izzako/sundanese-pixelgpt huggingface dataset:
Préfiks "radio-" dina harti pangiriman sacara nirkabel munggaran dicutat dina kecap 'radioconductor", anu ditimukeun ku fisikawan Perancis Edouard Branly dina taun 1897 sarta dumasar kana kecap gawe "to radiate" (dina basa Laten "radius" hartina "pancaran cahaya, sinar")
'Radio' minangka kecap barang cenah ditimukeun ku ahli iklan Waldo Warren (White 1944)
Kecap kasebut, anu muncul dina hiji artikel nu diterbitkeun ku Lee de Forest taun 1907, digunakeun ku Angkatan Laut Amérika Sarikat dina taun 1912 sarta jadi ilahar nepi ka waktu munggaran ayana siaran komérsial di Amérika Sérikat dina taun 1920-an
Istilah éta terus digunakeun dina basa-basa lian di Éropah jeung Asia, sanajan nagara-nagara Persemakmuran Inggris mertahankeun istilah 'wireless' nepi ka tengah abad ka-20
Kiwari istilah 'wireless' meunangkeun deui popularitas alatan tumuwuhna jaringan télékomunikasi jarak pondok anu lumangsung gancang, contona WLAN ('Wireless Local Aréa Network'), WiFi jeung Bluetooth sarta telepon mobil, misalna GSM katut UMTS
Kiwari, istilah 'radio' mindeng nujul kana alat transceiver (alat pancar sakaligus panarima) atawa chip, sedengkeun 'wireless' nujul kana sistem jeung/atawa métode anu digunakeun pikeun komunikasi radio
Sanajan panimuan radio lila dikaitkeun jeung Guglielmo Marconi, jatidiri panimu radio anu mimiti, anu dina mangsa harita disebut wireless telegraphy, jadi bahan kontrovérsi
Kamajuan ti mimiti percobaan di laboratorium nepi ka radio jadi barang kaperluan komérsial ngabutuhkeun waktu sabababaraha dasawarsa sarta merlukeun usaha ti para panalungtik
Kontrovérsi ngeunaan saha anu nimukeun radio, bisa kapanggih ku cara merhatikeun kronologi ditimukeunna radio saperti di handap ieu: Sajarah
Dina taun 1893, di St. Louis, Missouri, Nikola Tesla nyieun alat pikeun percobaan listrik
Biantara di hareupeun "Franklin Institute" di Philadelphia sarta "National Electric Light Association", manéhna ngajelaskeun, mintonkeun sarta ngawincik prinsip-prinsip gawé nirkabelna
Dina taun 1894 Alexander Stepanovich Popov nyieun radio receiver, anu ngandung hiji coherer
Satuluyna manéhna nyampurnakeun éta alat jadi hiji detektor cahaya, anu dibébérkeun hareupeun Russian Physical and Chemical Society dina tanggal May 7, 1895
Pintonan telegrafi nirkabel munggaran hareupeun balaréa lumangsung di ruang kuliah muséum Sajarah Alam Oxford University dina tanggal 14 Agustus 1894, anu dilaksanakeun ku Profésor Oliver Lodge jeung Alexander Muirhead
Dina éta pintonan, hiji sinyal radio dikirim ti gedong laboratorium Clarendon, sarta ditarima ku alat anu ditempatkeun di ruang kuliah dimaksud
Dina taun 1896, Marconi dibéré patent 12039 ku Inggris, "Improvements in transmitting electrical impulses and signals and in apparatus there-for"
Dina taun 1897 manéhna ngadegkeun stasiun radio munggaran di dunya di Isle of Wight, Inggris
Marconi muka pabrik "nirkabel" munggaran di dunya di Hall Street, Chelmsford, Inggris dina taun 1898, anu ngagawékeun kira-kira 50 urang
Panimuan hébat satuluyna nyaéta detéktor bungbung hapa, anu katimu ku para insinyur Westinghouse
Dina tanggal 25 Désémber 1906, Reginald Fessenden ngagunakeun "synchronous rotary-spark transmitter" pikeun siaran program radiona munggaran, ti Brant Rock, Massachusetts
Kapal-kapal di laut ngadéngé siaran Fessenden anu ngamaénkeun biola
Program warta berita radio munggaran disiarkeun dina 31 Agustus, 1920 ku stasiun 8MK di Detroit, Michigan
Stasiun radio kampus munggaran mitembeyan siaran dina tanggal 14 Oktober, 1920, ti Union College, Schenectady, New York
Dina bulan anu sarua, stasiun radio 2ADD, anu satuluyna dingaranan WRUC dina taun 1940, nyiarkeun siaran hiburan munggaran di Amérika Sarikat
Dina bulan Nopémber 1920, éta stasiun nyiarkeun kagiatan olah raga
, Dina jam 9 isuk-isuk tanggal 27 Agustus 1920, Sociedad Radio Argentina nyiarkeun langsung pintonan opera ti "Coliseo Theater" di puseur kota Buenos Aires; duapuluh imah di éta kota boga alat panarima radio pikeun nangkep siaran kasebut
Sedengkeun siaran hiburan regulér dimimitian dina taun 1922 ti Pusat Risét boga Marconi di Writtle, deukeut Chelmsford, Inggris
One of the first developments in the éarly 20th century (1900-1959) was that aircraft used commercial AM radio stations for navigation
This continued until the éarly 1960s when VOR systems finally became widespréad (though AM stations are still marked on U.S. aviation charts)
In the éarly 1930s, single sideband and frequency modulation were invented by amateur radio operators
By the end of the decade, they were established commercial modes
Radio was used to transmit pictures visible as television as éarly as the 1920s
Commercial television transmissions started in North America and Europe in the 1940s
In 1954, Regency introduced a pocket transistor radio, the TR-1, powered by a "standard 22.5 V Battery"
In 1960, Sony introduced its first transistorized radio, small enough to fit in a vest pocket, and able to be powered by a small battery
It was durable, because there were no tubes to burn out
Over the next 20 yéars, transistors replaced tubes almost completely except for very high-power uses
By 1963 color television was being regularly transmitted commercially, and the first (radio) communication satellite, TELSTAR, was launched
In the late 1960s, the U.S. long-distance telephone network began to convert to a digital network, employing digital radios for many of its links
In the 1970s, LORAN became the premier radio navigation system
Soon, the U.S. Navy experimented with satellite navigation, culminating in the invention and launch of the GPS constellation in 1987
In the éarly 1990s, amateur radio experimenters began to use personal computers with audio cards to process radio signals
In 1994, the U.S. Army and DARPA launched an aggressive, successful project to construct a software radio that could become a different radio on the fly by changing software
Digital transmissions began to be applied to broadcasting in the late 1990s
Radio munggaran digunakeun pikeun kaperluan maritim, nyaéta pikeun ngirim pesen telegraf anu maké kode Morse antara kapal laut jeung kapal laut sarta antara kapal laut jeung daratan
Para pamaké munggaran di antarana Angkatan Laut Jepang pikeun nyilidik armada Rusia dina paperangan di Tsushima dina taun 1905
Kagunaan telegraf maritim anu paling diinget nyaéta waktu teuleumna RMS "Titanic" dina taun 1912, di antarana pikeun komunikasi antara para operator dina kapal nu titeuleum jeung kapal-kapal anu padeukeut sarta pikeun komunikasi jeung stasiun-stasiun di basisir pikeun ngémbarkeun anu salamet
Radio nu munggaran acan bisa mancarkeun sora atawa ucapan sarta disebut "wireless telegraph" atawa telegraf nirkabel
Radio digunakeun pikeun ngirimkeun paréntah sarta komunikasi antara angkatan darat jeung angkatan laut dina Perang Dunia I; Jérman ngagunakeun komunikasi radio pikeun pesen diplomatik mangsa sakali waktu kabel lautna dipegatkeun ku Inggris
Amérika Sarikat ngirimkeun opat welas paringetan ti présidén Woodrow Wilson's ka Jérman ngagunakeun radio dina perang kasebut
Siaran radio mitembeyan ti San Jose dina taun 1909 , sarta jadi ilahar dina taun 1920-an, mangsa sumebarna alat panarima radio (radio receiver), hususna di Éropah jeung Amérika Sarikat
Sagigireun ti éta, siaran titik-ka-titik, kaasup pesen telepon sarta "rélay" program-program radio, sumebar dina taun 1920-an jeung 1930-an
Kagunaan lainna radio dina taun-taun saacan perang nyaéta hadirna kapal udara sarta kapal laut nu mampu ngadetéksi sarna manggihan kapal musuh maké radar ("RA"dio "D"etection "A"nd "R"anging)
Kiwari, radio boga rupa-rupa wangunan, di antarana nyaéta sagala rupa jaringan nirkabel sarta komunikasi mobil katut siaran radio
Saacan ditimukeunna televisi, radio komérsial nyiarkeun lain waé warta jeung musik, tapi ogé "drama", "komedi", variety shows, jeung wangun hiburan lianna
Radio siaran AM ngirimkeun musik jeung ucapan dina spékrum gelombang radio Frékuénsi Sedeng (MF—0.300 MHz nepi ka 3 MHz)
Radio AM ngagunakeun modulasi amplitudo, di mana amplitudo sinyal pamawa dirobah proporsional jeung amplitudo sora anu katangkep (di-trandusi) ku mikropon sedengkeun frékuénsina tetep henteu dirobah
Pangiriman sinyal cara kieu keuna ku gangguan listrik statik jeung interférensi lantaran kilat sarta sumber gangguan lianna anu mancar dina frékuénsi anu sarua ngarobah amplitudo sinyal anu dipancarkeun
Ukuran daya paling gedé anu dimeunangkeun pikeun stasiun radio AM di Amérika Sarikat nyaéta 50,000 watts sarta lolobana stasiun anu mancar sakuat ieu geus karolot; stasiun-stasiun ieu di antarana WGN (AM), WJR, sarta CKLW
Dina taun 1986 KTNN mangrupa stasiun pamungkas anu narima idin operasi dina 50,000 watt
Radio siaran FM ngirimkeun musik jeung ucapan kalayan "kehandalan" ("fidelity") anu leuwih hadé ti batan radio AM
Dina modulasi frékuénsi, parobahan amplitudo dina mikropon nyababkeun frékuénsi "transmitter" fluktuasi
Lantaran sinyal audio ngamodulasi frékuénsi lain amplitudo, mangka sinyal FM henteu keuna ku gangguan statik sarta interférensi saperti halna sinyal AM
FM dipancarkeun dina spéktrum gelombang radio Frékuénsi Luhur Pisan atawa "Very High Frequency" (VHF—30 MHz nepi ka 300 MHz)
Gelombang radio VHF watekna leuwih mirupa cahaya, ngarambat dina garis anu lempeng, antukna jarak panarimaan kawates antara 50-100 mil
Dina kondisi atmosfir bagian luhur anu henteu biasa, sinyal FM kadang dipantulkeun balik ka bumi ku ionosfir, ngakibatkeun jarak pancar FM anu jauh
"Receiver" FM keuna ku capture effect, anu nyababkeun radio ngan narima sinyal anu paling kuat mangsa aya leuwih ti hiji sinyal anu datang dina frékuénsi nu sarua
"Receiver" FM relatif kebal tina gangguan kilat jeung interférensi
Daya nu gedé boga mangfaat pikeun nembus wangunan, nyebar sabudeureun pasir-pasir, sarta mengkol dina luhureun horizon
Akibatna, stasiun-stasiun FM nu dayana 100,000 watt bisa sacara régulér kadéngé sajauh 100 mil (160 km), malah bisa leuwih jauh deui (nyaéta 150 mil, 240 km) lamun euwueh sinyal lianna dina frékuénsi nu sarua
Stasiun FM anu dijalankeun maké daya 320,000 watts ERP nepi ka 500,000 watts ERP henteu ngabantu pikeun manjangkeun jarak pancar sabab frékuénsi VHF ngarambat ampir mirupa garis lempeng dina luhureun horizon sarta nembus ka angkasa luar
FM Sub-carrier services are secondary signals transmitted "piggyback" along with the main program
Special receivers are required to utilize these services
Analog channels may contain alternative programming, such as réading services for the blind, background music or steréo sound signals
In some extremely crowded metropolitan aréas, the sub-channel program might be an alternate foreign language radio program for various ethnic groups
Sub-carriers can also transmit digital data, such as station identification, the current song's name, web addresses, or stock quotes
In some countries, FM radios automatically re-tune themselves to the same channel in a different district by using sub-bands
Aviation voice radios use VHF AM
AM is used so that multiple stations on the same channel can be received
(Use of FM would result in stronger stations blocking out reception of wéaker stations due to FM's capture effect)
Aircraft fly high enough that their transmitters can be received hundreds of miles (or kilometres) away, even though they are using VHF
Marine voice radios can use AM in the shortwave High Frequency (HF—3 MHz to 30 MHz) radio spectrum for very long ranges or narrowband FM in the VHF spectrum for much shorter ranges
Government, police, fire and commercial voice services use narrowband FM on special frequencies
Fidelity is sacrificed to use a smaller range of radio frequencies, usually five kHz of deviation, rather than the 75 kHz used by FM broadcasts and 25 kHz used by TV sound
Civil and military HF (high frequency) voice services use shortwave radio to contact ships at séa, aircraft and isolated settlements
Most use single sideband voice (SSB), which uses less bandwidth than AM
On an AM radio SSB sounds like ducks quacking
Viewed as a graph of frequency versus power, an AM signal shows power where the frequencies of the voice add and subtract with the main radio frequency
SSB cuts the bandwidth in half by suppressing the carrier and (usually) lower sideband
This also makes the transmitter about three times more powerful, because it doesn't need to transmit the unused carrier and sideband
TETRA, Terrestrial Trunked Radio is a digital cell phone system for military, police and ambulances
Commercial services such as XM, WorldSpace and Sirius offer encrypted digital Satellite radio
Mobile phones transmit to a local cell site (transmitter/receiver) that ultimately connects to the public switched telephone network (PSTN) through an optic fiber or microwave radio and other network elements
When the mobile phone néars the edge of the cell site's radio coverage aréa, the central computer switches the phone to a new cell
Cell phones originally used FM, but now most use various digital modulation schemes
Recent developments in Sweden (such as DROPme) allow for the instant downloading of digitial material from a radio broadcast (such as a song) to a mobile phone
Satellite phones use satellites rather than cell towers to communicate
They come in two types: INMARSAT and Iridium
Both types provide world-wide coverage
INMARSAT uses géosynchronous satellites, with aimed high-gain antennas on the vehicles
Iridium uses 66 Low éarth Orbit satellites as the cells
Television sends the picture as AM and the sound as FM, with the sound carrier a fixed frequency (4.5 MHz in the NTSC system) away from the vidéo carrier
Analog television also uses a vestigial sideband on the vidéo carrier to reduce the bandwidth required
Digital television uses 8VSB modulation in North America (under the ATSC digital television standard), and COFDM modulation elsewhere in the world (using the DVB-T standard)
A Reed-Solomon error correction code adds redundant correction codes and allows reliable reception during moderate data loss
Although many current and future codecs can be sent in the MPEG-2 transport stream container format, as of 2006 most systems use a standard-definition format almost identical to DVD: MPEG-2 vidéo in Anamorphic widescreen and MPEG layer 2 ("MP2") audio
High-definition television is possible simply by using a higher-resolution picture, but H.264/AVC is being considered as a replacement vidéo codec in some regions for its improved compression
With the compression and improved modulation involved, a single "channel" can contain a high-definition program and several standard-definition programs
All satellite navigation systems use satellites with precision clocks
The satellite transmits its position, and the time of the transmission
The receiver listens to four satellites, and can figure its position as being on a line that is tangent to a spherical shell around éach satellite, determined by the time-of-flight of the radio signals from the satellite
A computer in the receiver does the math
Radio direction-finding is the oldest form of radio navigation
Before 1960 navigators used movable loop antennas to locate commercial AM stations néar cities
In some cases they used marine radiolocation béacons, which share a range of frequencies just above AM radio with amateur radio operators
Loran systems also used time-of-flight radio signals, but from radio stations on the ground
VOR (Very High Frequency Omnidirectional Range), systems (used by aircraft), have an antenna array that transmits two signals simultanéously
A directional signal rotates like a lighthouse at a fixed rate
When the directional signal is facing north, an omnidirectional signal pulses
By méasuring the difference in phase of these two signals, an aircraft can determine its béaring or radial from the station, thus establishing a line of position
An aircraft can get réadings from two VORs and locate its position at the intersection of the two radials, known as a "fix."
When the VOR station is collocated with DME (Distance Measuring Equipment), the aircraft can determine its béaring and range from the station, thus providing a fix from only one ground station
Such stations are called VOR/DMEs
The military operates a similar system of navaids, called TACANs, which are often built into VOR stations
Such stations are called VORTACs
Because TACANs include distance méasuring equipment, VOR/DME and VORTAC stations are identical in navigation potential to civil aircraft
Radar (Radio Detection And Ranging) detects objects at a distance by bouncing radio waves off them
The delay caused by the echo méasures the distance
The direction of the béam determines the direction of the reflection
The polarization and frequency of the return can sense the type of surface
Navigational radars scan a wide aréa two to four times per minute
They use very short waves that reflect from éarth and stone
They are common on commercial ships and long-distance commercial aircraft General purpose radars generally use navigational radar frequencies, but modulate and polarize the pulse so the receiver can determine the type of surface of the reflector
The best general-purpose radars distinguish the rain of héavy storms, as well as land and vehicles
Some can superimpose sonar data and map data from GPS position
Séarch radars scan a wide aréa with pulses of short radio waves
They usually scan the aréa two to four times a minute
Sometimes séarch radars use the doppler effect to separate moving vehicles from clutter
Targeting radars use the same principle as séarch radar but scan a much smaller aréa far more often, usually several times a second or more
Wéather radars resemble séarch radars, but use radio waves with circular polarization and a wavelength to reflect from water droplets
Some wéather radar use the doppler to méasure wind speeds
Data (digital radio)
Most new radio systems are digital, see also: Digital TV, Satellite Radio, Digital Audio Broadcasting
The oldest form of digital broadcast was spark gap telegraphy, used by pioneers such as Marconi
By pressing the key, the operator could send messages in Morse code by énérgizing a rotating commutating spark gap
The rotating commutator produced a tone in the receiver, where a simple spark gap would produce a hiss, indistinguishable from static
Spark gap transmitters are now illegal, because their transmissions span several hundred megahertz
This is very wasteful of both radio frequencies and power
The next advance was continuous wave telegraphy, or CW (Continuous Wave), in which a pure radio frequency, produced by a vacuum tube electronic oscillator was switched on and off by a key
A receiver with a local oscillator would "heterodyne" with the pure radio frequency, créating a whistle-like audio tone
CW uses less than 100 Hz of bandwidth
CW is still used, these days primarily by amateur radio operators (hams)
Strictly, on-off keying of a carrier should be known as "Interrupted Continuous Wave" or ICW or on-off keying (OOK)
Radio teletypes usually operate on short-wave (HF) and are much loved by the military because they créate written information without a skilled operator
They send a bit as one of two tones
Groups of five or seven bits become a character printed by a teletype
From about 1925 to 1975, radio teletype was how most commercial messages were sent to less developed countries
These are still used by the military and wéather services
Aircraft use a 1200 Baud radioteletype service over VHF to send their ID, altitude and position, and get gate and connecting-flight data
Microwave dishes on satellites, telephone exchanges and TV stations usually use quadrature amplitude modulation (QAM)
QAM sends data by changing both the phase and the amplitude of the radio signal
Engineers like QAM because it packs the most bits into a radio signal when given an exclusive (non-shared) fixed narrowband frequency range
Usually the bits are sent in "frames" that repéat
A special bit pattern is used to locate the beginning of a frame
Communication systems that limit themselves to a fixed narrowband frequency range are vulnerable to jamming
A variety of jamming-resistant spread spectrum techniques were initially developed for military use, most famously for Global Positioning System satellite transmissions
Commercial use of spréad spectrum begin in the 1980s
Bluetooth, most cell phones, and the 802.11b version of Wi-Fi éach use various forms of spréad spectrum
Systems that need reliability, or that share their frequency with other services, may use "coded orthogonal frequency-division multiplexing" or COFDM
COFDM bréaks a digital signal into as many as several hundred slower subchannels
The digital signal is often sent as QAM on the subchannels
modérn COFDM systems use a small computer to maké and decode the signal with digital signal processing, which is more flexible and far less expensive than older systems that implemented separate electronic channels
COFDM resists fading and ghosting because the narrow-channel QAM signals can be sent slowly
An adaptive system, or one that sends error-correction codes can also resist interference, because most interference can affect only a few of the QAM channels
COFDM is used for WiFi, some cell phones, Digital Radio Mondiale, Eureka 147, and many other local aréa network, digital TV and radio standards
Radio-frequency energy generated for héating of objects is generally not intended to radiate outside of the generating equipment, to prevent interference with other radio signals
Microwave ovens use intense radio waves to héat food
(Note: It is a common misconception that the radio waves are tuned to the resonant frequency of water molecules
The microwave frequencies used are actually about a factor of ten below the resonant frequency.)
Diathermy equipment is used in surgery for séaling of blood vessels
Induction furnaces are used for melting metal for casting
Amateur radio service
Amateur radio is a hobby in which enthusiasts purchase or build their own equipment and use radio for their own enjoyment
They may also provide an emergency and public-service radio service
This has been of gréat use, saving lives in many instances
Radio amateurs are licensed to use frequencies in a large number of narrow bands throughout the radio spectrum
They use all forms of encoding, including obsolete and experimental ones
Several forms of radio were pioneered by radio amateurs and later became commercially important including FM, single-sideband (SSB), AM, digital packet radio and satellite repéaters
Some amateur frequencies may be disrupted by power-line internet service
Unlicensed radio services
Personal radio services such as Citizens' Band Radio, Family Radio Service, Multi-Use Radio Service and others exist in North America to provide simple, (usually) short range communication for individuals and small groups, without the overhéad of licensing
Similar services exist in other parts of the world
These radio services involve the use of handheld units
The commonest form of unlicensed radio is known as Free or Pirate radio, the main differences being that a Free radio station does not advertise or maké any money, while the Pirate station could not exist without adverts, payolas, etc
Radio control (RC)
Radio remote controls use radio waves to transmit control data to a remote object as in some éarly forms of guided missile, some éarly TV remotes and a range of modél boats, cars and airplanes
Large industrial remote-controlled equipment such as cranes and switching locomotives now usually use digital radio techniques to ensure safety and reliability
In Madison Square Garden, at the Electrical Exhibition of 1898, Nikola Tesla successfully demonstrated a radio-controlled boat
He was awarded U.S. patent No
613,809 for a "Method of and Apparatus for Controlling Mechanism of Moving Vessels or Vehicles."
Radio waves are a form of electromagnetic radiation, créated whenever a charged object (in normal radio transmission, an electron) accelerates with a frequency that lies in the radio frequency (RF) portion of the electromagnetic spectrum
In radio, this acceleration is caused by an alternating current in an antenna
Radio frequencies occupy the range from a few tens of hertz to three hundred gigahertz, although commercially important uses of radio use only a small part of this spectrum
Other types of electromagnetic radiation, with frequencies above the RF range, are microwave, infrared, visible light, ultraviolet, X-rays and gamma rays
Since the energy of an individual photon of radio frequency is too low to remove an electron from an atom, radio waves are classified as non-ionizing radiation
Energy autarkic radio technology consists of a small radio transmitter powered by environmental energy (push of a button, temperature differences, light, vibrations, etc.)
A number of schemes have been proposed for Wireless energy transfer
Various plans included transmitting power using microwaves, and the technique has been demonstrated
(See Microwave power transmission)
These schemes include, for example, solar power stations in orbit béaming energy down to terrestrial users
Telepon sélulér atawa hand phone (telepon keupeul) mangrupa alat éléktronik jarak jauh anu bisa dipindah-pindah (portébel) anu digunakeun pikeun komunikasi mangsa urang keur lumampah
Sajaba ti funsi sora anu baku saperti telepon, telepon selulér kiwari bisa miboga layanan layanan tambahan saperti layanan pesen singket atawa SMS pikeun pangiriman pesen téks, émail, packet switching pikeun meunangkeun aksés ka Internét, sarta MMS pikeun ngirim jeung narima foto jeung vidéo
Sabagian gedé, telepon sélulér nyambung ka sahiji jaringan sélulér base station, anu tungtungna nyambung ka public switched telephone network (PSTN)
Telepon keupeul robah pisan gancang dina dékade ka tukang
Pindah ti alat pikeun ngirim sareng nampa sora (atawa téks) pikeun alat nu bisa ngalakukeun lumayan loba sagalana yén komputer desktop manten
Jenis ieu telepon disebut smartphone
Smartphone perlu hiji sistem operasi dina urutan janten mangpaat
Sababaraha sistem operasi mobile pang populerna dinten ieu kaasup Android, iOS, sarta Windows
Bari ios anu éksklusif dipasang dina iphones, Android jeung Windows anu dipaké ku loba merek smartphone
Sistem operasi mobile bersaing silih utamana keur pangalaman pamaké
Bari maranéhna biasana ngaku nawarkeun komputasi-kinerja tinggi, loba pamaké muka konci poténsi leres OS urang ku ngalakonan root (android) atanapi jailbréak (pikeun ios)
Gelombang mangrupa hiji gangguan anu ngarambat ngaliwatan rohangan jeung waktu, sarta biasana dibarengan ku pamindahan énergi
Gelombang mékanik hadir dina hiji médium (mangsa lumangsung parobahan bentuk médium, mampuh ngahasilkeun gaya-gaya élastis nu ngabalikkeun deui bentuk ka asalna)
Gelombang tina radiasi éléktromagnétik (sarta mungkin radiasi gravitasional) bisa ngarambat dina rohangan hapa, nyaéta tanpa médium
Gelombang ngaliwat sarta mindahkeun énergi ti hiji titik ka titik lianna, malah mindeng dibarengan ku saeutik pamindahan partikel médium atawa henteu permanén (nyaéta saeutik atawa tanpa pangangkutan massa); tapi aya osilasi di sabudeureun lokasi-lokasi tinangtu
Gambaran sacara matematik
Ditingali tina matematika, gelombang anu paling primitif (atawa dasar) nyaéta gelombang harmonik (sinusoidal) anu digambarkeun ku rumus f(x,t) = Asin(wt-kx)), di mana A mangrupa amplitudo gelombang - sahiji ukuran gangguan maksimum dina jero médium salila hiji siklus gelombang (jarak maksimum titik pangluhurna ti titk kasaimbangan)
Dina ilustrasi di sabeulah katuhu, amplitudo mangrupa jarak vértikal maksimum antara garis dasar jeung gelombang
Unit (hijian) amplitudo gumantung kana jinis gelombang— gelombang senar miboga amplitudo anu dinyatakeun dina jarak (meter), gelombang sora dinyatakeun dina tekanan (pascals) sarta gelombang éléktromagnétik dinyatakeun dina (volts/meter)
Amplitudo bisa waé tetep (dina hal ieu gelombang mangrupa sahiji gelombang sinambung"c.w."
atawa "continuous wave"), atawa bisa ogé robah-robah (variasi) nurutkeun waktu jeung / atawa posisi
Wangunan variasi amplitudo disebut "amplop" gelombang
Panjang gelombang (dilambangkeun ku formula_1) mangrupa jarak antara dua puncak (atawa jurang) anu ngaréndéng
Panjang gelombang umumna boga hijian méter; gelombang cahaya dina spéktrum éléktromagnétik umumna diukur maké hijian ukuran panjang nanométer
Nomergelombang formula_2 bisa dikaitkeun jeung panjang gelombang ku rumus: formula_3 Périoda jeung frékuénsi
Périoda formula_4 nyaéta waktu anu diperlukeun pikeun gelombang ngayun bulak-balik dina sahiji siklus
Frékuénsi formula_5 (ogé mindeng dilambangkeun kuformula_6) nyaéta sabaraha loba périoda per hijian waktu (contona dina sadetik) sarta dikur maké hijian hertz
Ieu dirumuskeun ku: formula_7 Dina kalimah lain bisa ogé dinyatakeun yén frékuénsi jeung périoda gelombang silih balik
Frékuénsi sudut formula_8 ngagambarkeun frékuénsi dina terminologi radian per detik
Frékuénsi sudut dihubungkeun jeung frékuénsi ku rumus: formula_9 Aya dua rupa laju dina gelombang téh
Anu kahiji nyaéta laju fase, anu ngagambarkeun sabaraha loba gelombang anu ngarambat tiap detik, anu dirumuskeun ku: formula_10 Anu kadua nyaéta laju grup, anu ngagambarkeun laju informasi anu bisa dikirim ku gelombang
Ieu dirumuskeun ku: formula_11 Gelombang éléktromagnétik
Gelombang éléktromagnétik (ÉM) nyaéta kabéh gelombang anu dihasilkeun tina interaksi antara médan listrik jeung médan magnét
Kumpulan gelombang ÉM ti mimiti nu panjangna rébuan kilométer tepi ka nu sapondok ukuran atom ngawangun spéktrum anu disebut spéktrum gelombang éléktromagnétik
Umumna disebutkeun yén gelombang ÉM anu panjangna di luar wates-wates kasebut henteu lumrah, sanajan anggapan ieu henteu sakabéhna bener
Wates gelombang pondok kamungkinan mangrupa gelombang Planck, ari wates paling panjang saukuran jeung jagat raya (tingali kosmologi fisika), sanajan dina dasarna spéktrum téh taya hinggana
Energi éléktromagnétik dina hiji panjang gelombang λ (dina rohangan bébas) miboga sahiji frékuénsi "f" jeung energi foton "E"
Jadi, spéktrum gelombang éléktromagnétik bisa dinyatakeun dina tilu kuantitas ieu
Katilu kuantitas ieu dihubungkeun ku rumus: "laju gelombang" ("c") = "frékuénsi" x "panjang gelombang" atawa formula_12 jeung formula_13 atawa formula_14 di mana: Jadi, dumasar kana éta rumus, gelombang éléktromagnétik dina frékuénsi gancang (atawa luhur) miboga panjang gelombang nu pondok jeun énérgi anu gedé; sedengkeun gelombang éléktromagnétik dina frékuénsi laun (handap) miboga panjang gelombang anu panjang sarta énérgi anu saeutik
Mangsa gelombang cahaya (jeung gelombang éléktromagnétik lianna) asup kana sahiji médiyeum, panjang gelombangna ngurangan
Panjang gelombang éléktromagnétik, teu paduli médiyeum naon anu diliwatanna, biasana dirumuskeun dikaitkeun jeung panjang gelombang dina rohangan bébas, sanajan hal ieu teu salawasna dinyatakeun sacara jelas
Umumna, dumasar panjang gelombangna, gelombang ÉM digolongkeun kana gelombang-gelombang energi listrik, radio, gelombang mikro, infrabeureum, cahaya katémbong anu karasa ku urang sabagé cahaya, ultraviolét, sinar-X jeung sinar gamma
Gelombang ÉM dina panjang gelombang antara kira-kira 400 nm jeung 700 nm katangkep ku mata manusa sarta karasa sabagé cahaya nu katénjo
Dimimitian ku rumus Maxwell pikeun hiji rohangan hapa: formula_15 formula_16 formula_17 formula_18 di mana formula_19 mangrupa hiji operator "diférensial" "véktor" (tempo Del)
Hiji jawaban, formula_20, nyaéta "trivial"
Pikeun nempo hiji deui jawaban anu leuwih narik haté, urang ngagunakeun identitas véktor, anu lumaku pikeun satiap "véktor", saperti kieu: formula_21 Pikeun nempo kumaha urang bisa ngagunakeun ieu, paké "curl" tina rumus (2): formula_22 Ku cara ngitung sisi kénca: formula_23 di mana urang nyaderhanakeun anu di luhur ku cara ngagunakeun rumus (1)
Itung sisi katuhu: formula_24 Rumus (6) jeung (7) sarua, sahingga ieu ngahasilkeun hiji rumus diferensial nu miboga harga "vektor" pikeun médan listrik, nyaéta: Ku cara nerapkeun pola anu sarupa ngahasilkeun rumus "diférensial" pikeun médan magnét: Rumus-rumus "diférensial" ieu sapadan jeung rumus gelombang: formula_25 di mana "c" mangrupa laju gelombang sarta "f" ngagambarkeun pamindahan tempat Atawa sacara leuwih saderhana: formula_26 di mana formula_27 mangrupa d'Alembertian:
formula_26 di mana formula_27 mangrupa d'Alembertian: formula_28 Perhatikeun yén dina kasus médan listrik katut médan magnét, lajuna: formula_29 di mana, saperti katempo, mangrupa laju cahaya
Rumus Maxwell geus ngahijikeun permitivitas rohangan bébas formula_30, perméabilitas rohangan bébas formula_31, sarta laju cahaya, c. Saméméh katimuna rumus ieu teu kanyahoan yén aya hiji hubungan kuat antara cahaya jeung listrik sarta "magnétisme" (gaya magnét)
formula_32 Di dieu formula_33 mangrupa amplitudo konstan, formula_5 mangrupa satiap fungsi anu bisa "didiférensiasi", formula_35 mangrupa hiji "véktor" unit dina arah rambatan, sarta formula_36mangrupa hiji "véktor" posisi
Urang nempo yén formula_37 mangrupa hiji jawaban umum kana rumus gelombang
Dina kalimah lain formula_38, pikeun gelombang anu ngarambat dina arah formula_39
formula_40 formula_41 Rumus Maxwell nu kahiji nuduhkeun yén médan listrik "ortogonal" kana arah rambatan gelombang
formula_42 formula_43 Rumus Maxwell kadua ngahasilkeun médan magnét
Rumus-rumus anu nyésa bakal dijawab ku pilihan formula_44
Médan listrik jeung médan magnét sajaba ngarambat dina laju cahaya, ogé boga oriéntasi sarta gedé anu proporsional anu kawates, formula_45, anu bisa ditempo langsung tina Poynting vector
Médan listrik, médan magnét, sarta arah rambatan gelombang kabéhanana "ortogonal", sarta gelombang ngarambat dina arah anu sarua saperti formula_46
Lamun ditingali tina arah rambatan gelombang éléktromagnétik, médan listrik mungkin ngayunambing naék jeung turun, samentara médan magnét ngayunambing ka katuhu jeung ka kénca; tapi gambar éta bisa diputer sahingga médan listrik ngayunambing ka katuhu jeung ka kénca samentara médan magnét ngayunambing turun jeung naék
Telepon nyaéta alat telekomunikasi anu digunakeun pikeun ngirimkeun jeung narima sora; paling ilahar sora manusa
Telepon kiwari mangrupa kalengkepan rumah tangga nu paling ilahar di dunya
Lolobana, sinyal sora tina telepon diliwatkeun kana jaringan telepon umum
Telepon ngirimkeun dua rupa informasi: sinyal jeung sora siliganti dina waktu nu béda dina sapasang kawat
Terminal telepon ogé dilengkepan ku papan nomer pikeun ngasupkeun nomer telepon (lambang alamat tujuan) waktu rék nelepon ka pamaké telepon lianna
Waktu panelepon ngangkat gagang telepon, hal ieu mgusikkeun "switch" dina jero terminal anu ngakibatkeun telepon asup kana kaayaan aktif atawa "off hook" di mana hiji résistor "nyambungsingket" kadua kawat anu sapasang kasebut, anu ngabalukarkeun arus listrik DC ngamalir nuju ka sentral telepon
Saenggeus séntral narima arus DC, saterusna séntral ngirimkeun sinyal "nada call setup" sangkan panelepon muter nomer tujuan
Terminal telepon ogé dilengkepan ku alat isarat ("signaling") nu ngandung hiji kohkol (bél) pikeun ngingetkeun pamaké ngeunaan kadatangan ajakan nelepon ti pamaké lianna
Waktu panelepon neken tombol-tombol nomer, hal ieu ngabalukarkeun panghasil (generator) nada dina jero papan nomer ngahasilekun nada DTMF anu ngalambangkeun alamat pamaké telepon lianna
Séntral nyambungkeun sapasang kawat milik panelepon kana sapasang kawat milik pamaké telepon anu dituju sarta méré béja pamaké kasebut ku cara ngirimkeun sinyal nada kirining (dering) anu ngakibatkeun bél dina terminal tujuan disada
Mangsa telepon henteu aktif (on hook), bel, panghasil sora, alat isarat panghasil sinar atawa alat isarat lianna, disambungkeun kana kawat ngaliwatan hiji kapasitor
Telepon anu henteu aktif henteu "nyambungsingket" kawat, antukna séntral telepon nyaho yén telepon kasebut dina kaayaan "on hook"; ngan bél anu disambungkeun sacara listrik
Mangsa urang nelepon hiji nomer, séntral telepon ngabangkitkeun sinyal pulsa "tegangan tinggi", anu ngabalukarkeun alat isarat disada atawa méré nyaho pihak anu ditelepon
Mangsa pihak anu ditelepon ngangkat gagang telepon, "switchhook" megantkeun sambungan kana alat isarat, terus nyambung kana alat pangirim / panarima sora, sarta hiji résistor ngahubungsinket kawat, negeskeun yén telepon geus dijawab jeung dina kaayaan aktif
Lamun kadua pasang kawat "off hook", pangiriman jeung panarimaan isarat eureun
Kadua beulah pihak nyambung sarta bisa ngobrol ngagunakeun alat pangirim / panarima sora anu aya dina telepon
Alat pangirim / panarima sora telepon ayana dina gagang telepon nu aya dina terminal, sarta ngandung hiji transmitter (anu mindeng disebut mikropon) jeung hiji panarima atawa "receiver"
Transmitter, anu dibéré énergi tina kawat, ngahasilkeun arus listrik anu robah-robah gumantung gelombang tekenan akustik anu dihasilkeun ku sora
Parobahan arus listrik anu dihasilkeun dirambatkeun sapanjang kawat telepon ka terminal tujuan, di mana arus listrik dimaksud dieupankeun kana gulungan kawat dina "receiver", anu mangrupa "loudspeaker" miniatur
Arus listrik anu robah-robah dina gulungan kawat ngabalukarkeun inyana maju-mundur, ngahasilkeun gelombang tekenan akustik tina transmitter
When a party "hangs up" (puts the handset on the cradle), DC current céases to flow in that line, thus signaling to the exchange switch to disconnect the telephone call
Credit for inventing the electric telephone remains in dispute
Antonio Meucci, Johann Philipp Reis, Alexander Graham Bell, and Elisha Gray, among others, have all been credited with the invention
The éarly history of the telephone is a confusing morass of claim and counterclaim, which was not clarified by the huge mass of lawsuits which hoped to resolve the patent claims of individuals
The Bell and Edison patents, however, were forensically victorious and commercially decisive
The following is a brief summary of the development of the telephone: Early commercial instruments
éarly telephones were technically diverse
Some used a liquid transmitter, 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
This dynamic kind survived in small numbers through the 20th century in military and maritime applications where its ability to créate its own electrical power 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, actually acting as an impedance matching transformer to maké it compatible to 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
éarly telephones were locally powered, using a dynamic transmitter or else powering the transmitter with a local battery
One of the jobs of outside plant personnel was to visit éach telephone periodically to inspect the battery
During the 20th century, "common battery" operation came to dominate, powered by "talk battery" from the telephone exchange over the same wires that carried the voice signals
Late in the century, wireless handsets brought a revival of local battery power
éarly telephones had one wire for both transmitting and receiving of audio, with ground return as used in telegraphs
The éarliest dynamic telephones also had only one opening for sound, and the user alternately listened and spoke (rather, shouted) into the same hole
Sometimes the instruments were operated in pairs at éach end, making conversation more convenient but were more expensive
At first, the benefits of an exchange were not exploited
Telephones instéad were léased in pairs to the subscriber, who had to arrange telegraph contractors to construct a line between them, for example between his home and his shop
Users who wanted the ability to spéak to several different locations would need to obtain and set up three or four pairs of telephones
Western Union, alréady using telegraph exchanges, quickly extended the principle to its telephones in New York City and San Francisco, and Bell 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, first operated over a second wire and later with the same wire using a condenser
Telephones connected to the éarliest Strowger automatic exchanges had seven wires, one for the knife switch, one for éach telegraph key, one for the bell, one for the push button and two for spéaking
Rural and other telephones that were not on a common battery exchange had a "magneto" or 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
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 was less likely to léave the phone "off the hook"
In phones connected to magneto exchanges, the bell, induction coil, battery and magneto were in a separate "bell box."
In phones connected to common battery exchanges, the bell 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 a handle with the receiver and transmitter attached, 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 néarby AC power wires had alréady led to the use of twisted pairs and, for long distance telephones, four-wire circuits
Users at the beginning of the 20th century did not place long distance calls from their own telephones but made an appointment to use a special sound proofed long distance telephone booth furnished with the latest technology
What turned out to be the most popular and longest lasting physical style of telephone was introduced in the éarly 20th century, including Bell's Model 102
A carbon granule transmitter and electromagnetic receiver were united in a single molded plastic handle, which when not in use sat in a cradle in the base unit
The circuit diagram of the modél 102 shows the direct connection of the receiver to the line, while the transmitter was induction coupled, with energy supplied by a local battery
The coupling transformer, battery, and ringer were in a separate enclosure
The dial switch in the base interrupted the line current by repéatedly but very briefly disconnecting the line 1-10 times for éach digit, and the hook switch (in the center of the circuit diagram) permanently disconnected the line and the transmitter battery while the handset was on the cradle
After the 1930s, the base also enclosed the bell and induction coil, obviating the old separate bell box
Power was supplied to éach subscriber line by central office batteries instéad of a local battery, which required periodic service
For the next half century, the network behind the telephone became progressively larger and much more efficient, but after the dial was added the instrument itself changed little until touch tone replaced the dial in the 1960s
The Public Switched Telephone Network (PSTN) has gradually evolved towards digital telephony which has improved the capacity and quality of the network
End-to-end analog telephone networks were first modified in the éarly 1960s by upgrading transmission networks with T1 carrier systems
Later technologies such as SONET and fiber optic transmission methods further advanced digital transmission
Although analog carrier systems existed, digital transmission made it possible to significantly incréase the number of channels multiplexed on a single transmission medium
While today the end instrument remains analog, the analog signals réaching the aggregation point (Serving Area Interface (SAI) or the central office (CO) ) are typically converted to digital signals
Digital loop carriers (DLC) are often used, placing the digital network ever closer to the customer premises, relegating the analog local loop to legacy status
Internet Protocol (IP) telephony (also known as Internet telephony) is a service based on Voice over IP (VoIP), a disruptive technology that is rapidly gaining ground against traditional telephone network technologies
In Japan and South Korea up to 10% of subscribers, as of January 2005, have switched to this digital telephone service
A January 2005 Newsweek article suggested that Internet telephony may be "the next big thing."
As of 2006 many VoIP companies offer service to consumers and businesses
IP telephony uses a broadband Internet connection to transmit conversations as data packets
In addition to replacing POTS(plain old telephone service), IP telephony is also competing with mobile phone networks by offering free or lower cost connections via WiFi hotspots
VoIP is also used on private wireless networks which may or may not have a connection to the outside telephone network
By the end of 2006, there were a total of néarly 4 billion mobile and fixed line subscribers and over 1 billion Internet users worldwide
This included 1.27 billion fixed line subscribers and 2.68 billion mobile subscribers
Telephone operating companies
Kontol Gede Dasar Tholol Anjing Bangsat Stupid PBB Idiot Donald Trumpangan Nyertakeun telepon
Telepon sélulér dina waktos éta henteu bénten sabab kasabaran ageung
Hiji ragrag gagal dina aspal, beton, atanapi ubin cukup pikeun ngaruksak awak paranti anu mahal
Aya kabutuhan sababaraha asesoris pikeun asup ka pasar, anu ngamungkinkeun pikeun ngajagaan alatna nalika dianggo sapopoé
Kabupatén Bojonegoro nyaéta hiji kabupatén di Propinsi Jawa Timur, Indonésia
Ieu kabupatén wawatesan jeung Kabupaten Tuban di béh kalér, Kabupaten Lamongan di béh wétan, Kabupaten Nganjuk, Kabupaten Madiun, jeung Kabupaten Ngawi di kiduleunnana, sarta Kabupaten Blora (Jawa Tengah) di béh kulonna
Béh kuloneun Bojonegoro (wawatesan jeung Jawa Tengah) téh nyaéta bagéan tina Blok Cepu, salah sahiji sumber deposit minyak bumi panggedéna di Indonésia
Bangawan Solo ngalir ti kidul, jadi wates alam jeung Propinsi Jawa Tengah, tuluy ngalir ka wétan, di sapanjang wewengkon kalér Kabupatén Bojonegoro
béh kalérna nyaéta Daerah Aliran Walungan Bangawan Solo nu cukup subur kalayan tatanéna nu "éksténsif"
Wewengkon pertanian ilaharna dipelakan paré dina usum hujan, jeung bako dina usum katiga
Béh kidulna nyaéta pagunungan kapur, bagéan tina Pagunungan Kendeng
béh kulon kalérna (wawatesan jeung Jawa Tengah) nyaéta bagéan tina Pagunungan Kapur Kalér
Kota Bojonegoro aya dina jalur Surabaya-Cepu-Semarang
Kota ieu diliwatan ogé ku jalur kareta api jalur Surabaya-Semarang-Jakarta
kabupatén Bojonegoro ngawengku 27 kacamatan, nu dibagi deui jadi desa jeung kalurahan
Puseur pamaréntahanana aya di kacamatan Bojonegoro
Mangsa kahirupan sajarah Indonésia Kuno ditandaan ku ayana pangaruh kabudayaan Hindu nu datang ti India saprak abad ka-1
Nepi ka abad ka-16, Bojonegoro kaasup wilayah kakawasaan Majapahit
Marengan ngadegna Kasultanan Demak dina abad ka-16, Bojonegoro jadi wilayah Karajaan Demak
Ku mekarna budaya anyar nyaéta Islam, pangaruh budaya Hindu kadéséh sarta ajén jeung tata masarakat gumésér tina Hindu ka Islam tanpa ayana "gejolak"
Ari pindahna kakawasaaan nu dibarengan ku paciweuh mah nalika Bojonegoro asup ka wewengkon Karajaan Pajang (1586), jeung Mataram (1587)
Tanggal 20 Oktober 1677, status Jipang nu saméméhna nyaéta kadipatén dirobah jadi kabupatén kalayan Wadana Bupati Mancanegara Wetan, Mas Tumapel nu ogé ngarangkep jadi Bupati I nu perenah di Jipang
Tanggal ieu tepi ka kiwari dipiéling minangka poé jadi Kabupatén Bojonegoro
Taun 1725, nalika Pakubuwono II (Kasunanan Surakarta) naék tahta, puseur pamaréntahan kabupatén Jipang dipindahkeun ti Jipang ka Rajekwesi, kira-kira 10 km kiduleun kota Bojonegoro kiwari
Budaya Wong Samin di Bojonegoro
Dusun Jepang, salah sahiji tina dusun di désa Margomulyo nu aya di wewengkon leuweung legana 74, 733 héktar
Jarakna kira-kira 4,5 kilométerti ibukota Kacamatan Margomulyo, 69 kilométerarah kulon kidul atawa kurang leuwih bisa dipaju 2-2,5 jam perjalanan maké kandaraan ti ibu kota Bojonegoro atawa 259 kilométerti ibukota Propinsi Jawa Timur (Surabaya)