Esikhathini esingengakanani esidlule, kwezinye izinsiza ezihlukahlukene nakubhulogi yami, ngikhulume ngeqiniso lokuthi u-ZigBee ufile futhi sekuyisikhathi sokungcwaba isisebenzi sendiza. Ukuze ubeke ubuso obuhle kugeyimu embi nge-Thread esebenza phezulu kwe-IPv6 ne-6LowPan, i-Bluetooth (LE) efaneleke kakhulu kulokhu yanele. Kodwa ngizokutshela ngalokhu ngesinye isikhathi. Namuhla sizokhuluma ngokuthi iqembu elisebenzayo lekomiti lanquma kanjani ukucabanga kabili ngemva kuka-802.11ah futhi lanquma ukuthi kwase kuyisikhathi sokwengeza inguqulo egcwele yento efana ne-LRLP (Long-Range Low-Power) echibini lamazinga angu-802.11, afanayo. kwe LoRA. Kodwa lokhu kwabonakala kungenakwenzeka ukuqalisa ngaphandle kokuhlaba inkomo engcwele yokuhambisana emuva. Ngenxa yalokho, i-Long-Range yashiywa futhi kwasala Amandla Aphansi kuphela, nakho okuhle kakhulu. Umphumela waba ingxube engu-802.11 + 802.15.4, noma i-Wi-Fi + ZigBee nje. Okungukuthi, singasho ukuthi ubuchwepheshe obusha akuwona umncintiswano wezixazululo ze-LoraWAN, kodwa, ngokuphambene nalokho, kwakhiwa ukuze kugcwaliseke.
Ngakho-ke, ake siqale ngento ebaluleke kakhulu - Manje amadivaysi asekela i-802.11ba kufanele abe namamojula amabili omsakazo. Ngokusobala, sebebheke i-802.11ah/ax ngobuchwepheshe bayo beTarget Wake Time (TWT), onjiniyela banqume ukuthi lokhu akwanele futhi badinga ukunciphisa kakhulu ukusetshenziswa kwamandla. Kungani izinga lihlinzeka ngokuhlukaniswa ngezinhlobo ezimbili ezihlukene zomsakazo - Irediyo Yokuxhumana Eyisisekelo (PCR) kanye ne-Wake-Up Radio (WUR). Uma ngeyokuqala yonke into icacile, lo ngumsakazo oyinhloko, udlulisela futhi wamukele idatha, bese kuthi okwesibili akuningi kakhulu. Eqinisweni, i-WUR ngokuvamile iyisisetshenziswa sokulalela (i-RX) futhi yakhelwe ukusebenzisa amandla amancane kakhulu ukuze isebenze. Umsebenzi wayo oyinhloko ukuthola isignali yokuvuka ku-AP futhi unike amandla i-PCR. Okusho ukuthi, le ndlela inciphisa kakhulu isikhathi sokuqala esibandayo futhi ikuvumela ukuthi uvuse amadivaysi ngesikhathi esinikeziwe ngokunemba okuphezulu. Lokhu kuyasiza kakhulu uma une, uthi, hhayi amadivaysi ayishumi, kodwa ikhulu neshumi futhi udinga ukushintshanisa idatha nomunye wabo ngesikhathi esifushane. Futhi, ingqondo yemvamisa kanye ne-periodicity yokuvuka iya ohlangothini lwe-AP. Uma, uthi, i-LoRAWAN isebenzisa indlela ye-PUSH lapho ama-actuator ngokwawo evuka futhi adlulisele okuthile emoyeni, futhi alale isikhathi sonke, khona-ke kulokhu, ngokuphambene nalokho, i-AP inquma ukuthi iyiphi idivayisi okufanele ivuke nini futhi nini, futhi ama-actuator ngokwawo... awalali njalo.
Manje ake siqhubekele kumafomethi ozimele nokuhambisana. Uma i-802.11ah, njengomzamo wokuqala, idalelwe amabhendi angu-868/915 MHz noma i-SUB-1GHz, khona-ke i-802.11ba isivele ihloselwe amabhendi angu-2.4GHz kanye ne-5GHz. Kumazinga "amasha" adlule, ukuhambisana kwafinyelelwa kusetshenziswa isethulo esasiqondakala kumadivayisi amadala. Okusho ukuthi, ukubala bekulokhu kungukuthi amadivaysi amadala awadingi ngempela ukubona uhlaka lonke; kwanele ukuthi baqonde ukuthi lolu hlaka luzoqala nini nokuthi ukudluliswa kuzohlala isikhathi esingakanani. Yilolu lwazi abaluthatha esethulweni. 802.11ba bekunjalo, njengoba uhlelo lufakazelwe futhi lwafakazelwa (sizoyiziba indaba yezindleko okwamanje).
Ngenxa yalokho, uhlaka lwe-802.11ba lubukeka kanjena:
Isendlalelo esingesona se-HT nesiqeshana se-OFDM esifushane esinokumoduliswa kwe-BPSK sivumela wonke amadivayisi angu-802.11a/g/n/ac/ax ukuzwa ukuqala kokudluliswa kwalolu hlaka futhi angaphazamisi, aye kumodi yokulalela yokusakaza. Ngemva kwesendlalelo kuza inkambu yokuvumelanisa (SYNC), okuyi-analogue ye-L-STF/L-LTF. Isebenza ukwenza kube nokwenzeka ukulungisa imvamisa nokuvumelanisa umamukeli wedivayisi. Futhi kungalesi sikhathi lapho idivayisi yokudlulisela ishintshela kwesinye ububanzi besiteshi esingu-4 MHz. Kwani? Konke kulula kakhulu. Lokhu kuyadingeka ukuze amandla ehliswe futhi isilinganiso esiqhathanisekayo sesignali-kuya-noise (SINR) singafinyelelwa. Noma shiya amandla njengoba enjalo futhi uthole ukwenyuka okuphawulekayo ebangeni lokudlulisela. Ngingasho ukuthi lesi yisixazululo esihle kakhulu, esivumela futhi ukuthi umuntu anciphise kakhulu izidingo zokunikezwa kwamandla. Ake sikhumbule, isibonelo, i-ESP8266 ethandwayo. Kumodi yokudlulisa usebenzisa i-bitrate engu-54 Mbps namandla angu-16dBm, idla u-196 mA, ophakeme ngendlela enqatshelwe kokuthile okufana ne-CR2032. Uma sinciphisa ububanzi besiteshi ngokuphindwe kahlanu futhi sinciphisa amandla okuthumela izikhathi ezinhlanu, khona-ke ngeke silahlekelwe yibanga lokudlulisela, kodwa ukusetshenziswa kwamanje kuzoncishiswa ngenani, ake sithi, cishe ku-50 mA. Hhayi ukuthi lokhu kubalulekile engxenyeni ye-AP edlulisela ifreyimu ye-WUR, kodwa namanje akukubi. Kodwa ku-STA lokhu sekuvele kunengqondo, njengoba ukusetshenziswa okuphansi kuvumela ukusetshenziswa kwento efana ne-CR2032 noma amabhethri aklanyelwe ukugcinwa kwamandla esikhathi eside anesilinganiso esiphansi sokuphuma kwamanzi. Yiqiniso, akukho lutho oluza mahhala futhi ukunciphisa ububanzi besiteshi kuzoholela ekwehleni kwejubane lesiteshi ngokunyuka kwesikhathi sokudlulisela kohlaka olulodwa, ngokulandelana.
Ngendlela, mayelana nesivinini sesiteshi. Izinga ngendlela yalo yamanje linikeza izinketho ezimbili: 62.5 Kbps kanye 250 Kbps. Uyalizwa iphunga le-ZigBee? Lokhu akulula, njengoba inobubanzi besiteshi obungu-2Mhz esikhundleni sika-4Mhz, kodwa uhlobo oluhlukile lokuguquguquka olunokuminyana okuphezulu kwe-spectral. Ngenxa yalokho, ububanzi bamadivayisi angu-802.11ba kufanele bube bukhulu, obuwusizo kakhulu kuzimo ze-IoT zasendlini.
Nakuba, linda kancane... Ukuphoqelela zonke iziteshi endaweni ukuthi zithule, kuyilapho kusetshenziswa kuphela i-4 MHz yebhendi engu-20 MHz... βLOKHU UKUCHITHEKA!β - uzosho futhi uzobe ulungile. Kodwa cha, LO UMONYA WANGEMPELA!
Izinga linikeza amandla okusebenzisa amashaneli angu-40 MHz kanye nama-80 MHz. Kulokhu, ama-bitrate esiteshi esingaphansi ngasinye angahluka, futhi ukuze kufane nesikhathi sokusakaza, i-Padding yengezwa ekugcineni kohlaka. Okusho ukuthi, idivayisi ingakwazi ukusebenzisa isikhathi somoya kuwo wonke ama-80 MHz, kodwa isebenzise kuphela ku-16 MHz. Lokhu kuwukumosha kwangempela.
Ngendlela, amadivaysi e-Wi-Fi azungezile awanalo ithuba lokuqonda ukuthi yini esakazwa lapho. Ngoba i-OFDM evamile AYISETSHENZISIWE ukufaka ikhodi kumafreyimu angu-802.11ba. Yebo, kanjalo nje, umfelandawonye washiya umsebenzi owawusebenze kahle iminyaka eminingi. Esikhundleni se-OFDM yakudala, kusetshenziswa ukuguquguquka kwe-Multi-Carrier (MC)-OOK. Isiteshi esingu-4MHz sihlukaniswe ngabathwali abangaphansi abangu-16(?), ngayinye esebenzisa umbhalo wekhodi wase-Manchester. Ngesikhathi esifanayo, inkambu yeDATHA ngokwayo nayo ihlukaniswe ngokunengqondo ibe amasegimenti angu-4 ΞΌs noma 2 ΞΌs kuye nge-bitrate, futhi engxenyeni enjalo ngayinye ileveli yombhalo wekhodi ephansi noma ephezulu ingahambisana neyodwa. Lesi yisixazululo sokugwema ukulandelana okude kwamaqanda noma awodwa. Ukuthola amaholo amancane.
Izinga le-MAC nalo lenziwe lula kakhulu. Iqukethe kuphela izinkambu ezilandelayo:
- Ukulawula Uzimele
Ingathatha amanani e-Beacon, i-WUP, i-Discovery nanoma yiliphi elinye inani lenketho yomthengisi.
I-Beacon isetshenziselwa ukuvumelanisa isikhathi, i-WUP iklanyelwe ukuvusa idivayisi eyodwa noma iqembu, futhi i-Discovery isebenza ngokuphambene ukusuka ku-STA ukuya ku-AP futhi iklanyelwe ukuthola izindawo zokufinyelela ezisekela i-802.11ba. Le nkambu iqukethe nobude bohlaka uma ludlula amabhithi angu-48. - ID
Kuye ngohlobo lohlaka, ingakwazi ukuhlonza i-AP, noma i-STA, noma iqembu lama-STA lapho lolu hlaka luhloselwe khona. (Yebo, ungakwazi ukuvusa amadivayisi ngamaqembu, kubizwa ngokuthi i-groupcast wake-ups futhi kuhle kakhulu).
- Uhlobo Oluncike (TD)
Inkambu eguquguqukayo impela. Kukuyo lapho isikhathi esiqondile singadluliswa khona, isignali mayelana nesibuyekezo se-firmware/sokulungiselela ngenombolo yenguqulo, noma okuthile okuwusizo i-STA okufanele yazi ngakho.
- Inkambu ye-Frame Checksum (FCS)
Konke kulula lapha. Lena i-checksum
Kodwa ukuze ubuchwepheshe busebenze, akwanele ukumane uthumele ifreyimu ngefomethi edingekayo. I-STA kanye ne-AP kufanele bavumelane. I-STA ibika amapharamitha ayo, okuhlanganisa isikhathi esidingekayo ukuze kuqaliswe i-PCR. Konke ukuxoxisana kwenzeka kusetshenziswa amafreyimu avamile angu-802.11, ngemva kwalokho i-STA ingakhubaza i-PCR futhi ifake imodi yokunika amandla i-WUR. Noma mhlawumbe ulale kancane, uma kungenzeka. Ngoba uma ikhona, kungcono ukuyisebenzisa.
Okulandelayo kuza ukuminya okwengeziwe kwamahora ayigugu e-milliamp okubizwa ngokuthi i-WUR Duty Cycle. Akukho lutho oluyinkimbinkimbi, i-STA kanye ne-AP kuphela, ngokufanisa nokuthi bekuyi-TWT kanjani, bayavumelana ngesimiso sokulala. Ngemuva kwalokhu, i-STA ilala kakhulu, ivula i-WUR ngezikhathi ezithile ukuze ilalele ethi βIngabe kukhona okuwusizo okungifikele?β Futhi kuphela uma kunesidingo, ivusa imojula yomsakazo eyinhloko yokushintshaniswa kwethrafikhi.
Sishintsha kakhulu isimo uma siqhathaniswa ne-TWT ne-U-APSD, akunjalo?
Futhi manje i-nuance ebalulekile ongayicabangi ngokushesha. I-WUR akudingeki ukuthi isebenze ngemvamisa efanayo nemojula eyinhloko. Kunalokho, iyafiseleka futhi iyatuswa ukuthi isebenze esiteshini esihlukile. Kulokhu, ukusebenza kwe-802.11ba akuphazamisi nganoma iyiphi indlela ukusebenza kwenethiwekhi futhi, ngokuphambene nalokho, kungasetshenziswa ukuthumela imininingwane ewusizo. Indawo, Uhlu Lomakhelwane nokunye okuningi ngaphakathi kwamanye amazinga angu-802.11, isibonelo 802.11k/v. Futhi yiziphi izinzuzo ezivulekele amanethiwekhi we-Mesh... Kodwa lesi yisihloko se-athikili ehlukile.
Ngokuqondene nesiphetho sezinga ngokwalo njengombhalo, ke . Okusho ukuthi, kulo nyaka singalindela izinga langempela noma okungenani ukuqaliswa kokuqala. Isikhathi kuphela esiyosho ukuthi kuzosakazeka kangakanani.
Izinto ezinjalo... (c) .
Ukufundwa okunconyiwe:
Source: www.habr.com