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137-403: Typical walkie-talkies resemble a telephone handset , with a speaker built into one end and a microphone in the other (in some devices the speaker also is used as the microphone) and an antenna mounted on the top of the unit. They are held up to the face to talk. A walkie-talkie is a half-duplex communication device. Multiple walkie-talkies use a single radio channel, and only one radio on

274-523: A diminishing returns trend. Contrary to the largely noncommittal approach taken in NATO , with its stops and starts in civil defense depending on the whims of each newly elected government, the military strategy in the comparatively more ideologically consistent USSR held that, amongst other things, a winnable nuclear war was possible. To this effect the Soviets planned to minimize, as far as possible,

411-606: A disruptive technology that is rapidly replacing traditional telephone network infrastructure. By January 2005, up to 10% of telephone subscribers in Japan and South Korea had switched to this digital telephone service. A January 2005 Newsweek article suggested that Internet telephony may be "the next big thing." The technology has spawned a new industry comprising many VoIP companies that offer services to consumers and businesses . The reported global VoIP market in October 2021

548-483: A subscriber , who had to arrange for a telegraph contractor to construct a line between them, for example, between a home and a shop. Users who wanted the ability to speak to several different locations would need to obtain and set up three or four pairs of telephones. Western Union , already using telegraph exchanges, quickly extended the principle to its telephones in New York City and San Francisco , and Bell

685-437: A water microphone , some had a metal diaphragm that induced current in an electromagnet wound around a permanent magnet, and some were dynamic – their diaphragm vibrated a coil of wire in the field of a permanent magnet or the coil vibrated the diaphragm. The sound-powered dynamic variants survived in small numbers through the 20th century in military and maritime applications, where its ability to create its own electrical power

822-531: A "walkie-talkie". In 2001, Hings received the Order of Canada for the device's significance to the war effort. Hings' model C-58 "Handie-Talkie" was in military service by 1942, the result of a secret R&D effort that began in 1940. Alfred J. Gross , a radio engineer and one of the developers of the Joan-Eleanor system , also worked on the early technology behind the walkie-talkie between 1938 and 1941, and

959-479: A DC transformer which plugs into a wall AC power outlet. A mobile phone or cellphone or hand phone is a handheld telephone which connects via radio transmissions to a cellular telephone network . The cellular network consists of a network of ground based transmitter/receiver stations with antennas – which are usually located on towers or on buildings – and infrastructure connecting to land-based telephone lines. Analog cellular networks first appeared in 1979, with

1096-590: A case of war) from throughout the USSR to join the Chernobyl task force and formed on the basis of the Kyiv Civil Defense Brigade. The task force performed some high-risk tasks including, with the failure of their robotic machinery, the manual removal of highly- radioactive debris. Many of their personnel were later decorated with medals for their work at containing the release of radiation into

1233-432: A cellular plan. Applications on the market that offer this walkie-talkie style interaction for audio include Hytera , Voxer , Zello , Orion Labs , Motorola Wave , and HeyTell, among others. Other smartphone-based walkie-talkie products are made by companies like goTenna , Fantom Dynamics and BearTooth, and offer a radio interface. Unlike mobile data dependent applications, these products work by pairing to an app on

1370-439: A computer softphone application, utilizing the microphone and headset devices of a personal computer or smartphone. While traditional analog telephones are typically powered from the central office through the telephone line, digital telephones require a local power supply. Internet-based digital service also requires special provisions to provide the service location to the emergency services when an emergency telephone number

1507-445: A country's population is more valuable than all of the land, factories and other assets that it possesses. People rebuild a country after its destruction, and it is therefore important for the economic security of a country that it protect its people. According to psychology , it is important for people to feel as though they are in control of their own destiny, and preparing for uncertainty via civil defense may help to achieve this. In

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1644-628: A designated area/building and required to monitor the fall of incendiary bombs and pass on news of any fires that had broken out to the NFS. They could deal with an individual magnesium alloy ("Elektron") incendiary bomb by dousing it with buckets of sand or water or by smothering. Additionally, 'Gas Decontamination Teams' kitted out with gas-tight and waterproof protective clothing were to deal with any gas attacks . They were trained to decontaminate buildings, roads, rail and other material that had been contaminated by liquid or jelly gases. Little progress

1781-413: A display for caller ID . In addition, answering machine function may be built in. The cordless handset contains a rechargeable battery , which the base station recharges when the handset rests in its cradle. Muilt-handset systems generally also have additional charging stands. A cordless telephone typically requires a constant electricity supply to power the base station and charger units by means of

1918-430: A dynamic transmitter or by the powering of a transmitter with a local battery. One of the jobs of outside plant personnel was to visit each telephone periodically to inspect the battery. During the 20th century, telephones powered from the telephone exchange over the same wires that carried the voice signals became common. Early telephones used a single wire for the subscriber's line, with ground return used to complete

2055-462: A fixed radio might be impractical or expensive. Often such units will have switches to provide quick access to emergency and information channels. They are also used in recreational UTVs to coordinate logistics, keep riders out of the dust and are usually connected to an intercom and headsets Intrinsically safe walkie-talkies are often required in heavy industrial settings where the radio may be used around flammable vapors. This designation means that

2192-417: A handle with the receiver and transmitter attached, now called a handset , separate from the cradle base that housed the magneto crank and other parts. They were larger than the "candlestick" and more popular. Disadvantages of single-wire operation such as crosstalk and hum from nearby AC power wires had already led to the use of twisted pairs and, for long-distance telephones, four-wire circuits . Users at

2329-687: A keypad or dial, affixed to the telephone, to enter a telephone number , which is the address of the call recipient's telephone in the telecommunications system, but other methods existed in the early history of the telephone. The first telephones were directly connected to each other from one customer's office or residence to another customer's location. Being impractical beyond just a few customers, these systems were quickly replaced by manually operated centrally located switchboards . These exchanges were soon connected together, eventually forming an automated, worldwide public switched telephone network . For greater mobility, various radio systems were developed in

2466-492: A message using a Morse Code crib sheet attached as a sticker to the radio. However, as Morse Code has fallen out of wide use outside amateur radio circles, some such units either have a grossly simplified code label or no longer provide a sticker at all. In addition, Family Radio Service UHF radios will sometimes be bought and used as toys, though they are not generally explicitly marketed as such (but see Hasbro 's ChatNow line, which transmits both voice and digital data on

2603-560: A model civil defense structure for the U.S. Called the "Blue Book" by civil defense professionals in reference to its solid blue cover, it was the template for legislation and organization for the next 40 years. Perhaps the most memorable aspect of the Cold War civil defense effort was the educational effort made or promoted by the government. In Duck and Cover , Bert the Turtle advocated that children " duck and cover " when they "see

2740-628: A nuclear attack are effects from the blast, fires and radiation. One of the most prepared countries for a nuclear attack is Switzerland . Almost every building in Switzerland has an abri (shelter) against the initial nuclear bomb and explosion followed by the fall-out. Because of this, many people use it as a safe to protect valuables, photos, financial information and so on. Switzerland also has air-raid and nuclear-raid sirens in every village. A "radiologically enhanced weapon", or " dirty bomb ", uses an explosive to spread radioactive material. This

2877-550: A number of features that are not common to other gear, including: Digital voice modes are available on some amateur HTs. For example, newer additions to the Amateur Radio service are Next Generation Digital Narrowband (NXDN) and Digital Smart Technology for Amateur Radio or D-STAR . Handheld radios with these technologies have several advanced features, including narrower bandwidth, simultaneous voice and messaging, GPS position reporting, and callsign routed radio calls over

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3014-591: A satellite phone is that it can be used in such regions where local terrestrial communication infrastructures, such as landline and cellular networks, are not available. Satellite phones are popular on expeditions into remote locations, hunting, fishing, maritime sector, humanitarian missions, business trips, and mining in hard-to-reach areas, where there is no reliable cellular service. Satellite telephones rarely get disrupted by natural disasters on Earth or human actions such as war, so they have proven to be dependable communication tools in emergency situations, when

3151-404: A short distance from the base station. Base stations include a radio transceiver which enables full-duplex, outgoing and incoming signals and speech with the handsets. The base station often includes a microphone, audio amplifier , and a loudspeaker to enable hands-free speakerphone conversations, without needing to use a handset. The base station may also have a numeric keypad for dialing, and

3288-630: A significant investment in civil and military defense, British civilian losses during the Blitz were higher than in most strategic bombing campaigns throughout the war. For example, there were 14,000-20,000 UK civilian fatalities during the Battle of Britain, a relatively high number considering that the Luftwaffe dropped only an estimated 30,000 tons of ordinance during the battle. Granted, this resulting 0.47-0.67 civilian fatalities per ton of bombs dropped

3425-405: A simple discrete transistor circuit where "grown-up" walkie-talkies use chips ), may employ superregenerative receivers, and may lack even a volume control, but they may nevertheless be elaborately decorated, often superficially resembling more "grown-up" radios such as FRS or public safety gear. Unlike more costly units, low-cost toy walkie-talkies may not have separate microphones and speakers;

3562-429: A single molded plastic handle, which when not in use was secured in a cradle in the base unit. The circuit diagram of the model 202 shows the direct connection of the transmitter to the line, while the receiver was inductively coupled. In local battery configurations, when the local loop was too long to provide sufficient current from the exchange, the transmitter was powered by a local battery and inductively coupled, while

3699-1058: A specific frequency allocation. Consumer gear, on the other hand, is generally made to be small, lightweight, and capable of accessing any channel within the specified band, not just a subset of assigned channels. Military organizations use handheld radios for a variety of purposes. Modern units such as the AN/PRC-148 Multiband Inter/Intra Team Radio (MBITR) can communicate on a variety of bands and modulation schemes and include encryption capabilities. Walkie-talkies (also known as HTs or "handheld transceivers") are widely used among amateur radio operators. While converted commercial gear by companies such as Motorola are not uncommon, many companies such as Yaesu , Icom , and Kenwood design models specifically for amateur use. While superficially similar to commercial and personal units (including such things as CTCSS and DCS squelch functions, used primarily to activate amateur radio repeaters ), amateur gear usually has

3836-443: A walkie-talkie is classified as radio station / land mobile station . Handheld two-way radios were developed by the military from backpack radios carried by a soldier in an infantry squad to keep the squad in contact with their commanders. The Canadian inventor Donald Hings was the first to create a portable radio signaling system for his employer CM&S in 1937. He called the system a "packset", although it later became known as

3973-534: A wide brief for assisting in large scale civil emergencies such as flood, earthquake, invasion, or civil disorder. After the September 11 attacks in 2001, in the United States the concept of civil defense has been revisited under the umbrella term of homeland security and all-hazards emergency management. In Europe , the triangle CD logo continues to be widely used. Created in 1939 by Charles Coiner of

4110-458: A wide-ranging international network. As mentioned, commercial walkie-talkies can sometimes be reprogrammed to operate on amateur frequencies. Amateur radio operators may do this for cost reasons or due to the fact that Public Safety grade commercial gear is more solidly constructed and better designed than purpose-built amateur gear that is built to a price. The personal walkie-talkie has become popular also because of licence-free services (such as

4247-514: A wired interface, such as USB or Lightning connectors. Smartphones, being able to run apps , have vastly expanded functionality compared to previous mobile phones. Having internet access and built in cameras, smartphones have made video calling readily accessible via IP connections. Smartphones also have access to a large number of web services and web apps, giving them functionality similar to traditional computers, although smartphones are often limited by their relatively small screen size and

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4384-430: Is a theoretical risk, and such weapons have not been used by terrorists. Depending on the quantity of the radioactive material, the dangers may be mainly psychological. Toxic effects can be managed by standard hazmat techniques. The threat here is primarily from disease-causing microorganisms such as bacteria and viruses. Various chemical agents are a threat, such as nerve gas ( VX , Sarin , and so on.). Mitigation

4521-400: Is called. A cordless telephone or portable telephone consists of a base station unit and one or more portable cordless handsets . The base station connects to a telephone line, or provides service by voice over IP (VOIP). The handset communicates with the base station via radio frequency signals. A handset's operational range is limited, usually to within the same building or within

4658-445: Is characterised by a number of terms, each of which has its own specific shade of meaning, such as crisis management , emergency management , emergency preparedness , contingency planning , civil contingency , civil aid and civil protection . Some countries treat civil defense as a key part of defense in general. For example, total defence refers to the commitment of a wide range of national resources to defense, including

4795-597: Is currently widely used within the European Union to refer to government-approved systems and resources tasked with protecting the non-combat population, primarily in the event of natural and technological disasters. For example, the EU's humanitarian aid policy director on the Ebola Crisis, Florika Fink-Hooijer , said that civil protection requires "not just more resources, but first and foremost better governance of

4932-589: Is sometimes credited with inventing it. The first device to be widely nicknamed a "walkie-talkie" was developed by the US military during World War II, the backpacked Motorola SCR-300 . It was created by an engineering team in 1940 at the Galvin Manufacturing Company (forerunner of Motorola). The team consisted of Marion Bond, Lloyd Morris, Bill Vogel, Dan Noble , who conceived of the design using frequency modulation , and Henryk Magnuski , who

5069-456: Is the process of actively preventing war or the release of nuclear weapons . It includes policy analysis, diplomacy, political measures, nuclear disarmament and more military responses such as a National Missile Defense and air defense artillery . In the case of counter-terrorism, mitigation would include diplomacy, intelligence gathering and direct action against terrorist groups. Mitigation may also be reflected in long-term planning such as

5206-428: Is the responsibility of the volunteer-based State Emergency Service . In most former Soviet countries civil defense is the responsibility of governmental ministries, such as Russia's Ministry of Emergency Situations . Relatively small investments in preparation can speed up recovery by months or years and thereby prevent millions of deaths by hunger, cold and disease. According to human capital theory in economics ,

5343-425: Is to obtain potassium iodide (KI) tablets as a safety measure to protect the human thyroid gland from the uptake of dangerous radioactive iodine . Another measure is to cover the nose, mouth and eyes with a piece of cloth and sunglasses to protect against alpha particles , which are only an internal hazard. To support and supplement efforts at national, regional and local level with regard to disaster prevention,

5480-660: The Air Force . The Coast Guard Auxiliary performs a similar role in support of the U.S. Coast Guard . Like the Civil Air Patrol, the Coast Guard Auxiliary was established in the run up to World War II. Auxiliarists were sometimes armed during the war, and extensively participated in port security operations. After the war, the Auxiliary shifted its focus to promoting boating safety and assisting

5617-552: The Disaster Relief Act of 1974 (Public Law 93-288). In the portions of the civil defense statute incorporated into the Stafford Act, the primary modification was to use the term "Emergency Preparedness" wherever the term "Civil Defence" had previously appeared in the statutory language. An important concept initiated by President Jimmy Carter was the so-called "Crisis Relocation Program" administered as part of

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5754-663: The Earth instead of terrestrial cell sites , as cellphones do. Therefore, they can work in most geographic locations on the Earth's surface, as long as open sky and the line-of-sight between the phone and the satellite is provided. Depending on the architecture of a particular system, coverage may include the entire Earth or only specific regions. Satellite phones provide similar functionality to terrestrial mobile telephones; voice calling , text messaging , and low-bandwidth Internet access are supported through most systems. The advantage of

5891-535: The Gotha bombers surpassed the zeppelins. The most devastating raids inflicted 121 casualties for each ton of bombs dropped; this figure was then used as a basis for predictions. After the war, attention was turned toward civil defense in the event of war, and the Air Raid Precautions Committee (ARP) was established in 1924 to investigate ways for ensuring the protection of civilians from

6028-660: The National Fire Service (NFS)), fire watchers, rescue, first aid post, stretcher party and industry. Over 1.9 million people served within the CD; nearly 2,400 died from enemy action. The organization of civil defense was the responsibility of the local authority. Volunteers were ascribed to different units depending on experience or training. Each local civil defense service was divided into several sections. Wardens were responsible for local reconnaissance and reporting, and leadership, organization, guidance and control of

6165-572: The Reis telephone , in c. 1860. His device appears to be the first device based on the conversion of sound into electrical impulses. The term telephone was adopted into the vocabulary of many languages. It is derived from the Greek : τῆλε , tēle , "far" and φωνή, phōnē , "voice", together meaning "distant voice". Credit for the invention of the electric telephone is frequently disputed. As with other influential inventions such as radio , television ,

6302-854: The United States , the Office of Civilian Defense was established in May 1941 to coordinate civilian defense efforts. It coordinated with the Department of the Army and established similar groups to the British ARP. One of these groups that still exists today is the Civil Air Patrol , which was originally created as a civilian auxiliary to the Army . The CAP was created on December 1, 1941, with

6439-563: The United States , the sheer power of nuclear weapons and the perceived likelihood of such an attack precipitated a greater response than had yet been required of civil defense. Civil defense, previously considered an important and commonsense step, became divisive and controversial in the charged atmosphere of the Cold War . In 1950, the National Security Resources Board created a 162-page document outlining

6576-526: The flash ." Booklets such as Survival Under Atomic Attack , Fallout Protection and Nuclear War Survival Skills were also commonplace. The transcribed radio program Stars for Defense combined hit music with civil defense advice. Government institutes created public service announcements including children's songs and distributed them to radio stations to educate the public in case of nuclear attack. The US President Kennedy (1961–63) launched an ambitious effort to install fallout shelters throughout

6713-426: The light bulb , and the computer , several inventors pioneered experimental work on voice transmission over a wire and improved on each other's ideas. New controversies over the issue still arise from time to time. Charles Bourseul , Antonio Meucci , Johann Philipp Reis , Alexander Graham Bell , and Elisha Gray , amongst others, have all been credited with the invention of the telephone. Alexander Graham Bell

6850-544: The line of sight propagation of UHF signals, experienced users consider such ratings to be wildly exaggerated, and some manufacturers have begun printing range ratings on the package based on terrain as opposed to simple power output. While the bulk of personal walkie-talkie traffic is in the 27 MHz and 400–500 MHz area of the UHF spectrum, there are some units that use the "Part 15" 49 MHz band (shared with cordless phones, baby monitors, and similar devices) as well as

6987-420: The model 500 telephone in the United States, were developed that permitted larger local networks centered around central offices. A breakthrough new technology was the introduction of Touch-Tone signaling using push-button telephones by American Telephone & Telegraph Company (AT&T) in 1963. The invention of the transistor in 1947 dramatically changed the technology used in telephone systems and in

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7124-447: The smartphone , the dominant type of telephone in the world today. Before the development of the electric telephone, the term telephone was applied to other inventions, and not all early researchers of the electrical device used the term. Perhaps the earliest use of the word for a communications system was the telephon created by Gottfried Huth in 1796. Huth proposed an alternative to the optical telegraph of Claude Chappe in which

7261-463: The sound waves to electrical signals which are sent through the telecommunications system to the receiving telephone, which converts the signals into audible sound in the receiver or sometimes a loudspeaker . Telephones permit transmission in both directions simultaneously. Most telephones also contain an alerting feature, such as a ringer or a visual indicator, to announce an incoming telephone call. Telephone calls are initiated most commonly with

7398-407: The "Part 15" 900 MHz band; in the US at least, units in these bands do not require licenses as long as they adhere to FCC Part 15 power output rules. A company called TriSquare is, as of July 2007, marketing a series of walkie-talkies in the United States, based on frequency-hopping spread spectrum technology operating in this frequency range under the name eXRS (eXtreme Radio Service—despite

7535-418: The 1920s and were implemented in some countries during the 1930s as the threat of war and aerial bombardment grew. Civil-defense structures became widespread after authorities recognised the threats posed by nuclear weapons . Since the end of the Cold War , the focus of civil defense has largely shifted from responding to military attack to dealing with emergencies and disasters in general. The new concept

7672-658: The 1990s, mobile phones have gained other features which are not directly related to their primary function as telephones. These include text messaging, calendars, alarm clocks, personal schedulers, cameras, music players, games and later, internet access and smartphone functionality. Nearly all mobile phones have the ability to send text messages to other users via the SMS (Short Message Service) protocol. The multimedia messaging service (MMS) protocol enables users to send and receive multimedia content, such as photos, audio files and video files. As their functionality has increased over

7809-589: The AN/PRC-6 by a 5-foot cable. An adjustable strap was provided for carrying and support while operating. In the mid-1970s, the United States Marine Corps initiated an effort to develop a squad radio to replace the unsatisfactory helmet-mounted AN/PRR-9 receiver and receiver/transmitter handheld AN/PRT-4 (both developed by the US Army ). The AN/PRC-68, first produced in 1976 by Magnavox ,

7946-517: The Coast Guard in performing search and rescue and marine safety and environmental protection. In the United States a federal civil defense program existed under Public Law 920 of the 81st Congress, as amended, from 1951 to 1994. That statutory scheme was made so-called all-hazards by Public Law 103–160 in 1993 and largely repealed by Public Law 103–337 in 1994. Parts now appear in Title VI of

8083-481: The FRS band). Some cellular telephone networks offer a push-to-talk handset that allows walkie-talkie-like operation over the cellular network, without dialing a call each time. However, the cellphone provider must be accessible. In addition to land mobile use, waterproof walkie talkie designs are also used for marine VHF and aviation communications, especially on smaller boats and ultralight aircraft where mounting

8220-544: The N. W. Ayer Advertising Agency, it was used throughout World War II and the Cold War era. In the U.S., 2006 saw the retirement of the old triangle logo, to be replaced with a stylised EM (for emergency management ). A reference to the old CD logo (without the red CD letters) can be seen above the eagle's head in the FEMA seal. The name and logo continue to be used by Hawaii State Civil Defense and Guam Homeland Security/Office of Civil Defense. The term "civil protection"

8357-683: The Robert T. Stafford Disaster Relief and Emergency Assistance Act, Public Law 100-107 [1988 as amended]. The term EMERGENCY PREPAREDNESS was largely codified by that repeal and amendment. See 42 USC Sections 5101 and following. In most of the states of the North Atlantic Treaty Organization , such as the United States , the United Kingdom and West Germany , as well as the Soviet Bloc , and especially in

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8494-555: The SCR-536's military replacement, the AN/PRC-6 . The AN/PRC-6 circuit used 13 vacuum tubes (receiver and transmitter); a second set of thirteen tubes was supplied with the unit as running spares. The unit was factory set with one crystal which could be changed to a different frequency in the field by replacing the crystal and re-tuning the unit. It used a 24-inch whip antenna . There was an optional handset that could be connected to

8631-488: The U.S. FRS , Europe's PMR446 and Australia's UHF CB ) in other countries. While FRS walkie-talkies are also sometimes used as toys because mass-production makes them low in cost, they have proper superheterodyne receivers and are a useful communication tool for both business and personal use. The boom in licence-free transceivers has, however, been a source of frustration to users of licensed services which are sometimes interfered with. For example, FRS and GMRS overlap in

8768-605: The United Kingdom. Designs for personal walkie-talkies are in any case tightly regulated, generally requiring non-removable antennas (with a few exceptions such as CB radio and the United States MURS allocation ) and forbidding modified radios. Most personal walkie-talkies sold are designed to operate in UHF allocations, and are designed to be very compact, with buttons for changing channels and other settings on

8905-568: The United States, resulting in substantial pirate use of the GMRS frequencies. Use of the GMRS frequencies (USA) requires a license; however most users either disregard this requirement or are unaware. Canada reallocated frequencies for licence-free use due to heavy interference from US GMRS users. The European PMR446 channels fall in the middle of a United States UHF amateur allocation, and the US FRS channels interfere with public safety communications in

9042-492: The United States, the federal civil defense program was authorized by statute and ran from 1951 to 1994. Originally authorized by Public Law 920 of the 81st Congress, it was repealed by Public Law 93–337 in 1994. Small portions of that statutory scheme were incorporated into the Robert T. Stafford Disaster Relief and Emergency Assistance Act (Public Law 100–707) which partly superseded in part, partly amended, and partly supplemented

9179-409: The United States. These shelters would not protect against the blast and heat effects of nuclear weapons, but would provide some protection against the radiation effects that would last for weeks and even affect areas distant from a nuclear explosion. In order for most of these preparations to be effective, there had to be some degree of warning. In 1951, CONELRAD (Control of Electromagnetic Radiation)

9316-429: The ability to attach external microphones and speakers. Consumer and commercial equipment differ in a number of ways; commercial gear is generally ruggedized, with metal cases, and often has only a few specific frequencies programmed into it (often, though not always, with a computer or other outside programming device; older units can simply swap crystals), since a given business or public safety agent must often abide by

9453-493: The advent of smartphones, mobile phone manufacturers have also included consumer electronics companies, such as Apple , Samsung and Xiaomi . As of 2022, most mobile phones are smartphones, being a combination of a mobile phone and a personal computing device in the same unit. Most smartphones are primarily operated using a graphical user interface and a touch screen. Many phones have a secondary voice user interface, such as Siri on Apple iPhones , which can operate many of

9590-426: The beginning of the 20th century did not place long-distance calls from their own telephones but made an appointment and were connected with the assistance of a telephone operator. What turned out to be the most popular and longest-lasting physical style of telephone was introduced in the early 20th century, including Bell's 202-type desk set. A carbon granule transmitter and electromagnetic receiver were united in

9727-513: The bell coil to allow the AC ringer signal through while still blocking DC (keeping the phone " on hook "). Telephones connected to the earliest Strowger switch automatic exchanges had seven wires, one for the knife switch , one for each telegraph key , one for the bell, one for the push-button and two for speaking. Large wall telephones in the early 20th century usually incorporated the bell, and separate bell boxes for desk phones dwindled away in

9864-504: The channel can transmit at a time, although any number can listen. The transceiver is normally in receive mode; when the user wants to talk they must press a " push-to-talk " (PTT) button that turns off the receiver and turns on the transmitter. Some units have additional features such as sending calls, call reception with vibration alarm, keypad locking, and a stopwatch. Smaller walkie-talkies are also very popular among young children. In accordance with ITU Radio Regulations , article 1.73,

10001-439: The circuit (as used in telegraphs ). The earliest dynamic telephones also had only one port opening for sound, with the user alternately listening and speaking (or rather, shouting) into the same hole. Sometimes the instruments were operated in pairs at each end, making conversation more convenient but also more expensive. At first, the benefits of a telephone exchange were not exploited. Instead, telephones were leased in pairs to

10138-626: The city with 120,000 troops to force people back to work. A different government department proposed setting up camps for refugees for a few days before sending them back to London. A special government department, the Civil Defence Service , was established by the Home Office in 1935. Its remit included the pre-existing ARP as well as wardens, firemen (initially the Auxiliary Fire Service (AFS) and latterly

10275-402: The councillors had decided that hydrogen bombs meant that there could be no recovery from a nuclear attack. The British government opposed such a move and held a provocative Civil Defence exercise on the streets of Coventry which Labour council members protested against. The government also decided to implement its own committee at the city's cost until the council reinstituted its committee. In

10412-707: The crisis, the British Government decided to make these a permanent feature, with a standard design of precast concrete trench lining. They also decided to issue the Anderson shelter free to poorer households and to provide steel props to create shelters in suitable basements. During the Second World War , the ARP was responsible for the issuing of gas masks , pre-fabricated air-raid shelters (such as Anderson shelters , as well as Morrison shelters ),

10549-556: The danger of air-raids . The Committee produced figures estimating that in London there would be 9,000 casualties in the first two days and then a continuing rate of 17,500 casualties a week. These rates were thought conservative. It was believed that there would be "total chaos and panic" and hysterical neurosis as the people of London would try to flee the city. To control the population harsh measures were proposed: bringing London under almost military control, and physically cordoning off

10686-426: The design of the interstate highway system and the placement of military bases further away from populated areas. Preparation consists of building blast shelters and pre-positioning information, supplies, and emergency infrastructure. For example, most larger cities in the U.S. now have underground emergency operations centers that can perform civil defense coordination. FEMA also has many underground facilities for

10823-420: The device's functions, as well as enabling users to use spoken commands to interact with the internet. Typically alphanumeric text input is accomplished via an on-screen virtual keyboard, although some smartphones have a small physical keyboard. Smartphones offer the ability to access internet data through the cellular network and via wi-fi, and usually allow direct connectivity to other devices via Bluetooth or

10960-443: The effects of nuclear weapon strikes on its territory, and therefore spent considerably more thought on civil defense preparations than in U.S., with defense plans that have been assessed to be far more effective than those in the U.S. Soviet Civil Defense Troops played the main role in the massive disaster relief operation following the 1986 Chernobyl nuclear accident . Defense Troop reservists were officially mobilized (as in

11097-400: The environment , with a number of the 56 deaths from the accident being Civil defense troops. In Western countries, strong civil defense policies were never properly implemented, because it was fundamentally at odds with the doctrine of " mutual assured destruction " (MAD) by making provisions for survivors. It was also considered that a full-fledged total defense would have not been worth

11234-434: The face of the radio and a short, fixed antenna. Most such units are made of heavy, often brightly colored plastic, though some more expensive units have ruggedized metal or plastic cases. Commercial-grade radios are often designed to be used on allocations such as GMRS or MURS (the latter of which has had very little readily available purpose-built equipment). In addition, CB walkie-talkies are available, but less popular due to

11371-954: The federal civil defense program. That effort largely lapsed under President Ronald Reagan, who discontinued the Carter initiative because of opposition from areas potentially hosting the relocated population. Threats to civilians and civilian life include NBC ( Nuclear , Biological , and Chemical warfare ) and others, like the more modern term CBRN (Chemical Biological Radiological and Nuclear). Threat assessment involves studying each threat so that preventative measures can be built into civilian life. Refers to conventional explosives. A blast shelter designed to protect only from radiation and fallout would be much more vulnerable to conventional explosives. See also fallout shelter . Shelter intended to protect against nuclear blast effects would include thick concrete and other sturdy elements which are resistant to conventional explosives. The biggest threats from

11508-550: The financial crisis of the mid-1960s. Its neighbors, however, remained committed to Civil Defence, namely the Isle of Man Civil Defence Corps and Civil Defence Ireland (Republic of Ireland). In the United States, the various civil defense agencies were replaced with the Federal Emergency Management Agency (FEMA) in 1979. In 2002 this became part of the Department of Homeland Security . The focus

11645-524: The first digital cellular networks appearing in the early 1990s. Mobile phones require a SIM card to be inserted into the phone. The SIM card is a small PVC card containing a small integrated circuit which stores the user's international mobile subscriber identity (IMSI) number and its related key, which are used to identify and authenticate subscribers to the cellular network. Mobile phones generally incorporate an LCD or OLED display, with some types, such as smartphones, having touch screens. Since

11782-423: The general public. Wardens would also advise survivors of the locations of rest and food centers, and other welfare facilities. Rescue Parties were required to assess and then access bombed-out buildings and retrieve injured or dead people. In addition they would turn off gas , electricity and water supplies , and repair or pull down unsteady buildings. Medical services, including First Aid Parties, provided on

11919-577: The hands of ham radio operators immediately following World War II. Motorola's public safety radios of the 1950s and 1960s were loaned or donated to ham groups as part of the Civil Defense program. To avoid trademark infringement, other manufacturers use designations such as "Handheld Transceiver" or "Handie Transceiver" for their products. Walkie-talkies are widely used in any setting where portable radio communications are necessary, including business, public safety , military, outdoor recreation, and

12056-430: The handset was on the cradle. In the 1930s, telephone sets were developed that combined the bell and induction coil with the desk set, obviating a separate ringer box. The rotary dial becoming commonplace in the 1930s in many areas enabled customer-dialed service, but some magneto systems remained even into the 1960s. After World War II, the telephone networks saw rapid expansion and more efficient telephone sets, such as

12193-448: The knobs and switches in the radio are engineered to avoid producing sparks as they are operated. A variety of mobile apps exist that mimic a walkie-talkie/ push-to-talk style interaction. They are marketed as low-latency, asynchronous communication. The advantages touted over two-way voice calls include: the asynchronous nature not requiring full user interaction (like SMS ) and it is voice over IP ( VOIP ) so it does not use minutes on

12330-482: The late 1950s early 1960s, it was estimated that approximately 27 million US citizens would have been saved with civil defense education. At the time, however, the cost of a full-scale civil defense program was regarded as less effective in cost-benefit analysis than a ballistic missile defense ( Nike Zeus ) system, and as the Soviet adversary was increasing their nuclear stockpile , the efficacy of both would follow

12467-594: The like, and devices are available at numerous price points from inexpensive analog units sold as toys up to ruggedized (i.e. waterproof or intrinsically safe ) analog and digital units for use on boats or in heavy industry. Most countries allow the sale of walkie-talkies for, at least, business, marine communications , and some limited personal uses such as CB radio , as well as for amateur radio designs. Walkie-talkies for public safety, and commercial and industrial uses may be part of trunked radio systems , which dynamically allocate radio channels for more efficient use of

12604-438: The limited radio spectrum. Such systems always work with a base station that acts as a repeater and controller, although individual handsets and mobiles may have a mode that bypasses the base station. Walkie-talkies, thanks to increasing use of miniaturized electronics, can be made very small, with some personal two-way UHF radio models being smaller than a deck of cards (though VHF and HF units can be substantially larger due to

12741-443: The local communications system can be compromised. Civil Defense Civil defense or civil protection is an effort to protect the citizens of a state (generally non-combatants ) from human-made and natural disasters . It uses the principles of emergency management : prevention , mitigation, preparation, response, or emergency evacuation and recovery. Programs of this sort were initially discussed at least as early as

12878-428: The long-distance transmission networks, over the next several decades. With the development of stored program control and MOS integrated circuits for electronic switching systems , and new transmission technologies such as pulse-code modulation (PCM), telephony gradually evolved towards digital telephony , which improved the capacity, quality, and cost of the network. Integrated Services Digital Network (ISDN)

13015-412: The main civil defense mission of search and rescue. The CAP also sank two Axis submarines and provided aerial reconnaissance for Allied and neutral merchant ships. In 1946, the Civil Air Patrol was barred from combat by Public Law 79-476 . The CAP then received its current mission: search and rescue for downed aircraft. When the Air Force was created, in 1947, the Civil Air Patrol became the auxiliary of

13152-433: The mid-20th century for transmission between mobile stations on ships and in automobiles. Hand-held mobile phones were introduced for personal service starting in 1973. In later decades, the analog cellular system evolved into digital networks with greater capability and lower cost. Convergence in communication services has provided a broad spectrum of capabilities in cell phones, including mobile computing, giving rise to

13289-435: The middle of the century. Rural and other telephones that were not on a common battery exchange had a magneto hand-cranked generator to produce a high voltage alternating signal to ring the bells of other telephones on the line and to alert the operator. Some local farming communities that were not connected to the main networks set up barbed wire telephone lines that exploited the existing system of field fences to transmit

13426-535: The name, a proprietary design, not an official allocation of the US FCC). The spread-spectrum scheme used in eXRS radios allows up to 10 billion virtual "channels" and ensures private communications between two or more units. Low-power versions, exempt from licence requirements, are also popular children's toys such as the Fisher Price Walkie-Talkie for children illustrated in the top image on

13563-509: The need for larger antennas and battery packs). In addition, as costs come down, it is possible to add advanced squelch capabilities such as CTCSS (analog squelch) and DCS (digital squelch) (often marketed as "privacy codes") to inexpensive radios, as well as voice scrambling and trunking capabilities. Some units (especially amateur HTs) also include DTMF keypads for remote operation of various devices such as repeaters . Some models include VOX capability for hands-free operation, as well as

13700-453: The neutral countries, such as Switzerland and in Sweden during the 1950s and 1960s, many civil defense practices took place to prepare for the aftermath of a nuclear war , which seemed quite likely at that time. In the United Kingdom , the Civil Defence Service was disbanded in 1945, followed by the ARP in 1946. With the onset of the growing tensions between East and West , the service

13837-495: The operators in the signaling towers would shout to each other by means of what he called "speaking tubes", but would now be called giant megaphones . A communication device for sailing vessels, called telephone , was invented by Captain John Taylor in 1844. This instrument used four air horns to communicate with vessels in foggy weather. Johann Philipp Reis used the term in reference to his invention, commonly known as

13974-412: The propagation characteristics of the 27 MHz band and the general bulkiness of the gear involved. Personal walkie-talkies are generally designed to give easy access to all available channels (and, if supplied, squelch codes ) within the device's specified allocation. Personal two-way radios are also sometimes combined with other electronic devices; Garmin 's Rino series combine a GPS receiver in

14111-612: The protection of all aspects of civilian life. The advent of civil defense was stimulated by the experience of the bombing of civilian areas during the First World War . The bombing of the United Kingdom began on 19 January 1915 when German zeppelins dropped bombs on the Great Yarmouth area, killing six people. German bombing operations of the First World War were surprisingly effective, especially after

14248-409: The receiver was included in the local loop. The coupling transformer and the ringer were mounted in a separate enclosure, called the subscriber set. The dial switch in the base interrupted the line current by repeatedly but very briefly disconnecting the line one to ten times for each digit, and the hook switch (in the center of the circuit diagram) disconnected the line and the transmitter battery while

14385-460: The receiver's speaker sometimes doubles as a microphone while in transmit mode. An unusual feature, common on children's walkie-talkies but seldom available otherwise even on amateur models, is a "code key", that is, a button allowing the operator to transmit Morse code or similar tones to another walkie-talkie operating on the same frequency. Generally the operator depresses the PTT button and taps out

14522-423: The resources that are available including better synergies between humanitarian aid and civil protection". In recent years there has been emphasis on preparedness for technological disasters resulting from terrorist attack. Within EU countries the term "crisis-management" emphasizes the political and security dimension rather than measures to satisfy the immediate needs of the population. In Australia, civil defense

14659-665: The right. Prior to the change of CB radio from licensed to "permitted by part" (FCC rules Part 95) status, the typical toy walkie-talkie available in North America was limited to 100 milliwatts of power on transmit and using one or two crystal-controlled channels in the 27 MHz citizens' band using amplitude modulation (AM) only. Later toy walkie-talkies operated in the 49 MHz band, some with frequency modulation (FM), shared with cordless phones and baby monitors. The lowest cost devices are very simple electronically (single-frequency, crystal-controlled , generally based on

14796-560: The same package as an FRS/GMRS walkie-talkie (allowing Rino users to transmit digital location data to each other) Some personal radios also include receivers for AM and FM broadcast radio and, where applicable, NOAA Weather Radio and similar systems broadcasting on the same frequencies. Some designs also allow the sending of text messages and pictures between similarly equipped units. While jobsite and government radios are often rated in power output, consumer radios are frequently and controversially rated in mile or kilometer ratings. Because of

14933-908: The same purpose located near major railheads such as the ones in Denton, Texas and Mount Weather , Virginia. Other measures would include continual government inventories of grain silos, the Strategic National Stockpile , the uncapping of the Strategic Petroleum Reserve , the dispersal of lorry-transportable bridges, water purification, mobile refineries, mobile de-contamination facilities, mobile general and special purpose disaster mortuary facilities such as Disaster Mortuary Operational Response Team (DMORT) and DMORT-WMD , and other aids such as temporary housing to speed civil recovery. On an individual scale, one means of preparation for exposure to nuclear fallout

15070-403: The signal. In the 1890s a new smaller style of telephone was introduced, packaged in three parts. The transmitter stood on a stand, known as a " candlestick " for its shape. When not in use, the receiver hung on a hook with a switch in it, known as a "switchhook". Previous telephones required the user to operate a separate switch to connect either the voice or the bell. With the new kind, the user

15207-510: The size of their keyboards. Typically, smartphones feature such tools as cameras, media players, web browsers, email clients, interactive maps, satellite navigation and a variety of sensors, such as a compass , accelerometers and GPS receivers . In addition to voice calls, smartphone users commonly communicate using a wide variety of messaging formats, including SMS, MMS, email, and various proprietary messaging services, such as iMessage and various social media platforms. In 2002, only 10% of

15344-422: The sound to the receiving user. The term is derived from Ancient Greek : τῆλε , romanized :  tēle , lit.   'far' and φωνή ( phōnē , voice ), together meaning distant voice . In 1876, Alexander Graham Bell was the first to be granted a United States patent for a device that produced clearly intelligible replication of the human voice at a second device. This instrument

15481-477: The spot medical assistance. The expected stream of information that would be generated during an attack was handled by 'Report and Control' teams. A local headquarters would have an ARP controller who would direct rescue, first aid and decontamination teams to the scenes of reported bombing. If local services were deemed insufficient to deal with the incident then the controller could request assistance from surrounding boroughs . Fire Guards were responsible for

15618-453: The telephone switch, which allowed for the formation of telephone exchanges , and eventually networks. In the United Kingdom, the blower is used as a slang term for a telephone. The term came from navy slang for a speaking tube . In the U.S., a somewhat dated slang term refers to the telephone as "the horn," as in "I couldn't get him on the horn," or "I'll be off the horn in a moment." Early telephones were technically diverse. Some used

15755-408: The telephone to work a fluctuating current reproduced sounds the best. The fluctuating currents became the basis for the working telephone, creating Bell's patent. That first patent by Bell was the master patent of the telephone, from which other patents for electric telephone devices and features flowed. In 1876, shortly after Bell's patent application, Hungarian engineer Tivadar Puskás proposed

15892-445: The upkeep of local public shelters, and the maintenance of the blackout . The ARP also helped rescue people after air raids and other attacks, and some women became ARP Ambulance Attendants whose job was to help administer first aid to casualties, search for survivors, and in many grim instances, help recover bodies, sometimes those of their own colleagues. As the war progressed, the military effectiveness of Germany's aerial bombardment

16029-430: The user's smartphone and working over a radio interface. There are various types of accessories available for walkie-talkies such as rechargeable batteries, drop-in rechargers, multi-unit rechargers for charging as many as six units at a time, and an audio accessory jack that can be used for headsets or speaker microphones. Newer models allow the connection to wireless headsets via Bluetooth . Some models also came up with

16166-488: The very large expense. For whatever reason, the public saw efforts at civil defense as fundamentally ineffective against the powerful destructive forces of nuclear weapons, and therefore a waste of time and money, although detailed scientific research programs did underlie the much-mocked government civil defense pamphlets of the 1950s and 1960s. The Civil Defence Corps was stood down in Great Britain in 1968 due to

16303-497: The wifi integration such as Motorola XIRP 8600i series. Telephone A telephone , colloquially referred to as a phone , is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound , typically and most efficiently the human voice , into electronic signals that are transmitted via cables and other communication channels to another telephone which reproduces

16440-456: The world's population used mobile phones and by 2005 that percentage had risen to 46%. By the end of 2009, there were a total of nearly 6 billion mobile and fixed-line telephone subscribers worldwide. This included 1.26 billion fixed-line subscribers and 4.6 billion mobile subscribers. A satellite telephone, or satphone, is a type of mobile phone that connects to other phones or the telephone network by radio link through satellites orbiting

16577-517: The years, many types of mobile phone, notably smartphones, require an operating system to run. Popular mobile phone operating systems in the past have included Symbian , Palm OS , BlackBerry OS and mobile phone versions of Windows . As of 2022, the most used operating systems are Google's Android and Apple's iOS . Before the era of smartphones, mobile phones were generally manufactured by companies specializing in telecommunications equipment, such as Nokia , Motorola , and Ericsson . Since

16714-481: Was $ 85.2 billion with a projection of $ 102.5 billion by 2026. IP telephony uses high-bandwidth Internet connections and specialized customer premises equipment to transmit telephone calls via the Internet, or any modern private data network. The customer equipment may be an analog telephone adapter (ATA) which translates the signals of a conventional analog telephone; an IP Phone , a dedicated standalone device; or

16851-615: Was a Corps Authority, as were most county boroughs in England and Wales and large burghs in Scotland . Each division was divided into several sections, including the Headquarters, Intelligence and Operations, Scientific and Reconnaissance, Warden & Rescue, Ambulance and First Aid and Welfare. In 1954 Coventry City Council caused international controversy when it announced plans to disband its Civil Defence committee because

16988-570: Was crucial. Most, however, used the Edison/Berliner carbon transmitter , which was much louder than the other kinds, even though it required an induction coil which was an impedance matching transformer to make it compatible with the impedance of the line. The Edison patents kept the Bell monopoly viable into the 20th century, by which time the network was more important than the instrument. Early telephones were locally powered, using either

17125-412: Was established. Under the system, a few primary stations would be alerted of an emergency and would broadcast an alert. All broadcast stations throughout the country would be constantly listening to an upstream station and repeat the message, thus passing it from station to station. In a once classified US war game analysis, looking at varying levels of war escalation, warning and pre-emptive attacks in

17262-439: Was further developed by many others, and became rapidly indispensable in business , government , and in households . The essential elements of a telephone are a microphone ( transmitter ) to speak into and an earphone ( receiver ) which reproduces the voice at a distant location. The receiver and transmitter are usually built into a handset which is held up to the ear and mouth during conversation. The transmitter converts

17399-553: Was issued to the Marines in the 1980s, and was adopted by the US Army as well. The abbreviation HT, derived from Motorola's "Handie-Talkie" trademark, is commonly used to refer to portable handheld ham radios, with "walkie-talkie" often used as a layman's term or specifically to refer to a toy. Public safety and commercial users generally refer to their handhelds simply as "radios". Surplus Motorola Handie-Talkies found their way into

17536-521: Was launched in the 1980's, providing businesses and consumers with access to digital telephony services such as data, voice, video , and fax services. The development of digital data communications methods made it possible to digitize voice and transmit it as real-time data across computer networks and the Internet , giving rise to the field of Internet Protocol (IP) telephony, also known as voice over Internet Protocol (VoIP). VoIP has proven to be

17673-406: Was less likely to leave the phone "off the hook". In phones connected to magneto exchanges, the bell, induction coil, battery and magneto were in a separate bell box or " ringer box ". In phones connected to common battery exchanges, the ringer box was installed under a desk, or other out-of-the-way place, since it did not need a battery or magneto. Cradle designs were also used at this time, having

17810-479: Was lower than the earlier 121 casualties per ton prediction. However, in comparison, Allied strategic bombing of Germany during the war proved slightly less lethal than what was observed in the UK, with an estimated 400,000-600,000 German civilian fatalities for approximately 1.35 million tons of bombs dropped on Germany, an estimated resulting rate therefore of 0.30-0.44 civilian fatalities per ton of bombs dropped. In

17947-548: Was made over the issue of air-raid shelters , because of the apparently irreconcilable conflict between the need to send the public underground for shelter and the need to keep them above ground for protection against gas attacks. In February 1936 the Home Secretary appointed a technical Committee on Structural Precautions against Air Attack. During the Munich crisis , local authorities dug trenches to provide shelter. After

18084-407: Was not slow in appreciating the potential. Signalling began in an appropriately primitive manner. The user alerted the other end, or the exchange operator , by whistling into the transmitter. Exchange operation soon resulted in telephones being equipped with a bell in a ringer box , first operated over a second wire, and later over the same wire, but with a condenser ( capacitor ) in series with

18221-477: Was revived in 1949 as the Civil Defence Corps . As a civilian volunteer organization, it was tasked to take control in the aftermath of a major national emergency, principally envisaged as being a Cold War nuclear attack . Although under the authority of the Home Office , with a centralized administrative establishment, the corps was administered locally by Corps Authorities. In general every county

18358-413: Was shifted from nuclear war to an "all-hazards" approach of comprehensive emergency management . Natural disasters and the emergence of new threats such as terrorism have caused attention to be focused away from traditional civil defense and into new forms of civil protection such as emergency management and homeland security . Many countries maintain a national Civil Defence Corps, usually having

18495-550: Was the first to be awarded a patent for the electric telephone by the United States Patent and Trademark Office (USPTO) in March 1876. Before Bell's patent, the telephone transmitted sound in a way that was similar to the telegraph. This method used vibrations and circuits to send electrical pulses, but was missing key features. Bell found that this method produced a sound through intermittent currents, but in order for

18632-606: Was the principal RF engineer . The first handheld walkie-talkie was the AM SCR-536 transceiver from 1941, also made by Motorola, named the Handie-Talkie (HT). The terms are often confused today, but the original walkie-talkie referred to the back mounted model, while the handie-talkie was the device which could be held entirely in the hand. Both devices used vacuum tubes and were powered by high voltage dry cell batteries. Following World War II, Raytheon developed

18769-726: Was very limited. Thanks to the Luftwaffe's shifting aims, the strength of British air defenses, the use of early warning radar in combination with the Royal Observer Corps , and the life-saving actions of local civil defense units, the aerial "Blitz" during the Battle of Britain failed to break the morale of the British people, destroy the Royal Air Force or significantly hinder British industrial production. Despite

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