile backhaul networks. It outlines the rapid bandwidth growth requirements for LTE, higher service demands including enterprise services and security, and increased O&M challenges. Huawei's LTEhaul 2.0 solution is presented as addressing these issues through features like proactive O&M, SDN virtualization, seamless multicast, and carrier-grade security. Specific technologies like eMBMS, small cell backhaul, Ethernet demarcation services, and IPSec solutions are also summarized.
OTN is an ITU standard that uses optical transport networking to transparently transport client signals such as Ethernet, SDH, and OTN itself over optical fiber. It combines the benefits of SONET/SDH for operations, administration, and management with the high bandwidth of DWDM. OTN aims to provide networking functionality, management capabilities, and performance monitoring for WDM networks using an optical channel data unit framework.
This document discusses troubleshooting of OptiX RTN 600 equipment. It covers objectives of troubleshooting preparation, ideas and methods, and examples of classified troubleshooting situations. Common troubleshooting methods discussed include alarm and performance analysis, loopback, replacement, configuration data analysis, configuration modification, using testing instruments, and experience-based rules of thumb. Typical troubleshooting sequences are also presented, beginning with excluding external issues and locating faults to a single network element or board. Finally, examples of traffic interruptions, wrong configurations, and bit errors are analyzed.
An Optical Transport Network (OTN) uses optical fiber links to connect network elements and provide transport, multiplexing, routing, management and protection of client signals. OTN applies these functions from SDH/SONET to DWDM networks, and offers stronger error correction, more monitoring levels and transparent transport of client signals compared to SDH/SONET. This document describes OTN architecture, interfaces and standards, the optical transport hierarchy of multiplexing ODUk, OPUk and OTUk signals, and the containment and frame rates of these signals.
1. The document provides installation guidelines for Mini-Link 6366 All Outdoor Solution equipment, including details on power supply requirements, required tools, connection points, installing cables and connectors, securing cables, assembling various components, and quality assurance checks.
2. It describes how to assemble and connect the antennas, radios, Mini-Link 6366 MDU, cables, connectors, mounting brackets, and other accessories to implement a 1+0 or 1+1 XPIC configuration in an all-outdoor installation.
3. Key steps include assembling the Orthomode Transducer, transition hub, mounting brackets, installing radios and the MDU, attaching cables, and performing antenna alignment and
The document provides an introduction to the MINI-LINK 6600 transport network evolution nodes. It describes the MINI-LINK 6692 and 6693 medium and large aggregation nodes, including their specifications, modules, and capabilities. It also covers the software interface, configuration of radio links, performance monitoring, DCN setup, and alarm handling.
3G BTS and DBS Hardware at Ericsson, Huawei, ZTE and NSNibrahimnabil17
The document provides information on 3G product dimensions from four major vendors: Ericsson, Huawei, NSN, and ZTE. It includes the dimensions, weights, power requirements, and typical installation scenarios for indoor and outdoor nodeBs from each vendor. Implementation scenarios showing how the products can be configured and deployed are also illustrated for Ericsson, Huawei, NSN, and ZTE.
This document discusses the implementation and optimization of dual polarization microwave links using XPIC technology. It covers:
- Using dual polarization antennas and XPIC to create two radio links through one path for increased capacity and hardware protection.
- The hardware configuration including two MMUs and RAUs integrated to a dual polarization antenna at each terminal.
- Procedures for alignment and configuration of the dual polarization links.
- Tests and optimization of cross polarization discrimination (XPD) to ensure adequate isolation between the two polarizations.
- Using ML Craft to test for interference by turning off the far end transmitter and checking for unexpected signal levels.
What is 5G NR all about? Check out this presentation to see all the key design components of this new unifying air interface for the next decade and beyond.
The document describes the hardware structure and components of the Huawei BTS3900 base station system. The key points are:
- The BTS3900 system consists of the BBU3900 baseband processing unit, MRFU radio frequency unit, and indoor macro cabinet.
- The BBU3900 performs baseband signal processing and manages the system. It includes boards like the GTMU, WMPT, WBBP, UTRP, UPEU, and others.
- The MRFU contains the radio frequency components and connects to the BBU3900 via CPRI.
- The system supports GSM, UMTS and dual-mode operation with high capacity
1) DWDM combines multiple optical signals so that they can be amplified and transmitted over a single fiber, increasing network capacity.
2) Basic DWDM system components include terminal multiplexers and demultiplexers, line repeaters, and optical terminals. Optical add-drop multiplexers allow removal or insertion of wavelengths along the span.
3) Proper link budgeting is required to ensure optical power levels remain above minimum thresholds to maintain signal quality as light propagates long distances through fiber. Regular monitoring and troubleshooting helps ensure transmission quality parameters are met.
BTS Reserves for Installation, Preventative Maintenance and Acceptanceibrahimnabil17
1. Install the BTS cabinet and make sure bolts are fixed well to secure it to the shelter ground. Install L-angles to fix the cabinet to the wall.
2. Make sure proper cable installation including power, E1, fiber, alarm and jumper cables in good arrangement using clips and ties. Ensure spacing between cables and clips.
3. Configure the BTS and integrate it to ensure it is clear from alarms during performance and integration testing.
The document discusses Synchronous Digital Hierarchy (SDH) and its advantages over Plesiochronous Digital Hierarchy (PDH). It describes some key components of SDH including section overhead bytes, path overhead bytes, virtual containers, tributary units, and administrative units. It also provides definitions and functions of various overhead bytes used for frame alignment, error monitoring, data communication, and other purposes in SDH networks.
Dense wavelength division multiplexing (DWDM) is a fiber optic transmission technique that employs light wavelengths to transmit data parallel-by-bit or serial-by-character. It allows for increased fiber capacity and scalability. DWDM evolved from earlier WDM techniques and can transmit 64 or more channels through a single fiber using spacing between 25-50 GHz. Ongoing research focuses on reducing dispersion and developing tunable lasers. DWDM provides a robust, simple, and cost-effective solution for growing bandwidth demands.
Switching conditions in SDH protection schemes.MapYourTech
This document discusses different protection schemes for SDH networks including SNCP, LINEAR MSP, and MSP RING. SNCP and LINEAR MSP are protection schemes that provide backup in case of a failure along a path. MSP RING protection creates a ring topology and uses neighboring nodes to provide backup if a failure occurs on the ring.
Digital transformation is at a critical juncture, with a diverse range of industries making changes that signifi-
cantly transform the way people live and work. These shifts have been driving advancements in the financial,
transportation, manufacturing, governmental, and many more sectors. Innovative mobile broadband technologies,
an underlying infrastructure, are a key driving force behind the digitalization of all walks of life. With
the rapid development of 5G, an increasing number of new applications and business models will reshape
the social and economic formation.
Such changes will stimulate strategic planning regarding industry opportunities, technical evolution,
network architecture, and other areas. Telecom operators are growing increasingly concerned with the
creation of a new target network to maximize return on investment (ROI) and achieve business success while
maintaining a competitive edge for the future. Global operators are promoting early deployment of 5G and
innovative business models through continuous 4G evolution. This has led to today's business achievements
and has laid a solid foundation for the huge potential of 5G.
With a gradual consensus being formed for the entire industry, all related players in the industry chain will
develop close collaboration to embrace a brighter future for the wireless network industry.
Continuous 4G evolution, a road to 5G!
Handling Common Faults and Alarms for Huawei RTN Microwavesibrahimnabil17
This document provides guidance on locating faults on RTN microwave network links. It describes the general process of checking alarms, service flows, equipment configurations, and collecting diagnostic data. Specific sections cover locating faults for TDM services, packet services, protection schemes, clocks, links, data communication networks and other fault types. Procedures are provided for locating microwave link faults, including checking transmitter power, receiver power, fading issues, interference, and performing loopbacks. Common alarms are also described along with their possible causes and handling procedures.
This document summarizes modem modules for the Ericsson MINI-LINK R4 radio system. It describes several modem modules: MMU2 B and C for PDH transport; MMU2 CS as a standalone PDH modem; MMU2 D and MMU2 H for Ethernet and hybrid PDH/Ethernet transport with increasing capacities and modulation techniques up to 256 QAM; and MMU2 E 155 and MMU2 F 155 for SDH transport with integrated line interfaces. Each module type supports different modulation formats, capacities, and protection features for transport of Ethernet, PDH, and SDH signals over radio links.
The document discusses the framing structure of SDH and various alarms that can occur in SDH networks. It explains the hierarchy from STM-1 frame down to VC-4 and tributary unit levels. It then describes alarms like LOS, LOF, LOP that can happen at different levels due to issues like signal loss, missing frames, or lost pointers. It also covers alarms for indicating defects or errors like AIS, RDI, REI, BIP and methods for error monitoring using bytes in the SDH frame.
The document discusses key concepts in digital telecommunication networks including Pulse Code Modulation (PCM), Plesiochronous Digital Hierarchy (PDH), Synchronous Digital Hierarchy (SDH), and their frame structures and bit rates. It describes how lower bit rate signals such as E1 (2Mbps) are mapped into higher bit rate structures like STM-1 (155.52Mbps) through multiplexing techniques involving containers, virtual containers, tributary units, and administrative units. The document also outlines the section overhead bytes used in SDH for functions like frame alignment, error monitoring, and automatic protection switching.
The document describes the hardware structure and features of the Huawei BTS3900 base station system. The BTS3900 system includes a BBU3900 unit, MRFU units, and an indoor cabinet. The BBU3900 processes signals and manages resources, and contains boards like the GTMU, WMPT, WBBP, and UPEU. The system supports GSM, dual-mode GSM/UMTS, and UMTS networks and provides functions such as high capacity, transmission sharing, and flexible clock synchronization.
This document discusses wavelength division multiplexing (WDM) and dense wavelength division multiplexing (DWDM). It describes how WDM uses different wavelengths to transmit multiple signals over the same fiber, with wider channel spacing. DWDM is then introduced as a way to increase capacity by reducing channel spacing. The key advantages and disadvantages of both WDM and DWDM are outlined. Standards for DWDM channel plans are also mentioned.
The document is a diagram describing ThemeGallery, which is described as a design digital content and contents mall developed by Guild Design Inc. It includes descriptions of the company's products, services, technology, and market. There are also diagrams showing steps and charts for describing contents.
This document discusses troubleshooting of OptiX RTN 600 equipment. It covers objectives of troubleshooting preparation, ideas and methods, and examples of classified troubleshooting situations. Common troubleshooting methods discussed include alarm and performance analysis, loopback, replacement, configuration data analysis, configuration modification, using testing instruments, and experience-based rules of thumb. Typical troubleshooting sequences are also presented, beginning with excluding external issues and locating faults to a single network element or board. Finally, examples of traffic interruptions, wrong configurations, and bit errors are analyzed.
An Optical Transport Network (OTN) uses optical fiber links to connect network elements and provide transport, multiplexing, routing, management and protection of client signals. OTN applies these functions from SDH/SONET to DWDM networks, and offers stronger error correction, more monitoring levels and transparent transport of client signals compared to SDH/SONET. This document describes OTN architecture, interfaces and standards, the optical transport hierarchy of multiplexing ODUk, OPUk and OTUk signals, and the containment and frame rates of these signals.
1. The document provides installation guidelines for Mini-Link 6366 All Outdoor Solution equipment, including details on power supply requirements, required tools, connection points, installing cables and connectors, securing cables, assembling various components, and quality assurance checks.
2. It describes how to assemble and connect the antennas, radios, Mini-Link 6366 MDU, cables, connectors, mounting brackets, and other accessories to implement a 1+0 or 1+1 XPIC configuration in an all-outdoor installation.
3. Key steps include assembling the Orthomode Transducer, transition hub, mounting brackets, installing radios and the MDU, attaching cables, and performing antenna alignment and
The document provides an introduction to the MINI-LINK 6600 transport network evolution nodes. It describes the MINI-LINK 6692 and 6693 medium and large aggregation nodes, including their specifications, modules, and capabilities. It also covers the software interface, configuration of radio links, performance monitoring, DCN setup, and alarm handling.
3G BTS and DBS Hardware at Ericsson, Huawei, ZTE and NSNibrahimnabil17
The document provides information on 3G product dimensions from four major vendors: Ericsson, Huawei, NSN, and ZTE. It includes the dimensions, weights, power requirements, and typical installation scenarios for indoor and outdoor nodeBs from each vendor. Implementation scenarios showing how the products can be configured and deployed are also illustrated for Ericsson, Huawei, NSN, and ZTE.
This document discusses the implementation and optimization of dual polarization microwave links using XPIC technology. It covers:
- Using dual polarization antennas and XPIC to create two radio links through one path for increased capacity and hardware protection.
- The hardware configuration including two MMUs and RAUs integrated to a dual polarization antenna at each terminal.
- Procedures for alignment and configuration of the dual polarization links.
- Tests and optimization of cross polarization discrimination (XPD) to ensure adequate isolation between the two polarizations.
- Using ML Craft to test for interference by turning off the far end transmitter and checking for unexpected signal levels.
What is 5G NR all about? Check out this presentation to see all the key design components of this new unifying air interface for the next decade and beyond.
The document describes the hardware structure and components of the Huawei BTS3900 base station system. The key points are:
- The BTS3900 system consists of the BBU3900 baseband processing unit, MRFU radio frequency unit, and indoor macro cabinet.
- The BBU3900 performs baseband signal processing and manages the system. It includes boards like the GTMU, WMPT, WBBP, UTRP, UPEU, and others.
- The MRFU contains the radio frequency components and connects to the BBU3900 via CPRI.
- The system supports GSM, UMTS and dual-mode operation with high capacity
1) DWDM combines multiple optical signals so that they can be amplified and transmitted over a single fiber, increasing network capacity.
2) Basic DWDM system components include terminal multiplexers and demultiplexers, line repeaters, and optical terminals. Optical add-drop multiplexers allow removal or insertion of wavelengths along the span.
3) Proper link budgeting is required to ensure optical power levels remain above minimum thresholds to maintain signal quality as light propagates long distances through fiber. Regular monitoring and troubleshooting helps ensure transmission quality parameters are met.
BTS Reserves for Installation, Preventative Maintenance and Acceptanceibrahimnabil17
1. Install the BTS cabinet and make sure bolts are fixed well to secure it to the shelter ground. Install L-angles to fix the cabinet to the wall.
2. Make sure proper cable installation including power, E1, fiber, alarm and jumper cables in good arrangement using clips and ties. Ensure spacing between cables and clips.
3. Configure the BTS and integrate it to ensure it is clear from alarms during performance and integration testing.
The document discusses Synchronous Digital Hierarchy (SDH) and its advantages over Plesiochronous Digital Hierarchy (PDH). It describes some key components of SDH including section overhead bytes, path overhead bytes, virtual containers, tributary units, and administrative units. It also provides definitions and functions of various overhead bytes used for frame alignment, error monitoring, data communication, and other purposes in SDH networks.
Dense wavelength division multiplexing (DWDM) is a fiber optic transmission technique that employs light wavelengths to transmit data parallel-by-bit or serial-by-character. It allows for increased fiber capacity and scalability. DWDM evolved from earlier WDM techniques and can transmit 64 or more channels through a single fiber using spacing between 25-50 GHz. Ongoing research focuses on reducing dispersion and developing tunable lasers. DWDM provides a robust, simple, and cost-effective solution for growing bandwidth demands.
Switching conditions in SDH protection schemes.MapYourTech
This document discusses different protection schemes for SDH networks including SNCP, LINEAR MSP, and MSP RING. SNCP and LINEAR MSP are protection schemes that provide backup in case of a failure along a path. MSP RING protection creates a ring topology and uses neighboring nodes to provide backup if a failure occurs on the ring.
Digital transformation is at a critical juncture, with a diverse range of industries making changes that signifi-
cantly transform the way people live and work. These shifts have been driving advancements in the financial,
transportation, manufacturing, governmental, and many more sectors. Innovative mobile broadband technologies,
an underlying infrastructure, are a key driving force behind the digitalization of all walks of life. With
the rapid development of 5G, an increasing number of new applications and business models will reshape
the social and economic formation.
Such changes will stimulate strategic planning regarding industry opportunities, technical evolution,
network architecture, and other areas. Telecom operators are growing increasingly concerned with the
creation of a new target network to maximize return on investment (ROI) and achieve business success while
maintaining a competitive edge for the future. Global operators are promoting early deployment of 5G and
innovative business models through continuous 4G evolution. This has led to today's business achievements
and has laid a solid foundation for the huge potential of 5G.
With a gradual consensus being formed for the entire industry, all related players in the industry chain will
develop close collaboration to embrace a brighter future for the wireless network industry.
Continuous 4G evolution, a road to 5G!
Handling Common Faults and Alarms for Huawei RTN Microwavesibrahimnabil17
This document provides guidance on locating faults on RTN microwave network links. It describes the general process of checking alarms, service flows, equipment configurations, and collecting diagnostic data. Specific sections cover locating faults for TDM services, packet services, protection schemes, clocks, links, data communication networks and other fault types. Procedures are provided for locating microwave link faults, including checking transmitter power, receiver power, fading issues, interference, and performing loopbacks. Common alarms are also described along with their possible causes and handling procedures.
This document summarizes modem modules for the Ericsson MINI-LINK R4 radio system. It describes several modem modules: MMU2 B and C for PDH transport; MMU2 CS as a standalone PDH modem; MMU2 D and MMU2 H for Ethernet and hybrid PDH/Ethernet transport with increasing capacities and modulation techniques up to 256 QAM; and MMU2 E 155 and MMU2 F 155 for SDH transport with integrated line interfaces. Each module type supports different modulation formats, capacities, and protection features for transport of Ethernet, PDH, and SDH signals over radio links.
The document discusses the framing structure of SDH and various alarms that can occur in SDH networks. It explains the hierarchy from STM-1 frame down to VC-4 and tributary unit levels. It then describes alarms like LOS, LOF, LOP that can happen at different levels due to issues like signal loss, missing frames, or lost pointers. It also covers alarms for indicating defects or errors like AIS, RDI, REI, BIP and methods for error monitoring using bytes in the SDH frame.
The document discusses key concepts in digital telecommunication networks including Pulse Code Modulation (PCM), Plesiochronous Digital Hierarchy (PDH), Synchronous Digital Hierarchy (SDH), and their frame structures and bit rates. It describes how lower bit rate signals such as E1 (2Mbps) are mapped into higher bit rate structures like STM-1 (155.52Mbps) through multiplexing techniques involving containers, virtual containers, tributary units, and administrative units. The document also outlines the section overhead bytes used in SDH for functions like frame alignment, error monitoring, and automatic protection switching.
The document describes the hardware structure and features of the Huawei BTS3900 base station system. The BTS3900 system includes a BBU3900 unit, MRFU units, and an indoor cabinet. The BBU3900 processes signals and manages resources, and contains boards like the GTMU, WMPT, WBBP, and UPEU. The system supports GSM, dual-mode GSM/UMTS, and UMTS networks and provides functions such as high capacity, transmission sharing, and flexible clock synchronization.
This document discusses wavelength division multiplexing (WDM) and dense wavelength division multiplexing (DWDM). It describes how WDM uses different wavelengths to transmit multiple signals over the same fiber, with wider channel spacing. DWDM is then introduced as a way to increase capacity by reducing channel spacing. The key advantages and disadvantages of both WDM and DWDM are outlined. Standards for DWDM channel plans are also mentioned.
The document is a diagram describing ThemeGallery, which is described as a design digital content and contents mall developed by Guild Design Inc. It includes descriptions of the company's products, services, technology, and market. There are also diagrams showing steps and charts for describing contents.
Chapter - 8.2 Data Mining Concepts and Techniques 2nd Ed slides Han & Kambererror007
This document discusses techniques for mining time-series data. It describes how time-series data consists of sequences of values changing over time that are recorded at regular intervals. Common components of time-series include trends, cycles, seasonality, and irregular movements. Methods for analyzing time-series include estimating trends using moving averages, seasonal indexes, and decomposing time-series into systematic components. Similarity search techniques allow finding similar patterns that differ slightly in time-series databases.
We've reimagined network security for the big data era. Check out Uli Schlegel's slides on our new 100G Metro with built-in encryption – an industry first.
At the Society of Cable Telecommunications Engineers Expo 2014, Andy Smith of Juniper Networks presented Juniper’s vision and architecture for a cable oriented packet optical core and metro transport system. Access insights and network diagrams in his presentation and learn more in his blog post: http://juni.pr/1rwapCG.
Physics presentation(step index and graded index)Ritesh Goyal
This document discusses different types of optical fibers. It describes single mode fibers as having a small diameter that supports only one propagation mode, while multimode fibers have a larger core diameter supporting multiple modes. Index profiles can be step index, where the core and cladding have uniform but different refractive indices, or graded index, where the core index decreases from the center outward. Single mode fibers typically have a step index profile, while multimode fibers can be either step or graded index. The document provides illustrations and explanations of step index and graded index fiber structures and their light propagation characteristics.
An Architecture for Data Intensive Service Enabled by Next Generation Optical...Tal Lavian Ph.D.
DWDM-RAM - An architecture for data intensive Grids enabled by next generation dynamic optical networks, incorporating new methods for lightpath provisioning.
DWDM-RAM: An architecture designed to meet the
networking challenges of extremely large scale Grid applications.
Traditional network infrastructure cannot meet these demands,
especially, requirements for intensive data flows
DWDM-RAM Components Include:
Data management services
Intelligent middleware
Dynamic lightpath provisioning
State-of-the-art photonic technologies
Wide-area photonic testbed implementation
This presentation provides a primer in current 100G technology developments, with a focus on the two market available 100G transport approaches: multicarrier direct detection and single carrier coherent. Additionally, different application scenarios with hybrid 10G/100G and multiple 100G transmissions are discussed elucidating fiber impairments and compensation techniques.
This document discusses measurement of dispersion, numerical aperture (NA), and eye diagrams in optical fiber communication. It defines dispersion as pulse broadening of light wave signals, and describes three types: intermodal, chromatic, and polarization mode dispersion. Formulas are provided for calculating root mean square pulse width and chromatic dispersion. Measurement techniques are outlined for each dispersion type using devices like optical sampling oscilloscopes and vector voltmeters. Numerical aperture is defined as the maximum angle of light acceptance, and impacts the number of propagating modes. Eye diagrams provide a way to assess signal quality by overlaying segments of a data stream on an oscilloscope. Diagrams illustrate how an eye diagram is formed from a bit sequence.
This document discusses next-generation reconfigurable optical add-drop multiplexers (NG ROADMs). It outlines the functionality requirements of NG ROADMs, including being colorless, directionless, contentionless, and gridless. It describes the technology building blocks that enable these features, such as wavelength selective switches (WSS). The document also discusses the benefits of NG ROADMs, such as increased flexibility, automatic restoration, and support for higher data rates. It concludes that NG ROADM technology prepares networks to meet current and future traffic needs.
Transforming Packet Networks With Open Optical TransportADVA
Get the latest on the trend towards simple, open, disaggregated optical systems from Jörg-Peter Elbers’ slideshow, first delivered at ECOC Exhibition 2015
N-degree ROADM Architecture Comparison: Broadcast-and-Select vs Route-and-SelectADVA
The document compares the Broadcast-and-Select and Route-and-Select architectures for N-degree ROADM nodes in 120 Gb/s DP-QPSK transmission systems. It finds that Broadcast-and-Select has slightly lower penalties than Route-and-Select for N=4 and 9 due to less passband narrowing accumulation, but Route-and-Select has better isolation and fixed insertion loss. For larger N, Route-and-Select is preferable to mitigate higher potential crosstalk. Experimental results validated the predicted penalties from combined passband and isolation degradation analysis.
Building Next Generation Transport NetworksInfinera
This document discusses Infinera's vision for building next generation transport networks through radical innovation. It summarizes Infinera's technology, including its pioneering work with Photonic Integrated Circuits, and how this allows it to deliver instant bandwidth and scale networks efficiently. The document also outlines some of the challenges service providers face in scaling their networks cost-effectively and how Infinera's approach helps address these challenges through simplified architectures enabled by its intelligent transport solutions.
This document discusses multimedia data mining and spatial data mining. It defines multimedia data mining as dealing with different types of data, including text, images, video and audio. Spatial data mining is described as dealing with objects in space that have identities, locations and relationships. Several techniques for spatial data mining are discussed, including spatial association analysis, spatial classification, spatial trend analysis, spatial cluster analysis and mining spatiotemporal data.
CWDM and DWDM are both types of WDM systems that transmit multiple wavelengths of laser light through a single optical fiber. However, they differ in channel spacing, transmission reach, and cost. CWDM has a wider channel spacing of 20nm, a shorter transmission reach of 160km, and a lower cost compared to DWDM. DWDM has a narrower channel spacing of 0.2-0.8nm, can transmit signals over longer distances, and has a higher cost due to its use of temperature-controlled lasers. The key differences are that CWDM is cheaper but has lower performance, while DWDM has a higher performance but also a higher cost.
This document provides an overview of basic WDM optical networks. It describes WDM as a multiplexing technique that allows multiple wavelengths to be transmitted over the same fiber. There are two main architectures: broadcast and select, which uses a simple star topology, and wavelength routed, which establishes light paths between nodes using the same wavelength. The document outlines the key components and working principles of each architecture, including their advantages and disadvantages. Wavelength routed networks allow for wavelength reuse but require efficient wavelength assignment to avoid bandwidth loss.
This document discusses encryption in data center and fiber optic networks. It notes that Edward Snowden revealed that unencrypted communications are no longer safe. It then discusses how data centers secure physical access, hardware, software and fiber connections. It explains that encryption on the lowest network layer provides the highest security. The document presents ADVA's encryption solutions for 10G and 100G networks, including key lengths and management systems. It notes over 1,600 encrypted links are currently in operation across finance, government, healthcare and other industries.
Optical fiber communications networks use various topologies and protocols. A local area network interconnects users within a building, while metro and access networks connect between buildings and to homes. The physical layer refers to the transmission medium, while higher layers establish links and route data packets. Synchronous Optical Network (SONET) and Synchronous Digital Hierarchy (SDH) standards define optical carrier (OC) rates and frame formats to interconnect transmission equipment. Networks can be configured in ring or mesh topologies with self-healing capabilities. Passive optical networks (PON) use passive splitters and no electronic regeneration between transmitters and receivers.
The eye diagram is a visualization technique used to evaluate the quality of a received digital signal. It reveals the impact of intersymbol interference and noise by showing the variation in sample values and jitter sensitivity of the sampling instant. The eye diagram is created by overlapping traces of symbols and the open part represents the safe sampling region. It allows estimating the bit error rate, with a larger eye opening corresponding to a lower bit error rate.
Optical networks use fiber optic technologies and components to transmit data at high speeds. They employ network architectures like synchronous optical networks (SONET) and passive optical networks (PONs) to route data through the core transport network and provide access to customers. SONET uses time-division multiplexing and self-healing ring topologies to interconnect equipment from different vendors. PONs have a star topology and use different wavelengths to transmit data downstream and upstream without electronic regeneration between transmitters and receivers.
This document presents a cloud decision making framework developed by Andy Marshall as part of his MSc thesis in Cloud Computing at the National College of Ireland. The framework aims to help IT decision makers in SMEs determine whether to adopt cloud computing or continue using on-premise IT solutions.
The document provides background on cloud adoption trends, benefits and challenges for SMEs. It then describes the design of the cloud decision making framework, which evaluates cloud and on-premise options across quantitative and qualitative criteria such as cost, security and vendor lock-in. The framework was implemented as a web application hosted on Microsoft Azure. It was evaluated through feedback from organizations that used the framework.
This white paper discusses an integrated security solution from Juniper Networks for virtualized data centers and cloud environments. It addresses the security challenges of virtualized workloads, which lose visibility from traditional physical firewalls. The solution includes Juniper's SRX Series services gateways to protect physical workloads and a virtual gateway (vGW) to protect virtualized workloads. It provides integrated zone enforcement between the physical and virtual firewalls to consistently enforce security policies across physical and virtual systems.
This white paper discusses the challenges facing mobile data centers and a vision for next-generation architectures. Traditional data centers face issues including: too many network layers leading to complexity, lack of visibility and security, and limitations of centralized designs. The paper proposes that virtualization, MPLS, Juniper's Junos software, and product lines like MX routers and SRX gateways can help create scalable, efficient data centers that address these challenges and enable new mobile services.
The IT industry has gained significant efficiency and flexibility as a direct result of virtualization. Organizations are moving toward a virtual datacenter (VDC) model, and flexibility, speed, scale and automation are central to their success. Although compute and memory resources are pooled and automated, networks and network services, such as security, have not kept pace. Traditional network and security operations not only reduce efficiency but also limit the ability of businesses to rapidly deploy, scale and protect applications. VMware vCloud® Networking and Security™ offers a network virtualization solution to overcome these challenges. This paper describes various components of the network virtualization solution and explains one of the key technology - VXLAN. It also provides design considerations that will help virtualization and network architects deploy this solution successfully in their environment.
Cloud computing promises large gains in efficiency and flexibility for data centers facing exponentially growing demands. The document discusses Intel's vision for cloud computing in 2015, focusing on efficiency, simplification, and security. It outlines challenges in these areas and Intel's activities and recommendations to evolve cloud infrastructure over the next few years to be more efficient, secure, simplified, and use open standards.
This whitepaper features the transition from traditional networking to software-defined networking or SDN. Find outlines of next-generation architectures.
The document is a project report submitted by Kedar Khandeparkar for the partial fulfillment of the requirements for the degree of Master of Technology. It discusses the design and implementation of communication, storage, and archival of an IEEE C37.118 standard based Wide Area Measurement System (WAMS). WAMS uses Phasor Measurement Units (PMUs) to collect synchronized phasor measurements across the power grid to provide improved monitoring capabilities compared to traditional SCADA systems. The report covers the components of WAMS, communication protocols, existing WAMS implementations, and use of databases for storage and archival of PMU/PDC data.
The document discusses key trends driving the consolidation of processing workloads in embedded systems to make devices more secure, manageable and scalable. It describes how virtualization allows functions like security, communications, real-time processing and user interfaces to run separately on a single device. This enhances intelligence in Internet of Things applications by enabling features like remote management and analytics while improving performance, flexibility and reducing costs.
Im-ception - An exploration into facial PAD through the use of fine tuning de...Cooper Wakefield
This document is a thesis submitted by Cooper Wakefield to the University of Queensland for the degree of Bachelor of Engineering. The thesis proposes developing a presentation attack detection (PAD) system through fine tuning a deep convolutional neural network. It aims to leverage pre-trained networks and fine tune the upper layers to differentiate between real and fake facial images with a high degree of accuracy. The thesis outlines the problem of presentation attacks on facial recognition systems, reviews prior approaches to PAD, and describes the proposed solution of using transfer learning on a CNN to classify images as real or fake.
This document provides an abstract for Suman Srinivasan's 2015 PhD dissertation from Columbia University titled "Improving Content Delivery and Service Discovery in Networks". The dissertation aims to provide clarity on usage of core networking protocols and multimedia consumption on mobile and wireless networks as well as the network core. It presents research prototypes for potential solutions to problems caused by increased multimedia consumption on the Internet. The dissertation contains four main contributions: 1) Studies measuring data usage and protocols on networks; 2) New software architectures and implementations for service discovery on wireless networks; 3) On-path content delivery networks and a new distributed CDN architecture; 4) Research prototypes for content-centric networking.
Robust link adaptation in HSPA EvolvedDaniel Göker
This master's thesis studies a robust link adaptation technique for HSDPA networks. The technique adds an offset to the estimated channel quality indicator (CQI) to account for errors caused by measurement delay and noise. Simulations compare the robust technique to existing CQI adjustment in terms of block error rate stability and throughput. Results show the robust technique achieves the target block error rate on average across different user speeds, while existing CQI adjustment performs best only at high speeds with large packets. The robust technique provides stability but cannot adapt to interference variations. Both methods may be needed for a flexible system.
This document provides a feature guide for Junos OS Layer 2 Wholesale for Subscriber Services. It includes an overview of broadband subscriber management basics and hardware, as well as the Junos software features that enable layer 2 wholesale services. The document describes how to configure a layer 2 wholesale network with separate routing instances and VLAN interfaces to isolate traffic for different service retailers. It also covers RADIUS configuration and VLAN tagging for layer 2 wholesale subscriber services.
The use of synchrophasors for monitoring and improving the stability of power transmission networks is gaining in significance all over the world. The aim is to monitor the system state, to intensify awareness for system stability and to make optimal use of existing lines. This way, system stability can be improved overall and even the transmission performance can be increased. The data from so many PMU’s and PDC’s needs to be collected and directed to proper channels for its efficient use. Thus we need to develop an efficient, flexible and hybrid data concentrator that can serve this purpose. Besides accepting the data from PMU’s, PDC should be able to accept the data also from other PDC. We have designed such a PDC (iPDC) that accepts data from PMU & PDC that are IEEEC37.118 standard compliant.
WAMS architecture with iPDC and PMU at different levels. This architecture enables iPDC to receive data either from a PMU or other iPDC. Both PMU and iPDC from whom the data is being received should be IEEE C37.118 synchrophasor standard compliant. It is hybrid architecture.
iPDC Design
The client server architecture is common in networks when two peers are communicating with each other. Of the two peers (PMU and iPDC) that are communicating with each other in WAMS one acts as a client and the other as a server. Since PMU saves the requests coming
from iPDC by sending data or configuration frames it acts as a server. It listens for command frames from iPDC. PMU-iPDC communication can be either over TCP or UDP communication protocols. On receiving command frames, PMU replies to the iPDC with data or configuration frames according to the type of request.
iPDC functionality is bifurcated as server and client. iPDC as a Client - When iPDC receives data or configuration frames its acts as a client. When acting as a client, it creates a new thread for each PMU or a PDC from whom it is going to receive data/configuration frames. This thread would establish connection between the two communication entities. It handles both TCP and UDP connections. The first frame that the server (PMU/PDC) would receive is the command for sending the configuration frame. When the server replies with the configuration frame, iPDC (client) would generate another request to start sending the data frames. On receiving
such a command frame, the server starts sending the data frames. If there is some change in the status bits of data frame which the client (iPDC) notices, it would take an action. For example if it notices a bit 10 has been set, it would internally send a command to server to send the latest configuration frame.
iPDC as a Server- When iPDC receives command frames from another PDC it would acts as a server. There would be two reserved ports one for UDP and other for TCP on which the PDC would receive command frame requests. Thus PDC now plays the role of PMU waiting
for command frames.
Implementing QoS in IP Networks - Nikolaos TossiouNikolaos Tossiou
This document is a dissertation submitted by Nikolaos Tossiou to Brunel University in partial fulfillment of a Master of Science degree. The dissertation describes a case study where Tossiou designed and implemented a quality of service (QoS) enabled network. The case study involved identifying applications with QoS requirements, defining QoS classes, configuring the network topology and devices, and using measurement tools to validate that the network meets the QoS needs of different traffic types. The dissertation provides an overview of IP QoS, mechanisms to implement QoS, and architectures for QoS before detailing the case study network design and results from testing the network.
Ibm web sphere datapower b2b appliance xb60 revealednetmotshop
This document provides an overview of IBM WebSphere DataPower B2B Appliance XB60. It discusses business-to-business integration concepts and technologies. It then describes the XB60 appliance, how it facilitates B2B integration using industry standards, and how data flows through its B2B Gateway service. The document also covers device setup and administrative tasks for the XB60, including initializing the device, defining the base configuration, and configuring domains, groups and users.
Machine-Type-Communication in 5G Cellular System-Li_Yue_PhD_2018.pdfYAAKOVSOLOMON1
This document is a dissertation submitted by Yue Li for the degree of Doctor of Philosophy at the University of Victoria. The dissertation focuses on improving transmission efficiency for machine-type communication (MTC) devices in 5G cellular systems. Specifically, it proposes applying network coding and device-to-device communications to MTC devices to improve efficiency. It also proposes using floating relays deployed via unmanned aerial vehicles to proactively improve channel quality for MTC devices experiencing high shadowing. The dissertation provides theoretical analyses and performance evaluations of the proposed approaches.
This document provides an overview of a CDMA2000 1X network characterization seminar. The seminar will cover the network characterization process including collecting performance data, post-processing, and extracting key performance indicators (KPIs). Attendees will learn how to examine their own network and determine if it is operating well. The seminar materials include data files to open with various analysis software tools.
Software defined networks (SDNs) is one of the most emerging field and will cause
revolution in the Information Technology (IT) industry. The flexibility in the SDNs
make it most attractive technology to adopt in all type of networks. This flexibility in
the network made the SDNs more prone to the security issues so it is important to cater
these issues in start from the SDN design up-to the deployment and operations. This
Paper proposed a DNS based approach to prevent SDNs from botnet by applying one
million web database concept without reading packet payload. To do any activity, Bot
need to communicate with CnC and requires DNS to IP resolution. For any request
having destination port 53 (DNS) will be checked. The protocol will get all matching
traffic and will send it to 1Mdb. If URL Exists in 1Mdb then do not respond otherwise
send reply with remove flow and block flow to the controller. This approach will use
Machine learning algorithms to classify the traffic as BOT or normal traffic. Naive
Bayes Classifier is used to classify the data using python programming language. The
selection of dataset is very important task for machine learning based botnet detection
and prevention techniques. The poor selection of dataset possibly lead to biased results.
The real world and publically available dataset is a good choice for evaluation of botnet
detection techniques. To meet these criteria, publicly available CTU-43 botnet dataset
has been used. This dataset provide packet dumps (pcap files) of seven real botnets
(Neris, Rbot, Virut, Murlo, Menti, Sogou, and NSIS). We will use these files to generate
botnet traffic for evaluation and test our model. To generate normal traffic, we selected
ISOT dataset. This dataset provides a single pcap file having normal traffic and traffic
for weladec and zeus botnet.
The document discusses a white paper from Juniper Networks about their new QFabric data center network architecture. The QFabric architecture aims to address challenges with the traditional multi-tiered tree network structure in data centers. It proposes a "flattened" network with a single tier that operates like a single Ethernet switch to improve performance, scalability and simplify operations compared to legacy data center networks. The QFabric architecture is presented as enabling data centers to better support virtualized, converged environments.
DEFINITIONS
Avoided costs
Avoided cost is the marginal cost for the same amount of energy acquired through
another means such as construction of a new production facility or purchase from an
alternate supplier
Code
The Zambia Distribution Grid Code
Connection Agreement
An agreement between DNSP(s) and each Customer setting out terms relating to a
connection with the Distribution System
Connection charge
A charge recouped from the customer for the cost of providing new or additional
capacity (irrespective of whether new investment is required or not). This is
recovered in addition to the tariff charges as an up-front payment (connection fee)
or as a monthly charge where the distributor finances the connection
Customer
A person or entity whose premises are connected or has applied to have premises
connected to the Distribution System for the purpose of obtaining interconnection of
its premises to the Distribution System
Customer Asset
Electrical assets that are owned by the customer and are designed and installed in
accordance with Zambia Wiring of Premises standard, ZS 791
Customer Interruption Cost
This is the cost to customers due to interruptions of supply (cost of unserved
energy)
Dedicated Assets / Dedicated Network
The portions of the network which are dedicated to a specific customer - Customer
dedicated assets are assets created for the sole use of a customer to meet the
customer’s technical specifications, and are unlikely to be shared in the DNSP’s
planning horizon by any other end-use customer
Demand
The electrical power which is drawn from the system by a Customer, usually
expressed in MW, MVA or MVAr
1. Ciena.Final 6/3/97 5:56 PM Page 1
Dense
Wavelength
Division
Multiplexing
ATG’s Communications &
Networking Technology
Guide Series
This guide has been sponsored by
3. Ciena.Final 6/3/97 5:56 PM Page 2
Introduction Every aspect of human interplay—from business, to
entertainment, to government, to academia—increas-
ingly depends on rapid and reliable communication
Over the last decade, fiber optic cables have been networks. Indeed, the advent of the Internet alone is
installed by carriers as the backbone of their interoffice introducing millions of individuals to a new world of
networks, becoming the mainstay of the telecommuni- information and technology. The telecommunications
cations infrastructure. Using time division multiplexing industry, however, is struggling to keep pace with these
(TDM) technology, carriers now routinely transmit changes. Early predictions that current fiber capacities
information at 2.4 Gb/s on a single fiber, with some would be adequate for our needs into the next century
deploying equipment that quadruples that rate to 10 have proven wrong.
Gb/s. The revolution in high bandwidth applications
and the explosive growth of the Internet, however,
have created capacity demands that exceed traditional
TDM limits. As a result, the once seemingly
Bandwidth
inexhaustible bandwidth promised by the deployment Demand
of optical fiber in the 1980s is being exhausted. To
meet growing demands for bandwidth, a technology
called Dense Wavelength Division Multiplexing
(DWDM) has been developed that multiplies the Time
capacity of a single fiber. DWDM systems being
deployed today can increase a single fiber’s capacity
sixteen fold, to a throughput of 40 Gb/s! This cutting
edge technology—when combined with network Bandwidth Demand
management systems and add-drop multiplexers—
enables carriers to adopt optically-based transmission Driven By…
networks that will meet the next generation of band-
width demand at a significantly lower cost than
…Growing Competition
installing new fiber.
During the past several years, a trend has developed
throughout the world to encourage competition in the
telecommunication sector through government deregu-
The Growing Demand lation and market-driven economic stimulation. Since
competition was introduced into the US long-distance
market in 1984, revenues and access lines have grown 40
It is clear that as we approach the 21st century the
percent, while investment in outside plant has increased
remarkable revolution in information services has
60 percent. The 1996 Telecommunication Reform Act
permeated our society. Communication, which in the
is giving way to an even broader array of new operators,
past was confined to narrowband voice signals, now
both in the long-distance and local-exchange sectors,
demands a high quality visual, audio, and data context.
which promise to drive down telecommunications costs
2 • Dense Wavelength Division Multiplexing Technology Guide • 3
4. Ciena.Final 6/3/97 5:56 PM Page 4
and thereby create new demand for additional services usage, which some analysts predict will grow by 700
and capacity. Moreover, while early competition among percent annually in coming years, is threatening to
long distance carriers was based mainly on a strategy of overwhelm telephone access networks and further
price reduction, today’s competitive advantage depends strain the nation’s fiber backbone. The growth of
increasingly on maximizing the available capacity of cellular and PCS is also placing more demand on fiber
network infrastructures and providing enhanced relia- networks, which serve as the backbone even for wireless
bility. communications.
…Network Survivability
Another significant cause of bandwidth demand is Telecommunications
the carriers’ need to guarantee fail-safe networks. As
telecommunications has become more critical to busi- Infrastructure Good But
nesses and individuals, service providers have been Overwhelmed
required to ensure that their networks are fault tolerant
and impervious to outages. In many cases, telephone
companies must include service level guarantees in Since the early 1980s, the telecommunications
business contracts, with severe financial penalties infrastructure—built on a hierarchy of high
should outages occur. performance central office switches and copper lines—
To meet these requirements, carriers have broad- has been migrating to massive computerization and
ened route diversity, either through ring configurations deployment of fiber optic cables. The widespread use
or 1:1 point-to-point networks in which back-up of fiber has been made possible, in part, by the
capacity is provided on alternate fibers. Achieving industry’s acceptance of SONET and SDH as the
100% reliability, however, requires that spare capacity standard for signal generation.1 Using SONET/SDH
be set aside and dedicated only to a backup function. standards, telecommunication companies have gradu-
This potentially doubles the bandwidth need of an ally expanded their capacity by increasing data trans-
already strained and overloaded system, since the mission rates, to the point that many carriers now
“protective” path capacity must equal that of the routinely transport 2.4 Gb/s (STM–16/OC–48).
revenue-generating “working path.” The bad news, however, is that the once seemingly
inexhaustible capacity promised by ever increasing
SONET rates is reaching its limit. In fact, bandwidth
…New Applications demand is already approaching the maximum capacity
At the same time that carriers are enhancing available in some networks. Primarily because of tech-
network survivability, they must also accommodate nical limitations and the physical properties of
growing customer demand for services such as video, 1 SONET is a North American standard promulgated by the American National
high resolution graphics, and large volume data Standards Institute (ANSI). There is an equivalent standard approved by the
International Telecomunications Union (ITU) called Synchronous Digital
processing that require unprecedented amounts of Hierarchy (SDH). SONET and SDH refer to similar data transmission rates.
bandwidth. Technologies such as Frame Relay and Synchronous Transfer Mode (STM) is used to describe SDH rates, while the
Optical Carrier (OC) designation applies to SONET–based systems.
ATM are also adding to the need for capacity. Internet STM–16/OC–48 transmits 2.48 Gb/s, while STM–64/OC192 transmits
almost 10 Gb/s.
4 • Dense Wavelength Division Multiplexing Technology Guide • 5
5. Ciena.Final 6/3/97 5:56 PM Page 6
embedded fiber, today there is a practical ceiling of 2.4 associated support systems and electronics, has been
Gb/s on most fiber networks, although there are estimated to be about $70,000 per mile, with costs esca-
instances where STM–64/OC–192 is being deployed. lating in densely populated areas. While this projection
Surprisingly, however, the TDM equipment installed varies from place to place, installing new fiber can be a
today utilizes less than 1% of the intrinsic capacity of daunting prospect, particularly for carriers with tens of
the fiber! thousands of route miles. In many cases, the right-of-
way of the cable route or the premises needed to house
transmission equipment is owned by a third party, such
as a railroad or even a competitor. Moreover, single-
Achieving Bandwidth mode fiber is currently in short supply owing to produc-
Capacity Goals tion limitations, potentially adding to costs and delays.
For these reasons, the comprehensive deployment of
additional fiber is an impractical, if not impossible,
Confronted by the need for more capacity, carriers solution for many carriers.
have three possible solutions:
• Install new fiber. Higher Speed TDM — Deploying
• Invest in new TDM technology to achieve faster STM-64/OC-192 (10 Gb/s)
bit rates. As indicated earlier, STM–64/OC–192 is becoming
• Deploy Dense Wavelength Division Multiplexing. an option for carriers seeking higher capacity, but there
are significant issues surrounding this solution that may
restrict its applicability. The vast majority of the existing
fiber plant is single-mode fiber (SMF) that has high
dispersion in the 1550 nm window, making
Current
Bandwidth
Demand Fiber
STM–64/OC–192 transmission difficult. In fact, disper-
Capacity
sion has a 16 times greater effect with STM–64/OC–192
equipment than with STM–16/OC–48. As a result, effec-
tive STM–64/OC–192 transmission requires either some
Time form of dispersion compensating fiber or entire new fiber
builds using non-zero dispersion shifted fiber (NZDSF)—
which costs some 50 percent more than SMF. The greater
carrier transmission power associated with the higher bit
Installing New Fiber to Meet Capacity Needs
rates also introduces nonlinear optical effects that cause
For years, carriers have expanded their networks by degraded wave form quality.
deploying new fiber and transmission equipment. For The effects of Polarization Mode Dispersion
each new fiber deployed, the carrier could add capacity (PMD)—which, like other forms of dispersion affects the
up to 2.4 Gb/s. Unfortunately, such deployment is distance a light pulse can travel without signal degrada-
frequently difficult and always costly. The average cost tion—is of particular concern for STM-64/OC–192.
to deploy the additional fiber cable, excluding costs of This problem, barely noticed until recently, has become
6 • Dense Wavelength Division Multiplexing Technology Guide • 7
6. Ciena.Final 6/3/97 5:56 PM Page 8
significant because as transmission speeds increase, Evolution of WDM
dispersion problems grow exponentially thereby dramat-
16+ Channels
ically reducing the distance a signal can travel. PMD 0.8 nm spacing
appears to limit the reliable reach of STM–64/OC–192 Dense WDM, integrated systems
with network management,
to about 70 kms on most embedded fiber. Although 1996 add-drop functions.
there is a vigorous and ongoing debate within the 2–4 Channels
industry over the extent of PMD problems, some key Early 3–5 nm spacing
Passive WDM components/parts
1990s
issues are already known.
2 Channels
• PMD is particularly acute in the conventional single- 1980s Wideband WDM
1310, 1550
mode fiber that comprises the vast majority of the
existing fiber plant, as well as in aerial fiber.
• Unlike other forms of dispersion that are fairly
predictable and easy to measure, PMD varies
significantly from cable to cable. Moreover, PMD
is affected by environmental conditions, making it Dense Wavelength
difficult to determine ways to offset its effect on
high bit rate systems.
Division Multiplexing
• As a result, carriers must test nearly every span of
DWDM technology utilizes a composite optical
fiber for its compatibility with STM–64/OC–192;
signal carrying multiple information streams, each
in many cases, PMD will rule out its deployment
transmitted on a distinct optical wavelength. Although
altogether.
wavelength division multiplexing has been a known
technology for several years, its early application was
restricted to providing two widely separated
A Third Approach – DWDM
“wideband” wavelengths, or to manufacturing compo-
Dense Wavelength Division Multiplexing (DWDM) is nents that separated up to four channels. Only recently
a technology that allows multiple information streams to has the technology evolved to the point that parallel
be transmitted simultaneously over a single fiber at data wavelengths can be densely packed and integrated into
rates as high as the fiber plant will allow (e.g. 2.4 Gb/s). a transmission system, with multiple, simultaneous,
The DWDM approach multiplies the simple 2.4 Gb/s extremely high frequency signals in the 192 to 200 tera-
system by up to 16 times, giving an immense and imme- hertz (THz) range. By conforming to the ITU channel
diate increase in capacity—using embedded fiber! A
plan, such a system ensures interoperability with other
sixteen channel system (which is available today) supports
equipment and allows service providers to be well posi-
40 Gb/s in each direction over a fiber pair, while a 40
tioned to deploy optical solutions throughout their
channel system under development will support 100
networks. The 16 channel system in essence provides a
Gb/s, the equivalent of ten STM–64/OC–192 transmit-
virtual 16–fiber cable, with each frequency channel
ters! The benefits of DWDM over the first two options—
serving as a unique STM–16/OC–48 carrier.
adding fiber plant or deploying STM–64/OC–192—for
increasing capacity are clear.
8 • Dense Wavelength Division Multiplexing Technology Guide • 9
7. Ciena.Final 6/3/97 5:57 PM Page 10
Transmitter Receiver
1 Transmission 1
Transmitter Receiver
Demultiplexer
2 2
Multiplexer
Transmitter Receiver
3 3
Transmitter Receiver
n n
600 KM
Demultiplexers
To transmit 40 Gb/s over 600 kms using a
traditional system would require 16 separate With signals as precise and as dense as those used
fiber pairs with regenerators placed every 35 in DWDM, there needed to be a way to provide accu-
kms for a total of 272 regenerators. rate signal separation, or filtration, on the optical
A 16 channel DWDM system, on the other receiver. Such a solution also needed to be easy to
hand, uses a single fiber pair and 4 amplifiers implement and essentially maintenance free. Early
positioned every 120 kms for a total of 600 kms. filtering technology was either too imprecise for
DWDM, too sensitive to temperature variations and
polarization, too vulnerable to crosstalk from
neighboring channels, or too costly. This restricted the
evolution of DWDM. To meet the requirements for
16 channel WDM multiplexers higher performance, a more robust filtering technology
was developed that makes DWDM possible on a cost
effective basis: the in–fiber Bragg grating.
The new filter component, called a fiber grating,
The most common form of DWDM uses a fiber consists of a length of optical fiber wherein the refrac-
pair—one for transmission and one for reception. tive index of the core has been permanently modified
Systems do exist in which a single fiber is used for bi- in a periodic fashion, generally by exposure to an ultra-
directional traffic, but these configurations must sacri- violet interference pattern. The result is a component
fice some fiber capacity by setting aside a guard band to which acts as a wavelength dependent reflector and is
prevent channel mixing; they also degrade amplifier useful for precise wavelength separation. In other
performance. In addition, there is a greater risk that words, the fiber grating creates a highly selective,
reflections occurring during maintenance or repair narrow bandwidth filter that functions somewhat like a
could damage the amplifiers. In any event, the mirror and provides significantly greater wavelength
availability of mature supporting technologies, like selectivity than any other optical technology. The filter
precise demultiplexers and Erbium Doped Fiber wavelength can be controlled during fabrication
Amplifiers (EDFA), has enabled DWDM with eight, through simple geometric considerations which enable
sixteen, or even higher channel counts to be commer- reproducible accuracy. Because this is a passive device,
cially delivered. fabricated into glass fiber, it is robust and durable.
10 • Dense Wavelength Division Multiplexing Technology Guide • 11
8. Ciena.Final 6/3/97 5:57 PM Page 12
Fiber Circuits at Location A Fiber Circuits at Location C
Erbium Doped Fiber Amplifier
Network
Optical Amplifier Management
Unit
Amplified Line Add Drop Line
Amplified 1 1
Spontaneous Amplifier Multiplexer Amplifier
Demultiplexer
channel uits
Spontaneous
Multiplexer
Emissions • •
Emissions • •
• •
16 16
1550 nm band Erbium doped fiber W-E-E-W
signal input Terminal Terminal
pump signal
pump signal input output
Spectrum of a typical EDFA Fiber Circuits Dropped
-20 and Added to Location B
-30
-40
4,000 GHz
-50
-60
-70
Parlaying New Technologies
1500 1520 1540 1560 1580 1600
wavelength into a DWDM System
The fiber Bragg grating and the EDFA represented
The advent of the Erbium Doped Fiber Amplifier
significant technological breakthroughs in their own
(EDFA) enabled commercial development of DWDM
right, but the bandwidth potential associated with these
systems by providing a way to amplify all the
innovations could only be realized by their incorporation
wavelengths at the same time. This optical amplification
into integrated DWDM transport systems for optical
is done by incorporating Erbium ions into the core of a
networks. Without such a development the fiber grating
special fiber in a process known as doping. Optical pump
would retain component status similar to other passive
lasers are then used to transfer high levels of energy to
WDM devices, while the power potential of EDFAs
the special fiber, energizing the Eribum ions which then
would remain underutilized. The ability to harness the
boost the optical signals that are passing through.
potential of these technologies, however, is realizable
Significantly, the atomic structure of Erbium provides
today through commercially available, integrated,
amplification to the broad spectral range required for
DWDM systems. Such a system is attained through the
densely packed wavelengths operating in the 1550–nm
use of Optical Add–Drop Multiplexers (OADM) and
region, optically boosting the DWDM signals. Instead of
sophisticated network management tools.
multiple electronic regenerators, which required that the
optical signals be converted to electrical signals then back Add/Drop Configuration
again to optical ones, the EDFA directly amplifies the
Express
optical signals. Hence the composite optical signals can Traffic
travel up to 600 kms without regeneration and up to 120
Terminal
Terminal
kms between amplifiers in a commercially available, OADM
terrestrial, DWDM system.
Local Traffic Local Traffic
12 • Dense Wavelength Division Multiplexing Technology Guide • 13
9. Ciena.Final 6/3/97 5:57 PM Page 14
Optical Add–Drop Multiplexers Telecommunications Management Network (TMN).
Current systems utilize an optical service channel that is
The OADM based on DWDM technology is moving
independent of the working channels of the DWDM
the telecommunications industry significantly closer to the
product to create a standards–based data communications
development of optical networks. The OADM can be
network that allows service providers to remotely monitor
placed between two end terminals along any route and be
and control system performance and use. This network
substituted for an optical amplifier. Commercially avail-
manager communicates with each node in the system and
able OADMs allow carriers to drop and/or add up to
also provides dual homing access and self–healing routing
four STM–16/OC–48 channels between DWDM termi-
information in the event of a network disruption. By
nals. The OADM has “express channels” that allow
meeting ITU standards and utilizing a Q3 interface, the
certain wavelengths to pass through the node
system ensures that end users retain high Operations,
uninterrupted, as well as broadcast capabilities that enable
Administration, Maintenance, and Provisioning (OAM&P)
information on up to four channels to be dropped and
service.
simultaneously continue as “express channels.” By
deploying an OADM instead of an optical amplifier, Network Management
Layered Architecture
service providers can gain flexibility to distribute
EML • Element Management Layer
revenue–generating traffic and reduce costs associated – Standards based, GUI, Unix
– Equipment & Service MO Views
with deploying end terminals at low traffic areas along a DCN • DCN
route. The OADM is especially well-suited for meshed or – IP/Internet protocol based
– Self healing service channel
branched network configurations, as well as for ring archi- Agent
• Agent Layer
Backplane Protocol – Menu based craft interface
tectures used to enhance survivability. Such flexibility is – Protocol independent
less achievable with current STM64/OC–192 offerings. • Backplane
Instrumentation – Redundant NE M&C bus
• Instrumentation
– Intelligent plug-in modules
Network Management Measurements of Performance
A critical yet often under appreciated part of any There are several aspects that make the design of
telecommunications network is the management system— DWDM systems unique. A spectrum of DWDM chan-
whose reliability is especially vital in the complex and high nels may begin to accumulate tilt and ripple effects as
capacity world of DWDM. Indeed, dependable and the signals propagate along a chain of amplifiers.
easily accessible network management services increas- Furthermore, each amplifier introduces amplified spon-
ingly will become a distinguishing characteristic of high- taneous emissions (ASE) into the system, which cause a
performance, high-capacity systems. Today’s leading decrease in the signal to noise ratio, leading to signal
DWDM systems include integrated, network manage- degradation. Upon photodetection, some other features
ment programs that are designed to work in conjunction of optically amplified systems come into play. The Bit
with other operations support systems (OSSs) and are Error Rate (BER) is determined differently in an opti-
compliant with the standards the International cally amplified system than in a conventional regener-
Telecommunication Union (ITU) has established for ated one. The probability of error in the latter is domi-
14 • Dense Wavelength Division Multiplexing Technology Guide • 15
10. Ciena.Final 6/3/97 5:57 PM Page 16
nated by the amount of receiver noise. In a properly Fiber Non Linearities
designed optically amplified system, the probability of
In addition to ASE accumulation and dispersion, there are
error in the reception of a binary value of one is deter- several types of fiber nonlinearities that can further limit the perfor-
mined by the signal mixing with the ASE, while the mance of any fiber optic transmission system—including those that use
DWDM. These nonlinearities fall into two broad groups: scattering and
probability of error in the reception of a binary value refractive index phenomena.
of zero is determined by the ASE noise value alone. Scattering Phenomena
One subtype of this phenomena is known as Stimulated Brillouin
Scattering (SBS), which is caused by the interaction between the optical
Optical SNR and Transmitted Power signal and acoustic waves in the fiber. The result is that power from the
optical signal can be scattered back towards the transmitter. SBS is a
Requirements of DWDM Systems narrowband process that affects each channel in a DWDM system
individually, but which is even more pronounced in STM–64/OC–192
Ultimately, the BER performance of a DWDM systems, due to the greater power levels required for their transmission.
channel is determined by the optical SNR that is deliv- A second form of scattering is known as Stimulated Raman
ered to the photodetector. In a typical commercial Scattering (SRS), which is prompted by the interaction of the optical
signal with silica molecules in the fiber. This interaction can lead to the
system, an optical SNR of approximately 20 dB, transfer of power from shorter wavelength, higher photon energy chan-
measured in a 0.1 nm bandwidth, is required for an nels, to longer wavelength, lower photon energy channels. Unlike SBS,
SRS is a wideband phenomena that affects the entire optical spectrum
acceptably low BER of 10–15. This acceptable SNR is that is being transmitted. SRS can actually cause a spectrum of equal
delivered through a relatively sophisticated analysis of amplitude channels to tilt as it moves through the fiber. Moreover, its
impact worsens as power is increased and as the total width of the
signal strength per channel, amplifier distances, and DWDM spectrum widens. One way to combat this phenomena is to use
moderate channel powers as well as a densely packed channel plan that
the frequency spacing between channels. minimizes the overall width of the spectrum.
For a specific SNR at the receiver, the amount of Refractive Index Phenomena
transmit power required in each channel is linearly propor- This group of nonlinearities includes self-phase modulation
tional to the number of amplifiers as well as the noise and (SPM), cross-phase modulation (CPM), and four-wave mixing (FWM).
These are caused because the index of refraction, and hence the speed
SNR of each amplifier, and is exponentially proportional to of propagation in a fiber, is dependent on the intensity of light—a
the loss between amplifiers. Because total transmit power is dependency that can have particularly significant effects in long–haul
applications. SPM, which refers to the modulation that a light pulse has
constrained by present laser technology and fiber nonlin- on its own phase, acts on each DWDM channel independently. The
earities, the workable key factor is amplifier spacing. This is phenomena causes the signal’s spectrum to widen and can lead to
crosstalk or an unexpected dispersion penalty. By contrast, CPM is due
illustrated in the accompanying graph by showing the rela- to intensity fluctuations in another channel and is an effect that is
tionship for a fiber plant with a loss of .3 dB/km, a receiver unique to DWDM systems. Finally, four-wave mixing refers to the
nonlinear combination of two or more optical signals in such a way
with a .1nm optical bandwidth, and optical amplifiers with that they produce new optical frequencies. Although four-wave mixing
a 5 dB noise figure. The system illustrated is expected to is generally not a concern in conventional single-mode fiber, it can be
particularly troublesome in the dispersion shifted fiber that is used to
cover 600 kms and the optical SNR required at the receiver propagate STM64/OC192. As a result, carriers that opt for
is 20 dB measured in the 0.1 nm bandwidth. STM–64/OC–192 equipment to relieve today’s congestion may unin-
tentionally be limiting their ability to grow their capacity through future
600 Km total length, .3 dB/km loss, .1 nm bandwith, 20 dB SNR
deployment of DWDM.
30
25
All three types of refractive index phenomena can be controlled
20 either through careful choice of channel power or increases in channel
15
10
spacing.2
Power
in dBm 5
0
-5
-10
-15 2 See—Transmission of Many WDM Channels Through a Cascade of EDFAs in Long
-20
10 100 1000
distance Links and Ring Networks—Alan Willner and Syang Myau Hwang IEEE
0733–872/95 Journal of Lightwave Technology
Amplifier Spacing (Kms)
16 • Dense Wavelength Division Multiplexing Technology Guide • 17
11. Ciena.Final 6/3/97 5:57 PM Page 18
Applications for DWDM SONET RINGS
As occurs with many new technologies, the poten-
tial ways in which DWDM can be used are only begin-
ning to be explored. Already, however, the technology
has proven to be particularly well suited for several
vital applications.
• DWDM is ready made for long-distance telecom-
munications operators that use either
point–to–point or ring topologies. The sudden
availability of 16 new transmission channels where
there used to be one dramatically improves an
operator’s ability to expand capacity and simulta-
neously set aside backup bandwidth without
installing new fiber.
• This large amount of capacity is critical to the
development of self-healing rings, which charac-
terize today’s most sophisticated telecom networks.
By deploying DWDM terminals, an operator can
construct a 100% protected, 40 Gb/s ring, with
16 separate communication signals using only two
fibers.
• Operators that are building or expanding their
networks will also find DWDM to be an econom-
ical way to incrementally increase capacity, rapidly
provision new equipment for needed expansion,
• The transparency of DWDM systems to various
and future–proof their infrastructure against
bit rates and protocols will also allow carriers to
unforeseen bandwidth demands.
tailor and segregate services to various customers
• Network wholesalers can take advantage of along the same transmission routes. DWDM
DWDM to lease capacity, rather than entire fibers, allows a carrier to provide STM–4/OC–12
either to existing operators or to new market service to one customer and STM–16/OC–48
entrants. DWDM will be especially attractive to service to another all on a shared ring!
companies that have low fiber count cables that
• In regions with a fast growing industrial base
were installed primarily for internal operations but
DWDM is also one way to utilize the existing thin
that could now be used to generate telecommuni-
fiber plant to quickly meet burgeoning demand.
cations revenue.
18 • Dense Wavelength Division Multiplexing Technology Guide • 19
12. Ciena.Final 6/3/97 5:57 PM Page 20
The Future of DWDM— • For example, DWDM systems with open
interfaces give operators the flexibility to provide
Building Block of the SONET/SDH, asynchronous/PDH, ATM,
Photonic Network Frame Relay, and other protocols over the same
fiber. Open systems also eliminate the need for
additional high-performance optical transmitters
DWDM is already established as the preferred to be added to a network when the need arises to
architecture for relieving the bandwidth crunch many interface with specific protocols. Rather, open
carriers face. Several US carriers have settled on systems allow service providers to quickly adapt
DWDM at STM–16/OC–48 rates as their technology new technologies to the optical network through
of choice for gaining more capacity. With 16 channel the use of “off-the-shelf,” relatively inexpensive,
DWDM now being deployed throughout the carrier and readily available transmitters.
infrastructure, and with a 40 channel system coming,
DWDM will continue to be an essential element of • In contrast to DWDM equipment based on propri-
future interoffice fiber systems. Indeed, deployment of etary specifications, systems with open interfaces
DWDM is a critical first step toward the establishment provide operators greater freedom to provision
of photonic networks in the access, interoffice, and services and reduce long-term costs. Proprietary
interexchange segments of today’s telecommunication based systems, in which SONET/SDH equipment
infrastructure. is integrated into the optical multiplexer/demulti-
plexer unit, are adequate for straight point–to–point
The Photonic Network configurations. Nevertheless, they require additional
and costly transmission equipment when deployed
Channels
1
2
3
in meshed networks.
RING TOPOLOGY Terminals 4
5
6
7
8
for Protection 9
10
11
12
13
14
15
16
ATM
= Regenerators
OC-3 ASYNCH/PDH
OC-12 SONET/SDH
Proprietary
OC-48 Optical Optical DIG VIDEO Systems
PC-48 Amplifier Amplifier
Terminals
Optical Add/Drop
Multiplexer
Given the rapidly changing and unpredictable
nature of the telecommunications industry, it is impera-
tive that today’s DWDM systems have the ability to
Open
Terminal
Terminal
adapt to future technological deployments and network System
configurations. DWDM systems with an open architec-
ture provide such adaptability and prepare service
providers to take full advantage of the emerging Terminal
photonic network.
20 • Dense Wavelength Division Multiplexing Technology Guide • 21
13. Ciena.Final 6/3/97 5:57 PM Page 22
• Finally, DWDM systems that comply with the 1. Compatibility with Fiber Plant.
ITU channel plan will reassure carriers that they The majority of the legacy fiber plant cannot
are deploying technology with recognized industry support high bit rate TDM. Earlier vintage fiber
standards and the flexibility needed to grow their has some attributes that lead to significant disper-
optical networks into long distance, local sion and would, therefore, be incompatible with
exchange, and eventually access networks. high bit rate TDM. Recently produced fiber—
NZDSF, for example—is flexible enough for the
In the space of two years, DWDM has become latest TDM equipment, but it is expensive and
recognized as an industry standard that will find accep- may limit the ability of carriers to migrate to the
tance in any carrier environment. Deployment of greater bandwidth available through DWDM at
DWDM will allow new services to come on-line more STM–16/OC–48 rates.
quickly, help contain costs so that prospective customers 2. Transparency and Interoperability.
can more easily afford new services, and readily over- The chosen solution must provide interoperability
come technological barriers associated with more tradi- between all vendors’ transmission equipment,
tional solutions. Its acceptance will drive the expansion both existing and new. It must be vendor
of the optical layer throughout the telecommunications independent and conform to international stan-
network and allow service operators to exploit the enor- dards such as the proposed ITU channel spacing
mous bandwidth capacity that is inherent in optical and be based on the Open Systems
fiber but that has gone largely untapped—until now. Interconnection (OSI) model. Furthermore, it
must be capable of supporting mixed protocols
and signal formats. Some commercially available
DWDM systems provide such transparency and
ANNEX: Practical can be used with any SONET/SDH bit rates, as
Considerations of well as with asynchronous/PDH protocols.
DWDM Deployment 3. Migration and Provisioning Strategy.
The best solution must also offer the ability to
expand. It must be capable of supporting
Based on bit rate alone, DWDM has a fourfold
differing bit rates and have channel upgrade
advantage even over the latest—albeit nascent—TDM
capability. It has to be a long-term solution and
option, STM–64/OC–192. To fairly compare the two
not just a short-term fix. TDM systems already
technologies, however, we need to review and outline
are reaching their technological barriers and
what would be an ideal technological solution for
STM–64/OC–192, although rich in capacity,
expanding network capacity. This has to be done in a
may represent a practical limit that could only be
broad sense, recognizing that there are instances in
superseded by DWDM.
which TDM may offer a better solution than DWDM.
Analyzing the alternative attributes and benefits of 4. Network Management. A properly engineered
each approach would require a comparison of several solution should also support a comprehensive
key issues: network element management system. The solu-
22 • Dense Wavelength Division Multiplexing Technology Guide • 23
14. Ciena.Final 6/3/97 5:57 PM Page 24
tion must meet international standards, interface
with the carrier’s existing operating system, and
CASE STUDY:
provide direct connection for all of the network How CIENA Corporation
elements for performance monitoring, fault iden-
tification and isolation, and remedial action.
Teamed With Sprint to Break
Sophisticated and reliable network management the Fiber Bandwidth Barrier
programs will become increasingly important to
deal with the increased complexity and expanded “We knew we had the best kind of business
capacity that will be unleashed through migration problem,” said Douglas McKinley, Director of Network
to optical networks. Planning for Sprint, the global communications
5. Technical Constraints. The systems deployed company. “In early 1995, we forecast unprecedented
must be able to resolve some of the outstanding growth in the Sprint network. We had huge customers
technical issues present in current lightwave trans- all coming to us asking Sprint to carry their long
mission systems. For example, signal dispersion distance traffic. Along with all of our other customers,
compensation, filtering and channel cross talk, they wanted everything - voice, video, data - and they
nonlinear four-wave mixing, and physical equip- wanted it fast. How were we going to give them the
ment density are some of the more common prob- capacity they needed?”
lems. Ideally, an optimized system level architec- For Sprint, the challenge was to provide customers
ture that provides a coherent and unified with desperately needed bandwidth in a timely and reli-
approach should be chosen over one that involves able manner. The solution also needed to be cost effec-
the acquisition and deployment of components on tive. And, one of the most important requirements was
a piecemeal and uncoordinated basis. that the expanded network capacity had to take advan-
tage of the facilities Sprint already had in place.
Sprint had built the United States’ only nationwide
all-digital, fiber optic network that served more than 15
million businesses and residential customers. A leader
in the industry, Sprint was the country’s first major
provider of long distance, local, and wireless services.
In addition, Sprint is the world’s largest carrier of
Internet traffic.
The explosive growth of Internet-related applica-
tions coupled with the surge in all types of network
traffic made 1995 a watershed year for the company. In
addition, the passage of the Telecommunications Act of
1996 unleashed a torrent of activity in the telecommu-
nications marketplace with many of the new long
distance companies leasing facilities from Sprint.
24 • Dense Wavelength Division Multiplexing Case Study • 25
15. Ciena.Final 6/3/97 5:57 PM Page 26
Ideally, the bandwidth capacity expansion solution In short, the CIENA MultiWave 1600 builds on
Sprint sought would also complement the carrier’s existing fiber optic technology and increases its
complete commitment to a SONET fiber network. In efficiency dramatically. By expanding the transmission
1993, Sprint committed to a Synchronous Optical capability of fiber already installed, Sprint can meet
Network (SONET) technology, and the company is and exceed its customers’ current requirements, as well
now the only long-distance carrier with a four-fiber, bi- as the anticipated delivery of new interactive
directional, line-switching ring topology (four-fiber, multimedia services.
BLSR) installed from coast-to-coast and from border- Fiber optics transmit data as pulses of light moving
to-border. The four-fiber BLSR allows customers on at 124,000 miles per second. More than 2.5 billion bits
Sprint’s SONET network to survive network outages of information per second can be carried over long-
and fiber cuts in milliseconds. The company anticipates distance fiber. To keep the pulses from fading, fiber-
that the majority of its customers will be on the optic cables use amplifiers and regenerators to recharge
SONET network by the end of 1997. the power of the light approximately every 60 miles.
“We started looking for the solution at the concep- “Traditionally, we could carry about 32 thousand
tual stage,” recalled Bill Szeto, Manager of Engineering transmissions in a fiber at one time,” explains Szeto.
for Sprint. “We needed the best companies in the busi- “With CIENA’s MultiWave 1600 system we can carry
ness to focus their resources on this capacity problem so 16 times this. All at once, we essentially expanded from
we called in a few well-known manufacturers along our 32 thousand capacity to a capability of carrying
with CIENA Corporation, a relatively new company in 512 thousand calls at the same time.
Maryland which we knew was developing high-capacity “Efficiency is also a factor,” he continued. “When
fiber optic transmission systems. you used fiber without DWDM for high-bandwidth
“Teaming with CIENA was just the right thing to applications, you had to use more fiber. If we can use
do. Starting with just the concept, the solution took less fewer fibers, we can increase capacity for new services
than a year to complete. It was unheard of in the using our existing fiber base. And, that can translate into
industry, considering the complexity of the problem to cost savings for customers.” Economies of scale are also
have this happen in such a short time frame. One of apparent to Sprint with the technology offering 16 times
the reasons it was able to happen this way is because the capacity at a fraction of the cost, according to Szeto.
CIENA is knowledgeable. And, working right along The CIENA MultiWave product is a high-capacity,
with Sprint’s technical people, there was synergy to optical transmission system which enables aggregate
work efficiently, closely, and effectively.” transmission capacities up to 40 Gigabits per second
The solution that CIENA developed, called the (40 Gb/s) over existing fiber facilities. Sixteen discrete
CIENA MultiWave™ 1600 system, far exceeded the channels can transmit over one fiber. Each channel is
parameters required. The 16 window, dense wavelength bit-rate transparent from 150 Mb/s to 2.4 Gb/s and
division multiplexing (DWDM) technology allows Sprint operates with existing SONET/SDH/Asynchronous
to increase the capacity of its fiber network by a factor of fiber optic terminals.
16 without installing more fiber optic cable. In essence, it This available capacity per fiber allows Sprint’s
gives Sprint 16 virtual fibers where it once had one. The network designers to fine tune each network span
system meets the need for more bandwidth and provides according to the customer’s or Sprint’s own internal
Sprint with more capability in its installed plant. requirements.
26 • Dense Wavelength Division Multiplexing Case Study • 27
16. Ciena.Final 6/3/97 5:57 PM Page 28
The system also incorporates optical line ampli- to incrementally expand the transmission capacity of
fiers to extend the transmission range. Designed specifi- our network as we deliver new broadband services to
cally for DWDM, the amplifier is capable of our customers,”
amplifying the system’s entire 16 channel, 40 Gb/s And, demand for more capacity to deliver those
capacity. Two optical service channel modems enable services isn’t going away soon. “Nineteen months ago
access to local network management data and all the analysts were saying they thought four - and eight -
elements of the MultiWave system. channel WDM would be enough for the foreseeable
In addition, CIENA’s MultiWave system for Sprint future,” noted Steve Chaddick, senior vice president of
is equipped with an integrated network management products and technologies at CIENA. “The foreseeable
system that includes an optical service channel with a future turned out to be about three months.”
2.048 Mb/s capacity, that supports the Data
Communications Network (DCN). The DCN commu- “The CIENA solution protects our existing
nicates system management information throughout investment and allows us to incrementally
the Sprint network and enables vital remote access to expand the transmission capacity of our
performance monitoring and control, as well as network...” Marty Kaplan, Senior Vice President
multiple simultaneous craft interface access. Self- and Chief Technology Officer, Sprint
healing information routing in the event of network
disruption and dual homing access is also included.
Embedded throughout the system is instrumenta-
tion that observes, measures, and records the status and
operation of every module. Distributed system intelli-
gence analyzes, processes, and stores the data gleaned
from the instrumentation. On an element-by-element
basis, performance and fault information data can be
accessed and manipulated by Sprint network
managers.
Sprint is deploying CIENA’s MultiWave 1600 on
selected routes throughout its network. In fact, DWDM
is pervasive throughout the Sprint network, especially
in high traffic areas.
“CIENA was given a business problem and we
gave them only a short time to solve it. By working
closely with us, CIENA has helped Sprint maintain its
technology leadership in the telecommunications
industry,” McKinley commented.
Marty Kaplan, senior vice president and chief
technology officer for Sprint, added, “The CIENA
solution protects our existing investment and allows us
28 • Dense Wavelength Division Multiplexing Case Study • 29
17. Ciena.Final 6/3/97 5:57 PM Page 30
Glossary data. (2) A binary digit, either a zero or one. The
smallest element of a computer program. In the U.S.,
eight bits make up one byte.
Add-Drop (OADM)—Optionally allows up to four Bit Error Rate (BER)—Percentage of bits in a trans-
optical wavelengths to be added or dropped at any line mittal received in error. (2) The number of coding viola-
amplifier location. tions detected in a unit of time, usually one second.
Add/Drop Multiplexer (ADM)—A multiplexer Bits Per Second (bps)—(1) The number of bits
capable of extracting or inserting lower-rate signals passing a point every second. The transmission rate for
from a higher-rate multiplexed signal without digital information. (2) A measurement of how fast data
completely demultiplexing the signal. are moved from one place to another. (Example: a 28.8
American National Standards Institute modem can move 28,800 bps.)
(ANSI)—The coordinating body for voluntary Broadband—A data-transmission scheme in which
standards groups within the United States. ANSI is a multiple signals share the bandwidth of a medium. This
member of the International Organization for allows the transmission of voice, data, and video signals
Standardization (ISO). over a single medium. Cable television uses broadband
Backbone—(1) The part of a network used as the techniques to deliver dozens of channels over one cable.
primary path for transporting traffic between network Capacity—The information carrying ability of a
segments. (2) A high-speed line or series of connections telecommunications facility. What the “facility” is deter-
that forms a major pathway within a network. mines the measurement. You might measure a line’s
Bandwidth—(1) Measure of the information capacity capacity in bits per second. You might measure a
of a transmission channel. (2) The difference between switch’s capacity in the maximum number of calls it
the highest and lowest frequencies of a band that can can switch in one hour, or the maximum number of
be passed by a transmission medium without undue calls it can keep in conversation simultaneously.
distortion, such as the AM band - 535 to 1705 Carrier—A company which provides communications
kilohertz. (3) Information carrying capacity of a circuits. Carriers are split into “private” and
communication channel. Analog bandwidth is the “common.” A private carrier can refuse you service. A
range of signal frequencies that can be transmitted by a “common” carrier cannot. Most of the carriers in our
communication channel or network. (4) A term used to industry—your local phone company, AT&T, MCI US,
indicate the amount of transmission or processing Sprint, etc.—are common carriers. Common carriers
capacity possessed by a system or a specific location in a are regulated. Private carriers are not.
system (usually a network system).
Channel—(1) A communication path. Multiple chan-
Bandwidth On Demand Interoperability Group nels can be multiplexed over a single cable in certain
(BONDING)—Makers of inverse muxes. environments. The term is also used to describe the
Bit—(1) The smallest unit of information in the binary specific path between large computers and attached
system of notation. (2) One binary digit; a pulse of peripherals. (2) An electrical or photonic, in the case of
fiber optic-based transmission systems, communications
30 • Dense Wavelength Division Multiplexing Glossary • 31
18. Ciena.Final 6/3/97 5:57 PM Page 32
path between two or more points of termination. ingly simple, is that they are not frequency dependent,
(3) The smallest subdivision of a circuit that provides a and therefore allow bandwidth upgrades (within limits)
type of communication service; usually a path with without replacing the entire transmission systems.
only one direction. Undersea transmission systems, such as Americas 1,
TAT-12/13, and TCP-5 use EDFA technology.
CIENA MultiWave™ 1600—A dense wavelength
division multiplexing (DWDM) system that is capable Fiber In the Loop (FITL)—Optical technology
of transmitting up to sixteen (16) discrete optical chan- from CO to customer premises.
nels over one fiber pair. Each channel is bit-rate trans-
Fiber Optical Bragg Grating—An optical fiber
parent from 150 Mb/s to 2.4 Gb/s and operates with
grating is an optical fiber component consisting of a
existing SONET/SDH/Asynch fiber optic terminals.
length of optical fiber wherein the refractive index of
This system incorporates optical line amplifiers to
the core has been permanently modified in a periodic
extend the transmission range, and it offers integrated
fashion, generally by exposure to an optical interfer-
network management facilities.
ence pattern as generated by an ultraviolet laser.
Deregulation—The removal of regulatory authority
Fiber Optic Cable—A transmission medium that
to control certain activities of telephone companies. An
uses glass or plastic fibers, rather than copper wire, to
attempt by federal authorities to make the telephone
transport data or voice signals. The signal is imposed
industry more competitive. Deregulation is meant to
on the fiber via pulses (modulation) of light from a
benefit the consumer.
laser or a light-emitting diode (LED). Because of its
Erbium Doped Fiber Amplifier (EDFA)— high bandwidth and lack of susceptibility to interfer-
Erbium Doped Fiber Amplifiers have become the ence, fiber-optic cable is used in long-haul or noisy
dominant method for signal amplification in long-haul applications.
lightwave transmission systems. EDFAs differ from the
Fiber Optics—A method for the transmission of
normal method of regenerative or electro-optic
information (sound, pictures, data). Light is modulated
repeaters in that light does not have to be converted to
and transmitted over high purity, hair-thin fibers of
an electrical signal, amplified, and then converted back
glass. The bandwidth capacity of fiber optic cable is
to light. Optical amplifiers contain a length of fiber
much greater than that of conventional cable or
that is doped with erbium doped (a rare earth
copper wire.
substance) that provides the gain medium, an energy
source or “pump” from a laser source at the correct Fiber Plant—Arial or buried fiber optic cable that
frequency, and a coupler to couple the pump laser to established connectivity between fiber optic transmis-
the doped fiber. Both the signal to be amplified and the sion equipment locations.
pump energy are coupled into the doped fiber section Frequency—(1) Measures the number of electromag-
of the transmission system. The pump laser puts the netic waves that pass a given point in a given time
erbium-doped fiber into an excited state where it is period. It is equal to the speed of light, divided by
able to provide optical gain through emission wavelengths and is expressed in cycles per second or
stimulated by a passing signal photon. One of the most hertz. (2) The number of cycles of periodic activity
important features, after the fact that EDFAs are amaz- that occur in a discrete amount of time.
32 • Dense Wavelength Division Multiplexing Glossary • 33
19. Ciena.Final 6/3/97 5:57 PM Page 34
Gigabits Per Second (Gb/s)—Billion bits per Multimode—Used to describe optical fiber that
second. A measure of transmission speed. allows more than one mode of light signal transmission.
Multimode fibers are generally used for short-distance
Infrastructure—The basic facilities, services, and
links.
installations needed for the functioning of a commu-
nity or society such as transportation and communica- Multimode Fiber—Optical fiber supporting propa-
tions systems. gation of multiple modes of light.
Interexchange Carrier (IXC) or Interexchange Multiplexer (MUX)—Equipment that enables
Common Carrier—(1) Any individual, partnership, several data streams to be sent over a single physical
association, joint-stock company, trust, governmental line. It is also a function by which one connection from
entity, or corporation engaged for hire in interstate or an (ISO) layer is used to support more than one
foreign communication by wire or radio, between two connection to the next higher layer. (2) A device for
or more exchanges. (2) A long-distance telephone combining several channels to be carried by one line or
company offering circuit-switched, leased-line or fiber.
packet-switched service or some combination.
Multiplexing—In data transmission, a function that
Interoperability Technology Association for permits two or more data sources to share a common
Information Processing (INTAP)—The technical transmission medium such that each data source has its
organization which has the official charter to develop own channel.
Japanese OSI profiles and conformance tests.
Network Element (NE)—Any device which is part of
ITU—International Telecommunications Union a communications transmission path and serves one or
more of the section, line, or path terminating functions.
Local Exchange Company (LEC)—A telephone
company that provides customer access to the world- Network Management System (NMS)—A system
wide public switched network through one of its responsible for managing at least part of a network.
central offices. NMSs communicate with agents to help keep track of
network statistics, resources, and performance.
Megabit (Mb/s)—One million bits.
OC-192—Optical carrier Level 192. Sonet bit rate of
Megabits Per Second (Mb/s)—A digital transmis-
10 Gb/s.
sion speed of millions of bits per second.
OC-48—Optical carrier Level 48. Sonet bit rate of
Multi-conductor copper cable—Provides trans-
2.4 Gb/s.
mission facilities for VF and digital services up to
1.5MB/s. Upper bit rate growth possible through new Optical Carrier (OC-x)—Fundamental unit used in
technology such as ADSL (Adaptive Digital Subscriber SONET (Synchronous Optical NETwork) hierarchy.
Loop). OC indicates an optical signal and x represents incre-
ments of 51.84 Mbps. OC-1, -3, and -12 equal optical
rates of 51, 155, and 622 Mbps.
34 • Dense Wavelength Division Multiplexing Glossary • 35
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Optical Carrier 1 (OC-1)—ITU-ISS physical stan- Public Switched Network—The combined trans-
dard for optical fiber used in transmission systems mission facilities of the world’s telephone companies
operating at 51.84 Mb/s. and administrations, including all those circuits avail-
able to subscribers on an unrestricted basis.
Optical Carrier 3 (OC-3)—Optical Carrier level 3,
SONET rate of 155.52 Mb/s, matches STS-3. Regenerator—Device that restores a degraded digital
signal for continued transmission; also called a
OSI—Open Systems Interconnection. The only inter-
repeater.
nationally accepted framework of standards for
communication between different systems made by Regional Bell Operating Company (RBOC)—
different vendors. OSI was developed by the (1) One of six telephone companies created after
International Standards Organization (ISO). ISO’s AT&T divestiture. (2) The acronym for the local tele-
major goal is to create an open systems networking phone companies created in 1984 as part of the break-
environment where any vendor’s computer system, up of AT&T. The six RBOCs are Ameritech, Bell
connected to any network, can freely share data with Atlantic, Bell South, NYNEX, Southwestern Bell,
any other computer system on that network or a linked and U.S. West.
network. Most of the dominant communications proto-
Repeater—(1) A device that regenerates and propa-
cols used today have a structure based on the OSI
gates electrical signals between two network segments.
model. The OSI model organizes the communications
(2) Device that restores a degraded digital signal for
process into seven different categories and places the
continued transmission; also called a regenerator.
categories in a layered sequence based on their relation
to other user. Layers seven through four deal with end Ring—Connection of network elements in a circular
to end communications between the message source logical topology.
and the message destination, while layers three through Ring Topology—Topology in which the network
one deal with network access. consists of a series of repeaters, add-drop multiplexers,
Pleisiochronous Digital Hierarchy (PDH)— or terminals. Ring networks are relatively immune to
Asynchronous multiplexing scheme from T1 to T3 and interruption and fiber cuts, because of the multiple
higher; contrast with SDH. transmission paths that are implied in the ring.
Provider—A company that provides an interface Signaling—(1) The process of sending a transmission
between the teleservices platform and an installed tele- signal over a physical medium for purposes of commu-
phone device, such as a telephone line or a fax nication. (2) Method of communication between
machine. network components to provide control management
and performance monitoring.
Public Network—A network operated by common
carriers or telecommunications administrations for the
provision of circuit-switched, packet-switched and
leased-line circuits to the public.
36 • Dense Wavelength Division Multiplexing Glossary • 37