Radio Astronomy and Spectrum Management: The Impact of WARC-79

1981 ◽  
Vol EMC-23 (3) ◽  
pp. 308-317 ◽  
Author(s):  
Vwenon Pankonin ◽  
R. Price
Keyword(s):  
Radio Astronomy ◽  
Spectrum Management ◽  
The Impact

An Energy Efficient Spectrum Aware Routing for Cognitive Radio Networks (CRNs)

2020 ◽  
Vol 10 ◽  
Author(s):  
Dileep Reddy Bolla ◽  
Jijesh J J ◽  
Mahaveer Penna ◽  
Shiva Shankar
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Cognitive Radio Networks ◽  
Energy Efficient ◽  
Research Work ◽  
Spectrum Management ◽  
Residual Energy ◽  
Radio Networks ◽  
Traffic Load ◽  
The Impact

Back Ground/ Aims:: Now-a-days in the Wireless Communications some of the spectrum bands are underutilized or unutilized; the spectrum can be utilized properly by using the Cognitive Radio Techniques using the Spectrum Sensing mechanisms. Objectives:: The prime objective of the research work carried out is to achieve the energy efficiency and to use the spectrum effectively by using the spectrum management concept and achieve better throughput, end to end delay etc., Methods:: The detection of the spectrum hole plays a vital role in the routing of Cognitive Radio Networks (CRNs). While detecting the spectrum holes and the routing, sensing is impacted by the hidden node issues and exposed node issues. The impact of sensing is improved by incorporating the Cooperative Spectrum Sensing (CSS) techniques. Along with these issues the spectrum resources changes time to time in the routing. Results:: All the issues are addressed with An Energy Efficient Spectrum aware Routing (EESR) protocol which improves the timeslot and the routing schemes. The overall network life time is improved with the aid of residual energy concepts and the overall network performance is improved. Conclusion:: The proposed protocol (EESR) is an integrated system with spectrum management and the routing is successfully established to communication in the network and further traffic load is observed to be balanced in the protocol based on the residual energy in a node and further it improves the Network Lifetime of the Overall Network and the Individual CR user, along with this the performance of the proposed protocol outperforms the conventional state of art routing protocols.

scholarly journals Response of the Molonglo Observatory Synthesis Telescope to Terrestrial Interference

1997 ◽  
Vol 14 (3) ◽  
pp. 265-273 ◽  
Author(s):  
D. Campbell-Wilson ◽  
G. Davidson ◽  
M. I. Large
Keyword(s):  
Radio Astronomy ◽  
Experimental Tests ◽  
Spectrum Management ◽  
Management Agency ◽  
International Telecommunications ◽  
Commercial Use ◽  
Extensive Survey

AbstractIn conjunction with the Australian Government's Spectrum Management Agency, experimental tests have been carried out to determine the susceptibility of the Molonglo Observatory Synthesis Telescope (MOST) to interference from terrestrial transmitters. The motivation for the tests was to reconcile the conflicting requirements of the MOST, which is committed to an extensive survey of the southern sky at 843 MHz, with the commercial use of the 825–845 MHz band, which is being prepared for sale. The tests show that the far sidelobe gain of the MOST, relative to an isotropic antenna is generally less than 1, and that an appropriate interference criterion would be that in-band interference irradiance should not exceed −173 dBWm−2. This value is similar to that considered by the International Telecommunications Union to be detrimental to radio astronomy continuum observations at nearby frequencies.

scholarly journals A new era for low frequency Galactic center transient monitoring

2013 ◽  
Vol 9 (S303) ◽  
pp. 458-460
Author(s):  
N. E. Kassim ◽  
S. D. Hyman ◽  
H. Intema ◽  
T. J. W. Lazio
Keyword(s):  
Radio Astronomy ◽  
Galactic Center ◽  
Monitoring Program ◽  
Low Frequency ◽  
Frequency Range ◽  
New Era ◽  
The Impact ◽  
New System

AbstractAn upgrade of the low frequency observing system of the VLA developed by NRL and NRAO, called low band (LB), will open a new era of Galactic center (GC) transient monitoring. Our previous searches using the VLA and GMRT have revealed a modest number of radio-selected transients, but have been severely sensitivity and observing time limited. The new LB system, currently accessing the 236--492 MHz frequency range, promises ≥5 × improved sensitivity over the legacy VLA system. The new system is emerging from commissioning in time to catch any enhanced sub-GHz emission from the G2 cloud event, and we review existing limits based on recent observations. We also describe a proposed 24/7 commensal system, called the LOw Band Observatory (LOBO). LOBO offers over 100 VLA GC monitoring hours per year, possibly revealing new transients and helping validate ASTRO2010's anticipation of a new era of transient radio astronomy. A funded LOBO pathfinder called the VLA Low Frequency Ionosphere and Transient Experiment (VLITE) is under development. Finally, we consider the impact of LB and LOBO on our GC monitoring program.

scholarly journals Radio quiet, please! – protecting radio astronomy from interference

2009 ◽  
Vol 5 (S260) ◽  
pp. 457-464 ◽  
Author(s):  
W. van Driel
Keyword(s):  
Radio Astronomy ◽  
Radio Spectrum ◽  
Spectrum Management ◽  
International Telecommunication Union ◽  
Frequency Bands ◽  
International Telecommunication ◽  
Regulatory Limits ◽  
Regulatory Bodies ◽  
Precious Resource ◽  
Regulatory Measures

AbstractThe radio spectrum is a finite and increasingly precious resource for astronomical research, as well as for other spectrum users. Keeping the frequency bands used for radio astronomy as free as possible of unwanted Radio Frequency Interference (RFI) is crucial. The aim of spectrum management, one of the tools used towards achieving this goal, includes setting regulatory limits on RFI levels emitted by other spectrum users into the radio astronomy frequency bands. This involves discussions with regulatory bodies and other spectrum users at several levels – national, regional and worldwide. The global framework for spectrum management is set by the Radio Regulations of the International Telecommunication Union, which has defined that interference is detrimental to radio astronomy if it increases the uncertainty of a measurement by 10%. The Radio Regulations are revised every three to four years, a process in which four organisations representing the interests of the radio astronomical community in matters of spectrum management (IUCAF, CORF, CRAF and RAFCAP) participate actively. The current interests and activities of these four organisations range from preserving what has been achieved through regulatory measures, to looking far into the future of high frequency use and giant radio telescope use.

Radiation Aware Efficient Sensor Deployment and Optimal Routing in Dynamic Three-Dimensional WBAN Topology

2014 ◽  
Vol 5 (4) ◽  
pp. 67-89
Author(s):  
Hassine Moungla ◽  
Nora Touati ◽  
Ahmed Mehaoua
Keyword(s):  
Flow Model ◽  
Three Dimensional ◽  
Path Loss ◽  
Life Time ◽  
Spectrum Management ◽  
Delivery Ratio ◽  
Commodity Flow ◽  
Trade Offs ◽  
Dynamic Topology ◽  
The Impact

This work further investigates paradigm of radiation awareness three-dimentionnel models for WBAN network environments. The authors incorporate the effect of dynamic topology as well as the time domain and environment aspects. Even, if the impact of radiation to human health remains largely unexplored and controversial. They ask two fundamental issues, (a) deployment and (b) information routing taking into account radiation awarness. The authors first propose a multi objectives flow model which allows describing a new optimal deployment model for WBAN sensor devices with dynamic topology and the relevant possible trade-offs between coverage, connectivity, network life time while maintaining at low levels the radiation cumulated by wireless transmissions. They propose oblivious deployment heuristics that are radiation aware. The authors then combine them with dynamic spectrum management is proposed based multi-commodity flow model which allows to prevent sensor node saturation and take best action against reliability and the path loss, by imposing an equilibrium use of sensors during the routing process in order to “spread” radiation in a spatio-temporal way. Experimental results show that the proposed models and algorithms balances the energy consumption of nodes effectively, maximize the network lifetime . It will meet the enhanced WBANs requirements, including better delivery ratio, less reliable routing overhead. Their proposed radiation aware deployment and routing heuristics succeed to keep radiation levels low.

scholarly journals Radio Astronomy at WARC MOB-87

1991 ◽  
Vol 112 ◽  
pp. 296-304
Author(s):  
T. E. Gergely
Keyword(s):  
Radio Astronomy ◽  
Mobile Services ◽  
Radio Spectrum ◽  
Satellite Systems ◽  
The World ◽  
Mobile Satellite ◽  
Primary Basis ◽  
Similar Basis ◽  
Satellite Service ◽  
The Impact

ABSTRACTThe World Administrative Radio Conference for the Mobile Services (WARC Mob-87), held in Geneva in September-October, 1987, took several actions that will have an impact on radio astronomy. Worldwide frequency allocations were made for the Radiodetermination Satellite Service (RDSS) in the 1610 to 1626.5 MHz band. The secondary allocation to radio astronomy in this band has received strong protection, however. The 1660 to 1660.5 MHz band, which radio astronomy shared on a primary basis with the Aeronautical Mobile Satellite Service has been reallocated to the Land Mobile Satellite Service, shared with radio astronomy on a similar basis. The impact that this reallocation will have on radio astronomy is not clear. Since the Radioastronomy Service is primary in the band, Mobile Satellite Systems that evolve will have to provide adequate protection. Perhaps most significantly, WARC Mob-87 recommended that a conference be convened to reallocate all bands in the 1 to 3 GHz range, no later than in 1992. Several other conferences dealing with particular services have been proposed. At first glance, some of these some of these proposals may not appear to have an impact on radio astronomy. They will, however, increase the pressure on the entire radio spectrum. Finally, it is highly likely that a General WARC will be proposed to be held before the end of the 1990s. The radio astronomy community will have to prepare for these conferences.

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