A5091019748- Advanced Frequency and Time Standards
- Semiconductor Lasers and Optical Devices
- Advanced Fiber Laser Technologies
- Advanced Photonic Communication Systems
- Optical Network Technologies
- Network Time Synchronization Technologies
- Quantum optics and atomic interactions
- Advanced Optical Network Technologies
- Quantum Information and Cryptography
- Power Line Communications and Noise
- Context-Aware Activity Recognition Systems
- Smart Cities and Technologies
- ICT Impact and Policies
- Smart Grid Energy Management
- Smart Grid Security and Resilience
- Cold Atom Physics and Bose-Einstein Condensates
- IoT and Edge/Fog Computing
- Atomic and Subatomic Physics Research
- Quantum Computing Algorithms and Architecture
- Digital and Traditional Archives Management
- Information Technology Governance and Strategy
- Software-Defined Networks and 5G
- Photovoltaic System Optimization Techniques
- Blockchain Technology Applications and Security
- Hand Gesture Recognition Systems
CESNET, zájmové sdružení právnických osob
2016-2025
University of South Bohemia in České Budějovice
2016-2024
Sewanee: The University of the South
2010
In the era of Industry 5.0, technology promises rapid and smart growth industries to improve system performance substantially be sustainable more secure. 5.0 enabled conventional unmanned aerial vehicle (UAV) represent a dynamic result that can offer various services irrespective time, place, in broader physical range. Hence, satellite systems high having advanced pre-processing transmission capabilities are gaining considerable attention increase overall throughput. enhancing efficiency...
The infrastructure essentialities for accurate time and stable frequency distribution are presented. Our solution is based on sharing fibers a research educational network carrying live data traffic with transfer in parallel. Accurate transmission uses mainly dark channels amplified by dedicated bidirectional amplifiers the same propagation path both directions of transmission. This paper targets challenges related to transmission, particularly, directional nonreciprocities.
Living Lab, one of the recent emerging smart city concepts, faces long-term sustainability challenges associated with its complexity and breadth use. To be efficient, it must rely on comprehensive set information distributed appropriately among all stakeholders to unleash full innovation potential. This is especially true in case positive energy districts, where timely data dissemination essential for prosumager decisions their greedy behaviour. paper interconnects intelligent exchange,...
Evolution in the field of optical networking National Research and Education Networks led to utilization Alien Wavelengths (AWs) disaggregated Open Line Systems. Dynamic provisioning AWs, general spectrum services, is achieved via Reconfigurable Optical Add Drop Multiplexers (ROADMs) operating with flexible allocation. Northbound interface these usually implemented NETCONF protocol through an appropriate Yet Another Next Generation (YANG) model. This paper presents a self-contained spectral...
With changes in climatic conditions, the performance of photovoltaic power plant installations fluctuates, mainly due to excessive heat. The question their efficient cooling comes fore, especially direct cooling, either by media or air. Here, it is proven that active panels leads an increase performance, but overall costs may exceed benefits (especially for smaller/household installations). Moreover, conventional approaches, increasing efficiency does not take into account sudden weather...
This paper introduces a novel metric and approach for link quality measurement new algorithm human-intervention-free optical balancing, specifically designed fiber transfer systems that require bidirectional amplification. Bidirectional amplification, essential reciprocal paths to compensate fluctuations non-data applications like accurate time ultrastable coherent frequency transfer, complexities such as feedback loops phase inconsistencies. Our work ensures amplified signals maintain...
In this paper, we present results of experimental two way transmission precise time over 400 km fully reciprocal bi-directionally amplified optical path outside the telecommunication C band. Used was White Rabbit system, which combines synchronous Ethernet and Precise Time Protocol (IEEE-1588) however previously developed Transfer Adapters should provide slightly better performance.
We present a preliminary study of bidirectional ultra-stable optical frequency and precise time transmission over 406 km long path in the telecom-grade fiber optic infrastructure dense wavelength division multiplexing. The main challenge this application is need amplification to compensate for signal loss. Directional non-reciprocities transfer are evaluated together with their uncertainties. Solutions proposed significantly limit final uncertainty.
Smart transportation is one of the key components smart city. A significant amount data produced by numerous vehicles connected via wireless networks. This demands spectrum management for efficient communication. The optimal bandwidth usage can be obtained opportunistically sharing among high-priority class primary and low-priority secondary users’ vehicles. In this study, we develop a mathematical model to ensure effective resource allocation in cognitive-radio-based networks (CR-STNs)...
This contribution focuses on experimental verification of the QKD system deployment in a multi-domain network environment managed by Czech and Polish National Research Educational Network (NREN) operators. We demonstrate full functionality such solution for transmission secret keys boundary conditions, with this we open up new possibilities further use extremely secure communication between two neighboring entities, services built upon it. Moreover, have shared cross-border link among strong...
In the article, we introduce Czech Infrastructure for Time and Frequency activity which is a non-commercial, open focused on transfer of accurate time very stable frequency using optical networks. The national infrastructure operated top CESNET network infrastructure, to have operational costs under control. We briefly summarize history its development, together with used types stabilization. also address running planned upgrades future development plans regarding wavelength bands considered...
Precise time and also stable frequency transfers are approaching the state to become almost standard applications for optical fiber networks, especially they becoming supported in multiple research education networks. In principle, not possible be implemented over data transport layer, which hasn’t been was designed essential stability, thus dedicated wave band is required such implementation. To achieve even better stability precise frequency, bidirectional transmission single physical...
Long distance precise frequency and accurate time transfer methods based on optical fiber links have evolved rapidly in recent years, demonstrating excellent performance. They are attractive both for very high-performance applications as a secure alternative complement to radio- satellite-based methods. In this paper, we present development of infrastructure such transmission containing 700+km lines, with planned cross border connectivity. According our knowledge, will be the third line...
In the Internet of Things (IoT), Wireless Sensor Networks (WSNs) play a pivotal role in landscape, connecting devices for smart applications. The IoT is groundbreaking innovation modern era, particularly vital advancing healthcare through Leveraging sensor data from consumer electronics mobile such as phones, physicians can remotely monitor patients' health within system. Efficiency, rapid response, and security are system aids patients with limited battery life. Yet, patient monitoring...
Long-distance time and frequency transfer methods in optical fiber links have matured recent years, including into this parallel operation with data. On other hand quantum entanglement over shared are really rare. This paper presents the initial steps of verifying potential for sharing classical data entangled states on same fiber..
There has been an increased focus on precise time and frequency transmission dissemination at a national international level recently. We would like to present the situation in Czech Republic, our strategy, approach, experience with non-commercial, cost-effective solution that utilizes shared optical networks. The presented provides accurate stable lower operational cost, utilizing spectrum of CESNET3 network infrastructure. are committed future developments upgrades will include next...
Precise time and ultra-stable optical frequency transfers over fiber networks are deployed relatively often these days. When size of such infrastructure for precise bidirectional transmission is becoming significant, aspects associated with operational cost needed deployment must be considered. First can decreased via sharing telecommunication traffic, however spectral allocation considered carefully to avoid mutual disturbance versus data allow future accommodation growing demands. In text,...
Precise time and ultra-stable optical frequency transfers over fiber networks are deployed often in the present days. When size of such infrastructure for precise bidirectional transmission is becoming significant, aspects associated with operational costs needed deployment must be considered. First can decreased via sharing telecommunication traffic, however spectral allocation considered carefully to avoid mutual disturbance versus data, allow future accommodation growing demands. In text,...
In this paper, we introduce and verify direct wavelength tuning of V-cavity laser based transceiver as a method for optical stabilization the end-to-end delay an fiber link. Other mostly deployed methods are briefly overviewed together with particular lasers available in commercial transceivers. Fine procedure chosen is proposed, such process verified, increasing finesse at least 13 times (40 on selected intervals).
Optical fibers are becoming commonly used beside data transmissions for dissemination of ultra-precise and stable quantities or alternatively as distributed sensors example acoustic mechanic vibrations, seismic waves, temperature etc. There have been developed methods these transfers their stabilization, allowing thus to achieve excellent performances. Such performance is bound with utilization single physical medium both ways propagation. These attractive very high-performance applications...