scholarly journals Programmable Spectral Filter in C-Band Based on Digital Micromirror Device

Micromachines ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 163 ◽  
Author(s):  
Yunshu Gao ◽  
Xiao Chen ◽  
Genxiang Chen ◽  
Zhongwei Tan ◽  
Qiao Chen ◽  
...  
Keyword(s):  
High Power ◽  
Optical Filters ◽  
Digital Micromirror Device ◽  
Center Wavelength ◽  
International Telecommunication Union ◽  
International Telecommunication ◽  
Programmable Filter ◽  
Channel Bandwidth ◽  
Power Handling Capability ◽  
Minimum Bandwidth

Optical filters have been adopted in many applications such as reconfigurable telecommunication switches, tunable lasers and spectral imaging. However, most of commercialized filters based on a micro-electrical-mechanical system (MEMS) only provide a minimum bandwidth of 25 GHz in telecom so far. In this work, the programmable filter based on a digital micromirror device (DMD) experimentally demonstrated a minimum bandwidth of 12.5 GHz in C-band that matched the grid width of the International Telecommunication Union (ITU) G.694.1 standard. It was capable of filtering multiple wavebands simultaneously and flexibly by remotely uploading binary holograms onto the DMD. The number of channels and the center wavelength could be adjusted independently, as well as the channel bandwidth and the output power. The center wavelength tuning resolution of this filter achieved 0.033 nm and the insertion loss was about 10 dB across the entire C-band. Since the DMD had a high power handling capability (25 KW/cm2) of around 200 times that of the liquid crystal on silicon (LCoS) chip, the DMD-based filters are expected to be applied in high power situations.

scholarly journals The graph neural networking challenge

2021 ◽  
Vol 51 (3) ◽  
pp. 9-16
Author(s):  
José Suárez-Varela ◽  
Miquel Ferriol-Galmés ◽  
Albert López ◽  
Paul Almasan ◽  
Guillermo Bernárdez ◽  
...  
Keyword(s):  
Machine Learning ◽  
Computer Networks ◽  
Real World ◽  
Large Scale ◽  
Lessons Learned ◽  
Educational Resources ◽  
Global Competition ◽  
International Telecommunication Union ◽  
International Telecommunication ◽  
Broad Audience

During the last decade, Machine Learning (ML) has increasingly become a hot topic in the field of Computer Networks and is expected to be gradually adopted for a plethora of control, monitoring and management tasks in real-world deployments. This poses the need to count on new generations of students, researchers and practitioners with a solid background in ML applied to networks. During 2020, the International Telecommunication Union (ITU) has organized the "ITU AI/ML in 5G challenge", an open global competition that has introduced to a broad audience some of the current main challenges in ML for networks. This large-scale initiative has gathered 23 different challenges proposed by network operators, equipment manufacturers and academia, and has attracted a total of 1300+ participants from 60+ countries. This paper narrates our experience organizing one of the proposed challenges: the "Graph Neural Networking Challenge 2020". We describe the problem presented to participants, the tools and resources provided, some organization aspects and participation statistics, an outline of the top-3 awarded solutions, and a summary with some lessons learned during all this journey. As a result, this challenge leaves a curated set of educational resources openly available to anyone interested in the topic.

scholarly journals A line-of-sight channel model for the 100–450 gigahertz frequency band

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Joonas Kokkoniemi ◽  
Janne Lehtomäki ◽  
Markku Juntti
Keyword(s):  
Channel Model ◽  
Full Range ◽  
Line Of Sight ◽  
Absorption Loss ◽  
Radio Communication ◽  
International Telecommunication Union ◽  
International Telecommunication ◽  
Fifth Generation ◽  
Proposed Model ◽  
Actual Response

AbstractThis paper documents a simple parametric polynomial line-of-sight channel model for 100–450 GHz band. The band comprises two popular beyond fifth generation (B5G) frequency bands, namely, the D band (110–170 GHz) and the low-THz band (around 275–325 GHz). The main focus herein is to derive a simple, compact, and accurate molecular absorption loss model for the 100–450 GHz band. The derived model relies on simple absorption line shape functions that are fitted to the actual response given by complex but exact database approach. The model is also reducible for particular sub-bands within the full range of 100–450 GHz, further simplifying the absorption loss estimate. The proposed model is shown to be very accurate by benchmarking it against the exact response and the similar models given by International Telecommunication Union Radio Communication Sector. The loss is shown to be within ±2 dBs from the exact response for one kilometer link in highly humid environment. Therefore, its accuracy is even much better in the case of usually considered shorter range future B5G wireless systems.

Gradient honeycomb absorber with high power handling capability

2021 ◽  
Vol 127 (2) ◽  
Author(s):  
L. Liu ◽  
Y. Zhang ◽  
J. Q. Sheng ◽  
Y. M. Wei ◽  
R. M. Liu ◽  
...  
Keyword(s):  
High Power ◽  
Power Handling ◽  
Power Handling Capability

THE ROLE OF HARMONIZATION OF ACTIVITIES TO IMPROVE THE RATING OF RUSSIA IN THE INTERNATIONAL STATISTICAL COMPARISONS IN TELECOMMUNICATIONS AND ICT

2020 ◽  
Author(s):  
Н.П. РЕЗНИКОВА ◽  
Г.С. АРТЕМЬЕВА ◽  
Д.В. КАЛЮГА
Keyword(s):  
Sustainable Development ◽  
Sustainable Development Goals ◽  
International Telecommunication Union ◽  
The Sustainable Development ◽  
International Telecommunication ◽  
Development Goals ◽  
The Russian Federation ◽  
Ict Development ◽  
The Impact

Представлены основные направления для поиска путей улучшения рейтинга Российской Федерации в международных статистических сопоставлениях в сфере электросвязи/ИКТ с учетом необходимости гармонизации разнообразных направлений деятельности, связанных с оценкой влияния электросвязи/ИКТ на достижение Целей устойчивого развития, а также с появлением Нового индекса Международного союза электросвязи (МСЭ) взамен Индекса развития ИКТ(IDI). OThe main directions for finding ways to improve the rating of the Russian Federation in international statistical comparisons in the field of telecommunications/ICT are presented, taking into account the need to harmonize various activities related to assessing the impact of telecommunications/ICTs on achieving the sustainable development goals, as well as the advent of the new International Telecommunication Union Index instead of the ICT Development Index (IDI).

Based on Estimation of the Ionospheric Characteristics HF Frequency Prediction Method

2012 ◽  
Vol 190-191 ◽  
pp. 936-939
Author(s):  
Chao Li ◽  
Yun Jiang Liu ◽  
Heng Yang Zhang ◽  
Xiao Peng Yang ◽  
Feng Wang
Keyword(s):  
Calculation Method ◽  
Prediction Method ◽  
Engineering Calculation ◽  
International Telecommunication Union ◽  
International Telecommunication ◽  
Time Availability ◽  
Hf Channel

To grasp Complex characteristics of shortwave (HF) channel is the key and difficulty to research HF communication. On the premise of comprehending the ionosphere prediction method in the Asia Oceania region, HF frequency prediction method recommended by the International Telecommunication Union (ITU) is improved in this paper, and the engineering calculation method of predicting HF frequency in the Asia Oceania region is concluded and summarized. Comparing with the ITS (the Institute for Telecommunication Science) software’s predicting result, the method is improved to some extent in time availability and SNR in the receiving point.

International Telecommunication Union

1957 ◽  
Vol 11 (3) ◽  
pp. 538-538
Keyword(s):  
Experimental Data ◽  
Technical Assistance ◽  
Study Groups ◽  
Great Difficulty ◽  
Consultative Committee ◽  
Sufficient Time ◽  
International Telecommunication Union ◽  
International Telecommunication ◽  
Definition Of ◽  
New System

The eighth plenary assembly of the International Radio Consultative Committee (CCIR) was held in Warsaw from August 9 to September 13, 1956, under the chairmanship of Professor Pawel Szulkin (Poland). The assembly elected with an absolute majority Dr. E. Metzler (Switzerland) as Director. The assembly considered a report which dealt with the activities of the fourteen established study groups as well as proposals to reorganize the study groups. The Warsaw decisions modifying procedures experimentally for the future were the outcome of proposals by the Organization and Finance Committees, the CCIR Secretariat and of discussions of the problem in the plenary assembly. The study groups were to remain the same in number and the allocation of work was in general the same, though it was felt desirable to give a more precise definition of their terms of reference. Among the resolutions adopted by the assembly, a number dealt with the length, content and quantity of documents submitted to the chairmen of the study groups, emphasizing that these should be as short as possible, as few as possible and that they should contain only the minimum indispensable mathematical formulae or numerical and experimental data. The new system was also expected to improve the position of distant countries which had so far experienced great difficulty in receiving preliminary documentation in sufficient time before plenary assemblies. The Technical Assistance Committee recommended the creation of a joint CCIR-International Telegraph and Telephone Consultative Committee (CCITT) committee to consider the ways and means whereby technical assistance was at present granted and to make suggestions for improvements, as far as telecommunication was concerned, to the ITU Administrative Council.

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