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Author

Slavisa Aleksic

Other affiliations: University of Vienna
Bio: Slavisa Aleksic is an academic researcher from Vienna University of Technology. The author has contributed to research in topics: Optical burst switching & Optical switch. The author has an hindex of 18, co-authored 89 publications receiving 1229 citations. Previous affiliations of Slavisa Aleksic include University of Vienna.


Papers
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Journal ArticleDOI
TL;DR: The results show that implementation in optics is generally more power efficient; especially circuit-switched architectures have a low power consumption and when taking into account possible future developments of Si CMOS technology, even very large electronic packet routers having capacities of more than hundreds of terabits per second seem to be feasible.
Abstract: Power consumption and the footprint of future network elements are expected to become the main limiting factors for scaling the current architectures and approaches to capacities of hundreds of terabits or even petabits per second. Since the underlying demand for network capacity can be satisfied only by contemporaneously increasing transmission bit rate, processing speed, and switching capacity, it unavoidably will lead to increased power consumption of network nodes. On the one hand, using optical switching fabrics could relax the limitations to some extent, but large optical buffers occupy larger areas and dissipate more power than electronic ones. On the other hand, electronic technology has made fast progress during the past decade regarding reduced feature size and decreased power consumption. It is expected that this trend will continue in the future. This paper addresses power consumption issues in future high-capacity switching and routing elements and examines different architectures based on both pure packet-switched and pure circuit-switched designs by assuming either all-electronic or all-optical implementation, which can be seen as upper and lower bounds regarding power consumption. The total power consumption of a realistic and appropriate technology for future high-performance core network nodes would probably lie somewhere between those two extreme cases. Our results show that implementation in optics is generally more power efficient; especially circuit-switched architectures have a low power consumption. When taking into account possible future developments of Si CMOS technology, even very large electronic packet routers having capacities of more than hundreds of terabits per second seem to be feasible. Because circuit switching is more power efficient and easier to implement in optics than pure packet switching, the scalability limitation due to increased power consumption could be considerably relaxed when a kind of dynamic optical circuit switching is used within the core network together with an efficient flow aggregation at edge nodes.

233 citations

Journal ArticleDOI
TL;DR: Three major types of passive optical interconnects are presented and a performance assessment is carried out with respect to the ability to host data center traffic, scalability, optical power budget, complexity of the required interface, cost, and energy consumption.
Abstract: The growing popularity of cloud and multimedia services is dramatically increasing the traffic volume that each data center needs to handle. This is driving the demand for highly scalable, flexible, and energy-efficient networks inside data centers, in particular for the edge tier, which requires a large number of interconnects and consumes the dominant part of the overall power. Optical fiber communication is widely recognized as the highest energy- and cost-efficient technique to offer ultra-large capacity for telecommunication networks. It has also been considered as a promising transmission technology for future data center applications. Taking into account the characteristics of the traffic generated by the servers, such as locality, multicast, dynamicity, and burstiness, the emphasis of the research on data center networks has to be put on architectures that leverage optical transport to the greatest possible extent. However, no feasible solution based on optical switching is available so far for handling the data center traffic at the edge tier. Therefore, apart from conventional optical switching, we investigate a completely different paradigm, passive optical interconnects, and aim to explore the possibility for optical interconnects at the top of the rack. In this article, we present three major types of passive optical interconnects and carry out a performance assessment with respect to the ability to host data center traffic, scalability, optical power budget, complexity of the required interface, cost, and energy consumption. Our results have verified that the investigated passive optical interconnects can achieve a significant reduction of power consumption and maintain cost at a similar level compared to its electronic counterpart. Furthermore, several research directions on passive optical interconnects have been pointed out for future green data centers.

91 citations

Journal ArticleDOI
TL;DR: This work proposes a novel data center network architecture realized by combining broadcast-and-select approach with elastic channel spacing technology that is able to scale efficiently with the number of servers and offers lower energy consumption at a competitive cost compared to the existing solutions.
Abstract: To address the urgent need for high-capacity, scalable and energy-efficient data center solutions, we propose a novel data center network architecture realized by combining broadcast-and-select approach with elastic channel spacing technology We demonstrate that the proposed architecture is able to scale efficiently with the number of servers and offers lower energy consumption at a competitive cost compared to the existing solutions

73 citations

Journal ArticleDOI
TL;DR: A proposal for a smooth integration of QKD in optical metro networks, which implies removing spurious background photons caused by optical transmitters, amplifiers and nonlinear effects in fibers, is presented and discussed.
Abstract: Quantum key distribution (QKD) systems have already reached a reasonable level of maturity. However, a smooth integration and a wide adoption of commercial QKD systems in metropolitan area networks has still remained challenging because of technical and economical obstacles. Mainly the need for dedicated fibers and the strong dependence of the secret key rate on both loss budget and background noise in the quantum channel hinder a practical, flexible and robust implementation of QKD in current and next-generation optical metro networks. In this paper, we discuss these obstacles and present approaches to share existing fiber infrastructures among quantum and classical channels. Particularly, a proposal for a smooth integration of QKD in optical metro networks, which implies removing spurious background photons caused by optical transmitters, amplifiers and nonlinear effects in fibers, is presented and discussed. We determine and characterize impairments on quantum channels caused by many classical telecom channels at practically used power levels coexisting within the same fiber. Extensive experimental results are presented and indicate that a practical integration of QKD in conventional optical metro networks is possible.

48 citations

Journal ArticleDOI
TL;DR: A novel model for evaluating the energy efficiency of combined optical/wireless networks is presented that takes into account the main architectural and implementational aspects of both RF wireless and optical parts of the access network.

40 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the authors survey the state-of-the-art in NFV and identify promising research directions in this area, and also overview key NFV projects, standardization efforts, early implementations, use cases, and commercial products.
Abstract: Network function virtualization (NFV) has drawn significant attention from both industry and academia as an important shift in telecommunication service provisioning. By decoupling network functions (NFs) from the physical devices on which they run, NFV has the potential to lead to significant reductions in operating expenses (OPEX) and capital expenses (CAPEX) and facilitate the deployment of new services with increased agility and faster time-to-value. The NFV paradigm is still in its infancy and there is a large spectrum of opportunities for the research community to develop new architectures, systems and applications, and to evaluate alternatives and trade-offs in developing technologies for its successful deployment. In this paper, after discussing NFV and its relationship with complementary fields of software defined networking (SDN) and cloud computing, we survey the state-of-the-art in NFV, and identify promising research directions in this area. We also overview key NFV projects, standardization efforts, early implementations, use cases, and commercial products.

1,634 citations

Journal ArticleDOI
TL;DR: To support bursty traffic on the Internet (and especially WWW) efficiently, optical burst switching (OBS) is proposed as a way to streamline both protocols and hardware in building the future gener...
Abstract: To support bursty traffic on the Internet (and especially WWW) efficiently, optical burst switching (OBS) is proposed as a way to streamline both protocols and hardware in building the future gener...

674 citations

Journal ArticleDOI
TL;DR: An estimation of the global electricity usage that can be ascribed to Communication Technology between 2010 and 2030 suggests that CT electricity usage could contribute up to 23% of the globally released greenhouse gas emissions in 2030.
Abstract: This work presents an estimation of the global electricity usage that can be ascribed to Communication Technology (CT) between 2010 and 2030. The scope is three scenarios for use and production of consumer devices, communication networks and data centers. Three different scenarios, best, expected, and worst, are set up, which include annual numbers of sold devices, data traffic and electricity intensities/efficiencies. The most significant trend, regardless of scenario, is that the proportion of use-stage electricity by consumer devices will decrease and will be transferred to the networks and data centers. Still, it seems like wireless access networks will not be the main driver for electricity use. The analysis shows that for the worst-case scenario, CT could use as much as 51% of global electricity in 2030. This will happen if not enough improvement in electricity efficiency of wireless access networks and fixed access networks/data centers is possible. However, until 2030, globally-generated renewable electricity is likely to exceed the electricity demand of all networks and data centers. Nevertheless, the present investigation suggests, for the worst-case scenario, that CT electricity usage could contribute up to 23% of the globally released greenhouse gas emissions in 2030.

644 citations

Journal Article
TL;DR: The Health Insurance Portability and Accountability Act, also known as HIPAA, was designed to protect health insurance coverage for workers and their families while between jobs and establishes standards for electronic health care transactions.
Abstract: The Health Insurance Portability and Accountability Act, also known as HIPAA, was first delivered to congress in 1996 and consisted of just two Titles. It was designed to protect health insurance coverage for workers and their families while between jobs. It establishes standards for electronic health care transactions and addresses the issues of privacy and security when dealing with Protected Health Information (PHI). HIPAA is applicable only in the United States of America.

561 citations

Journal ArticleDOI
TL;DR: 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.
Abstract: 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.

406 citations