Telecommunications Research and Engineering at the Communications Technology Laboratory of the Department of Commerce Meeting the Nation's Telecommunications Needs (2015) / Chapter Skim
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Appendix D: The Value and Use of Wireless Technology
Appendix D: The Value and Use of Wireless Technology
Pages 41-49
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From page 41... ...
The terms airwaves and radio waves are sometimes used for EM waves, and the entire range of EM frequencies available for applications is called spectrum. Governments all over the world control their own airwaves by allocating separate bands of spectrum for separate applications.
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From page 42... ...
, as well as standard frequency and time signals, discrete frequencies that require exclusivity for radio astronomy, and amateur radio. Through extensive negotiation, the entire radio spectrum has been divided into specific blocks of frequencies for each application; most often, several blocks at different carrier frequencies can service the same application.
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From page 43... ...
FirstNet will build, operate, and maintain the first high-speed, nationwide wireless broadband network dedicated to public safety. The spectrum license issued to FirstNet is for two 10 MHz channels of paired spectrum at 758-768 MHz and 788-798 MHz, plus guard bands at 768-769 MHz and 798-799 MHz to reduce interference from adjacent channels.
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From page 44... ...
Higher carrier frequencies designated with larger bandwidths can carry more information, but walls and other obstacles may block it. The highest frequencies -- millimeter waves (mmband)
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From page 45... ...
• Scientific applications. There is a multitude of scientific users of radio spectrum including radio astronomers and Earth scientists using remote sensing.
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From page 46... ...
A sharp heat boundary is created between the affected tissue and that surrounding it allowing for surgeons to operate with a high level of precision and control, without much sacrifice to the adjacent normal tissue. The lower operating temperatures of RF, as compared to traditional electrosurgical or laser surgery tools, enables surgeons to remove, shrink, or sculpt soft tissue while simultaneously sealing blood vessels.
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From page 47... ...
and WiMax mobile networks." 7 Similar to the WLAN unlicensed products moving from 1 to 5 GHs frequencies in early generation to 60 GHz today, the cellular industry is moving 4 United States CFR Title 47, Part 15 -- Radio Frequency Devices, Subpart E -- Unlicensed National Information Devices, Paragraph 15.407 -- General technical requirements. 5 Millimeter Wave Transmission Website, European Telecommunications Standards Institute, Quarter 1, 2015, http://www.etsi.org/images/files/ETSITechnologyLeaflets/MillimetreWaveTransmission.pdf.
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From page 48... ...
Thus, it permits aggressive frequency reuse while simultaneously operating networks that do not hinder each other. 11 Highly directional antennas needed for path loss mitigation actually work to promote security as long as network protocols and front-end hardware enabled antenna arrays are flexibly steered.
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From page 49... ...
13 It is worth mentioning that work is already under way to understand what might be done in the Terahertz bands. This is a wide open research area at this point, and the Boulder telecommunications laboratories could be engaged to think about this very unique spectrum and how it might be measured and used in the future.
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