A ƙarshe mun yi magana game da fasalulluka na sabon ma'auni na NB-IoT daga ra'ayi na gine-ginen hanyar sadarwa ta hanyar rediyo. Yau za mu tattauna abin da ya canza a cikin Core Network karkashin NB-IoT. Don haka, mu tafi.
An sami manyan canje-canje ga ainihin hanyar sadarwar. Bari mu fara da gaskiyar cewa wani sabon abu ya bayyana, da kuma hanyoyin da yawa, waɗanda aka ayyana ta ma'auni a matsayin "CIoT EPS Optimization" ko inganta cibiyar sadarwar cibiyar sadarwar salula na abubuwa.
Kamar yadda kuka sani, a cikin hanyoyin sadarwar wayar hannu akwai manyan hanyoyin sadarwa guda biyu, wadanda ake kira Control Plane (CP) da User Plane (UP). An yi nufin Control Plane don musayar saƙonnin sabis tsakanin abubuwan cibiyar sadarwa daban-daban kuma ana amfani dashi don tabbatar da motsi (Gudanar da Motsi) na na'urori (UE) da kuma kafa / kiyaye zaman watsa bayanai (Gudanar da Zama). Jirgin mai amfani, a haƙiƙa, tashar ce don watsa zirga-zirgar mai amfani. A cikin classic LTE, rarraba CP da UP a cikin musaya shine kamar haka:
Ana aiwatar da hanyoyin ingantawa na CP da UP na NB-IoT akan nodes na MME, SGW da PGW, waɗanda aka saba haɗa su zuwa kashi ɗaya da ake kira C-SGN (Cellular IoT Serving Gateway Node). Hakanan mizanin yana ɗaukan fitowar sabon ɓangaren cibiyar sadarwa - SCEF (Aikin Ƙarfin Ƙarfin Sabis). Ana kiran hanyar sadarwa tsakanin MME da SCEF T6a kuma ana aiwatar da ita bisa ka'idar DIAMETER. Duk da cewa DIAMETER yarjejeniya ce ta sigina, a cikin NB-IoT an daidaita shi don watsa ƙananan bayanan da ba IP ba.
Kamar yadda sunanta ya nuna, SCEF Node Ƙarfin Ƙarfin Sabis. Ma’ana, SCEF tana boye sarkakiyar hanyar sadarwa ta ma’aikaci, sannan kuma tana saukaka wa masu samar da aikace-aikace bukatar ganowa da tantance na’urorin wayar hannu (UE), da kyale sabobin aikace-aikacen (Application Server, daga nan AS) su karbi bayanai da sarrafa na’urori ta hanyar guda daya. API dubawa.
Mai gano UE ya zama ba lambar waya (MSISDN) ko adireshin IP ba, kamar yadda ya kasance a cikin cibiyar sadarwa ta 2G/3G/LTE na yau da kullun, amma abin da ake kira “ID na waje”, wanda aka ayyana ta daidaitaccen tsarin da aka saba. zuwa aikace-aikace developers" @ " Wannan babban batu ne daban wanda ya cancanci abu daban, don haka ba za mu yi magana game da shi dalla-dalla ba yanzu.
Yanzu bari mu dubi mafi mahimmancin sababbin abubuwa. "CIoT EPS Ingantawa" shine haɓaka hanyoyin watsa labarai da sarrafa zaman masu biyan kuɗi. Ga manyan su:
- DONAS
- NIDD
- PSM da eDRX hanyoyin ceton wutar lantarki
- Farashin HLCOM
DonAS (Bayanan kan NAS):
Wannan wata hanya ce da aka ƙera don inganta canja wurin ƙananan bayanai.
A cikin LTE na al'ada, lokacin yin rajista a cikin hanyar sadarwa, na'urar biyan kuɗi tana kafa haɗin PDN (wanda ake kira PDN daga baya) ta eNodeB zuwa MME-SGW-PGW. Haɗin UE-eNodeB-MME shine abin da ake kira "Mai Saƙon Radiyo" (SRB). Idan ya zama dole don aikawa / karɓar bayanai, UE ta kafa wani haɗin gwiwa tare da eNodeB - "Data Radio Bearer" (DRB), don aika da zirga-zirgar mai amfani zuwa SGW kuma gaba zuwa PGW (musamman S1-U da S5, bi da bi) . A ƙarshen musayar kuma idan babu zirga-zirga na ɗan lokaci (yawanci 5-20 seconds), waɗannan haɗin suna ƙare kuma na'urar ta shiga yanayin jiran aiki ko "Yanayin Rage". Idan ya zama dole don musanya sabon yanki na bayanai, SRB da DRB an sake saita su.
A cikin NB-IoT, ana iya aiwatar da watsa zirga-zirgar mai amfani ta hanyar tashar sigina (SRB), a cikin saƙonnin yarjejeniya ta NAS (). Ba a buƙatar kafa DRB. Wannan yana rage nauyin siginar mahimmanci, yana adana albarkatun rediyo na cibiyar sadarwa kuma, mafi mahimmanci, yana ƙara rayuwar baturin na'urar.
A cikin sashin eNodeB-MME, bayanan mai amfani ya fara watsawa ta hanyar S1-MME, wanda ba haka bane a cikin fasahar LTE na gargajiya, kuma ana amfani da ka'idar NAS don wannan, wanda a cikinsa ya bayyana "kwandon bayanan mai amfani".
Don aiwatar da canja wurin "Jirgin Mai amfani" daga MME zuwa SGW, sabon S11-U ya bayyana, wanda aka tsara don canja wurin ƙananan bayanan mai amfani. Ka'idar S11-U ta dogara ne akan GTP-U v1, wanda ake amfani da shi don watsa jirgin sama mai amfani akan sauran hanyoyin sadarwa na gine-ginen 3GPP.
NIDD (ba sadar da bayanan IP):
A matsayin wani ɓangare na ƙarin inganta hanyoyin don watsa ƙananan bayanai, ban da nau'ikan PDN da suka rigaya, kamar IPv4, IPv6 da IPv4v6, wani nau'in ya bayyana - ba IP ba. A wannan yanayin, UE ba a sanya adireshin IP ba kuma ana watsa bayanai ba tare da amfani da ka'idar IP ba. Akwai dalilai da yawa akan hakan:
- Na'urorin IoT kamar na'urori masu auna firikwensin na iya watsa bayanai kaɗan kaɗan, 20 bytes ko ƙasa da haka. Ganin cewa mafi ƙarancin girman kai na IP shine 20 bytes, IP encapsulation na iya zama wani lokacin tsada sosai;
- Babu buƙatar aiwatar da tari na IP akan guntu, wanda ke haifar da raguwar farashin su (tambaya don tattaunawa a cikin sharhi).
Gabaɗaya, adireshin IP ya zama dole don na'urorin IoT don watsa bayanai akan Intanet. A cikin tunanin NB-IoT, SCEF yana aiki azaman hanyar haɗin AS guda ɗaya, kuma musayar bayanai tsakanin na'urori da sabar aikace-aikacen yana faruwa ta hanyar API. Idan babu SCEF, bayanan da ba IP ba za a iya aikawa zuwa AS ta hanyar rami na Point-to-Point (PtP) daga PGW kuma za a yi encapsulation IP akansa.
Duk wannan ya dace da tsarin NB-IoT - matsakaicin sauƙi da rage farashin na'urori.
Hanyoyin ceton wutar lantarki na PSM da eDRX:
Ɗaya daga cikin mahimman fa'idodin hanyoyin sadarwar LPWAN shine ingantaccen makamashi. An yi iƙirarin cewa na'urar tana ɗaukar tsawon shekaru 10 na rayuwar batir akan baturi ɗaya. Bari mu gano yadda ake samun irin waɗannan dabi'u.
Yaushe na'urar ke cinye mafi ƙarancin kuzari? Gyara lokacin da aka kashe shi. Kuma idan ba zai yiwu a cire wutar lantarki gaba ɗaya ba, bari mu rage kuzarin tsarin rediyo muddin ba a buƙata ba. Kuna buƙatar fara daidaita wannan tare da hanyar sadarwa da farko.
PSM (Yanayin ajiyar wuta):
Yanayin ceton wutar lantarki na PSM yana bawa na'urar damar kashe tsarin rediyo na dogon lokaci, yayin da ake ci gaba da rijista a cikin hanyar sadarwa, kuma kada ta sake shigar da PDN a duk lokacin da take buƙatar watsa bayanai.
Don sanar da cibiyar sadarwar cewa har yanzu na'urar tana nan, lokaci-lokaci tana fara aiwatar da sabuntawa - Sabunta Yanki (TAU). An saita mitar wannan hanya ta hanyar hanyar sadarwa ta hanyar amfani da mai ƙidayar lokaci T3412, ƙimar wanda aka watsa zuwa na'urar yayin da aka haɗa hanya ko TAU na gaba. A cikin al'ada LTE, ƙimar tsoho na wannan lokacin shine mintuna 54, kuma matsakaicin shine mintuna 186. Koyaya, don tabbatar da ingantaccen ƙarfin kuzari, buƙatar tafiya cikin iska kowane minti 186 yana da tsada sosai. An samar da tsarin PSM don magance wannan matsala.
Na'urar tana kunna yanayin PSM ta hanyar isar da ƙimar masu ƙidayar lokaci biyu T3324 da T3412-Extended a cikin saƙon "Maƙalla Buƙatun" ko "Buƙatar Yanki na Bibiya". Na farko yana ƙayyade lokacin da na'urar za ta kasance bayan an canza zuwa "Idle Mode". Na biyu shi ne lokacin da dole ne a yi TAU, kawai a yanzu darajarsa za ta iya kaiwa dakika 35712000 ko kwanaki 413. Dangane da saitunan, MME na iya karɓar ƙimar ƙididdiga da aka karɓa daga na'urar ko canza su ta hanyar aika sabbin dabi'u a cikin saƙon "Maɗaukaki Yarda" ko " Karɓar Sabunta Wurin Bibiya ". Yanzu na'urar ba za ta iya kunna tsarin rediyo na tsawon kwanaki 413 ba kuma ta kasance cikin rajista a cikin hanyar sadarwa. A sakamakon haka, muna samun babban tanadi a albarkatun cibiyar sadarwa da ingantaccen makamashi na na'urori!
Koyaya, a wannan yanayin babu na'urar don sadarwa mai shigowa kawai. Idan ya zama dole don aika wani abu zuwa uwar garken aikace-aikacen, na'urar za ta iya fita daga PSM a kowane lokaci kuma ta aika da bayanai, bayan haka ta ci gaba da aiki yayin lokacin T3324 don karɓar saƙonnin bayanai daga AS (idan akwai).
eDRX (kyawawan liyafar katsewa):
eDRX, Ingantacciyar liyafar Tsayawa. Don canja wurin bayanai zuwa na'urar da ke cikin "Yanayin rashin aiki", cibiyar sadarwar tana aiwatar da hanyar sanarwa - "Paging". Bayan karɓar shafi, na'urar ta fara kafa SRB don ƙarin sadarwa tare da hanyar sadarwa. Amma don kada a rasa sakon da aka yi masa na Paging, dole ne na'urar ta rika lura da iskar rediyon, wanda kuma yake cin makamashi sosai.
eDRX wani yanayi ne wanda na'urar ba ta karɓar saƙonni daga cibiyar sadarwa akai-akai, amma lokaci-lokaci. A lokacin Haɗa ko TAU hanyoyin, na'urar ta yarda da cibiyar sadarwa a kan tazarar lokaci lokacin da zai "saurari" ga watsa shirye-shirye. A sakamakon haka, za a yi tsarin Paging a lokaci guda. A cikin yanayin eDRX, aikin na'urar ya kasu zuwa hawan keke (zagayen eDRX). A farkon kowane sake zagayowar akwai abin da ake kira "taga taga" (Paging Time Window, daga baya PTW) - wannan shine lokacin da na'urar ke sauraron tashar rediyo. A ƙarshen PTW, na'urar tana kashe tsarin rediyo har zuwa ƙarshen zagayowar.
HLCOM (Sadarwar latency mai girma):
Idan yana buƙatar canja wurin bayanai zuwa Uplink, na'urar zata iya fita ɗaya daga cikin waɗannan hanyoyin ceton wutar lantarki guda biyu ba tare da jiran sake zagayowar PSM ko eDRX ba. Amma yana yiwuwa don canja wurin bayanai zuwa na'urar kawai lokacin da yake aiki.
Ayyukan HLCOM ko babban latency sadarwa shine buffer na Downlink fakiti akan SGW yayin da na'urar ke cikin yanayin ceton wutar lantarki kuma baya samuwa don sadarwa. Za a kawo fakitin buffered da zaran na'urar ta fita PSM ta hanyar yin TAU ko wucewar zirga-zirgar Uplink, ko lokacin da PTW ta faru.
Wannan, ba shakka, yana buƙatar wayar da kan masu haɓaka samfuran IoT, tunda ba a samun sadarwa tare da na'urar a ainihin lokacin kuma yana buƙatar wata hanya ta ƙira dabarun kasuwanci na aikace-aikace.
A ƙarshe, bari mu ce: gabatarwar wani sabon abu koyaushe yana da ban sha'awa, amma yanzu muna hulɗa da ma'auni wanda ba a gwada shi ba har ma da "bison" na duniya, kamar Vodafone da Telefonica - don haka yana da ban sha'awa sau biyu. Gabatarwar kayan ba ta yin kamar ta zama cikakke, amma muna fatan zai ba da isasshen fahimtar fasaha. Za mu yaba da ra'ayoyin ku.
Mawallafi: Masanin Ma'aikatar Magance Mahimmanci da Sabis na Multimedia Alexey Lapshin
source: www.habr.com