The optical fiber communication conference and exhibition, san diego, ca, 2009. Elastic optical networks using hitless spectrum retuning techniques mingyangzhang, yaweiyin, roberto proietti, zuqingzhu, s. What is flexigrid or elastic optical network eon igi global. V av gos 1 c ompu t er e ng iee and i fmati csd p me,u v ity p, g d research academic computer technology institute, patras, greece. Routing and spectrum allocation in elastic optical networks. Distance adaptive dynamic routing and spectrum allocation. On minimization of the spectrum usage in elastic optical networks with joint unicast and anycast traffic. Routing, spectrum, and transponder assignment rsta in elastic optical networks m. Spectrum assignment in mesh elastic optical networks. This is my favorite book on optical network design and planning. The book explains the fragmentation problem in eons, discusses, and analyzes the major conventional spectrum allocation policies in terms of the fragmentation effect in a network. Spectrum utilization efficiency of elastic optical networks informatica 42 2018 293300 295 while the number of spectrum slots per fiber, s, of elastic optical network is given by. Computing exact and approximate blocking probabilities in.
From static to elastic networks provides a qualitative foundation for what followspresenting an overview. The transceivers can generate elastic optical paths eops. An experimental comparison of routing and spectrum assignment. The major difference between rwa and rsa lies in the slice network architecture as it flexibly adjusts to the format of the modulation. Challenges and requirements of a control plane for elastic optical. Dynamic cooperative spectrum sharing and defragmentation for elastic optical networks. Spectrum defragmentation algorithms for elastic optical. In recent years, ofdm has been the focus of extensive research efforts in optical transmission and networking, initially as a means to overcome physical impairments in optical communications. Schedulinginspired spectrum assignment algorithms for. Pdf an overview of elastic optical networks and its.
Routing and spectrum assignment in spectrum flexible. Comparison in spectrum domain between conventional and elastic optical paths. As introduced in previous chapters, this issue is called spectrum fragmentation. In optical networks, another critical issue for the service provider is the failure of network elements e. The material reflects the authors extensive research and industrial activities and includes contributions from preeminent researchers and practitioners in optical networking. Routing and spectrum assignment rsa is the fundamental problem in elastic optical networks eons, which is an \\mathcaln\mathcalp\complete problem. Planning and algorithms for elastic optical networks eons are presented. The emerging technology of elastic optical network eon has appeared to satisfy bandwidth hungry demands of todays world. Elastic optical network also known as flexgrid optical network let us see what is optical network. These new transceivers are called bandwidth variable transceivers bvts. Explains the importance of elastic optical networks eons and how they can be implemented by the worlds carriers this book discusses elastic optical networks eons from an operational perspective. Jaume comellas abstract performance comparison between elastic optical networks and multirate optical networks, using different spectrum allocation algorithms to prevent fragmentation.
The elastic optical network eon architecture has been proposed in response to the large capacity and diverse traffic granularity needs of the future inte. It rise compensates for the shortcomings of conventional wdm network which are the rigidity of the frequency spectrum and. Elastic optical networks eons have emerged as the preferred technology for future optical networks because of its ability to manage network resources efficiently and provide better spectrum utilization to cope with recent rapid changes in traffic behavior and the tremendous growth in bandwidth demand. These novel networks were introduced in reference and are also known in the literature as networks without a gridded, adaptive, spectrum flexible, elastic optical paths, or simply elastic optical networks eons. Backbone networks are evolving toward elastic optical network eon architecture that allows a flexible and efficient use of spectrum resources. Introduction the flexible optical network constitutes an efficient alternative facing the exponential of traffic. Spectrum management strategies for performance improvement in elastic and multirate optical networks author.
Computers and office automation applied research bridgerouters data communications research fiber optic networks optical communications optical communications technologies radio spectrum usage routers network. Spectrum utilization efficiency of elastic optical networks utilizing coarse granular routing. Elastic optical network eon architecture has been proposed as a promising technology for a new generation of ofdm networks. In this paper, we address the resource provisioning in elastic optical network, by considering. Spectrum defragmentation in elastic optical networks. Routing and spectrum allocation in ofdmbased optical networks with elastic bandwidth allocation 1k. The considered problem covers routing and spectrum allocation problem rsa problem in elastic optical networks while maintaining the spectrum continuity constraints, nonoverlapping spectra. Spectrum continuity awareness for virtual network construction in elastic optical networks badr mochizuki the kyoto college of graduate studies for informatics abstract with network virtualization technology, network resources are managed efficiently because multiple virtual networks vns can be constructed over a shared physical network.
Spectrumefficient and scalable elastic optical path network. Evolution of the wson technology where spectrum resources are reserved over a. Recent research progress on spectrum management approaches in. The challenges in the dwdm technology are the spectrum wastage due to its fixed grid of 50 or 25 ghz, which is specified by international telecommunication union. An overview of elastic optical networks and its enabling. What is elastic optical network flexible spectrum distribution, based in ofdm. In this paper, we compare the performances of two typical rsa algorithms namely spectrum first and routefirst, and put forward a connection between the performances and the request distributions. The book starts with a brief introduction to optical fiber transmission system, and then provides an overview of the wavelength division multiplexing wdm, and wdm optical networks. About this book this book presents advances in the field of optical networks specifically on research and applications in elastic optical networks eon. A new strategy for energy saving in spectrumsliced. Architecture, benefits, and enabling technologies abstract the sustained growth of data traffic volume calls for an introduction of an efficient and scalable transport platform for links of 100 gbs and beyond in the future optical network. Yoo university of science and technology of china, ucd we propose several algorithms to achieve hitless bandwidth defragmentation usingspectrum retuning in elastic optical networks. Elastic optical path network or spectrum sliced elastic optical path networks, etc summary elastic optical networks implementation.
Provisioning, recovery and inoperation planning in elastic optical network also examines multilayer scenarios. The slice architecture enables subwavelength, superwavelength, multiplerate data traffic accommodation, and elastic variation of allocated resources in a highly spectrumefficient manner. It covers virtual network topology reconfiguration and multilayer recovery, and includes provisioning customer virtual networks and the use of data analytics in order to bring cognition to the network. Review and analysis of elastic optical network and. Two retuning techniques, spectrum sweeping and hop tuning, are studied. This paper evaluates spectrum utilization and regenerating spectrum requirement in regeneration capable elastic optical.
Elastic optical networks architectures, technologies, and control. Spectrum convertible bvwxc placement in ofdmbased elastic optical networks mohammad hadi1, and mohammad reza pakravan1 1sharif university of technology, azadi st. Spectrum fragmentation issue in flexible optical networks. Efficient heuristic algorithms based on spectrum window planes are proposed for implementing distance and modulation format adaptive rsa so as to maximize spare capacity sharing among multiple protection. Immediate request vs book ahead request allocation in elastic. Pdf routing and spectrum allocation in elastic optical networks. Ber measurements experimentally demonstrate efficient adaptive switching and processing of variable fragmented traffic, leading to improved network scalability and efficiency. Adaptive routing and spectrum allocation in elastic optical. Efficient spectrum provisioning in elastic optical networks. Provisioning, recovery, and inoperation planning in elastic. The book series in optical networks and optical communication systems encompasses both optical communications and networks, including both theoretical and applied topics. A deep reinforcement learning framework for routing, modulation and spectrum assignment in elastic optical networks abstract.
Ofdm technology is the foundation of the elastic optical network eon concept, also referred to as spectrum sliced elastic optical path network or slice. Danilo borquezparedes, alejandra beghelli, ariel leiva, ruth murrugarra, does fragmentation avoidance improve the performance of dynamic spectrum allocation in elastic optical networks. Spectrum allocation in elastic optical networks with sharedprotection speakers. Concept and enabling technologies of spectrumsliced elastic. Elastic optical networking that enables flexible spectrum resource allocation and bitratedistanceadaptive modulation is one of the hot trends in optical networks to cope with both legacy lowbitrate services and emerging new bandwidthabundant superchannel services. Spectrum utilization efficiency in elastic optical. Although the scheme results in better spectrum utilization, still lots of rerouting operations can. There are essentially two types of dynamic traffic.
Multi spectrum bands allocation for timevarying traffic in. This book presents advances in the field of optical networks specifically on research and applications in elastic optical networks eon. Spectrum and energyefficient survivable routing algorithm in. On minimization of the spectrum usage in elastic optical. Eon is the advanced version or nextgeneration dwdm technology. This paper introduces split spectrum, which enhances elastic optical networking by splitting a bulk traffic demand into multiple channels, when a singlechannel transmission is prohibited by distance or spectrum availability. Zukerman, multicast routing and distanceadaptive spectrum allocation in elastic optical networks with shared. Elastic optical networking in the microsoft cloud mark filer, jamie gaudette, monia ghobadi, ratul mahajan, tom issenhuth, buddy klinkers, and jeff cox abstractto keep pace with the tremendous bandwidth growth in cloud networking, webscale providers, such as microsoft, have been quick to adopt elastic features of modern optical networks. For serving timevarying traffic in an elastic optical network eon, the spectrum allocated for the connection can be expanded or contracted to meet the traffic requirement.
This book addresses challenges and potential solutions surrounding the. Optical network design and planning optical networks. Network virtualization over elastic optical networks. In elastic optical networks eons, overcoming spectrum contiguity and continuity constraints is a challenging task while allocating spectrum slots ss to an incoming traffic demand. From a networking perspective, the increased complexity of the underlying transmission systems is re. Routing and spectrum allocation in ofdmbased optical. A spectrum consolidation scheme is proposed to solve the defragmentation problem by reconfiguring connections to the lower available spectrum in elastic optical path networks 1. A novel adaptive spectrum defragmentation algorithm for. Elastic spectrum allocation in flexgrid optical networks.
Definition of flexigrid or elastic optical network eon. The series describes current advances at the cutting edge of the field and is aimed especially at industry practitioners, researchers, and doctoral students. The novel concept of elastic optical network eon can help to improve network flexibility by allocating multiple subchannels to incoming connection requests with finer bandwidth granularity hence the term elastic over a flexible spectrum grid. An overview on application of machine learning techniques in. Spectrum management techniques for elastic optical networks. Blockchainassisted spectrum trading between elastic virtual. Pdf spectrum allocation policy in elastic optical networks. To overcome this, we propose a new spectrum trading st scheme between virtual optical networks vons in the context of an elastic optical network eon. The realization of eons 1 is considered a realistic perspective because. In this thesis, i have studied the concept and different techniques for spectrum defragmentation in elastic optical networks eons. The spectrum fragmentation is a serious issue in eons, which needs to be managed. Node architectures for elastic and flexible optical networks.
In an eon, the optical spectrum is divided into finer bandwidth portions called. Optical networks form the foundation of the global network infrastructure. Elastic optical networks, spectrum switched optical network, control. The considered problem of routing and spectrum assignment rsa takes into consideration minimizing the length of the transmission distance under spectrum continuity constraints and relationship between the traffic bitrates and the spectrum. Routing and spectrum assignment is a major problem in eon for efficient spectrum utilization.
This book places great emphasis on the network concepts, technology, and methodologies that will stand the test of time and also help in understanding and developing advanced optical network systems. Routing, spectrum, and transponder assignment in elastic. A novel, spectrumefficient and scalable optical transport network architecture called spectrumsliced elastic optical path network slice is presented. In addition, this capacity depends on other factors like the. In elastic optical networks eons, dynamic setup and release tear down of lightpaths will lead to spreading the optical spectrum into nonaligned, isolated and small sized spectrum blocks. The major difference between rwa and rsa lies in the slice network architecture as it flexibly adjusts to the format of the modulation 14. Spectrum expansioncontraction problem for multipath.
In the traditional wdm optical network, international telecommunication union itut defines the wavelength channel spacing, which is. Genetic algorithm for routing and spectrum allocation in. Eon uses optical orthogonal frequency division multiplexing oofdm technology which provides. Flexibility in eons is also guaranteed by emerging sliceable bandwidth variable transponders sbvts that support the simultaneous generation of multiple optical carriers. Consequently, in the quest for a truly agile, resourceef.
This paper proposes deeprmsa, a deep reinforcement learning framework for routing, modulation and spectrum assignment rmsa in elastic optical networks eons. Provisioning, recovery, and inoperation planning in elastic optical network. The os defines a certain capacity within the fiber optic link and it is measured in gigahertz ghz. We propose several algorithms to achieve hitless bandwidth defragmentation using spectrum retuning in elastic optical networks. In them, the fiber spectrum is treated as a continuing resource, allowing greater compression and efficiency in the use of it. Spectrum conversion can improve the performance of ofdmbased elastic optical net. Efficient spectrum assignment in elastic optical networks ieee. Spectrum management techniques for elastic optical.
It is written in an easy to follow approach that starts with basics such as optical network elements, routing, regeneration, wavelength assignment, grooming and ramps up to take on advanced and timely bundle of technology such as shared mesh protection, flexible optical network, and dynamic optical network with emphasis on. Management of spectral resources in elastic optical networks. Benefits of elastic spectrum allocation in optical. At data plane, the elastic optical network eon concept 1215 has emerged as a novel optical network architecture able to.
Conversely, idealist expressly focuses on shortto mediumterm industrial outcomes. Management of spectral resources in elastic optical networks by sunny shakya under the direction of xiaojun cao, phd abstract recent developments in the area of mobile technologies, data center networks, cloud computing and social networks have triggered the growth of a wide range of network applications. By overcoming the rigid spectrum allocation of current fixed. Adaptive spectrum allocation algorithm for elastic optical. Elastic optical networks eons are new generation optical networks that provide flexible bandwidth and spectrum assignment characteristics to accommodate diverse demand range over traditional. V av gos 1 c ompu t er e ng iee and i fmati csd p me,u v ity p, g d. A study of the routing and spectrum allocation in spectrum.
This tutorial paper starts with a brief introduction of the elastic optical network and its unique characteristics. This new approach is called elastic optical networking eon. We performed transmission simulations to determine the maximum reach as a function of modulation format dual polarization bpsk, qpsk, 16qam, baudrate from 5 to 28 gbd. In addition, they posit that by using a flexible grid the optical spectrum can be used in a. Simulation results show that the hop tuning technique achieves better defragmentation performance. The mismatch between the fixed capacity allocation and the actual fluctuating traffic would lead to degradation of provisioned network services and inefficiency in the assigned network capacity. Spectrum utilization efficiency of elastic optical.
The spectrum continuity and spectrum contiguity are in fact two fundamental constraints for routing and spectrum allocation in elastic optical networks. For this project, a set of elasticity schemes is proposed and these schemes are. Abstractelastic optical network eon efficiently utilize spectral resources for optical fiber communication by allocating minimum necessary bandwidth to client. Consequently, network wide spectrum management arises as the key challenge to be addressed in network design and control.
Spectrum efficient and scalable elastic optical path network. There is in one hand, traffic of connections that have some finite amount of time, and their spectrum paths are released after this short. This paper considers distance adaptive dynamic routing and spectrum assignment rsa for elastic optical networks with shared backup path protection sbpp. A challenging problem in the design and operation of. Elastic optical networks architectures, technologies. Multi spectrum bands allocation for timevarying traffic. The spectrum allocated to an endtoend connection between source and destination nodes varies dynamically with time denoted as timevarying traffic. In this paper the heuristic algorithm for the selection lightpaths in flexible transparent optical networks has been presented. Ofdm technology is the foundation of the elastic optical network eon concept 7, also referred to as spectrumsliced elastic optical path network or slice. Optimized routing and spectrum assignment for video. What is flexigrid or elastic optical network eon igi. Benefits of elastic spectrum allocation in optical networks. Spectrum allocation problem in elastic optical networks a. Basically optical network means of communication that uses signals encoded onto light to transmit information among various nodes of a telecommunications network.
Routing, spectrum, and transponder assignment rsta in. Evolution from wavelength switch to flexgrid optical networks taking advantage of elastic optical networks routing and spectrum allocation part ii data plane transmission in elastic optical networks node architecture sliceable bandwidth variable transponders part iii control plane control plane architecture openflow in. An overview of elastic optical networks and its enabling technologies article pdf available in international journal of engineering and technology 93. In the operational phaseof the network, traffic is dynamic and fluctuates. Evolution of the wson technology where spectrum resources are reserved over a flexible grid. Spectrum utilization efficiency of elastic optical networks. A proper request provisioning and scheduling mechanism can impact the network performance signi. Castoldi abstractbackbone networks are evolving toward elastic optical network eon architecture that allows a.