Mukuvandudza kwayo, Huawei anovimba neWi-Fi 6. Uye mibvunzo kubva kune vatinoshanda navo uye vatengi nezve chizvarwa chitsva cheiyo chiyero chakaita kuti tinyore chinyorwa pamusoro peiyo theoretical nheyo uye misimboti yemuviri yakaiswa mairi. Ngatifambei kubva munhoroondo kuenda kufizikisi uye titarise zvakadzama kuti sei OFDMA neMU-MIMO matekinoroji achidiwa. Ngatikurukureiwo pamusoro pekuti yakagadziridzwa sei dhizaini yekufambisa data yakaita kuti zvikwanise kuwana yakavimbiswa chiteshi uye kudzikisira kwakadai kwehuwandu hwekunonoka zvekuti vakafanana neaya anoshanda. Uye izvi zvisinei nekuti yemazuva ano 5G-yakavakirwa network inodhura (paavhareji 20-30 nguva) pane yemukati Wi-Fi 6 network ine hunyanzvi hwakafanana.
Kuna Huawei, musoro wacho hausi wekuita zvisina basa: mhinduro dzinotsigira Wi-Fi 6 dziri pakati pezvigadzirwa zvedu zvebudiriro muna 2020, umo zviwanikwa zvakakura zvakaiswa mari. Heino muenzaniso mumwechete: tsvakiridzo mumunda wezvekushandisa sainzi yakatibvumira kusarudza alloy, kushandiswa kwayo muredhiyo zvinhu zvenzvimbo yekuwana kwakawedzera chiratidzo-ku-ruzha reshiyo ne2-3 dB: hats kuenda kuDoron Ezri kubudirira uku.
A bit of history
Zvinonzwisisika kuverenga nhoroondo yeWi-Fi kudzokera ku1971, apo paYunivhesiti yeHawaii, Purofesa Norman Abramson neboka revamwe vashandi vakagadzira, vakavaka uye vakatanga ALOHAnet wireless packet data network.
Muna 1980, boka rezviyero uye mapuroteni IEEE 802 yakatenderwa, ichitsanangura kurongeka kwezvikamu zviviri zvezasi zveanomwe-layer OSI network modhi. Taifanira kumirira 802.11 makore akareba isati yaburitswa yekutanga vhezheni ye17.
Nekugamuchirwa kweiyo 1997 yakajairwa muna 802.11, makore maviri kusati kwazvarwa Wi-Fi Alliance, chizvarwa chekutanga chemazuva ano chakanyanya kufarirwa data tekinoroji chakapinda munyika yakafara.
IEEE 802 chiyero. Wi-Fi zvizvarwa
Muyero wekutanga kutsigirwa zvakanyanya nevagadziri vemidziyo yaive 802.11b. Sezvauri kuona, kuwanda kwezvinhu zvitsva kwakanyatso kugadzikana kubva pakupera kwezana ramakore rechiXNUMX: shanduko yemhando inotora nguva. Mumakore achangopfuura, basa rakawanda rakaitwa kuvandudza svikiro rekutumira masaini. Kuti tinzwisise zviri nani matambudziko emazuva ano eWi-Fi, ngatitendeukei kunheyo dzayo dzemuviri.
Ngatirangarirei zvinhu zvinokosha!
Mafungu eredhiyo inyaya yakakosha yemafungu emagetsi - kupararira kubva kune sosi yekuvhiringidza kwemagetsi uye magineti. Izvo zvinoratidzwa nematatu makuru ma parameters: wave vector, pamwe nemagetsi uye magnetic field simba vectors. Ose ari matatu anoenderana perpendicular kune mumwe nemumwe. Muchiitiko ichi, kuwanda kwemafungu kunowanzo kunzi nhamba yekudzokorora oscillations inokodzera muchikamu chenguva.
Zvose izvi zvinhu zvinonyatsozivikanwa. Zvisinei, kuti tisvike kumagumo, tinomanikidzwa kutanga kubva pakutanga.
Pachiyero chakajairwa che frequency renji yemagetsi emagetsi, redhiyo inotora chikamu chakaderera (chakaderera-frequency). Inosanganisira mafungu emagetsi ane oscillation frequency kubva ku3 Hz kusvika 3000 GHz. Mamwe mabhendi ese, kusanganisira chiedza chinooneka, ane frequency yakanyanya.
Iyo yakakwira frequency, simba rakawanda rinogona kupihwa kune redhiyo wave, asi panguva imwechete inokotama zvipingamupinyi zvishoma uye inodzikama nekukurumidza. Zvakapesana ndezvechokwadiwo. Tichifunga nezvezvinhu izvi, maviri makuru ma frequency akasarudzwa eWi-Fi mashandiro - 2,4 GHz (frequency bhendi kubva 2,4000 kusvika 2,4835 GHz) uye 5 GHz (frequency mabhendi 5,170-5,330, 5,490-5,730 uye 5,735 GHz 5,835 GHz).
Mafungu eredhiyo anopararira kumativi ese, uye kuitira kudzivirira mameseji kubva kupesvedzerana nekuda kwekukanganisa, bhendi re frequency rinowanzo kupatsanurwa kuita zvikamu zvakatetepa zvakapatsanurwa - chiteshi chine chimwe kana chimwe. . Dhiagiramu iri pamusoro inoratidza kuti migero yakatarisana 1 uye 2 ine bandwidth ye20 MHz ichakanganisa mumwe nemumwe, asi 1 ne6 hazvizoiti.
Chiratidzo chiri mukati mechiteshi chinofambiswa pachishandiswa radio wave pane imwe frequency yekutakura. Kuendesa ruzivo, wave parameters inogona kuva ne frequency, amplitude kana phase.
Kuparadzaniswa kwechiteshi muWi-Fi frequency range
Iyo 2,4 GHz frequency renji yakakamurwa kuita gumi nemana inopindirana zvishoma nehupamhi hwakakwana hwe14 MHz. Zvakambodavirwa kuti izvi zvaive zvakakwana kuronga network yakaoma isina waya. Nenguva isipi zvakava pachena kuti huwandu hwehuwandu hwaive huchikurumidza kupera, saka iyo 20 GHz renji yakawedzerwa kwairi, iyo spectral kugona kwayo kwakakwira zvakanyanya. Mariri, kuwedzera kune 5 MHz chiteshi, zvinokwanisika kugovera chiteshi nehupamhi hwe20 uye 40 MHz.
Kuenderera mberi nekuvandudza kugona kwekushandisa redhiyo frequency spectrum, orthogonal frequency division multiplexing tekinoroji yava kushandiswa zvakanyanya ().
Izvo zvinosanganisira kushandisa, pamwe neiyo inotakura frequency, akati wandei subcarrier frequency mune imwechete chiteshi, izvo zvinoita kuti zvikwanise kuita parallel data kufambisa. OFDM inokutendera iwe kugovera traffic nenzira iri nyore "granular", asi nekuda kwezera rayo rinoremekedzeka, inochengeta zvakati wandei zvakakomba. Pakati pavo pane mitemo yekushanda uchishandisa CSMA/CA (Carrier Sense Multiple Access neCollision Avoidance) network protocol, maererano neyo mushandisi mumwe chete anogona kushanda pane imwe mutakuri uye subcarrier pane dzimwe nguva.
Spatial inoyerera
Nzira yakakosha yekuwedzera wireless network throughput ndeyekushandisa nzvimbo nzizi.
Nzvimbo yekupinda inotakura akati wandei radio module (imwe, maviri kana anopfuura), ayo akabatana kune imwe nhamba yeantennas. Aya antenna anopenya zvinoenderana neimwe pateni uye modulation, uye iwe neni tinogashira ruzivo rwunofambiswa pamhepo isina waya. Rukova rwepamhepo runogona kuumbwa pakati peiyo antenna yemuviri (radio module) yenzvimbo yekuwana uye mudziyo wemushandisi. Nekuda kweizvi, huwandu hwese hweruzivo rwunofambiswa kubva kunzvimbo yekuwana hunowedzera nehuwandu hwehuwandu hwehova (antennas).
Zvinoenderana nezviyero zvazvino, anosvika mana enzvimbo nzizi anogona kuitwa mu2,4 GHz bhendi, uye anosvika masere mu5 GHz bhendi.
Kare, pakushanda mumabhendi e2,4 uye 5 GHz, taingotarisa pahuwandu hwemamodule eredhiyo. Kuvapo kweyechipiri redhiyo module kwakapa kuwedzera kuchinjika, sezvo yaibvumira ekare madhijitari zvishandiso kushanda pane frequency ye2,4 GHz, uye mitsva kushanda pane frequency ye5 GHz. Nekuuya kweyechitatu uye inotevera redhiyo modules, mamwe matambudziko akamuka. Zvinhu zvinopenya zvinogara zvichikanganisa mumwe nemumwe, izvo zvinowedzera mutengo wemudziyo nekuda kwekuda kwedhizaini iri nani uye kushongedza nzvimbo yekuwana nemafirita ekubhadhara. Saka zvangove nguva pfupi yadarika kutsigira panguva imwe chete 16 spatial hova pane imwe nzvimbo yekuwana.
Kushanda uye theoretical kumhanya
Nekuda kwemashandiro eOFDM, hatina kukwanisa kuwana yakanyanya network throughput. Theoretical kuverenga kwekuita kwekuita kweOFDM kwakaitwa kare kare uye chete maererano nenzvimbo dzakanaka, uko kwakaringana chiratidzo-ku-ruzha ratio (SNR) uye bit kukanganisa mwero (BER) zvaitarisirwa. Mumamiriro ezvinhu emazuva ano eruzha rwakasimba mune ese radio frequency spectrum inotifarira, kubuda kweOFDM-based network kwakadzikira zvinosiririsa. Uye iyo protocol yakaramba iine zvikanganiso izvi kusvika nguva pfupi yadarika, kudzamara OFDMA (orthogonal frequency-division multiple access) tekinoroji yakauya kuzonunura. Pamusoro pake - zvishoma mberi.
Ngatitaure nezve antennas
Sezvaunoziva, antenna imwe neimwe ine pfuma, zvichienderana nekukosha kweiyo spatial pateni yekuparadzira chiratidzo (beamforming) inoumbwa neimwe nzvimbo yekuvhara (hatitarise chiratidzo chekudzokorora, nezvimwewo). Izvi ndizvo chaizvo izvo vagadziri vagara vachitsigira kufunga kwavo kuti ndepapi chaipo nzvimbo dzekuwana dzinofanirwa kuiswa. Kwenguva yakareba, chimiro chechimiro chakaramba chisina kuchinjwa uye chakangowedzera kana kuderera maererano nemaitiro eiyo antenna.
Mazuva ano antenna zvinhu zviri kuwedzera uye zvakanyanya kudzoreka uye zvinobvumidza shanduko ine simba mune yepasipaiti yekuparadzira chiratidzo munguva chaiyo.
Mufananidzo wekuruboshwe pamusoro unoratidza musimboti wekuparadzira radio wave uchishandisa yakajairwa omnidirectional antenna. Nekuwedzera simba rechiratidzo, isu taingokwanisa kushandura radius yekuvhara pasina kugona kupesvedzera zvakanyanya kunaka kwekushandiswa kwechiteshi - KQI (Key Quality Indicators). Uye ichi chiratidzo chakakosha zvakanyanya pakuronga kutaurirana mumamiriro ezvinhu ekufamba kazhinji kwemunyoreri mudziyo munzvimbo isina waya.
Mhinduro yedambudziko yaive kushandiswa kwenhamba huru yeantenna madiki, mutoro pairi unogona kugadziriswa munguva chaiyo, kugadzira mapatani ekuparadzira zvichienderana nenzvimbo yemushandisi.
Saka, zvaive zvichikwanisika kuswedera pedyo nekushandiswa kweMU-MIMO (Multi-User Multiple Input, Multiple Output) teknolojia. Nerubatsiro rwayo, nzvimbo yekuwana chero nguva inogadzira radiation inoyerera yakanangana kune vanonyorera zvishandiso.
Kubva kufizikisi kusvika ku802.11 zviyero
Sezvo mazinga eWi-Fi akashanduka, misimboti yekushanda neyemuviri wetiweki yakachinja. Kushandiswa kwedzimwe modulation nzira kwaita kuti zvikwanisike - kutanga neshanduro dze802.11g/n - kuti ikwane huwandu hwakakura hweruzivo muchikamu chenguva uye, zvinoenderana, kushanda nenhamba huru yevashandisi. Pakati pezvimwe zvinhu, izvi zvakawanikwa kuburikidza nekushandiswa kwekuyerera kwenzvimbo. Uye iko kutsva kuchinjika muhupamhi hwechiteshi kwakaita kuti zvikwanise kugadzira zvimwe zviwanikwa zveMIMO.
Kubvumidzwa kweWi-Fi 7 standard kwakarongerwa gore rinouya. Chii chichachinja nekusvika kwayo? Kuwedzera kune yakajairika kuwedzera kumhanya uye kuwedzera kwe6 GHz bhendi, zvinogoneka kushanda nematanho akaunganidzwa akakura, akadai se320 MHz. Izvi zvinonyanya kunakidza mumamiriro ekushandiswa kwemaindasitiri.
Theoretical Wi-Fi 6 throughput
Iyo theoretical formula yekuverenga iyo yezita kumhanya yeWi-Fi 6 yakanyanya kuoma uye zvinoenderana neakawanda paramita, kutanga nenhamba yenzvimbo hova uye kupera neruzivo rwatinogona kuisa mune subcarrier (kana subcarriers, kana paine akati wandei. them) pachikamu chenguva.
Sezvauri kuona, zvakawanda zvinoenderana nekuyerera kwenzvimbo. Asi zvisati zvaitika, kuwedzera kwenhamba yavo pamwe chete nekushandiswa kwe STC (Space-Time Coding) uye MRC (Maximum Ratio Combining) yakawedzera kushanda kweiyo wireless solution zvachose.
New Key Physical Layer Technologies
Ngatienderere mberi kune akakosha matekinoroji eiyo yemuviri layer - uye tanga neyekutanga layer yeOSI network modhi.
Ngatiyeukei kuti OFDM inoshandisa imwe nhamba yevatakuri, iyo, isina kukanganisa mumwe nemumwe, inokwanisa kuendesa huwandu hweruzivo.
Mumuenzaniso, tinoshandisa 5,220 GHz bhendi, iyo ine 48 subchannels. Nekuunganidza chiteshi ichi, tinowana nhamba yakakura yevatakuri, imwe neimwe inoshandisa yayo modulation scheme.
Wi-Fi 5 inoshandisa quadrature amplitude modulation 256 QAM (Quadrature Amplitude Modulation), iyo inokutendera iwe kuti ugadzire munda we16 x 16 mapoinzi mukati meiyo inotakura frequency mune imwe nguva slot, inosiyana muamplitude uye chikamu. Izvo zvinokanganisa ndezvekuti chero nguva chiteshi chimwe chete chinogona kufambisa pane inotakura frequency.
Orthogonal frequency division multiplexing (OFDMA) yakabva kunyika yevafambisi venhare, yakapararira panguva imwe chete neLTE uye inoshandiswa kuronga downlink (yekutaurirana chiteshi kune anonyoresa). Inokubvumira kushanda nechiteshi pamwero weanonzi maresource units. Aya mayunitsi anobatsira kuputsa block pasi kuita nhamba chaiyo yezvikamu. Mukati mebhuroka, panguva yega yega hatigone kushanda zvakasimba nechinhu chimwe chinoburitsa (mushandisi kana nzvimbo yekupinda), asi sanganisa akawanda ezvinhu. Izvi zvinokutendera kuti uwane mhedzisiro inoshamisa.
Kubatana kuri nyore kwemachaneli muWi-Fi 6
Chiteshi Bonding muWi-Fi 6 inokutendera iwe kuti uwane yakasanganiswa chiteshi nehupamhi hwe20 kusvika 160 MHz. Uyezve, kubatana hakufanirwe kuitwa munzvimbo dziri pedyo. Semuenzaniso, bhuroka rimwe rinogona kutorwa kubva ku5,17 GHz bhendi, uye yechipiri kubva ku5,135 GHz bhendi. Izvi zvinokutendera kuti ugone kuchinjika kuvaka nharaunda yeredhiyo kunyangwe pamberi pezvakasimba zvinokanganisa zvinhu kana padyo nedzimwe nhepfenyuro dzinogara dzichibuda.
Kubva kuSIMO kuenda kuMIMO
Iyo MIMO nzira haina kugara inesu. Pane imwe nguva, nharembozha dzaifanira kuganhurirwa kune iyo SIMO modhi, iyo yaireva kuvapo kwemaantenna akati wandei pachiteshi chevanyoreri, panguva imwe chete ichishanda kugamuchira ruzivo.
MU-MIMO yakagadzirirwa kuendesa ruzivo kune vashandisi vachishandisa yese iripo antenna stock. Izvi zvinobvisa zvirambidzo zvakambotemerwa neCSMA/CA protocol ine chekuita nekutumira ma tokens kune vanonyoresa zvishandiso zvekutumira. Iye zvino vashandisi vakabatana muboka uye nhengo yega yega yeboka inogamuchira mugove wavo wenzvimbo yekuwana antenna sosi, pane kumirira nguva yavo.
Radio danda kuumbwa
Mutemo wakakosha wekushanda kweMU-MIMO kuchengetedza maitiro ekushanda kweantenna array izvo zvaisazotungamira mukupindirana kwemafungu eredhiyo uye kurasikirwa neruzivo nekuda kwekuwedzera kwechikamu.
Izvi zvinoda masvomhu akaoma kunzwisisa padivi rekuwana. Kana iyo terminal ikatsigira ichi chimiro, MU-MIMO inoibvumira kuti iudze nzvimbo yekuwana kuti zvinotora nguva yakareba sei kugamuchira chiratidzo pane imwe neimwe antenna. Uye nzvimbo yekupinda, zvakare, inogadzirisa antennas ayo kuti iite danda rakanangwa zvakanangana.
Izvi zvinotipei pane zvese?
Madenderedzwa machena ane manhamba ari patafura anoratidza mamiriro azvino ekushandisa Wi-Fi yezvizvarwa zvakapfuura. Iwo madenderedzwa ebhuruu (ona mufananidzo uri pamusoro) anotsanangura kugona kweWi-Fi 6, uye iwo grey inyaya yeramangwana riri pedyo.
Mabhenefiti makuru anounzwa neOFDMA-akagonesa mhinduro ane hukama nezvikamu zvezviwanikwa zvinoiswa pamwero wakafanana neTDM (Nguva Division Multiplexing). Izvi zvaisambove zvakadaro neWi-Fi kare. Izvi zvinokutendera kuti unyatso kudzora iyo yakagoverwa bandwidth, kuve nechokwadi shoma chiratidzo chekufambisa nguva kuburikidza nepakati uye inodiwa mwero wekuvimbika. Neraki, hapana anokahadzika kuti Wi-Fi kuvimbika zviratidzo zvinoda kuvandudzwa.
Nhoroondo inofamba mumhepo, uye mamiriro ezvinhu aripo akafanana neaya akagadzirwa kumativi eEthernet panguva imwe chete. Kunyangwe ipapo, pfungwa yakasimbiswa kuti CSMA/CD (Carrier Sense Multiple Access neCollision Detection) transmission medium haipe chero yakavimbiswa kubuda. Uye izvi zvakaenderera kusvika pakuchinja kuenda kuIEEE 802.3z.
Kana ari iwo akajairwa mashandisirwo emhando, sezvauri kuona, nechizvarwa chimwe nechimwe cheWi-Fi, mashandisiro ayo mamiriro ari kuwedzera, anowedzera uye anowedzera kunonoka kunonoka, zvakajairika. uye kuvimbika.
Uye zvakare pamusoro pemamiriro ekunze
Zvakanaka, zvino ngatitaure pamusoro pekuti nzvimbo itsva yemuviri inoumbwa sei. Paunenge uchishandisa CSMA/CA neOFDM, kuwedzera kwenhamba yeSTAs inoshanda kwakakonzera kudonha kwakakomba mukubuda kweiyo 20 MHz chiteshi. Izvi zvakakonzerwa nezvakatotaurwa: kwete tekinoroji nyowani STC (Space-Time Coding) uye MRC (Maximum Ratio Combining).
OFDMA, kuburikidza nekushandiswa kwezviwanikwa zvezviwanikwa, inogona kunyatso kupindirana neakareba-kure uye yakaderera-simba zviteshi. Isu tinowana mukana wekushanda mune imwechete inotakura renji nevashandisi vari kushandisa huwandu hwakasiyana hwezviwanikwa. Mumwe mushandisi anogona kutora imwe unit, uye imwe - vamwe vese.
Sei pakanga pasina OFDMA kare?
Uye pakupedzisira, mubvunzo mukuru: nei pakanga pasina OFDMA kare? Oddly zvakakwana, zvese zvakauya kumari.
Kwenguva yakareba zvakatendwa kuti mutengo weWi-Fi module unofanirwa kuve wakaderera. Iyo protocol payakatangwa mukushanda kwekutengeserana muna 1997, zvakasarudzwa kuti mutengo wekugadzira weiyo module haugone kudarika $1. Nekuda kweizvozvo, kuvandudzwa kwetekinoroji kwakatora nzira isina kunaka. Pano isu hatitarise mushandisi LTE, uko OFDMA yakashandiswa kwenguva yakareba.
Pakupedzisira, boka rekushanda reWi-Fi rakasarudza kutora izvi zvigadziriso kubva kunyika yevafambisi venhare uye vauye nazvo kune nyika yemabhizinesi network. Basa guru raive shanduko yekushandiswa kwemhando yepamusoro zvinhu, senge mafirita uye oscillator.
Nei zvanga zvakatiomera kudaro kuti tishande mukare MRC encodings tiine kana pasina kukanganiswa? Nekuti iyo MVDR (Minimum Variance Distortionless Response) inovhenekera meshini yakawedzera zvakanyanya huwandu hwezvikanganiso patakaedza kusanganisa nhamba huru yekutumira mapoinzi. OFDMA yakaratidza kuti dambudziko rinogona kugadziriswa.
Hondo yekurwisa kupindira iko zvino yakavakirwa pamasvomhu. Kana iyo hwindo rekutapurirana rakareba zvakakwana, zvinokonzeresa kupindira zvine simba kunokonzera matambudziko. Matsva ekushandisa maalgorithms anoita kuti zvibvire kuvanzvenga, kubvisa pesvedzero kwete chete yekukanganisa kwakabatana neWi-Fi kutapurirana, asiwo kune chero ipi zvayo inoitika mune ino renji.
Kutenda kune adaptive anti-kupindira, tinogona kuwana zviwanikwa zvekusvika gumi nerimwe dB kunyangwe munzvimbo dzakaoma dzakasiyana. Iko kushandiswa kweHuawei's own algorithmic solutions kwakaita kuti zvikwanisike kuwana yakakomba optimization chaipo paidiwa - mumhinduro dzemukati. Chii chakanaka mu11G hachina kunaka munzvimbo yeWi-Fi 5. Mamiriro makuru eMIMO neMU-MIMO anosiyana mune zvemukati nekunze mhinduro. Pazvinenge zvichidiwa, zvakakodzera kushandisa zvinodhura zvinogadzirisa, sepa6G. Asi dzimwe sarudzo dzinodiwa, senge Wi-Fi 5, iyo inogona kuendesa latency uye mamwe ma metrics atauya kutarisira kubva kune vatakuri.
Isu tinokwereta kubva kwavari maturusi anozobatsira kwatiri sevatengi vebhizinesi, zvese mukuedza kupa nharaunda yemuviri yatinogona kuvimba nayo.
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Nenzira, usakanganwa nezve edu akawanda webinars pane zvitsva zveHuawei zvigadzirwa zve2020, zvakabatwa kwete chete muchikamu chemutauro weRussia, asiwo padanho repasi rose. Rondedzero yemawebinars emavhiki anouya inowanikwa pa .
Source: www.habr.com