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<title>Shortwave bands</title>

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<span id="openzim-page-title" class="mw-page-title-main"><span class="mw-page-title-main">Shortwave bands</span></span>

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<p><b>Shortwave bands</b> are frequency allocations for use within the <a href="Shortwave_radio" title="Shortwave radio">shortwave radio</a> spectrum (the upper <a href="Medium_frequency" title="Medium frequency">medium frequency</a> [MF] band and all of the <a href="High_frequency" title="High frequency">high frequency</a> [HF] band). <a href="Radio_wave" title="Radio wave">Radio waves</a> in these frequency ranges can be used for very long distance (transcontinental) communication because they can reflect off layers of <a href="Charged_particle" title="Charged particle">charged particles</a> in the <a href="Ionosphere" title="Ionosphere">ionosphere</a> and return to Earth beyond the horizon, a mechanism called <a href="Skywave" title="Skywave">skywave</a> or “skip” propagation. They are allocated by the <a href="International_Telecommunication_Union" title="International Telecommunication Union">ITU</a> for radio services such as maritime communications, international shortwave broadcasting and worldwide <a href="Amateur_radio" title="Amateur radio">amateur radio</a>. The bands are conventionally named by their <a href="Wavelength" title="Wavelength">wavelength</a> in metres, for example the ‘20 meter band’. <a href="Radio_propagation" title="Radio propagation">Radio propagation</a> and possible communication distances vary depending on the time of day, the season and the level of <a href="Solar_cycle" title="Solar cycle">solar activity</a>.

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<div class="mw-heading mw-heading2"><h2 id="International_broadcast_bands">International broadcast bands</h2></div>

<p>These bands are used by powerful long range AM radio stations, many operated by governments, which broadcast to multiple countries. Most international broadcasters use <a href="Amplitude_modulation" title="Amplitude modulation">amplitude modulation</a> with 5 kHz steps between channels; a few use <a href="Single_sideband" class="mw-redirect" title="Single sideband">single sideband</a> or reduced carrier single sideband modulation.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> The <a href="World_Radiocommunication_Conference" title="World Radiocommunication Conference">World Radiocommunication Conference</a> (WRC), organized under the auspices of the <a href="International_Telecommunication_Union" title="International Telecommunication Union">International Telecommunication Union</a>, allocates bands for various services in periodic conferences. The most recent WRC took place in 2012. At WRC-97 in 1997, the following bands were allocated for <a href="International_broadcasting" title="International broadcasting">international broadcasting</a>:

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<th style="text-align: center; width:80px;">Frequency range (MHz)

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<th>Remarks

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<td>Mostly used locally in tropical regions, with time stations at 2.5 MHz. Although this is regarded as <a href="Shortwave_radio" title="Shortwave radio">shortwave</a>, it is a <a href="Medium_frequency" title="Medium frequency">MF</a> band.

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<td>Mostly used locally in tropical regions, with limited long-distance reception at night. A notable example of a station using this band is Canadian time station <a href="CHU_(radio_station)" title="CHU (radio station)">CHU</a> on 3.33 MHz.

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<td>Mostly used in the <a href="Eastern_Hemisphere" title="Eastern Hemisphere">Eastern Hemisphere</a> after dark; not widely received in North and South America. Shared with the North American <a href="Amateur_radio" title="Amateur radio">amateur radio</a> <a href="80-meter_band" title="80-meter band">80 m band</a>.

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<td>Mostly used locally in <a href="Tropics" title="Tropics">tropical regions</a>, especially Brazil, although widely usable at night. Time stations use 5 MHz.

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<td>Good year-round night band; daytime (long distance) reception poor

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<td>Reception varies by region—reasonably good night reception, but few transmitters in this band target North America. According to the WRC-03 Decisions on HF broadcasting,<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> in <a href="International_Telecommunication_Union_region" class="mw-redirect" title="International Telecommunication Union region">International Telecommunication Union regions</a> 1 and 3, the segment 7.1–7.2 MHz is reserved for amateur radio use and there are no new broadcasting allocations in this portion of the band. 7.35–7.4 MHz is newly allocated; in Regions 1 and 3, 7.4–7.45 MHz was also allocated effective March 29, 2009. In Region 2, 7.2–7.3 MHz is part of the amateur radio <a href="40-meter_band" title="40-meter band">40 m band</a>.

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<td>Most heavily used band. Good year-round night band; seasonal during the day, with best reception in winter. Time stations are clustered around 10 MHz.

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<td>Generally best during summer and <a href="Critical_hours" title="Critical hours">the period before and after sunset</a> year-round

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<td>Substantially used in Eurasia. Similar to the 19 m band; best in summer.

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<td>Day reception good, night reception variable; best during summer. <a href="Time_signal" title="Time signal">Time stations</a> such as <a href="WWV_(radio_station)" title="WWV (radio station)">WWV</a> use 15 MHz.

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<td>Day reception good; night reception varies seasonally, with summer best.

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<td>Lightly utilized; may become a <a href="Digital_Radio_Mondiale" title="Digital Radio Mondiale">Digital Radio Mondiale</a> (DRM) band in future

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<td>Erratic daytime reception, with very little night reception. Similar to 11 metres, but long-distance daytime broadcasting (best on north–south paths) keeps this band active in the Asia-Pacific region.

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<td>Seldom used. Daytime reception is poor in the low solar cycle, but potentially excellent when the solar cycle (generally indicated by the <a href="Wolf_number" class="mw-redirect" title="Wolf number">number of sunspots</a>) is high. Nighttime reception nonexistent, except for local <a href="Surface_wave" title="Surface wave">groundwave</a> propagation. DRM has proposed that this band be used for local digital shortwave broadcasts, testing the concept in <a href="Mexico_City" title="Mexico City">Mexico City</a> in <a href="2005_in_radio" title="2005 in radio">2005</a>. <a href="Citizens_band_radio" title="Citizens band radio">Citizens band</a> (CB) allocation in most countries, is slightly higher in frequency than the broadcasting 11m band. There are reports of pirate CB radio users operating equipment on frequencies as low as 25.615 MHz. In the United States, this band is also shared with <a href="Remote_pickup_unit" title="Remote pickup unit">remote pickup units</a> (RPUs), from 25.87 to 26.1 MHz in FM mode.

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<p>Particularly in the United States and at frequencies under 10 MHz, shortwave broadcasters may operate in between those bands in bands allocated for <a href="Fixed_wireless" title="Fixed wireless">fixed service</a>, with the 60-meter band extending as high as <a href="WBCQ_(SW)" title="WBCQ (SW)">5.13 MHz</a>, the 49-meter band down to <a href="WRMI" title="WRMI">5.8 MHz</a>, the 41-meter band as high as <a href="WRMI" title="WRMI">7.78 MHz</a> and the 31-meter band extending as low as <a href="WINB" title="WINB">9.265 MHz</a>.

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<div class="mw-heading mw-heading2"><h2 id="Amateur_HF_bands">Amateur HF bands</h2></div>

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</style><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="Amateur_radio_frequency_allocations" title="Amateur radio frequency allocations">Amateur radio frequency allocations</a></div>

<p>Amateur radio operators in many countries are allocated several shortwave bands for private, non-commercial use. <a href="Amateur_radio" title="Amateur radio">Amateur radio</a> is a communications service, educational tool and hobby. It is particularly useful in providing emergency communication where standard telecommunications infrastructure is compromised or nonexistent, such as a disaster area or remote region of the globe.

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<div class="mw-heading mw-heading2"><h2 id="Marine,_air,_land_mobile_and_fixed_allocations">Marine, air, land mobile and fixed allocations</h2></div>

<p>Designated bands in the shortwave spectrum are used for ships, aircraft, and land vehicles. Shortwave (HF radio) is used by transoceanic aircraft for communications with air-traffic control centers out of <a href="Radio_propagation" title="Radio propagation">VHF radio range</a>. Most countries with HF citizens'-band allocations use 40 or 80 channels between approximately 26.5 MHz and 27.9 MHz, in 10 kHz steps.

</p><p>Due to antenna-length requirements and the band's long-distance propagation characteristics (undesirable in these cases), much <a href="Land_Mobile_Radio_System" class="mw-redirect" title="Land Mobile Radio System">land-mobile radio</a> activity has moved to <a href="Very_high_frequency" title="Very high frequency">VHF</a> or <a href="Ultra_high_frequency" title="Ultra high frequency">UHF</a> and most cordless-phone use is at UHF or higher. Some segments of the HF spectrum are allocated for fixed services, providing point-to-point communication between sites with no access to wired communications.

</p><p>Illegal "freeband" CB activity can be heard from 25 to 28 MHz, steps with operators generally using AM below 26.965 (US and European CB channel 1) and SSB above 27.405 (US and European CB channel 40). <a href="27_MHz_CB27/81_Bandplan" title="27 MHz CB27/81 Bandplan">CB radio in the UK</a> can be heard from 27.60125 to 27.99125 MHz in 10 kHz steps as well as the lower 26.965 to 27.405 MHz allocation.

</p><p>The UK and Ireland both operate Community Audio Distribution (CADS) in the UK or Wireless Public Address System (WPAS) in Ireland services in the 27.600 to 27.995 MHz portion, AM and FM mode, with two overlapping sets of 40 channels (27.60125 to 27.99125 MHz in 10 kHz steps, and 27.605 to 27.995 MHz in 10 kHz steps).<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> These transmissions are usually rebroadcasts of church services and can sometimes be heard hundreds or even thousands of km (miles). Part of the 11 m/27 MHz band was also allocated in many countries for early-model <a href="Cordless_phone" class="mw-redirect" title="Cordless phone">cordless phones</a>.

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<div class="mw-heading mw-heading2"><h2 id="Military_HF_use">Military HF use</h2></div>

<p>In the US and Canada, as well as the Americas (ITU Region 2) as a whole, there are no pre-designated HF allocations for military use.

Similar rules exist in Europe, where it has become necessary for European amateurs to police the bands due to overcrowding. Most military HF band incursions into the HF ham bands occur in Europe or Africa. Since the end of the <a href="Cold_War" title="Cold War">Cold War</a> specific military HF allocations have gradually disappeared from the HF bands, except for Africa and some parts of Asia. In Australia, the military shares the HF bands with civilian users; this is mainly due to low population density and relative under-use of the HF bands. The military in the Americas and Australia has tended to use the civilian fixed, maritime mobile and aeronautical mobile allocations on an <i>ad hoc</i> (non-interference) basis.

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<div class="mw-heading mw-heading2"><h2 id="Industrial/Scientific/Medical_(ISM)_and_other_HF_allocations">Industrial/Scientific/Medical (ISM) and other HF allocations</h2></div>

<div role="note" class="hatnote navigation-not-searchable">See also: <a href="ISM_radio_band" title="ISM radio band">ISM radio band</a></div>

<p>Above 10 MHz there are numerous frequencies set aside for <a href="Radio_astronomy" title="Radio astronomy">radio astronomy</a>, space research (FCC terminology) and standard- frequency-and-time services. RF <a href="Diathermy" title="Diathermy">diathermy</a> equipment uses 27.12 MHz to heat bulk materials or adhesives for the purpose of drying or improving <a href="Curing_(chemistry)" title="Curing (chemistry)">curing</a>. The industrial use of the frequency suggested the use of the 11 m band for CB radio. About a dozen narrow ("sliver") allocations for ISM exist throughout the radio spectrum. These allocations are among the smallest in the HF band, with respect to national HF allocations.

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<ul><li><a href="World_Administrative_Radio_Conference" title="World Administrative Radio Conference">World Administrative Radio Conference</a></li></ul>

<div class="mw-heading mw-heading2"><h2 id="References">References</h2></div>

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</style><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.monitoringtimes.com/html/swb.html">"Short wave broadcast bands"</a>. <i>MonitoringTimes.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2010-11-19</span></span>.</cite></span>

</li>

<li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text">Introduction on digital technology in the HFBC bands <a rel="nofollow" class="external text" href="http://www.itu.int/ITU-R/terrestrial/broadcast/hf/wrc-03/index.html">Accessed 2011-10-20. (Archived by WebCite at https://www.webcitation.org/62aCbliW6?url=http://www.itu.int/ITU-R/terrestrial/broadcast/hf/wrc-03/index.html</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20080415204116/http://www.itu.int/ITU-R/terrestrial/broadcast/hf/wrc-03/index.html">Archived</a> 2008-04-15 at the <a href="Wayback_Machine" title="Wayback Machine">Wayback Machine</a></span>

</li>

<li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20110118131015/http://stakeholders.ofcom.org.uk/binaries/consultations/cads_scheme/statement/statement.pdf">"Community Audio Distribution Systems (CADS) - Policy Statement"</a> <span class="cs1-format">(PDF)</span>. 2006-09-12. Archived from <a rel="nofollow" class="external text" href="http://stakeholders.ofcom.org.uk/binaries/consultations/cads_scheme/statement/statement.pdf">the original</a> <span class="cs1-format">(PDF)</span> on 2011-01-18.</cite></span>

</li>

</ol></div></div>

<div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2></div>

<ul><li><a rel="nofollow" class="external text" href="http://www.arrl.org">American Radio Relay League</a> – the United States lobbying body for <a href="Amateur_radio" title="Amateur radio">amateur radio</a> and the body responsible for the ARRL Handbook</li>

<li><a rel="nofollow" class="external text" href="http://www.rac.ca">Radio Amateurs of Canada</a> – Canada's National Amateur Radio Society</li>

<li><a rel="nofollow" class="external text" href="http://www.eibispace.de">EiBi & DX</a> – Complete list of International Broadcasting Stations worldwide, frequently updated</li>

<li><a rel="nofollow" class="external text" href="http://www.unwantedemissions.com">UnwantedEmissions.com</a> – Radio spectrum allocations reference</li>

<li><a rel="nofollow" class="external text" href="http://www.short-wave.info">short-wave.info</a> – Easy to interrogate frequency schedules of short wave broadcasters</li>

<li><a rel="nofollow" class="external text" href="http://www.arrl.org/files/file/Regulatory/Band%20Chart/Band%20Chart%20-%2011X17%20Color.pdf">US Amateur Radio Bands chart</a></li>

<li><a rel="nofollow" class="external text" href="http://www.iarums-r1.org/">IARU Region 1 Monitoring System</a> – English and German languages monthly reports on HF amateur bands intruders</li></ul>

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</style><div id="Telecommunications802" style="font-size:114%;margin:0 4em"><a href="Telecommunications" title="Telecommunications">Telecommunications</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="History_of_telecommunication" title="History of telecommunication">History</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Beacon#For_defensive_communications" title="Beacon">Beacon</a></li>

<li><a href="History_of_broadcasting" title="History of broadcasting">Broadcasting</a></li>

<li><a href="Cable_protection_system" title="Cable protection system">Cable protection system</a></li>

<li><a href="Cable_television" title="Cable television">Cable TV</a></li>

<li><a href="Communications_satellite#History" title="Communications satellite">Communications satellite</a></li>

<li><a href="Computer_network#History" title="Computer network">Computer network</a></li>

<li><a href="Data_compression" title="Data compression">Data compression</a>

<ul><li><a href="Audio_coding_format" title="Audio coding format">audio</a></li>

<li><a href="Image_compression" title="Image compression">image</a></li>

<li><a href="Video_coding_format" title="Video coding format">video</a></li></ul></li>

<li><a href="Digital_media" title="Digital media">Digital media</a>

<ul><li><a href="Internet_video" title="Internet video">Internet video</a></li>

<li><a href="Online_video_platform" title="Online video platform">online video platform</a></li>

<li><a href="Social_media" title="Social media">social media</a></li>

<li><a href="Streaming_media" title="Streaming media">streaming</a></li></ul></li>

<li><a href="Drums_in_communication" title="Drums in communication">Drums</a></li>

<li><a href="Edholm's_law" title="Edholm's law">Edholm's law</a></li>

<li><a href="Electrical_telegraph#History" title="Electrical telegraph">Electrical telegraph</a></li>

<li><a href="Heliograph#History" title="Heliograph">Heliographs</a></li>

<li><a href="Hydraulic_telegraph#Greek_hydraulic_semaphore_system" title="Hydraulic telegraph">Hydraulic telegraph</a></li>

<li><a href="Information_Age" title="Information Age">Information Age</a></li>

<li><a href="Information_revolution" class="mw-redirect" title="Information revolution">Information revolution</a></li>

<li><a href="History_of_the_Internet" title="History of the Internet">Internet</a></li>

<li><a href="Mass_media#History" title="Mass media">Mass media</a></li>

<li><a href="History_of_mobile_phones" title="History of mobile phones">Mobile phone</a>

<ul><li><a href="Smartphone" title="Smartphone">Smartphone</a></li></ul></li>

<li><a href="Optical_communication" title="Optical communication">Optical telecommunication</a></li>

<li><a href="Optical_telegraph" title="Optical telegraph">Optical telegraphy</a></li>

<li><a href="Pager" title="Pager">Pager</a></li>

<li><a href="Photophone" title="Photophone">Photophone</a></li>

<li><a href="History_of_prepaid_mobile_phones" title="History of prepaid mobile phones">Prepaid mobile phone</a></li>

<li><a href="History_of_radio" title="History of radio">Radio</a></li>

<li><a href="Radiotelephone" title="Radiotelephone">Radiotelephone</a></li>

<li><a href="Communications_satellite" title="Communications satellite">Satellite communications</a></li>

<li><a href="Semaphore" title="Semaphore">Semaphore</a>

<ul><li><a href="Phryctoria" title="Phryctoria">Phryctoria</a></li></ul></li>

<li><a href="Semiconductor" title="Semiconductor">Semiconductor</a>

<ul><li><a href="Semiconductor_device" title="Semiconductor device">device</a></li>

<li><a href="MOSFET" title="MOSFET">MOSFET</a></li>

<li><a href="History_of_the_transistor" title="History of the transistor">transistor</a></li></ul></li>

<li><a href="Smoke_signal" title="Smoke signal">Smoke signals</a></li>

<li><a href="History_of_telecommunication" title="History of telecommunication">Telecommunications history</a></li>

<li><a href="Telautograph" title="Telautograph">Telautograph</a></li>

<li><a href="Telegraphy" title="Telegraphy">Telegraphy</a></li>

<li><a href="Teleprinter" title="Teleprinter">Teleprinter</a> (teletype)</li>

<li><a href="History_of_the_telephone" title="History of the telephone">Telephone</a></li>

<li><i><a href="The_Telephone_Cases" title="The Telephone Cases">The Telephone Cases</a></i></li>

<li><a href="History_of_television" title="History of television">Television</a>

<ul><li><a href="Digital_television" title="Digital television">digital</a></li>

<li><a href="Streaming_television" title="Streaming television">streaming</a></li></ul></li>

<li><a href="Submarine_communications_cable#Early_history:_telegraph_and_coaxial_cables" title="Submarine communications cable">Undersea telegraph line</a></li>

<li><a href="History_of_videotelephony" title="History of videotelephony">Videotelephony</a></li>

<li><a href="Whistled_language" title="Whistled language">Whistled language</a></li>

<li><a href="Wireless_revolution" class="mw-redirect" title="Wireless revolution">Wireless revolution</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Pioneers</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Nasir_Ahmed_(engineer)" title="Nasir Ahmed (engineer)">Nasir Ahmed</a></li>

<li><a href="Edwin_Howard_Armstrong" title="Edwin Howard Armstrong">Edwin Howard Armstrong</a></li>

<li><a href="Mohamed_M._Atalla" title="Mohamed M. Atalla">Mohamed M. Atalla</a></li>

<li><a href="John_Logie_Baird" title="John Logie Baird">John Logie Baird</a></li>

<li><a href="Paul_Baran" title="Paul Baran">Paul Baran</a></li>

<li><a href="John_Bardeen" title="John Bardeen">John Bardeen</a></li>

<li><a href="Alexander_Graham_Bell" title="Alexander Graham Bell">Alexander Graham Bell</a></li>

<li><a href="Emile_Berliner" title="Emile Berliner">Emile Berliner</a></li>

<li><a href="Tim_Berners-Lee" title="Tim Berners-Lee">Tim Berners-Lee</a></li>

<li><a href="Francis_Blake_(inventor)" title="Francis Blake (inventor)">Francis Blake</a></li>

<li><a href="Jagadish_Chandra_Bose" title="Jagadish Chandra Bose">Jagadish Chandra Bose</a></li>

<li><a href="Charles_Bourseul" title="Charles Bourseul">Charles Bourseul</a></li>

<li><a href="Walter_Houser_Brattain" class="mw-redirect" title="Walter Houser Brattain">Walter Houser Brattain</a></li>

<li><a href="Claude_Chappe" title="Claude Chappe">Claude Chappe</a></li>

<li><a href="Yogen_Dalal" class="mw-redirect" title="Yogen Dalal">Yogen Dalal</a></li>

<li><a href="Donald_Davies" title="Donald Davies">Donald Davies</a></li>

<li><a href="Daniel_Davis_Jr." title="Daniel Davis Jr.">Daniel Davis Jr.</a></li>

<li><a href="Amos_Dolbear" title="Amos Dolbear">Amos Dolbear</a></li>

<li><a href="Thomas_Edison" title="Thomas Edison">Thomas Edison</a></li>

<li><a href="Philo_Farnsworth" title="Philo Farnsworth">Philo Farnsworth</a></li>

<li><a href="Reginald_Fessenden" title="Reginald Fessenden">Reginald Fessenden</a></li>

<li><a href="Lee_de_Forest" title="Lee de Forest">Lee de Forest</a></li>

<li><a href="Elisha_Gray" title="Elisha Gray">Elisha Gray</a></li>

<li><a href="Oliver_Heaviside" title="Oliver Heaviside">Oliver Heaviside</a></li>

<li><a href="Robert_Hooke" title="Robert Hooke">Robert Hooke</a></li>

<li><a href="Erna_Schneider_Hoover" title="Erna Schneider Hoover">Erna Schneider Hoover</a></li>

<li><a href="Harold_Hopkins_(physicist)" title="Harold Hopkins (physicist)">Harold Hopkins</a></li>

<li><a href="Gardiner_Greene_Hubbard" title="Gardiner Greene Hubbard">Gardiner Greene Hubbard</a></li>

<li><a href="Dawon_Kahng" title="Dawon Kahng">Dawon Kahng</a></li>

<li><a href="Charles_K._Kao" title="Charles K. Kao">Charles K. Kao</a></li>

<li><a href="Narinder_Singh_Kapany" title="Narinder Singh Kapany">Narinder Singh Kapany</a></li>

<li><a href="Hedy_Lamarr" title="Hedy Lamarr">Hedy Lamarr</a></li>

<li><a href="Roberto_Landell_de_Moura" title="Roberto Landell de Moura">Roberto Landell</a></li>

<li><a href="Innocenzo_Manzetti" title="Innocenzo Manzetti">Innocenzo Manzetti</a></li>

<li><a href="Guglielmo_Marconi" title="Guglielmo Marconi">Guglielmo Marconi</a></li>

<li><a href="Robert_Metcalfe" title="Robert Metcalfe">Robert Metcalfe</a></li>

<li><a href="Antonio_Meucci" title="Antonio Meucci">Antonio Meucci</a></li>

<li><a href="Samuel_Morse" title="Samuel Morse">Samuel Morse</a></li>

<li><a href="Jun-ichi_Nishizawa" title="Jun-ichi Nishizawa">Jun-ichi Nishizawa</a></li>

<li><a href="Charles_Grafton_Page" title="Charles Grafton Page">Charles Grafton Page</a></li>

<li><a href="Radia_Perlman" title="Radia Perlman">Radia Perlman</a></li>

<li><a href="Alexander_Stepanovich_Popov" class="mw-redirect" title="Alexander Stepanovich Popov">Alexander Stepanovich Popov</a></li>

<li><a href="Tivadar_Pusk%C3%A1s" title="Tivadar Puskás">Tivadar Puskás</a></li>

<li><a href="Johann_Philipp_Reis" title="Johann Philipp Reis">Johann Philipp Reis</a></li>

<li><a href="Claude_Shannon" title="Claude Shannon">Claude Shannon</a></li>

<li><a href="Almon_Brown_Strowger" title="Almon Brown Strowger">Almon Brown Strowger</a></li>

<li><a href="Henry_Sutton_(inventor)" title="Henry Sutton (inventor)">Henry Sutton</a></li>

<li><a href="Charles_Sumner_Tainter" title="Charles Sumner Tainter">Charles Sumner Tainter</a></li>

<li><a href="Nikola_Tesla" title="Nikola Tesla">Nikola Tesla</a></li>

<li><a href="Camille_Tissot" title="Camille Tissot">Camille Tissot</a></li>

<li><a href="Alfred_Vail" title="Alfred Vail">Alfred Vail</a></li>

<li><a href="Thomas_A._Watson" title="Thomas A. Watson">Thomas A. Watson</a></li>

<li><a href="Charles_Wheatstone" title="Charles Wheatstone">Charles Wheatstone</a></li>

<li><a href="Vladimir_K._Zworykin" title="Vladimir K. Zworykin">Vladimir K. Zworykin</a></li>

<li><i><a href="List_of_Internet_pioneers" title="List of Internet pioneers">Internet pioneers</a></i></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Transmission_medium" title="Transmission medium">Transmission<br>media</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Coaxial_cable" title="Coaxial cable">Coaxial cable</a></li>

<li><a href="Fiber-optic_communication" title="Fiber-optic communication">Fiber-optic communication</a>

<ul><li><a href="Optical_fiber" title="Optical fiber">optical fiber</a></li></ul></li>

<li><a href="Free-space_optical_communication" title="Free-space optical communication">Free-space optical communication</a></li>

<li><a href="Molecular_communication" title="Molecular communication">Molecular communication</a></li>

<li><a href="Radio_wave" title="Radio wave">Radio waves</a>

<ul><li><a href="Wireless" title="Wireless">wireless</a></li></ul></li>

<li><a href="Transmission_line" title="Transmission line">Transmission line</a>

<ul><li><a href="Telecommunication_circuit" title="Telecommunication circuit">telecommunication circuit</a></li></ul></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Network_topology" title="Network topology">Network topology</a><br>and switching</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Bandwidth_(computing)" title="Bandwidth (computing)">Bandwidth</a></li>

<li><a href="Telecommunications_link" title="Telecommunications link">Links</a></li>

<li><a href="Network_switch" title="Network switch">Network switching</a>

<ul><li><a href="Circuit_switching" title="Circuit switching">circuit</a></li>

<li><a href="Packet_switching" title="Packet switching">packet</a></li></ul></li>

<li><a href="Node_(networking)" title="Node (networking)">Nodes</a>

<ul><li><a href="Terminal_(telecommunication)" title="Terminal (telecommunication)">terminal</a></li></ul></li>

<li><a href="Telephone_exchange" title="Telephone exchange">Telephone exchange</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Multiplexing" title="Multiplexing">Multiplexing</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Space-division_multiple_access" title="Space-division multiple access">Space-division</a></li>

<li><a href="Frequency-division_multiplexing" title="Frequency-division multiplexing">Frequency-division</a></li>

<li><a href="Time-division_multiplexing" title="Time-division multiplexing">Time-division</a></li>

<li><a href="Polarization-division_multiplexing" title="Polarization-division multiplexing">Polarization-division</a></li>

<li><a href="Orbital_angular_momentum_multiplexing" title="Orbital angular momentum multiplexing">Orbital angular-momentum</a></li>

<li><a href="Code-division_multiple_access" title="Code-division multiple access">Code-division</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Concepts</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Communication_protocol" title="Communication protocol">Communication protocol</a></li>

<li><a href="Computer_network" title="Computer network">Computer network</a></li>

<li><a href="Data_communication" title="Data communication">Data transmission</a></li>

<li><a href="Store_and_forward" title="Store and forward">Store and forward</a></li>

<li><a href="Telecommunications_equipment" title="Telecommunications equipment">Telecommunications equipment</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Telecommunications_network" title="Telecommunications network">Types of network</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Cellular_network" title="Cellular network">Cellular network</a></li>

<li><a href="Ethernet" title="Ethernet">Ethernet</a></li>

<li><a href="Mobile_telephony" title="Mobile telephony">Mobile</a></li>

<li><a href="Public_switched_telephone_network" title="Public switched telephone network">Public Switched Telephone</a></li>

<li><a href="Radio_network" title="Radio network">Radio</a></li>

<li><a href="Television_broadcasting" class="mw-redirect" title="Television broadcasting">Television</a></li>

<li><a href="Telex" title="Telex">Telex</a></li>

<li><a href="Wireless_network" title="Wireless network">Wireless network</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Telecommunications_network" title="Telecommunications network">Notable networks</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="ARPANET" title="ARPANET">ARPANET</a></li>

<li><a href="BITNET" title="BITNET">BITNET</a></li>

<li><a href="CYCLADES" title="CYCLADES">CYCLADES</a></li>

<li><a href="FidoNet" title="FidoNet">FidoNet</a></li>

<li><a href="Internet" title="Internet">Internet</a></li>

<li><a href="Internet2" title="Internet2">Internet2</a></li>

<li><a href="JANET" title="JANET">JANET</a></li>

<li><a href="NPL_network" title="NPL network">NPL network</a></li>

<li><a href="TANet" title="TANet">TANet</a></li>

<li><a href="Toasternet" title="Toasternet">Toasternet</a></li>

<li><a href="Usenet" title="Usenet">Usenet</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Locations</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li>Africa</li>

<li>Americas

<ul><li>North</li>

<li>South</li></ul></li>

<li>Antarctica</li>

<li>Europe</li>

<li>Oceania</li>

<li><i><a href="List_of_telecommunications_regulatory_bodies" title="List of telecommunications regulatory bodies">Global telecommunications regulation bodies</a></i></li></ul>

</div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div>

<ul><li><span class="nowrap"><span class="noviewer" typeof="mw:File"><span></span></span> </span><a href="Portal%3ATelecommunication" title="Portal:Telecommunication">Telecommunication portal</a></li>

<li><span class="noviewer" typeof="mw:File"><span title="Category"></span></span> Category</li>

<li><span class="noviewer" typeof="mw:File"><span title="List-Class article"></span></span> <a href="Outline_of_telecommunication" title="Outline of telecommunication">Outline</a></li>

<li><span class="noviewer" typeof="mw:File"><span title="Commons page"></span></span> <a href="https://commons.wikimedia.org/wiki/Category:Telecommunications" class="extiw external" title="commons:Category:Telecommunications">Commons</a></li></ul>

</div></td></tr></tbody></table></div></div><div><div class="zim-footer">

This article is issued from <a class="external text" title="Last edited on 2025-07-19" href="https://en.wikipedia.org/wiki/?title=Shortwave_bands&oldid=1301449860">Wikipedia</a>. The text is available under <a class="external text" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en">Creative Commons Attribution-Share Alike 4.0</a> unless otherwise noted. Additional terms may apply for the media files.

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