Radio that can both transmit and receive a signal, used for bidirectional voice communication

<span class="mw-page-title-main">Two-way radio</span>

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Two-way radio

<p>A <b>two-way radio</b> is a <a href="/en/Radio" title="Radio" class="wl">radio</a> <a href="/en/Transceiver" title="Transceiver" class="wl">transceiver</a> (a radio that can both transmit and receive <a href="/en/Radio_wave" title="Radio wave" class="wl">radio waves</a>), which is used for bidirectional person-to-person voice communication with other users with similar radios;<span class="mw-ref reference" id="cite_ref-Graf_1-0"><a href="#cite_note-Graf-1" style="counter-reset: mw-Ref 1;"><span class="mw-reflink-text">[1]</span></a></span> in contrast to a broadcast receiver, which only receives transmissions.  </p>

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<div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none" about="#mwt4">Radio that can both transmit and receive a signal, used for bidirectional voice communication</div>
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<figure class="mw-default-size wiki-thumb"><a href="/en/File:US_Navy_091101-N-8960W-009_Air_Traffic_Controller_3rd_Class_Elliott_Young,_assigned_to_the_aircraft_carrier_USS_Nimitz_(CVN_68),_performs_a_traffic_call_to_departing_aircraft.jpg" class="mw-file-description image media-thumb" data-hash="File:US_Navy_091101-N-8960W-009_Air_Traffic_Controller_3rd_Class_Elliott_Young,_assigned_to_the_aircraft_carrier_USS_Nimitz_(CVN_68),_performs_a_traffic_call_to_departing_aircraft.jpg"><img loading="lazy" src="//upload.wikimedia.org/wikipedia/commons/thumb/0/0d/US_Navy_091101-N-8960W-009_Air_Traffic_Controller_3rd_Class_Elliott_Young%2C_assigned_to_the_aircraft_carrier_USS_Nimitz_%28CVN_68%29%2C_performs_a_traffic_call_to_departing_aircraft.jpg/220px-thumbnail.jpg" decoding="async" data-file-width="3008" data-file-height="2000" data-file-type="bitmap" height="146" width="220" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/0d/US_Navy_091101-N-8960W-009_Air_Traffic_Controller_3rd_Class_Elliott_Young%2C_assigned_to_the_aircraft_carrier_USS_Nimitz_%28CVN_68%29%2C_performs_a_traffic_call_to_departing_aircraft.jpg/330px-thumbnail.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/0d/US_Navy_091101-N-8960W-009_Air_Traffic_Controller_3rd_Class_Elliott_Young%2C_assigned_to_the_aircraft_carrier_USS_Nimitz_%28CVN_68%29%2C_performs_a_traffic_call_to_departing_aircraft.jpg/440px-thumbnail.jpg 2x" alt="US_Navy_091101-N-8960W-009_Air_Traffic_Controller_3rd_Class_Elliott_Young%2C_assigned_to_the_aircraft_carrier_USS_Nimitz_%28CVN_68%29%2C_performs_a_traffic_call_to_departing_aircraft.jpg"></a><figcaption>Naval <a href="/en/Air_traffic_controller" title="Air traffic controller" class="wl">air traffic controller</a> communicates with aircraft over two-way radio headset</figcaption></figure>
<figure class="mw-default-size wiki-thumb"><a href="/en/File:Recreational_Walkie_Talkies.jpg" class="mw-file-description image media-thumb" data-hash="File:Recreational_Walkie_Talkies.jpg"><img loading="lazy" src="//upload.wikimedia.org/wikipedia/commons/thumb/b/bd/Recreational_Walkie_Talkies.jpg/220px-Recreational_Walkie_Talkies.jpg" decoding="async" data-file-width="640" data-file-height="480" data-file-type="bitmap" height="165" width="220" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/bd/Recreational_Walkie_Talkies.jpg/330px-Recreational_Walkie_Talkies.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/bd/Recreational_Walkie_Talkies.jpg/440px-Recreational_Walkie_Talkies.jpg 2x" alt="Recreational_Walkie_Talkies.jpg"></a><figcaption>A variety of portable handheld two-way radios for private use</figcaption></figure>
<p>Two-way radios usually use a half-duplex communication channel, which permits two-way communication, albeit with the limitation that only one user can transmit at a time. (This is in contrast to <a href="/en/Simplex_communication" title="Simplex communication" class="wl">simplex communication</a>, in which transmission can only be sent in one direction, and full-duplex, which allows transmission in both directions simultaneously.) This requires users in a group to take turns talking. The radio is normally in receive mode so the user can hear all other transmissions on the channel. When the user wants to talk, they press a "<a href="/en/Push_to_Talk" title="Push to Talk" class="mw-redirect wl">push-to-talk</a>" button, which turns off the receiver and turns on the transmitter; when the button is released, the receiver is activated again. Multiple channels are provided so separate user groups can communicate in the same area without interfering with each other and some radios are designed to scan the channels in order to find a valid transmission. Other two-way radio systems operate in <a href="/en/Duplex_(telecommunications)" title="Duplex (telecommunications)" class="wl">full-duplex</a> mode, in which both parties can talk simultaneously. This requires either two separate radio channels or channel sharing methods such as <a href="/en/Time-division_duplex" title="Time-division duplex" class="mw-redirect wl">time-division duplex</a> (TDD) to carry the two directions of the conversation simultaneously on a single radio frequency.<span class="mw-ref reference" id="cite_ref-2"><a href="#cite_note-2" style="counter-reset: mw-Ref 2;"><span class="mw-reflink-text">[2]</span></a></span></p> 

<p>The first two-way radio was an AM-only device introduced by the Galvin Manufacturing Corporation in 1940 for use by the police and military during <a href="/en/World_War_II" title="World War II" class="wl">World War II</a>, and followed by the company's 1943 introduction of the Walkie-Talkie,<span class="mw-ref reference" id="cite_ref-3"><a href="#cite_note-3" style="counter-reset: mw-Ref 3;"><span class="mw-reflink-text">[3]</span></a></span> the best-known example of a two-way radio.<span class="mw-ref reference" id="cite_ref-CrystalRadio_4-0"><a href="#cite_note-CrystalRadio-4" style="counter-reset: mw-Ref 4;"><span class="mw-reflink-text">[4]</span></a></span></p>



A two-way radio is a radio transceiver , which is used for bidirectional person-to-person voice communication with other users with similar radios; in contrast to a broadcast receiver, which only receives transmissions.   Two-way radios usually use a half-duplex communication channel, which permits two-way communication, albeit with the limitation that only one user can transmit at a time. This requires users in a group to take turns talking. The radio is normally in receive mode so the user can hear all other transmissions on the channel. When the user wants to talk, they press a "push-to-talk" button, which turns off the receiver and turns on the transmitter; when the button is released, the receiver is activated again. Multiple channels are provided so separate user groups can communicate in the same area without interfering with each other and some radios are designed to scan the channels in order to find a valid transmission. Other two-way radio systems operate in full-duplex mode, in which both parties can talk simultaneously. This requires either two separate radio channels or channel sharing methods such as time-division duplex to carry the two directions of the conversation simultaneously on a single radio frequency. The first two-way radio was an AM-only device introduced by the Galvin Manufacturing Corporation in 1940 for use by the police and military during World War II, and followed by the company's 1943 introduction of the Walkie-Talkie, 