High Speed Communication Networks Laboratory (HSCNL) of the School of Electrical and Computer Engineering at the National Technical University of Athens, is developing solutions to some of the most challenging problems in networking, optical communications, data centers and cloud computing, and smart grids. The High Speed Communication Networks Laboratory,led by Professor Emmanouel (Manos) Varvarigos, is entirely devoted to research activities, and it includes 5 Post-Doctoral researchers and over 10 students pursuing their PhD. The group has strong cooperation with other research centers, universities, industrial partners and important scientists worldwide.

HSCNL’s research activities are in the areas of protocols and algorithms for high-speed networks, optical and wireless networking, high-performance switch architectures, data center architectures and technologies, grid and cloud computing, communication aspects of distributed computation, interconnection networks, smart energy grids and internet of things.

Optical Networking
The objectives of this research are to design, develop, and understand the properties of various architectures for the next generation of optical networks. Existing O/E/O networks are being upgraded to all-optical or translucent fixed-grid WDM wavelength routed networks, which in turn will give way in the near future to flex-grid and flex-rate elastic optical networks. At the same time, Software Defined Networking promises to make networking programmable and agile. The use of IP over WDM, the joint optimization of the IP and the Physical layer, coherent detection, tunable transponders, OFDM, 100G and higher transmission systems, energy efficiency, PONs and backhaul networks, the availability of software optical performance monitors for free through DSP at coherent receivers, impairment-aware Routing and Wavelength (or Spectrum) Assignment, the closing of the observe-decide-control loop in optical networks, and krigging and MSE optimization algorithms for estimating the state of the optical networks are some of the themes where the High-Speed Networks Research Group has a significant track record, We are developing Mantis, a cross-layer network planning and operation tool for IP over WDM and IP over flexible networks, which is interfaced to an SDN control plane aiming to serve as the optimization logic behind SDN in the optical networking domain.
Data Center Technologies and Optical Interconnect
Optical technologies have replaced most of copper in telecom WAN and MAN networks, and have already found their way to Datacom networks – inside Datacenters (DC) and Supercomputers (SC). Currently, in DC, fibers are used for implementing the point-to-point communication between electrical Top of Rack (ToR) switches, achieving higher bandwidth and reduced power consumption. To cope with both the energy and bandwidth limitations of the electrical interconnects, optical technologies target even shorter distances in the near future: board-to-board, on-board, and even on-chip communication to implement point-to-point, but also passive or even active optically switched networks.
The High-Speed Communication Networks Research Lab researches various directions in which emerging optical technologies would be integrated in DC and SC: architectures for interconnection networks for the whole system or focused on a specific packaging hierarchy (board, board-to-board, rack-to-rack) which range from hybrid electrical and (circuit or packet-switched) optical to all-optical networks, on-board and board-to-board layouts of optical networks, taking into account the particularities of the physical layer and the optical technologies used, in order to perform performance evaluation studies using both theoretical and simulation tools.
Cloud, Grid, Parallel and Distributed Computing
The main objective of this research is the networking interconnection of computing and storage resources installed around the world, combining resource management decisions and operations (e.g., task execution, disaster recovery, virtual machine migration) with the capabilities and the status of the underlying network. The kind of computing resources considered change over the years: parallel and distributed computing, desktop grids, grids, clouds and lately edge and fog computing. These resources are connected with IP and optical transport networks in the core and the metro segments that are programmable with the use of Software Defined Networking (SDN). The High-Speed Networks Research Group research focus on the development and evaluation of algorithms that select the computing, networking and storage resources, along with the associated characteristics, required for performing efficiently computations and data movements between sites.
Smart Energy Grids
The main objective of this research is the use of Information and Communication Technologies (ICT) in the energy sector for the realization of Smart Energy Grid (SEG). Information technologies are needed to support the decentralization trend of SEG data management systems, while research is undertaken on intelligent data acquisition (i.e. monitoring, pattern analysis, etc), modeling (i.e. forecasting, uncertainty management, etc), decision-making (i.e. clustering, scheduling, etc), market and pricing mechanisms, and active network management (i.e. demand response, load balancing, etc) infrastructures. The High-Speed Networks Research Group is developing a Decision Support System (DSS), which is able to orchestrate and efficiently manage the resources of multiple renewable energy “prosumers” (i.e. both producers and consumers of renewable energy), which runs over the cloud a large variety of research algorithms for near-real-time decision making and efficient participation of RES prosumers in the liberalized electricity markets.
Advanced Management of Smart Energy Grids
The objective is the development of Energy Services (ESs) that facilitate energy sector stakeholders (i.e. Transmission System Operators (TSOs), Distribution System Operators (DSOs), market operators, Renewable Energy Source (RES) producers, retailers, flexibility aggregators) to: i) automate and optimize the planning (investments) and operation/management of their systems/assets, and ii) interact in a dynamic and efficient way with their environment (electricity grid) and the rest of the stakeholders. In this way, this thread envisages secure, sustainable and affordable smart grids. In more detail this thread spans around the development of:
  • efficient aggregation ESs of end user’s DERs, which are flexible loads of end user’s (e.g. Heating Ventilation and Air Conditioning - HVACs, Electric Vehicles - EVs, etc.) and flexibility assets (e.g. Energy Storage Systems - ESS), from DER operators towards their optimal and parallel use in multiple energy markets according to the innovative energy market landscape
  • ESs relevant with the optimal operation of DERs and the advanced planning of DER investments according to a sophisticated and data driven examination of: innovative markets, transmission/distribution network topology and competition
  • monitoring and management systems of the transmission and the distribution networks in smart grids and in resolution of problems related with the network upgrades with respect to market power mitigation and DER exploitation
Innovative Energy Market Architectures
Existing electricity markets, that operate the management of modern smart grids, do not consider the constraints of local distribution networks. In this way large scale and/or bottom up Renewable Energy Source (RES) penetration is prevented and/or follows a conservative way (in order to avoid unpredicted voltage deviations and line congestions). Towards the efficient management of modern smart grids this thread develops innovative energy market architectures able to exploit and ensure the optimal use of Distributed Energy Resources (DERs) as flexible loads of end user’s (e.g. Heating Ventilation and Air Conditioning - HVACs, Electric Vehicles - EVs, etc.) and flexibility assets (e.g. Energy Storage Systems - ESS). In order to achieve this, the proposed architectures develop and exploit: i) an effective interaction between Transmission System Operators (TSOs) and Distribution System Operators (DSOs), ii) advanced models of DERs and iii) accurate network models and iv) advanced market clearing algorithms (that derive dispatch and payments).
Internet of Things (IoT)
Internet of Things (IoT) impact our lives in everything we do from the way we travel and do our shopping, to the way we keep fit and we keep our household. Internet of Things generally describe systems consisting of computing devices and sensors connected between them and over the internet.
The High-Speed Communication Networks Research (HSCNL) Lab researches various directions. We research and develop software platforms for system and network management of devices, including IoT related ones like TinyOS based systems, Rasbperries pi and other. The supported operations include sensor data collection, monitoring, software installation and command execution. We also develop home energy monitoring systems consisting of smart plugs, smart switches and user friendly dashboards that not only present information regarding the energy consumption of a house but also give control on a number of enabled devices, to turn them on or off. HSCNL also develops robotics solutions based on Lego Mindstorms EV3 robotics kit.
Software Tools
The High-Speed Networks Research Group is developing software tools for the monitoring and management of cloud resources, desktop machines, mobile and IoT devices. Advanced analytics are applied in the collected information, while gamification methods are also used for increasing the interaction of the users with the monitored systems.