4G

**4G** Shine ƙarni na huɗu na fasahar sadarwar salula, nasara 3G , da 5G da suka gabata. Tsarin 4G dole ne ya samar da damar da ITU ya bayyana a cikin IMT Advanced. Mai yuwuwa da aikace-aikacen yanzu sun haɗa da damar amfani da gidan yanar gizo na wayoyin hannu , wayar tarho ta IP, sabis ɗin caca, TV mai wayo mai ma'ana, taron bidiyo, da talabijin 3D.

Sakin fitowar farko na WIMAX kasuwanci ne da aka tura a Koriya ta Kudu a cikin shekarar 2006 kuma tun daga wannan lokacin aka tura yawancin sassan duniya

Matsayi na farko da aka fitar na Long Term Evolution (LTE) an tura shi cikin kasuwanci a Oslo, Norway, da Stockholm, Sweden a cikin shekarata 2009, kuma tun daga wannan lokacin an tura shi ko'ina cikin sassan duniya. Ya kasance, duk da haka, an yi muhawara ko yakamata a ɗauki sifofin fitarwa na farko 4G LTE.

## Siffar fasaha
A cikin Nuwamban shekarar 2008, sashen sadarwa na Unionungiyoyin Sadarwa na -ungiyar Sadarwa-Rediyo (ITU-R) ya ƙayyade jerin buƙatu don ƙa'idodin 4G, mai suna ƙayyadaddun Sadarwar Sadarwa ta Mobileasa ta Duniya (IMT-Advanced), da saita ƙimar ƙaƙƙarfan buƙatun don sabis na 4G akan megabits 100 a kowace na biyu (Mbit / s) (= megabytes 12.5 a kowace dakika) don sadarwa mai motsi (kamar ta jiragen ƙasa da motoci) da kuma gigabit 1 a kowace dakika (Gbit / s) don sadarwa mara motsi (kamar masu tafiya a kafa da masu amfani a tsaye). 

Tun farkon fitowar sigar Wayar WiMAX da LTE suna tallafawa ƙasa da ƙimar 1 Gbit / s, ba su cika cika IMT-Advanced ba, amma ana ba su alama ta 4G ta masu ba da sabis. A cewar masu aiki, wani ƙarni na cibiyar sadarwar yana nufin ƙaddamar da sabuwar fasahar da ba ta dace da ta dace ba. A ranar 6 ga Disamba,shekara  ta 2010, ITU-R ta fahimci cewa waɗannan fasahohin guda biyu, da ma wasu fasahohin da ba su wuce 3G ba waɗanda ba sa biyan bukatun IMT-Advanced, duk da haka ana iya ɗaukar su "4G", in har suna wakiltar waɗanda suka gabaci IMT-Advanced sigogi da "ingantaccen matakin haɓaka aiki da iyawa game da tsarin ƙarni na farko da aka tura yanzu".

Sakin Sakin waya na WiMAX na 2 (wanda aka fi sani da *WirelessMAN-Advanced* ko *IEEE 802.16m* ) da LTE Advanced (LTE-A) sune IMT-Advanced waɗanda suka dace da jigo na tsarin biyu da ke sama, an daidaita su a lokacin bazara 2011 da saurin gudu a cikin tsari na 1 Gbit / s. An yi tsammanin ayyuka a cikin 2013. [ yana buƙatar sabuntawa ]

Sabanin mutanen da suka gabata, tsarin 4G baya tallafawa sabis na wayar tarho da aka sauya, amma a maimakon haka ya dogara ne da duk hanyar sadarwa ta Intanet (IP) kamar su wayar IP . Kamar yadda aka gani a ƙasa, an watsar da fasahar rediyo mai yaduwa wacce aka yi amfani da ita a cikin tsarin 3G a cikin dukkanin tsarin takarar ɗan takarar 4G kuma an maye gurbin ta da watsa shirye-shiryen watsa shirye -shiryen OFDMA da yawa da makircin daidaita daidaiton yanki-yanki (FDE), yana ba da damar canja wuri mai tsada sosai duk da mai yawa yaduwar rediyo da yawa (amsa kuwwa). Furtheraramar ƙimar bit an ƙara haɓaka ta shirye-shiryen eriya mai wayo don sadarwa mai yawa-fitarwa mai yawa (MIMO).

## Bayan Fage
A fagen sadarwar wayar hannu, "tsara" gabaɗaya tana nufin canji a cikin asalin yanayin sabis ɗin, fasahar watsawa mai jituwa da baya-baya, ƙimar kuɗi mafi girma, sabbin makadai madogara, faɗakarwar tashar tashar rediyo a cikin Hertz, kuma mafi girma capacityarfin aiki don canja wurin bayanai da yawa a lokaci ɗaya (ingantaccen tsarin aiki a cikin bit / na biyu / Hertz / site).

Sabbin tsararrun wayoyi sun bayyana kusan kowane shekaru goma tunda farkon motsi daga watsa analog na 1981 (1G) zuwa watsawar dijital (2G) a 1992. Wannan ya biyo bayan haka, a cikin 2001, ta hanyar tallafi na kafofin watsa labarai na 3G da yawa, yada yaduwar bakan da mafi ƙarancin ƙimar bit na 200 kbit / s, a cikin 2011/2012 da za a bi ta "ainihin" 4G, wanda ke nufin duk- Yarjejeniyar Intanet ( IP) cibiyoyin sadarwar da aka sauya cikin fakiti suna ba wa masu amfani da babbar hanyar sadarwa mai saurin gaske (saurin gigabit).

A tsakiyar shekarun 1990s, kungiyar daidaita ITU-R ta fitar da bukatun IMT-2000 a matsayin tsarin abin da ya kamata a yi la’akari da tsarin 3G, wanda ke bukatar 200 kbit / s peak bit bit. A cikin 2008, ITU-R sun ayyana bukatun IMT Advanced (International Mobile Telecommunications Advanced) na tsarin 4G.

Tsarin 3G mafi sauri cikin dangin UMTS shine tsarin HSPA +, wanda ake samunsa a kasuwa tun shekara ta 2009 kuma yana ba da 28 Mbit / s zuwa ƙasa (22 Mbit / s gaba ɗaya) ba tare da MIMO ba, watau tare da eriya ɗaya kawai, kuma a cikin 2011 ya haɓaka har zuwa 42 Mbit / s peak bit low downstream ta hanyar amfani da DC-HSPA + (amfani guda biyu guda 5MHz masu ɗaukar UMTS)  ko 2x2 MIMO. A ka'idar saurin gudu zuwa 672 Mbit / s mai yiwuwa ne, amma ba a tura su ba tukuna. Matsakaicin tushen 3G mafi sauri a cikin dangin CDMA2000 shine EV-DO Rev. B, wanda ke samuwa tun shekara ta 2010 kuma yana ba da 15.67 Mbit / s zuwa ƙasa.

## Mitoci don hanyoyin sadarwar 4G LTE
*Duba nan: bandungiyoyin mitar LTE*

### IMT-Advanced bukatun
Wannan labarin yana nufin 4G ta amfani da IMT-Advanced ( *International Mobile Telecommunications Advanced* ), kamar yadda ITU-R ya bayyana . Dole ne tsarin salula na IMT-Advanced ya cika wadannan bukatun:

* LTE Advanced an daidaita shi ta 3GPP
* 802.16m ya daidaita ta IEEE

Aiwatar da Wayar WiMAX na WMAX da saki na farko LTE an ɗauka mafi yawa a matsayin mafita na dakatarwa wanda zai ba da babban ci gaba har zuwa WiMAX 2 (dangane da ƙayyadaddun 802.16m) kuma an tura LTE Advanced. An inganta ingantattun sifofin karshen a bazarar 2011.

Saitin farko na bukatun 3GPP akan LTE Advanced an amince dashi a watan Yunin 2008. LTE Advanced an daidaita shi a cikin 2010 azaman ɓangare na Saki 10 na ƙayyadaddun 3GPP.

Wasu kafofin suna la'akari da sakin farko na LTE da Mobile WiMAX aiwatarwa azaman pre-4G ko kusa-4G, tunda basu cika cika abubuwan da aka tsara na 1 ba.Gbit / s don karɓar maraba a tsaye da 100Mbit / s don wayar hannu

Rikici ya samo asali ne daga wasu dillalan wayoyin hannu wadanda suka kaddamar da kayayyakin da aka tallata a matsayin 4G amma wanda a cewar wasu kafofin wasu sigar pre-4G ce, wacce ake kira 3.9G, wadanda basa bin ka'idojin ITU-R na ka'idojin 4G, amma a yau ana iya kiran shi 4G bisa ga ITU-R. Misali Vodafone Netherlands, ta tallata LTE kamar 4G, yayin tallata LTE Advanced azaman sabis ɗin '4G +'. Hujja ta gama gari don sanya alama ga tsarin 3.9G azaman sabon ƙarni shine cewa suna amfani da nau'ikan mitar daban daban daga fasahar 3G; cewa sun dogara ne da sabon tsarin yanayin rediyo; kuma cewa ƙa'idodin ba su da jituwa baya da 3G, yayin da wasu ƙa'idodin suka dace da gaba tare da sigar IMT-2000 masu daidaitattun ka'idodi iri ɗaya.

## Matsayin tsarin

### IMT-2000 ka'idodi 4G masu dacewa
Ya zuwa Oktoba 2010, ITU-R Working Party 5D ta amince da fasahohin masana'antu guda biyu (LTE Advanced da WirelessMAN-Advanced)  don shiga cikin shirin ITU na International Mobile Telecommunications Advanced program ( IMT-Advanced program), wanda ke mai da hankali kan duniya tsarin sadarwar da za'a samar dashi shekaru da yawa daga yanzu.

### LTE Na ci gaba
LTE Advanced (Long Term Evolution Advanced) dan takara ne na tsarin IMT-Advanced , wanda kungiyar 4GPP ta gabatar dashi bisa tsari ga ITU-T a daminar shekarar 2009, kuma ana sa ran za a sake shi a shekarar 2013. [ yana bukatar sabuntawa ] Burin 3GPP LTE Advanced shine isa da wuce bukatun ITU. LTE Advanced yana da mahimmanci haɓakawa ga LTE. Ba sabuwar fasaha ba ce, amma dai ci gaba ne a kan hanyar sadarwar LTE da ake da ita. Wannan hanyar haɓakawa ta sa ya zama mafi ƙarancin farashi ga masu siyarwa don ba da LTE sannan kuma haɓaka zuwa LTE Advanced wanda yake kama da haɓaka daga WCDMA zuwa HSPA. LTE da LTE Advanced suma zasuyi amfani da ƙarin bakan da yawaita abubuwa don ba shi damar cin nasarar saurin bayanai. Haɓakawa da Rarraba Multi-aya zai kuma ba da damar ƙarin ƙarfin tsarin don taimakawa ɗaurin haɓaka saurin bayanai. Saki na 10 na LTE ana tsammanin samun nasarar saurin IMT. Saki na 8 a halin yanzu yana tallafawa har zuwa 300 Mbit / s na saurin saukarwa wanda har yanzu yana da ƙarancin ƙa'idodin IMT-Advanced.
IEEE 802.16m ko WirelessMAN-Advanced evolution na 802.16e yana ci gaba, tare da burin cika IMT-Advanced sharudda na 1 Gbit / s don maraba maraƙi da 100 Mbit / s don liyafar ta hannu.

### Sigogin farko

### Juyin Halitta na 3GPP (LTE

Fasahar pre-4G 3GPP Long Term Evolution (LTE) galibi ana sanya mata alama "4G - LTE", amma sakin LTE na farko bai cika cika ƙa'idodin IMT ba. LTE yana da ƙididdigar ƙimar ƙarfin kuɗi kaɗan har zuwa 100 Mbit / s a cikin ƙananan ƙasa da 50 Mbit / s a cikin haɗin sama idan 20&nbsp;Ana amfani da tashar MHz - kuma ƙari idan an yi amfani da abubuwa da yawa da yawa (MIMO), watau tsararren eriya.

Tsarin rediyo na zahiri ya kasance a farkon matakin mai suna *High Speed OFDM Packet Access* (HSOPA), wanda yanzu ake kira Evolved UMTS Terrestrial Radio Access (E-UTRA). Na farko LTE USB dongles ba sa goyan bayan kowane nau'in rediyo.

An buɗe sabis na LTE na farko a duniya a cikin manyan biranen Scandinavia biyu, Stockholm ( Ericsson da Nokia Siemens Networks system) da Oslo (tsarin Huawei ) a ranar 14 ga Disamba, 2009, kuma an sanya musu 4G. Samsung ne ya ƙera tashoshin masu amfani. Ya zuwa Nuwamba 2012, ayyukan LTE guda biyar da ake dasu a cikin Amurka ana bayar dasu ne ta hanyar MetroPCS, Mara waya ta Verizon, AT&T Mobility, US Cellular,Sprint, da T-Mobile US .

T-Mobile Hungary ta ƙaddamar da gwajin beta na jama'a (wanda ake kira *gwajin mai amfani* ) a ranar 7 ga Oktoba 2011, kuma ta ba da sabis na 4G LTE na kasuwanci tun daga 1 Janairu 2012.

A Koriya ta Kudu, SK Telecom da LG U + sun ba da damar shiga sabis na LTE tun daga 1 ga Yuli 2011 don na'urori na bayanai, wanda aka tsara zai je ko'ina cikin ƙasar nan da 2012. KT Telecom ya rufe aikinsa na 2G zuwa Maris 2012 kuma ya kammala sabis ɗin LTE na ƙasa baki ɗaya a cikin wannan mitar kusan 1.8&nbsp;GHz zuwa Yuni 2012.

A cikin Burtaniya, LTE sabis sun ƙaddamar da EE a cikin Oktoba 2012, ta O2 da Vodafone a watan Agusta 2013, da uku a Disamba 2013.

### WaMA WiMAX (IEEE 802.16e)
Matsakaicin Wayar WiMAX (IEEE 802.16e-2005) daidaitaccen hanyar shigar waya ta hannu mara waya (MWBA) (wanda aka fi sani da WiBro a Koriya ta Kudu) wani lokacin ana sanya masa suna 4G, kuma yana bayar da adadin ƙimar bayanai na 128 Mbit / s downlink da 56 Mbit / s uplink over 20&nbsp;MHz manyan tashoshi.

A watan Yunin 2006, Kamfanin WiMAX na wayoyin hannu na farko da duniya ta bude ta KT a Seoul, Koriya ta Kudu .

Gudu ya fara amfani da Wayar WiMAX, tun daga 29 ga Satumba 2008, sanya shi a matsayin hanyar sadarwa "4G" duk da cewa sigar da ake amfani da ita a yanzu ba ta cika abubuwan IMT Advanced da ake buƙata akan tsarin 4G ba. 

A cikin Rasha, Belarus da Nicaragua WiMax damar sadarwar intanet ta hanyar wani kamfanin Rasha na Scartel, kuma an sanya musu suna 4G, Yota .

A cikin sabon sigar na misali, WiMax 2.1, an sabunta daidaitaccen don ba zai dace da daidaitaccen WiMax ba, kuma a maimakon haka yana musanyawa tare da tsarin LTE-TDD, yana haɗaka daidaitaccen WiMax tare da LTE.

### TD-LTE don kasuwar China
Kamar dai yadda Juyin Halitta na Zamani (LTE) da WiMAX ke haɓaka da ƙarfi a cikin masana'antar sadarwa ta duniya, tsohon (LTE) kuma shine mafi ƙarfin fasahar sadarwar tafi-da-gidanka 4G kuma ya mamaye kasuwannin China da sauri. TD-LTE, ɗayan bambance-bambancen biyu na fasahar kera iska ta LTE, bai riga ya balaga ba, amma yawancin masu jigilar mara waya ta cikin gida da na ƙasa da ƙasa suna ɗaya bayan ɗayan suna juya zuwa TD-LTE.

Bayanai na IBM sun nuna cewa kashi 67% na masu aiki suna la'akari da LTE saboda wannan shine babban tushen kasuwar su ta gaba. Labaran da ke sama sun kuma tabbatar da bayanin IBM cewa yayin da kashi 8% na masu aiki ke duba amfani da WiMAX, WiMAX na iya samar da hanyar sadarwa mafi sauri ga abokan cinikin ta a kasuwa kuma zai iya kalubalantar LTE.

TD-LTE ba shine farkon tsarin sadarwar hanyar sadarwa mara waya ta 4G mara waya ba, amma ƙa'idar 4G ce ta China wacce babban kamfanin sadarwar China - China Mobile ya inganta kuma ya buga. Bayan jerin gwajin filin, ana sa ran za a sake shi zuwa cikin kasuwancin kasuwanci a cikin shekaru biyu masu zuwa. Ulf Ewaldsson, mataimakin shugaban kamfanin na Ericsson ya ce: "Ma'aikatar Masana'antu ta China da China Mobile a zango na hudu na wannan shekarar za su gudanar da wani babban gwajin filin, zuwa lokacin, Ericsson zai taimakawa hannu." Amma kallo daga yanayin ci gaban da ake ciki yanzu, ko wannan kwatankwacin China Mobile zai iya zama sananne ga kasuwar duniya har yanzu ana tattaunawa.

### UMB (tsohon EV-DO Rev. C)
UMB ( Ultra Mobile Broadband ) shine sunan suna don dakatar da aikin 4G a cikin rukunin daidaitaccen 3GPP2 don haɓaka ƙirar wayar hannu ta CDMA2000 don aikace-aikace na ƙarni na gaba da buƙatu. A cikin Nuwamba Nuwamba 2008, Qualcomm, jagoran UMB, ya sanar da cewa yana kawo ƙarshen ci gaban fasaha, yana fifita LTE maimakon haka.  Makasudin shine cimma nasarar saurin bayanai sama da 275 Mbit / s zuwa kasa da kuma sama da 75 Mbit / s daga gaba.

### Flash-OFDM
A matakin farko ana tsammanin tsarin Flash-OFDM zai kasance mai haɓaka zuwa daidaitaccen 4G.

### tsarin iBurst da MBWA (IEEE 802.20)
Tsarin iBurst (ko HC-SDMA, High Capacity Spatial Division Multiple Access) ya kasance a farkon matakin da aka ɗauka a matsayin magajin 4G. Daga baya aka kara inganta shi zuwa tsarin wayar salula mai dauke da wayar hannu (MBWA), wanda kuma ake kira IEEE 802.20.

## Babban fasaha a cikin duk tsarin takarar

### Mahimman fasali
Ana iya kiyaye fasalullan maɓallan masu zuwa a cikin duk fasahar 4G da aka ba da shawara:

* Dabarun watsa layin jiki kamar haka:
** MIMO : Don samin ingancin kyan gani ta hanyar sarrafa sararin samaniya gami da eriya mai yawa da masu amfani da MIMO da yawa
** Yanayin-yanki-daidaitawa, misali *sauyin yanayi mai ɗaukar abubuwa da yawa* ( OFDM ) a cikin ƙananan ƙasa ko *mai ɗauke da mitar-yanki-daidaitawa* (SC-FDE) a cikin haɗin sama: Don amfani da dukiyar tashar tashar tashoshi ba tare da daidaitaccen daidaitawa ba
** Xarfafa yawan ƙididdigar yanki, misali ( OFDMA ) ko (mai ɗauke da FDMA ɗaya) (SC-FDMA, wanda aka gabatar da layi na OFDMA, LP-OFDMA) a cikin haɓaka: :ari mai saurin canzawa ta hanyar sanya ƙananan tashoshi daban-daban ga masu amfani daban-daban yanayin tashar
** Lambobin gyara kuskuren turbo : Don rage girman SNR da ake buƙata a gefen liyafar
* Tsarin lokaci mai dogaro da Tashar : Don amfani da tashar canjin lokaci
* Haɗin haɗin haɗin haɗi : Haɗin daidaitawa da lambobin gyara kuskure
* IP mai amfani da wayar hannu don motsi
* IP-based femtocells (gidajen gida waɗanda aka haɗa da tsayayyen hanyoyin sadarwar Intanet)

Sabanin mutanen da suka gabata, tsarin 4G ba sa goyan bayan zagayewar tarho. Matakan IEEE 802.20, UMB da OFDM ba su da goyan bayan miƙa wuya, wanda kuma aka sani da haɗin gwiwa .

### Tsarin abubuwa da yawa da yawa
Kwanan nan, sabbin hanyoyin samun dama kamar su Orthogonal FDMA (OFDMA), Single Carrier FDMA (SC-FDMA), Interleaved FDMA, da Multi-carrier CDMA (MC-CDMA) suna samun ƙarin mahimmanci ga tsarin tsara masu zuwa. Waɗannan suna dogara ne da ingantaccen algorithms na FFT da daidaita daidaiton yanki, wanda ke haifar da ƙananan lambobi na biyu. Hakanan suna ba da damar sarrafa bandwidth da samar da bakan a cikin sassauƙa. Koyaya, suna buƙatar haɓakar tashar tashoshi mai ƙarfi da tsara jadawalin zirga-zirga.

WiMax yana amfani da OFDMA a cikin downlink da kuma a cikin uplink. Don LTE (sadarwa), OFDMA ana amfani dashi don saukarwa; ya bambanta, Ana amfani da FDMA mai ɗauke da Maɗaukaki don haɓaka tunda OFDMA yana ba da gudummawa sosai ga lamuran da suka shafi PAPR da sakamakon sakamako mara aiki na masu kara ƙarfi. IFDMA yana ba da fluarfin jujjuyawar ƙarfi kuma don haka yana buƙatar haɓakar layi mai ƙarfi mara ƙarfi. Hakanan, MC-CDMA yana cikin tsari don ƙimar IEEE 802.20 . Wadannan tsare-tsaren samun damar suna ba da inganci iri ɗaya kamar tsofaffin fasahohi kamar CDMA. Baya ga wannan, ana iya cimma daidaituwa da ƙimar yawan bayanai.

Sauran mahimmancin fa'idar hanyoyin da aka ambata a sama shine cewa suna buƙatar ƙananan rikitarwa don daidaitawa a mai karɓar. Wannan sigar kara amfani musamman a cikin MIMO yanayin tun da na sarari multiplexing watsa MIMO tsarin inherently bukatar high rikitaccen equalization a karɓa.

Baya ga ingantattun abubuwa a cikin waɗannan tsarin haɗa abubuwa da yawa, ana amfani da ingantattun hanyoyin haɓaka. Ganin cewa mizanan da suka gabata sunyi amfani da maɓallin sauyawa na zamani, ana samar da ingantattun tsarin kamar 64 QAM don amfani tare da ƙa'idodin Juyin Halitta na 3GPP Long Term Evolution .

### Tallafin IPv6
Ba kamar 3G ba, wanda ya dogara ne akan ababen more rayuwa iri biyu waɗanda suka haɗa da sauyawar kewaya da nodes ɗin cibiyar sadarwar da aka sauya, 4G ya dogara ne da sauya fakiti *kawai* . Wannan yana buƙatar watsa bayanai mai ƙarancin ƙarfi.

Kamar yadda adiresoshin IPv4 (kusan) suka ƙare,   IPv6 yana da mahimmanci don tallafawa adadi mai yawa na na'urori masu amfani da mara waya da ke sadarwa ta amfani da IP. Ta hanyar ƙara adadin adiresoshin IP da ke akwai, IPv6 yana cire buƙatar fassarar adireshin cibiyar sadarwa (NAT), hanya ce ta raba adadi mai yawa na adiresoshin tsakanin manyan rukuni na na'urori, wanda ke da matsaloli da iyakancewa . Lokacin amfani da IPv6, ana buƙatar wasu nau'in NAT don sadarwa tare da abubuwan gado na IPv4 waɗanda ba a haɗa IPv6 ba.

, Verizon has posted Specifications that require any 4G devices on its network to support IPv6.

### Tsarin eriya mai ci gaba

Aikin sadarwa na rediyo ya dogara da tsarin eriya, wanda ake kira eriya mai wayo ko mai hankali. Kwanan nan, fasahar eriya da yawa suna tasowa don cimma burin tsarin 4G kamar ƙimar girma, aminci mai ƙarfi, da sadarwa mai dogon zango. A farkon shekarun 1990s, don biyan buƙatun haɓakar haɓakar ƙididdigar ƙimar sadarwar bayanai, an tsara dabarun watsawa da yawa. Technologyaya daga cikin fasaha, haɓaka abubuwa da yawa na sararin samaniya, ya sami mahimmancin kiyayewa ta bandwidth da ingancin ikonta. Haɓakawar sararin samaniya ya haɗa da tura eriya da yawa a watsawa da a mai karɓar. Sannan ana iya watsa kwayoyi masu zaman kansu lokaci guda daga dukkan eriya. Wannan fasahar, ana kiranta MIMO (a matsayin reshe na eriya mai hankali ), yana ninka ƙimar bayanan tushe da (ƙarami) lambar eriya mai aikawa ko lambar eriya mai karɓa. Baya ga wannan, za a iya inganta amincin watsa bayanai mai saurin gaske a cikin tashar da ke shuɗewa ta amfani da ƙarin eriya a cikin mai watsawa ko a mai karɓar. Ana kiran wannan *watsa* ko *karɓar bambancin* . Dukansu masu watsawa / karɓar banbanci da watsa yawancin sararin samaniya an rarraba su cikin dabarun tsara lokaci-lokaci, wanda ba lallai bane ya buƙaci ilimin tashar a cikin mai watsawa. Sauran nau'ikan an rufe-madauki da fasahar eriya da yawa, wanda ke buƙatar ilimin tashar a cikin mai watsawa.

### Gine-gine mara mara waya da rediyo da aka ƙayyade software (SDR)
daya daga cikin mahimman fasahohi don 4G da gaba shine ake kira Open Wireless Architecture (OWA), yana tallafawa ɗakunan hanyoyin iska mara waya da yawa a cikin tsarin gine-ginen da ya buɗe .

SDR wani nau'i ne na buɗe mara waya mara waya (OWA). Tunda 4G tarin ƙa'idodi ne mara waya, fasalin ƙarshe na na'urar 4G zai zama mizanai daban-daban. Ana iya fahimtar wannan ta hanyar amfani da fasahar SDR, wanda aka rarraba shi zuwa yankin haɗin rediyo.

## Tarihin 4G da fasahar pre-4G
Tsarin Daraktan 4G shine asalin DARPA, Hukumar Kula da Ingantaccen Binciken Tsaro ta Amurka DARPA ta zaɓi tsarin gine-ginen da aka rarraba da kuma yarjejeniyar Intanet ta ƙarshe-zuwa-ƙarshe (IP), kuma sun yi imani a matakin farko a cikin hanyar sadarwar abokai-da-aboki wanda kowane na'ura ta hannu zata kasance mai karɓar hanya ne da kuma hanyar sadarwa don wasu na'urori. a cikin hanyar sadarwar, kawar da raunin magana-da-cibiya na tsarin salula na 2G da 3G.  Tun da tsarin 2.5G GPRS, tsarin salula sun samar da kayan aiki biyu: fakiti ya sauya nodes don sabis ɗin bayanai, kuma mahaɗan kewaye masu sauyawa don kiran murya. A cikin tsarin 4G, an watsar da abubuwan more rayuwa ta hanyar zagaye kuma kawai ana samar da cibiyar sadarwar fakiti, yayin da tsarin 2.5G da 3G suna buƙatar maɓuɓɓugan fakiti da sauya hanyoyin sadarwa, watau hanyoyin samar da abubuwa biyu a layi daya. Wannan yana nufin cewa a cikin 4G kiran murya na gargajiya an maye gurbinsu ta wayar tarho ta IP.

Tun daga 2009, LTE-Standard ya sami ci gaba sosai tsawon shekaru, wanda ya haifar da tura da yawa daga wasu masu aiki a duk faɗin duniya. Don dubawa game da hanyoyin sadarwar LTE na kasuwanci da ci gaban tarihin su duba: Jerin hanyoyin sadarwar LTE . Daga cikin yawancin jigilar abubuwan da aka tura, yawancin masu aiki suna la'akari da turawa da aiki na hanyoyin sadarwar LTE. Ana iya samun tattara abubuwan da aka tsara na LTE a: Jerin hanyoyin sadarwar LTE da aka tsara .

## Rashin amfani
4G yana gabatar da damuwa mara kyau ga waɗanda suke tafiya a ƙasashen duniya ko masu son canza jigilar kayayyaki. Domin yin kira da karɓar kiran murya na 4G, wayar salula mai rijista ba lallai ne ta kasance tana da mitar mitar daidai ba (kuma a wasu lokuta ana buƙatar buɗewa ), dole ne ya kasance yana da saitunan kunnawa daidai don mai jigilar yankin da / ko ƙasa. Duk da yake ana sa ran wayar da aka saya daga mai ɗauka da aka ba ta aiki tare da wannan jigilar, yin kiran murya na 4G a kan hanyar sadarwar wani mai ɗaukar hoto (gami da yawo ta duniya) na iya zama ba zai yiwu ba tare da ɗaukaka software na musamman ga mai ɗaukar waya na gida da samfurin wayar da ake tambaya ba, maiyuwa ko bazai yuwu ba (kodayake komawa zuwa 3G don kiran murya na iya yuwuwa idan akwai hanyar sadarwar 3G tare da ƙungiyar mitar daidaitawa)

## Bayan binciken 4G
Babban batun a cikin tsarin 4G shine samar da ƙananan ƙimar da ake samu a cikin babban ɓangaren sel, musamman ga masu amfani a cikin halin da aka fallasa tsakanin tashoshin tushe da yawa. A cikin bincike na yanzu, ana magance wannan batun ta hanyar fasahar macro-bambancin, wanda aka fi sani da relay na haɗin gwiwa, da kuma ta Beam-Division Multiple Access (BDMA). 

Cibiyoyin sadarwar da ke yaduwa abubuwa ne na amo kuma a halin yanzu gaba daya tunanin tsinkaye ne inda mai amfani zai iya hadewa lokaci guda da fasahohin samun damar mara waya da yawa kuma zai iya tafiya ba tare da wata matsala ba (Duba takaddun tsaye, IEEE 802.21 ). Waɗannan fasahohin samun damar na iya zama Wi-Fi, UMTS, EDGE, ko kuma duk wata fasahar samun dama ta gaba. Hada da wannan ra'ayi har ila yau, fasaha ce mai kaifin-rediyo (wacce aka fi sani da rediyo mai hankali ) don sarrafa ingantaccen amfani da kewayon bakan da kuma karfin watsawa da kuma amfani da ladabi na hanyar raga don kirkirar hanyar sadarwa mai yaduwa.

## Duba kuma

* 4G-LTE  tace
* Kwantanta Matsayin Wayar HannauGSM, CDMA, LTE
* Kwatanta Daidaitattun Bayanan Mara Waya HSPA +, WiMAX, EV-DO
* Mara Waya Na'urar da Lafiya
* 5G

## Manazarta