scholarly journals Propagation measurements and analysis on MF and HF bands in urban areas in The Netherlands

2021 ◽  
Author(s):  
Koos T.W.H. Fockens ◽  
Robert Vogt-Ardatjew ◽  
Frank Leferink
Keyword(s):  
The Netherlands ◽  
Urban Areas ◽  
Propagation Model ◽  
Propagation Loss ◽  
Frequency Range ◽  
International Telecommunication Union ◽  
International Telecommunication ◽  
Set Up ◽  
Propagation Measurement ◽  
Ground Wave

Using a new propagation measurement set-up, which produces a high number of data, enabling a proper statistical analysis, and resulting in very concise results, propagation measurements were performed and analized at 16 residential locations in The Netherlands in the frequency range from 1.8 to 28 MHz. In the whole frequency range the propagation loss appear to be higher than according the International Telecommunication Union ground-wave propagation model might be expected. Also typical characteristics of that model are not present, but instead the propagation shows a constant roll-off in dBs per decade, which slope is increasing with frequency. A regression curve could be established, and constants filled in. This statistical information may be used for building an accumulation model to lay a causality between source powers, source densities, and local Man-Made Noise levels.<br><br>

scholarly journals Propagation measurements and analysis on MF and HF bands in urban areas in The Netherlands

2021 ◽  
Author(s):  
Koos T.W.H. Fockens ◽  
Robert Vogt-Ardatjew ◽  
Frank Leferink
Keyword(s):  
The Netherlands ◽  
Urban Areas ◽  
Propagation Model ◽  
Propagation Loss ◽  
Frequency Range ◽  
International Telecommunication Union ◽  
International Telecommunication ◽  
Set Up ◽  
Propagation Measurement ◽  
Ground Wave

Using a new propagation measurement set-up, which produces a high number of data, enabling a proper statistical analysis, and resulting in very concise results, propagation measurements were performed and analized at 16 residential locations in The Netherlands in the frequency range from 1.8 to 28 MHz. In the whole frequency range the propagation loss appear to be higher than according the International Telecommunication Union ground-wave propagation model might be expected. Also typical characteristics of that model are not present, but instead the propagation shows a constant roll-off in dBs per decade, which slope is increasing with frequency. A regression curve could be established, and constants filled in. This statistical information may be used for building an accumulation model to lay a causality between source powers, source densities, and local Man-Made Noise levels.<br><br>

scholarly journals International Telecommunication Union

1948 ◽  
Vol 2 (3) ◽  
pp. 536-537 ◽  
Keyword(s):  
The Netherlands ◽  
South African ◽  
Consultative Committee ◽  
International Telecommunication Union ◽  
Vice Chairman ◽  
International Telecommunication ◽  
Quality Of Transmission ◽  
Interim Period ◽  
Chairman Committee

The sixth meeting of the International Telegraph Consultative Committee was held in Brussels from May 10 to 27, 1948, the first meeting of the committee since 1936. C. Caenepenne, head of the Belgian delegation, was elected chairman of the conference, and E. C. Smith, head of the South African delegation, was elected vice-chairman. Committee reports presented to the conference included studies of the quality of transmission, standardization of telegraphic devices, relays, and general telegraphic and telephonic problems. Organizational matters for the interim period between meetings of the committee were discussed and a budget accepted. The seventh meeting of the Consultative Committee was scheduled for 1951 in the Netherlands.

Development of Movable and Deployable ICT Resource Unit (MDRU) and its Overseas Activities

2019 ◽  
Vol 14 (2) ◽  
pp. 363-374 ◽  
Author(s):  
Yoshitaka Shimizu ◽  
Yasuo Suzuki ◽  
Ryota Sasazawa ◽  
Yuichi Kawamoto ◽  
Hiroki Nishiyama ◽  
...  
Keyword(s):  
The Philippines ◽  
Lessons Learned ◽  
Local Network ◽  
Great Earthquake ◽  
International Telecommunication Union ◽  
Resident Participation ◽  
International Telecommunication ◽  
Ict Service ◽  
Improved Performance ◽  
Set Up

Based on the lessons learned from the East Japan Great Earthquake of March 11, 2011, the authors have been engaged in the research and development of movable and deployable information and communication technology (ICT) resource units (MDRUs), which provide immediate and minimally required ICT service in areas struck by disaster. The MDRU is a transportable unit that contains equipment necessary for ICT service provisions and is designed to be quickly transported to and set up in affected areas after a natural disaster has struck. The unit is used to quickly construct a wireless local network in the area, and thus provide immediate and minimally required ICT service to the people in the area. In this paper, we describe MDRU technology and other technologies that lead to improved performance and/or service when connected or linked up with the unit. Along with this development, we have conducted various activities aimed at its international deployment. Specifically, we conducted trials with resident participation in the Philippines and Nepal to verify the validity of these technologies overseas, where we were able to confirm its validity under various conditions. Furthermore, we have undertaken activities for its standardization, and have succeeded in the standardization of MDRU at International Telecommunication Union Telecommunication Standardization Sector (ITU-T).

The International Telecommunication Union: Origin and Role

2021 ◽  
Author(s):  
Francis Lyall
Keyword(s):  
High Frequency ◽  
Study Groups ◽  
Radio Communication ◽  
Modern Life ◽  
International Telecommunication Union ◽  
Satellite Systems ◽  
International Telecommunication ◽  
International Body ◽  
Set Up ◽  
Modern Technologies

Integral to modern life, electrical telecommunications have to work within the constraints set by the unalterable laws of physics. Transborder systems require that technologies and protocols be harmonized if there is to be interconnectivity and interoperability. International agreements on wired services date back to the 1850s. Separate bodies set up to deal with international communications in east and west Europe, were brought together in 1865 in a single international body, the International Telegraph Union. Wireless communication—radio—presented the additional problem of broadcast signals interfering with each other. From 1906, it was regulated on the basis of principles that still undergird the modern arrangements, but no formal international body was established for the purpose. Instead, radio was dealt with by a sequence of plenipotentiary conferences. The separate regimes for wired and wireless services were united in 1932 when the International Telecommunication Union was established. The 193-member union is the UN specialized agency that deals with all forms of telecommunication. It underwent a major reconstruction in 1992–1994 in order to cope with modern technologies and now works within a four-year cycle. Its institutions are its plenipotentiary conference, a council, a secretariat, and three sectors responsible, respectively, for development, standardization, and radio communication. Each of these last three has a bureau and holds international world and regional conferences, and is aided by a large number of specialized study groups. In radiocommunication, that sector supervises the operation of the Radio Regulations, in which a Table of Allocations prescribes which radio frequencies are used for what purpose and maintains a Master International Frequency Register, which records the active frequency assignments made by states to transmitting stations under their control. Its work has increased markedly with development of high-frequency systems and the proliferation of satellite systems serving various purposes.

International Telecommunication Union

1960 ◽  
Vol 14 (2) ◽  
pp. 338-339 ◽  
Keyword(s):  
The Netherlands ◽  
Future Development ◽  
Buenos Aires ◽  
Secretary General ◽  
Atlantic City ◽  
International Telecommunication Union ◽  
International Telecommunication ◽  
New Radio ◽  
Made In ◽  
The Way

At the conclusion of the two International Telecommunication Union (ITU) conferences held in Geneva in 1959—the Plenipotentiary (October 14 to December 16) and the Administrative Radio (August 17 to December 17)—two international documents were officially signed by the representatives of 85 and 84 countries respectively, namely: 1) the new Convention, replacing the International Telecommunication Convention of Buenos Aires, 1952; and 2) the new Radio Regulations, replacing those of Atlantic City, 1947. The Convention was to take effect on January 1, 1961, and the Radio Regulations on May i, 1961. Some additional protocols had to be signed as well, so that certain decisions (for example, the elections of the newly-constituted Administrative Council, the Secretary-General, and the Deputy Secretary-General, and changes made in the budget system) could take effect forthwith. Numerous recommendations and resolutions were also adopted, and decisions concerning the way ITU was organized, how it was run, and its future development were reached by the Plenipotentiary Conference, the chairman of which was Mr. J. D. H. van der Toorn, head of the Netherlands delegation. The chairman of the Radio Conference was Mr. Charles J. Acton, head of the Canadian delegation.

International Telecommunication Union

1966 ◽  
Vol 20 (3) ◽  
pp. 650-651
Keyword(s):  
Study Group ◽  
Main Task ◽  
Sufficient Time ◽  
International Telecommunication Union ◽  
International Telecommunication ◽  
Set Up ◽  
One Year

The ninth Plenipotentiary Conference of the International Telecommunication Union (ITU) took place in Montreux, Switzerland, between September 14 and November 12, 1965, under the chairmanship of Gustav-Adolf Wettstein (Switzerland). The main task of the Conference was the revision of the previous Convention, drawn up by the preceding Plenipotentiary Conference in Geneva in 1959. The new Convention was to enter into force on January 1, 1967. In one of its major decisions the Conference agreed in principle on a Constitutional Charter eventually to replace the Convention, and it instructed the Administrative Council to set up a study group to prepare the draft of such a charter in sufficient time for it to be distributed at least one year prior to the next Conference, scheduled to be held in 1971. The Conference approved the Union's accounts for the years 1959–1964 and fixed the limits of expenditure for the period 1966–1971, providing for slight annual increases in this expenditure. It also approved the purchase of the new headquarters building by December 31, 1965.

scholarly journals Investigation on the Frequency Allocation for Radio Astronomy at the L Band

2013 ◽  
Vol 30 ◽  
Author(s):  
Z. Z. Abidin ◽  
R. Umar ◽  
Z. A. Ibrahim ◽  
Z. Rosli ◽  
K. Asanok ◽  
...  
Keyword(s):  
Population Density ◽  
Radio Astronomy ◽  
Spiral Galaxies ◽  
Civil Aviation ◽  
Radio Frequency Interference ◽  
Frequency Range ◽  
Frequency Allocation ◽  
International Telecommunication Union ◽  
International Telecommunication ◽  
L Band

AbstractIn this paper, the frequency allocation reserved for radio astronomy in the L band set by the International Telecommunication Union (ITU), which is between 1400 and 1427 MHz, is reviewed. We argue that the nearby frequencies are still very important for radio astronomers on the ground by investigating radio objects (H i sources) around 1300–1500 MHz. The L-band window is separated into a group of four windows, namely 1400–1427 MHz (window A), 1380–1400 MHz (window B), 1350–1380 MHz (window C), and 1300–1350 MHz (window D). These windows are selected according to their redshifts from a rest frequency for hydrogen spectral line at 1420.4057 MHz. Radio objects up to z ≈ 0.1 or frequency down to 1300 MHz are examined. We argue that since window B has important radio objects within the four windows, this window should also be given to radio astronomy. They are galaxies, spiral galaxies, and galaxy clusters. This underlines the significance of window B for radio astronomers on the ground. By investigating the severeness of radio frequency interference (RFI) within these windows, we have determined that window B still has significant, consistent RFI. The main RFI sources in the four windows have also been identified. We also found that the Department of Civil Aviation of Malaysia is assigned a frequency range of 1215–1427 MHz, which is transmitted within the four windows and inside the protected frequency for radio astronomy. We also investigated the RFI in the four windows on proposed sites of future radio astronomy observatories in Malaysia and Thailand and found the two best sites as Universiti Pendidikan Sultan Idris (UPSI) and Ubon Ratchathani, respectively. It has also been determined that RFI in window B increases with population density.

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 Calibration and Validation of ArcGIS Solar Radiation Tool for Photovoltaic Potential Determination in the Netherlands

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1865
Author(s):  
Bala Bhavya Kausika ◽  
Wilfried G. J. H. M. van Sark
Keyword(s):  
Solar Radiation ◽  
The Netherlands ◽  
Urban Areas ◽  
Input Data ◽  
Solar Irradiation ◽  
Energy Yield ◽  
Atmospheric Parameters ◽  
Factors Affecting ◽  
Calibration And Validation ◽  
Solar Radiation Model

Geographic information system (GIS) based tools have become popular for solar photovoltaic (PV) potential estimations, especially in urban areas. There are readily available tools for the mapping and estimation of solar irradiation that give results with the click of a button. Although these tools capture the complexities of the urban environment, they often miss the more important atmospheric parameters that determine the irradiation and potential estimations. Therefore, validation of these models is necessary for accurate potential energy yield and capacity estimations. This paper demonstrates the calibration and validation of the solar radiation model developed by Fu and Rich, employed within ArcGIS, with a focus on the input atmospheric parameters, diffusivity and transmissivity for the Netherlands. In addition, factors affecting the model’s performance with respect to the resolution of the input data were studied. Data were calibrated using ground measurements from Royal Netherlands Meteorological Institute (KNMI) stations in the Netherlands and validated with the station data from Cabauw. The results show that the default model values of diffusivity and transmissivity lead to substantial underestimation or overestimation of solar insolation. In addition, this paper also shows that calibration can be performed at different time scales depending on the purpose and spatial resolution of the input data.

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