Ioannis Tomkos

Ioannis Tomkos
University of Patras | UP · Department of Electrical and Computer Engineering

Ph.D. Optical Communications
Working on defining the technologies that will revolutionize the telecom networks of the future

About

765
Publications
158,588
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
9,707
Citations
Introduction
Ioannis is one of the most published/cited/read Greeks in the general fields of Electrical Engineering and among the top worldwide on optical communications/networking (over 650 conference/journal articles; including over 400 available at IEEEXplore). He is the only Greek to be elected "Fellow" of the IET (2010), OSA (2012) and IEEE (2018). He is included in the "Top H-Index" list of "Guide2Research" for the fields of "Computer Science & Electronics". 5 of his articles were designated as "Highly Cited" (belonging to the top 1%) by Web of Science during 2010-2018. His research group has raised over 8.5M€ funding. Updated ORCID profile and funding info: http://orcid.org/0000-0001-9721-3405
Additional affiliations
November 2019 - present
University of Patras
Position
  • Professor (Full)
January 2017 - August 2018
University Carlos III de Madrid
Position
  • Chair
January 2014 - present
University of Cyprus
Position
  • Adjunct Research Professor
Education
September 1996 - October 1999
National and Kapodistrian University of Athens
Field of study
  • Telecommunications
September 1994 - June 1996
National and Kapodistrian University of Athens
Field of study
  • Telecommunications
September 1990 - June 1994
University of Patras
Field of study
  • Applied Physics - Electronics

Publications

Publications (765)
Conference Paper
Full-text available
Export Date: 29 November 2013, Source: Scopus
Article
Spatially integrated switching architectures have been recently investigated in an attempt to provide switching capability for networks based on spatial division multiplexing (SDM) fibers, as well as to reduce the implementation cost. These architectures rely on the following switching paradigms, furnishing different degrees of spectral and spatial...
Article
Full-text available
The next generation of telecommunication networks will integrate the latest developments and emerging advancements in telecommunications connectivity infrastructures. In this article, we discuss the transformation and convergence of the fifth-generation (5G) mobile network and the internet of things technologies, toward the emergence of the smart s...
Book
Full-text available
The “Handbook of Optical Networks” was edited by Biswanath Mukherjee, Ioannis Tomkos, Massimo Tornatore, Peter Winzer, and Yongli Zhao with the goal to describe and review the underlying photonics technologies that enable today’s global opticalcommunications infrastructure (used in high-performance-computing, datacenter, 5G, access, metro, core, sa...
Article
Full-text available
In 5G and beyond telecommunication infrastructures a crucial challenge in achieving the strict Key Performance Indicators (KPIs) regarding capacity, latency, and guaranteed quality of service, is the efficient handling of the fronthaul bottleneck. This part of the next generation networks is expected to comprise the New Radio (NR) access and the Ne...
Conference Paper
Since we have entered the research era of 6G networks, disruptive approaches should be investigated about the optical x-haul technologies associated with advance optical nodes and their transceiver Interfaces that will enable flexible capacity scaling (up to 10Tbps rate per interface, 10Pbps capacity per transmission link and over 100Pbps throughpu...
Article
Full-text available
Submarine networks have evolved alongside terrestrial ones over the past several decades. Although there are similarities between these two network categories (e.g., the need to cover ultra-long-haul distances and transport huge amounts of data), there are also important differences that have dictated their different evolutionary paths. Space divis...
Article
We propose, model and optimize an optical Digital to Analog Converter (oDAC) significantly improving the tradeoffs between spectral-, energy- and footprint- efficiencies, based on modifying our recently introduced multi-parallel oDAC [1], by adopting Multi-Level-Driven modulation for the individual Mach-Zehnder Modulators (MZM) in the parallelized...
Article
Full-text available
In this work, deep graph convolutional neural networks (DGCNN) are applied for estimating the quality-of-transmission (QoT) of unseen network states in elastic optical networks (EONs) in the presence of physical layer impairments (PLIs), including inter- and intra-channel crosstalk (XT). The objective is to find a DGCNN-QoT model that accurately es...
Technical Report
Full-text available
The White Paper covers key areas related to 6G research from a technical, societal, policy and business perspective providing a vision for the future networks and services. In the coming decade, 6G will bring a new era in which billions of things, humans, connected vehicles, robots and drones will generate zettabytes of digital information. 6G will...
Article
Full-text available
We develop a ‘perfect’ design for PAM4 Segmented Mach-Zehnder Modulators (SEMZM), featuring a fully linear (uniform) optical DAC (oDAC) staircase (i.e., having equi-spaced PAM4 levels) and no intrinsic modulation loss (the qualifier ‘perfect’ pertains to ideal conditions, barring optical excess losses and other impairments). This is achieved by lev...
Article
This work presents optimization algorithms on attack-aware routing and spectrum allocation (Aa-RSA) in conjunction with spectrum selective switch (SSS) placement, taking into account variations in traffic demands. The objectives of the algorithms are to minimize the required number of SSSs, as well as the number of lightpath re-allocations between...
Article
Full-text available
This work presents efficient connection provisioning techniques mitigating high-power jamming attacks in spectrally-spatially flexible optical networks (SS-FONs) utilizing multicore fibers. High-power jamming attacks are modeled based on their impact on the lightpaths’ quality of transmission (QoT) through inter-core crosstalk. Based on a desired t...
Article
Full-text available
In optical transmitters generating multi-level constellations, optical modulators are preceded by Electronic Digital-to-Analog-Converters (eDAC). It is advantageous to use eDAC-free Optical Analog to Digital Converters (oDAC) to directly convert digital bitstreams into multilevel PAM/QAM optical signals. State-of-the-art oDACs are based on Segmente...
Article
Full-text available
Dynamic network slicing has emerged as a promising and fundamental framework for meeting 5G’s diverse use cases. As machine learning (ML) is expected to play a pivotal role in the efficient control and management of these networks, in this work, we examine the ML-based quality-of-transmission (QoT) estimation problem under the dynamic network slici...
Article
Full-text available
The offering of demanding telecommunication services as promised by the 5G specifications raise the necessity for high capacity, flexible, adaptive, and power conserving fronthaul. Toward this goal, the role of the passive optical network which is responsible for interconnecting the central office (CO) with the cell-sites is crucial. Among the late...
Book
This handbook is an authoritative, comprehensive reference on optical networks, the backbone of today’s communication and information society. The book reviews the many underlying technologies that enable the global optical communications infrastructure, but also explains current research trends targeted towards continued capacity scaling and enhan...
Preprint
Full-text available
Dynamic network slicing has emerged as a promising and fundamental framework for meeting 5G's diverse use cases. As machine learning (ML) is expected to play a pivotal role in the efficient control and management of these networks, in this work we examine the ML-based Quality-of-Transmission (QoT) estimation problem under the dynamic network slicin...
Conference Paper
Full-text available
Coherent detection could in principle offer a nice solution in that direction, enabling to scale the transceivers towards higher capacities; however, the cost and power consumption issues stemming mainly from the use of ultra-high-speed DSP chips and analogue to digital converters (ADCs), which consume over 8 W, even at 7 nm technology, must be add...
Conference Paper
The role of fixed optical networking and the opportunities from joint FTTH/A co-deployment in the new 5G era
Conference Paper
Analogue Optical Signal Processor based intra-datacenter coherent receiver
Conference Paper
Full-text available
We apply deep graph convolutional neural networks for Quality-of-Transmission estimation of unseen network states capturing, apart from other important impairments, the inter-core crosstalk that is prominent in optical networks operating with multicore fibers
Poster
Full-text available
Digital back propagation based on split-step Fourier method (DBP-SSF) has being tested in multi-channel equalization scheme providing 3.8 dB Q 2-factor improvement with 80 steps-per-span after 3,200 km but at the expense of vast computational complexity [G. Ligas et al., Opt. Express, vol. 22, no. 24, 2014]. • In this work, we present the performan...
Preprint
Full-text available
We apply deep graph convolutional neural networks for Quality-of-Transmission estimation of unseen network states capturing, apart from other important impairments, the inter-core crosstalk that is prominent in optical networks operating with multicore fibers.
Cover Page
Full-text available
Received a notification by the President and CEO of IEEE that I received a 2019 Fellowship
Article
In this work, we compare the performance of several Space Division Multiplexing (SDM) network realizations utilizing different types of transmission media. In this regard, we first present a tool developed for the estimation of signal quality degradation in SDM based optical networks. The tool supports SDM networks utilizing Few-Mode Fibers (FMFs),...
Article
Full-text available
Data centers are continuously growing in scale and can contain more than one million servers spreading across thousands of racks; requiring a large-scale switching network to provide broadband and reconfigurable interconnections of low latency. Traditional data center network architectures, through the use of electrical packet switches in a multi-t...
Article
The eight papers included in this special section focus on optical networks supporting interoperability and white boxes. The goal is to introduce the key challenges, trends, and innovations. In the recent years, network operators and service providers have shown their interest in pushing vendors to disaggregate networks and to guarantee multi-vendo...
Conference Paper
Space division multiplexing (SDM) has been proposed as the ultimate solution to address the capacity crunch of optical transport networks. The efficient utilization of SDM requires some forms of spatial integration which is expected to bring huge cost savings for the deployment of SDM-based optical networks. Spatially integrated components with dif...
Conference Paper
Full-text available
This paper presents efficient connection provisioning techniques for spectrally-spatially flexible optical networks (SS-FON) utilizing multicore fibers (MCFs) when physical layer effects are taken into consideration. To account for the physical layer effects, two approaches are presented that are used to establish a given set of demands. One approa...
Article
Full-text available
Large scale Data Centers (DC) and High Performance Computing (HPC) systems require more and more computing power at higher energy efficiency. They are already consuming megawatts of power, and a linear extrapolation of trends reveals that they may eventually lead to unrealistic power consumption scenarios in order to satisfy future requirements (e....
Conference Paper
Full-text available
In this work, efficient routing, spectrum, and core allocation (RSCA) techniques are proposed for spatial division multiplexed (SDM) elastic optical networks (EONs) utilizing multicore fibers (MCFs). These techniques provide efficient resource utilization with minimal computational complexity, while also taking into consideration physical layer eff...
Article
Two 1.6 Tb/s coherent optical wavelength division multiplexed (WDM) systems targeting inter-data center links of up to 40-km reach over conventional single-mode fiber (CSMF) on C-band are proposed and numerically analyzed: a DP-QPSK-based 16 × 112 Gb/s system and a DP-16-QAM-based 8 × 224 Gb/s system. To satisfy the metro access space, noise and po...
Conference Paper
Full-text available
In dynamic networks with diverse application requirements, Software Defined Networking (SDN) principles enable application-aware in-operation planning. Project ACINO built a network orchestrator as the connecting component between network applications and the underlying network infrastructure.
Conference Paper
The cost evolution and power consumption of different 400G transceivers are modeled and the benefits of constructing and scaling the Facebook’s datacenter Fabric utilizing different technologies is presented through comparative cost and power consumption analysis
Conference Paper
We evaluate the performance and benefits of novel integrated Free-Space-Optics (FSO) transceivers, supporting optical beam steering at low power consumption with ns steering speed. A proper intra-datacenter network architecture is also presented.
Conference Paper
A four-node, four-lane SDM mesh network with CD-ROADM nodes performing dual spatial channel routing and lane changes is reported, under centralized SDN control for space/spectrum assignments. The architecture achieves high utilization and low implementation cost.
Conference Paper
Full-text available
In this invited presentation we will discuss the technologies developed by INSPACE in order to support the operation of spectrally-spatially flexible optical networks, focusing on spatial integration of elastic optical network switching elements, in a way that their use can be shared efficiently by parallel elastic WDM systems running over multiple...
Article
Full-text available
The future scaling of optical networks will rely on higher capacity fiber links employing space-division multiplexing (SDM) in addition to established wavelength division multiplexing (WDM). Realizing such spatial-spectral optical networks in a cost-effective manner, balancing flexibility and complexity, was investigated in European Project INSPACE...
Conference Paper
Full-text available
We evaluate our method for dynamically accommodating applications that require more than just bandwidth. Our simulations show the advantages of two availability-aware approaches on a network equipped with an SDN orchestrator. Introduction Many network applications today want more than just connectivity and a bandwidth pipe. Examples include autonom...
Chapter
Many physical attributes of light, including intensity, phase, and polarization, have been exploited so far to increase the capacity of optical transport systems and keep pace with the exponential traffic growth. This chapter reviews the recent progress in the development of space division multiplexing (SDM)-based optical networks. It describes the...
Conference Paper
In this work, we investigate the performance specifications of the components comprising the suggested intra- and inter-Data Centres (DCs) systems according to DIMENSION project. More specifically, we deal with the performance specifications of the laser sources and the respective modulators. The intra-DC system employs a novel Directly Modulated L...
Conference Paper
Space division multiplexing (SDM) has been proposed to cost-effectively increase the capacity of optical transmission systems. The cost savings can be realized by introducing some levels of spatial integration of elements. However, spatial densification increases the crosstalk (XT) interactions among spatial channels. The XT is expected to be mitig...
Conference Paper
Multidimensional approach based on employment of both spatial and spectral modes in an optical access network can enable not only increase in the network throughput, but also enhance its dynamic and elastic character through spectral-spatial interworking and employment of an advanced software defined (SDN) networking model. In this paper we introdu...
Conference Paper
Full-text available
The need for achieving more flexibility, higher capacity, programmability and embedded cognition at reasonable extra cost in future optical communication networks, is one of the immediate consequences of the overwhelming developments of real-time person-to-person and machine-to-machine interactions and online services. These features are expected t...
Conference Paper
An eight-channel multi-format coherent optical transceiver is proposed as an alternative to implement terabit metro inter-data centre interconnects (DCI) transmitting from 800 to 1600 Gb/s over conventional single mode fibre (CSMF). The maximum reach of the system as a function of transmitted power and overall capacity is numerically estimated for...
Conference Paper
Full-text available
Internet traffic is generated by a multitude of applications, each one with diverse service requirements in terms of bandwidth, latency, reliability, etc. Today traffic engineering techniques can provide service differentiation at the IP/MPLS layer, but not at the optical layer. In this paper we propose a framework where application service require...
Presentation
Full-text available
We describe the approaches followed in H2020 EU project ACINO to enable application-centric service differentiation all the way down to the optical layer, by means of an open source modular SDN orchestrator enabling applications to program the IP/Optical transport network by means of high-level primitives.
Article
Space division multiplexing (SDM) is a promising approach to overcome the looming fiber capacity crunch. Joint and fractional joint switching (JoS and FJoS) architectures, which switch multiple spatial dimensions together as atomic units, have been proposed to reduce the cost of implementing SDM and cater to strongly coupled transmission media. How...
Article
The proliferation of data centers deployed within the networks of national and international operators is enabling the creation of innovative added-value services offered through consumer and business applications. This trend is constantly triggering the adaptation of network operations to the needs of the applications. Indeed, they would be better...
Article
As traffic volumes carried by optical networks continue to grow by tens of percent year over year, we are rapidly approaching the capacity limit of the conventional communication band within a single-mode fiber. New measures such as elastic optical networking, spectral extension to multi-bands, and spatial expansion to additional fiber overlays or...
Article
Full-text available
Transport IP/optical networks are evolving in capacity and dynamicity of configuration. This evolution gives little to no attention to the specific needs of applications, beyond increasing raw capacity. The ACINO concept is based on allowing applications to explicitly specify requirements for requested services in terms of high-level (technology- a...
Conference Paper
We show cascaded 100-Gb/s sub-channel add/drop from a 1-Tb/s MB-OFDM or Nyquist-WDM super-channel having ultra-low inter-sub-channel guard-bands within a recirculating loop via a hierarchical ROADM using high-resolution filters, showcasing up to 1000-km transmission reach and five ROADM node passages for the add/drop sub-channel when hybrid Raman-E...
Conference Paper
Full-text available
In an SDN-based network, connection requests can be accommodated according to application requirements. We devise a framework where such requirements drive IP and optical network resource allocation, dynamic optimization, and instantiation through an SDN orchestrator.
Conference Paper
The power consumption of MIMO-DSP for SDM networks is investigated, assuming emerging sub-20-nm CMOS technology. Significant limitations on the network performance are revealed when scaling to large MIMO multiplicity (i.e. 12×12).
Conference Paper
We compare different architectures of CD and CDC ROADMs supporting spatial superchannel routing in terms of required components, revealing the most cost-effective designs.
Cover Page
Full-text available