A survey on OFDM-based elastic core optical networking

Orthogonal frequency-division multiplexing (OFDM) is a modulation technology that has been widely adopted in many new and emerging broadband wireless and wireline communication systems. Due to its capability to transmit a high-speed data stream using multiple spectral-overlapped lower-speed subcarriers, OFDM technology offers superior advantages of high spectrum efficiency, robustness against inter-carrier and inter-symbol interference, adaptability to server channel conditions, etc. In recent years, there have been intensive studies on optical OFDM (O-OFDM) transmission technologies, and it is considered a promising technology for future ultra-high-speed optical transmission. Based on O-OFDM technology, a novel elastic optical network architecture with immense flexibility and scalability in spectrum allocation and data rate accommodation could be built to support diverse services and the rapid growth of Internet traffic in the future. In this paper, we present a comprehensive survey on OFDM-based elastic optical network technologies, including basic principles of OFDM, O-OFDM technologies, the architectures of OFDM-based elastic core optical networks, and related key enabling technologies. The main advantages and issues of OFDM-based elastic core optical networks that are under research are also discussed

Optimal RWA for SDM Optical Network under Dynamic Traffic

With the rapid increase in demand for data transmission in our generation where Internet and cloud concepts play an essential role, it has become mandatory that we handle data most efficiently. A promising solution to overcome the capacity crunch problem which is so evident in future is applications of Space Division Multiplexing, where we explore the remaining unused domain that is the spectral and spatial domain. Space Division Multiplexing using multi-core fibers (MCF), and few-mode fibers (FMF) has been studied in our work to enhance the data-carrying capacity of optical fibers while minimizing the transmission cost per bit. The objective is to develop a path protection scheme to handle communication requests in the data center (DC) networks using elastic optical networking and space division multiplexing (SDM). Our approach to this problem is to 1) determining the initial allocation of light path on the topology, 2) possible spectrum allocation using the flex-grid flexible-SDM model, 3) choose the best possible route to minimize the number of subcarriers needed for data transfer. We propose to evaluate the developed Integer Linear Programming (ILP) formulation based on this scheme

Robust Data Center Network Design using Space Division Multiplexing

With the ever-increasing demand for data transmission in our generation where Internet and cloud concepts play a vital role, it has become essential that we handle data in a most efficient way. A possible solution to overcome the capacity crunch problem which is so evident in future, is applications of Space Division Multiplexing, where we explore the remaining unused domain that is the spatial domain. Space Division Multiplexing using multi-core fibers (MCFs), and few-mode fibers (FMFs) has been studied in our work to enhance the data-carrying capacity of optical fibers while minimizing the transmission cost per bit. The objective of our work is to develop a path protection scheme to handle communication requests in data center (DC) networks using elastic optical networking and space division multiplexing (SDM). Our approach to this problem is to 1) determine a dedicated primary and backup path, 2) possible allocation of spectrum using the flex-grid fixed-SDM model, 3) choose the best possible modulation format to minimize the number of subcarriers needed for data transfer, 4) measure the cost of the resources required to handle the new requests. We propose to evaluate the developed Integer Linear Programming (ILP) formulation based on this scheme, considering the possibility of disasters. We study the impact of the design on the cost of the solution, hence explore whether it promotes significant resource savings

Enhanced WDM-OFDM-PON System Based on Higher Data Transmitted with Modulation Technique

ABSTRACT:- Studies among the field communication system existing technique and proposes and by experimentation demonstrate a multiuser wavelengthdivision-multiplexing passive optical network (WDM-PON) system combining with orthogonal frequency division multiple (OFDM) technique. A tunable multiwavelength optical comb is intended to provide flat optical lines for helping the configuration of the multiple source-free optical network units WDM-OFDM-PON system supported normal single-mode fiber (SSMF). In WDM based on fiber, optical network communications using wavelength with multiplex or demultiplex may be a technology that multiplexes a variety of optical carrier signals onto one fiber by victimization completely different wavelengths of optical device lightweight. this system allows bidirectional communications over one strand of fiber, also as multiplication of capability and calculate BER (Bit Error Rate) and OSNR (optical signal noise ratio) finally; a comparison of by experimentation achieved receiver sensitivities and transmission distances victimization these receivers is given. The very best spectral potency and longest transmission distance at the very best bit rate. WDM based applications like transmission data, medical imaging data, and digital audio data and video conferencing data are information measure-intensive with the Advance in optical technology providing verdant bandwidth, it's natural to increase the multicast construct to optical networks so as to realize increased performance. Our projected scheme (PGA) based on information load transmitted capability improve supported higher information transmitted over these channels and high data up to develop in Matlab tool and using optical Interleaved the OFDM model and analysis the performance of the WDM-PON system

Management of Spectral Resources in Elastic Optical Networks

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. The data rate of these applications also vary from a few megabits per second (Mbps) to several Gigabits per second (Gbps), thereby increasing the burden on the Inter- net. To support this growth in Internet data traffic, one foremost solution is to utilize the advancements in optical networks. With technology such as wavelength division multiplexing (WDM) networks, bandwidth upto 100 Gbps can be exploited from the optical fiber in an energy efficient manner. However, WDM networks are not efficient when the traffic demands vary frequently. Elastic Optical Networks (EONs) or Spectrum Sliced Elastic Optical Path Networks (SLICE) or Flex-Grid has been recently proposed as a long-term solution to handle the ever-increasing data traffic and the diverse demand range. EONs provide abundant bandwidth by managing the spectrum resources as fine-granular orthogonal sub-carriers that makes it suitable to accommodate varying traffic demands. However, the Routing and Spectrum Allocation (RSA) algorithm in EONs has to follow additional constraints while allocating sub-carriers to demands. These constraints increase the complexity of RSA in EONs and also, make EONs prone to the fragmentation of spectral resources, thereby decreasing the spectral efficiency. The major objective of this dissertation is to study the problem of spectrum allocation in EONs under various network conditions. With this objective, this dissertation presents the author\u27s study and research on multiple aspects of spectrum allocation in EONs: how to allocate sub-carriers to the traffic demands, how to accommodate traffic demands that varies with time, how to minimize the fragmentation of spectral resources and how to efficiently integrate the predictability of user demands for spectrum assignment. Another important contribution of this dissertation is the application of EONs as one of the substrate technologies for network virtualization

Lightpath fragmentation for efficient spectrum utilization in dynamic elastic optical networks

The spectrum-sliced elastic optical path network (SLICE) architecture has been presented as an efficient solution for flexible bandwidth allocation in optical networks. An homologous problem to the classical Routing and Wavelength Assignment (RWA) arises in such an architecture, called Routing and Spectrum Assignment (RSA). Imposed by current transmission technologies enabling the elastic optical network concept, the spectrum contiguity constraint must be ensured in the RSA problem, meaning that the bandwidth requested by any connection must be allocated over a contiguous portion of the spectrum along the path between source and destination nodes. In a dynamic network scenario, where incoming connections are established and disconnected in a quite random fashion, spectral resources tend to be highly fragmented, preventing the allocation of large contiguous spectrum portions for high data-rate connection requests. As a result, high data-rate connections experience unfairly increased bocking probability in contrast to low data-rate ones. In view of this, the present article proposes a lightpath fragmentation mechanism that makes use of the idle transponders in the source node of a high data-rate connection request to fragment it into multiple low data-rate ones, more easily allocable in the network. Besides, aiming to support such an operation, a light-weight RSA algorithm is also proposed so as to properly allocate the generated lightpath fragments over the spectrum. Benefits of the proposed approach are quantified through extensive simulations, showing drastically reduced high data-rate connection blocking probability compared to a usual contiguous bandwidth allocation, while keeping the performance of low data-rate requests to similar levels.Postprint (author’s final draft