Nthawi yapitayi tidalankhula za mawonekedwe atsopano a NB-IoT kuchokera pamawonekedwe aukadaulo waukadaulo wama wailesi. Lero tikambirana zomwe zasintha mu Core Network pansi pa NB-IoT. Kotero, tiyeni tizipita.
Pakhala kusintha kwakukulu pachimake cha intaneti. Tiyeni tiyambe ndikuti chinthu chatsopano chawoneka, komanso njira zingapo, zomwe zimatanthauzidwa ndi muyezo monga "CIoT EPS Optimization" kapena kukhathamiritsa kwa netiweki yapaintaneti yapaintaneti ya zinthu.
Monga mukudziwa, pamanetiweki am'manja pali njira ziwiri zoyankhulirana, zotchedwa Control Plane (CP) ndi User Plane (UP). Control Plane cholinga chake ndi kusinthana kwa mauthenga a mautumiki pakati pa zinthu zosiyanasiyana zapaintaneti ndipo amagwiritsidwa ntchito pofuna kuonetsetsa kuyenda (Mobility management) ya zipangizo (UE) ndikukhazikitsa / kusunga gawo lotumizira deta (Session Management). User Plane ndiye njira yotumizira anthu ambiri. Mu LTE yachikale, kugawa kwa CP ndi UP pamitundu yonse kuli motere:
Njira zokwaniritsira za CP ndi UP za NB-IoT zimayikidwa pa MME, SGW ndi PGW node, zomwe zimaphatikizidwa kukhala chinthu chimodzi chotchedwa C-SGN (Cellular IoT Serving Gateway Node). Muyezowu umatengeranso kutuluka kwa chinthu chatsopano cha netiweki - SCEF (Service Capability Exposure Function). Maonekedwe apakati pa MME ndi SCEF amatchedwa T6a ndipo amayendetsedwa motengera DIAMETER protocol. Ngakhale kuti DIAMETER ndi ndondomeko yowonetsera, mu NB-IoT imasinthidwa kuti iperekedwe kwazing'ono zomwe sizili za IP.
Monga dzina lake likusonyezera, SCEF ndi Service Capability Exhibit Node. Mwanjira ina, SCEF imabisa zovuta za netiweki ya ogwiritsa ntchito, komanso imathandizira opanga mapulogalamu pakufunika kozindikira ndi kutsimikizira zida zam'manja (UE), kulola ma seva ogwiritsira ntchito (Application Server, pano AS) kuti alandire deta ndikuwongolera zida pogwiritsa ntchito imodzi. API mawonekedwe.
Chizindikiritso cha UE sichikhala nambala yafoni (MSISDN) kapena adilesi ya IP, monga zinalili mu netiweki yapamwamba ya 2G/3G/LTE, koma yotchedwa "ID yakunja", yomwe imatanthauzidwa ndi mulingo wodziwika bwino. kwa opanga mapulogalamu "@". Uwu ndi mutu waukulu wosiyana womwe umayenera kukhala ndi zinthu zosiyana, kotero sitilankhula mwatsatanetsatane tsopano.
Tsopano tiyeni tiwone zatsopano zatsopano. "CIoT EPS Optimization" ndiye kukhathamiritsa kwa njira zotumizira anthu magalimoto komanso kasamalidwe ka gawo lolembetsa. Nazi zazikulu:
- DoNAS
- NIDD
- PSM ndi eDRX njira zopulumutsira mphamvu
- Mtengo wa HLCOM
DoNAS (Data over NAS):
Iyi ndi njira yopangidwira kukhathamiritsa kusamutsa kwa data yaying'ono.
Mu classic LTE, polembetsa mu netiweki, chida cholembetsa chimakhazikitsa cholumikizira cha PDN (pambuyo pake chimatchedwa PDN) kudzera pa eNodeB kupita ku MME-SGW-PGW. Kulumikizana kwa UE-eNodeB-MME ndizomwe zimatchedwa "Signaling Radio Bearer" (SRB). Ngati kuli kofunikira kutumiza/kulandira deta, UE imakhazikitsanso kulumikizana kwina ndi eNodeB - "Data Radio Bearer" (DRB), kutumiza kuchuluka kwa ogwiritsa ntchito ku SGW ndi kupitilira ku PGW (mawonekedwe a S1-U ndi S5, motsatana) . Pamapeto pa kusinthanitsa ndipo ngati palibe magalimoto kwa nthawi ndithu (nthawi zambiri 5-20 masekondi), malumikizidwewa amathetsedwa ndipo chipangizocho chimapita ku standby mode kapena "Idle Mode". Ngati kuli kofunikira kusinthanitsa gawo latsopano la data, SRB ndi DRB zimakonzedwanso.
Mu NB-IoT, kufalitsa kwa magalimoto ogwiritsira ntchito kumatha kuchitidwa kudzera mu njira yowonetsera (SRB), mu mauthenga a protocol a NAS (). Kukhazikitsa DRB sikufunikanso. Izi zimachepetsa kwambiri kuchuluka kwa ma siginecha, zimapulumutsa zida zamawayilesi amtaneti ndipo, chofunikira kwambiri, zimakulitsa moyo wa batri la chipangizocho.
Mu gawo la eNodeB - MME, deta ya ogwiritsa ntchito imayamba kutumizidwa pa mawonekedwe a S1-MME, zomwe sizinali choncho muukadaulo wakale wa LTE, ndipo protocol ya NAS imagwiritsidwa ntchito pa izi, momwe "chidebe cha data cha ogwiritsa" chikuwonekera.
Kuti muthe kutumiza "User Plane" kuchokera ku MME kupita ku SGW, mawonekedwe atsopano a S11-U amawonekera, omwe adapangidwa kuti asamutsire ziwerengero zazing'ono za ogwiritsa ntchito. Protocol ya S11-U idakhazikitsidwa ndi GTP-U v1, yomwe imagwiritsidwa ntchito potumiza ndege ya User Plane pama network ena omanga a 3GPP.
NIDD (yopanda IP data delivery):
Monga gawo la kukhathamiritsa kwina kwa njira zotumizira pang'onopang'ono deta, kuwonjezera pa mitundu yomwe ilipo kale ya PDN, monga IPv4, IPv6 ndi IPv4v6, mtundu wina wawonekera - womwe si wa IP. Pachifukwa ichi, EU sikupatsidwa adilesi ya IP ndipo deta imatumizidwa popanda kugwiritsa ntchito protocol ya IP. Pali zifukwa zingapo zochitira izi:
- Zipangizo za IoT monga masensa zimatha kutumiza zidziwitso zochepa kwambiri, ma byte 20 kapena kuchepera. Popeza kuti kukula kochepa kwa mutu wa IP ndi ma byte 20, IP encapsulation nthawi zina imakhala yodula;
- Palibe chifukwa chogwiritsira ntchito stack ya IP pa chip, zomwe zimapangitsa kuti achepetse mtengo (funso lokambirana mu ndemanga).
Mwambiri, adilesi ya IP ndiyofunikira kuti zida za IoT zitumize deta pa intaneti. Mu lingaliro la NB-IoT, SCEF imakhala ngati malo amodzi olumikizira AS, ndipo kusinthana kwa data pakati pa zida ndi ma seva ogwiritsira ntchito kumachitika kudzera pa API. Popanda SCEF, deta yosakhala ya IP ikhoza kutumizidwa ku AS kudzera mumsewu wa Point-to-Point (PtP) kuchokera ku PGW ndi IP encapsulation idzachitidwa pamenepo.
Zonsezi zikugwirizana ndi NB-IoT paradigm - kuphweka kwambiri komanso kuchepetsa mtengo wa zipangizo.
PSM ndi eDRX njira zopulumutsira mphamvu:
Chimodzi mwazabwino zazikulu zama netiweki a LPWAN ndikugwiritsa ntchito mphamvu. Chipangizochi chimanenedwa kuti chimakhala ndi moyo wa batri kwa zaka 10 pa batri imodzi. Tiyeni tiwone momwe mfundo zotere zimakwaniritsidwira.
Ndi liti pamene chipangizo chimagwiritsa ntchito mphamvu zochepa? Zolondola zikathimitsidwa. Ndipo ngati n'kosatheka kuchotseratu mphamvu chipangizocho, tiyeni tichepetse mphamvu pawayilesi kwa nthawi yonse yomwe sikufunika. Mukungoyenera kugwirizanitsa izi ndi netiweki poyamba.
PSM (njira yosungira mphamvu):
Njira yopulumutsira mphamvu ya PSM imalola chipangizocho kuti chizimitse gawo la wailesi kwa nthawi yayitali, pokhalabe olembetsedwa pa intaneti, komanso kuti asakhazikitsenso PDN nthawi iliyonse yomwe ikufunika kutumiza deta.
Kuti ma netiweki adziwe kuti chipangizocho chikupezekabe, nthawi ndi nthawi chimayambitsa njira yosinthira - Tracking Area Update (TAU). Kuchuluka kwa njirayi kumayikidwa ndi netiweki pogwiritsa ntchito timer T3412, mtengo wake womwe umaperekedwa ku chipangizocho panthawi ya Attach kapena TAU yotsatira. Mu classic LTE, mtengo wosasinthika wa timer iyi ndi mphindi 54, ndipo kuchuluka kwake ndi mphindi 186. Komabe, kuwonetsetsa kuti mphamvu zamagetsi zikuyenda bwino, kufunikira koyenda pamlengalenga mphindi 186 zilizonse ndikokwera mtengo kwambiri. Makina a PSM adapangidwa kuti athetse vutoli.
Chipangizocho chimayambitsa mawonekedwe a PSM potumiza zikhalidwe za nthawi ziwiri T3324 ndi T3412-Zowonjezera mu mauthenga a "Attach Request" kapena "Tracking Area Request". Yoyamba imatsimikizira nthawi yomwe chipangizocho chidzakhalapo mutasinthira ku "Idle Mode". Yachiwiri ndi nthawi yomwe TAU iyenera kupangidwa, tsopano mtengo wake ukhoza kufika masekondi 35712000 kapena masiku 413. Kutengera makonda, a MME amatha kuvomereza zowerengera zomwe zalandilidwa kuchokera pachidacho kapena kuzisintha potumiza zatsopano mu mauthenga a "Attach Accept" kapena "Tracking Area Update Accept". Tsopano chipangizocho sichingayatse gawo la wailesi kwa masiku 413 ndikukhalabe olembetsedwa pamaneti. Zotsatira zake, timapeza ndalama zochulukirapo pazogwiritsa ntchito maukonde komanso kugwiritsa ntchito mphamvu zamagetsi pazida!
Komabe, munjira iyi chipangizocho sichipezeka pazolumikizana zomwe zikubwera zokha. Ngati kuli kofunikira kutumiza china chake ku seva yogwiritsira ntchito, chipangizocho chikhoza kutuluka PSM nthawi iliyonse ndikutumiza deta, pambuyo pake imakhala yogwira ntchito panthawi ya T3324 kuti ilandire mauthenga ochokera ku AS (ngati alipo).
eDRX (kulandila kopitilira muyeso):
eDRX, Kulandila Kwapakatikati Kowonjezera. Kusamutsa deta ku chipangizo chomwe chili mu "Idle mode", netiweki imachita zidziwitso - "Paging". Mukalandira paging, chipangizocho chimayambitsa kukhazikitsidwa kwa SRB yolumikizananso ndi netiweki. Koma kuti musaphonye uthenga wa Paging wopita kwa icho, chipangizocho chiyenera kuyang'anira mpweya wa wailesi nthawi zonse, womwe umakhalanso wowononga kwambiri.
eDRX ndi njira yomwe chipangizochi sichilandira mauthenga kuchokera pa intaneti nthawi zonse, koma nthawi ndi nthawi. Pamachitidwe a Attach kapena TAU, chipangizocho chimagwirizana ndi netiweki pazigawo za nthawi yomwe "idzamvera" kuwulutsa. Chifukwa chake, njira ya Paging idzachitidwa nthawi yomweyo. Mu mawonekedwe a eDRX, magwiridwe antchito a chipangizocho amagawidwa mozungulira (eDRX cycle). Kumayambiriro kwa kuzungulira kulikonse pali chotchedwa "paging zenera" (Paging Time Window, pano PTW) - iyi ndi nthawi yomwe chipangizocho chimamvera wailesi. Kumapeto kwa PTW, chipangizocho chimazimitsa gawo la wailesi mpaka kumapeto kwa kuzungulira.
HLCOM (kulumikizana kwakukulu kwa latency):
Ngati ikufunika kusamutsa deta ku Uplink, chipangizocho chikhoza kutuluka mwa njira ziwirizi zopulumutsira mphamvu popanda kuyembekezera kuti kuzungulira kwa PSM kapena eDRX kumalize. Koma n'zotheka kusamutsa deta ku chipangizo kokha pamene ikugwira ntchito.
Kugwira ntchito kwa HLCOM kapena kulankhulana kwanthawi yayitali ndiko kusungitsa mapaketi a Downlink pa SGW pomwe chipangizocho chili munjira yosungira mphamvu ndipo sichipezeka kuti ilumikizana. Mapaketi osungidwa adzaperekedwa chipangizocho chikangotuluka pa PSM pochita TAU kapena kudutsa magalimoto a Uplink, kapena PTW ikachitika.
Izi, ndithudi, zimafuna kuzindikira kwa opanga zinthu za IoT, chifukwa kulankhulana ndi chipangizo sikutheka mu nthawi yeniyeni ndipo kumafuna njira ina yopangira malingaliro a bizinesi.
Pomaliza, tiyeni tinene: kuyambitsidwa kwa chinthu chatsopano nthawi zonse kumakhala kosangalatsa, koma tsopano tikulimbana ndi muyezo womwe sunayesedwe mokwanira ngakhale ndi "bisons" zapadziko lapansi, monga Vodafone ndi Telefonica - kotero ndizosangalatsa kawiri. Kafotokozedwe kathu ka zinthuzo sikumanamizira kukhala kokwanira, koma tikukhulupirira kuti kumapereka chidziwitso chokwanira chaukadaulo. Tingayamikire ndemanga zanu.
Wolemba: Katswiri wa dipatimenti ya Convergent Solutions ndi Multimedia Services Alexey Lapshinβ¨
Source: www.habr.com