Kwete kare-kare, pane zvimwe zviwanikwa zvakasiyana uye mubhurogi rangu, ndakataura nezve chokwadi chekuti ZigBee afa uye yave nguva yekuviga mushandi wendege. Kuti uise chiso chakanaka pamutambo wakashata neThread kushanda pamusoro pe IPv6 uye 6LowPan, Bluetooth (LE) iyo inonyanya kukodzera kune iyi yakakwana. Asi ndichakutaurirai pane imwe nguva. Nhasi tichataura pamusoro pekuti boka rekushanda rekomiti rakasarudza sei kufunga kaviri mushure me802.11ah uye rakasarudza kuti yakanga yava nguva yekuwedzera shanduro yakazara yechinhu chakaita seLRLP (Long-Range Low-Power) kune dziva re802.11 zviyero, zvakafanana. kuLoRA. Asi izvi zvakazova zvisingabviri kuita pasina kuuraya mhou inoera yekudzokera kumashure. Somugumisiro, Long-Range yakasiiwa uye chete Low-Power yakasara, iyo yakanaka kwazvo. Mhedzisiro yacho yaive musanganiswa we802.11 + 802.15.4, kana kungoti Wi-Fi + ZigBee. Ndiko kuti, tinogona kutaura kuti tekinoroji nyowani haisi mukwikwidzi weLoraWAN mhinduro, asi, pane zvinopesana, iri kugadzirwa kuti ibatsire ivo.
Saka, ngatitangei nechinhu chinonyanya kukosha - Zvino zvishandiso zvinotsigira 802.11ba zvinofanirwa kunge zvine mamodule maviri eredhiyo. Sezviri pachena, mushure mekutarisa 802.11ah / demo neiyo Target Wake Time (TWT) tekinoroji, mainjiniya akafunga kuti izvi zvakanga zvisina kukwana uye vaifanira kuderedza zvakanyanya kushandiswa kwesimba. Nei chiyero ichipa kupatsanurwa mumhando mbiri dzakasiyana dzeredhiyo - Yekutanga Kukurukurirana Radio (PCR) uye Wake-Up Radio (WUR). Kana nekutanga zvinhu zvose zvakajeka, iyi ndiyo redhiyo huru, inotumira uye inogamuchira data, uye neyechipiri haisi yakawanda. Muchokwadi, iyo WUR inonyanya kuterera mudziyo (RX) uye yakagadzirirwa kushandisa simba shoma kuti rishande. Basa rayo guru ndere kugamuchira chiratidzo chekumuka kubva kuAP uye kugonesa PCR. Ndokunge, iyi nzira inoderedza zvakanyanya kutonhora kwekutanga nguva uye inobvumidza iwe kumutsa zvishandiso panguva yakapihwa nekunyatso kurongeka. Izvi zvinobatsira zvakanyanya kana iwe uine, taura, kwete gumi zvishandiso, asi zana negumi uye iwe unofanirwa kuchinjana data nemumwe wavo munguva pfupi. Uyezve, iyo logic yeiyo frequency uye periodicity yekumuka inoenda kudivi reAP. Kana, toti, LoRAWAN inoshandisa PUSH methodology apo ivo vanosimudza ivo pachavo vanomuka uye vanotumira chimwe chinhu pamhepo, uye vakarara nguva yose, saka munyaya iyi, pane zvinopesana, AP inosarudza kuti ndeipi uye chii chinofanira kumuka, uye iwo actuators pachavo ... kwete nguva dzose kurara.
Zvino ngatienderere mberi kune mafomati mafomati uye kuenderana. Kana 802.11ah, seyekutanga kuedza, yakasikirwa mabhendi e868/915 MHz kana kungoti SUB-1GHz, ipapo 802.11ba yatove yakagadzirirwa 2.4GHz uye 5GHz mabhendi. Mune zvakapfuura "zvitsva" zviyero, kuenderana kwakagadziriswa kuburikidza nenhanganyaya yainzwisiswa kumidziyo yekare. Ndokunge, kuverenga kwagara kuri kuti zvishandiso zvekare hazvidi hazvo kukwanisa kuziva iyo furemu yese; zvakakwana kuti vanzwisise kuti furemu iyi ichatanga rinhi uye kuti kutapurirana kuchagara kwenguva yakareba sei. Ndirwo ruzivo rwavanotora kubva munhanganyaya. 802.11ba yakanga isiri iyo, sezvo chirongwa ichi chakaratidza uye chakaratidza (tisingatarise nyaya yemitengo ikozvino).
Nekuda kweizvozvo, iyo 802.11ba furemu inotaridzika seizvi:
A non-HT preamble uye pfupi yeOFDM fragment ine BPSK modulation inobvumira zvose 802.11a/g/n/ac/ax madivayiri kuti anzwe kutanga kwekufambiswa kwefuremu iyi uye kwete kupindira, kupinda munhepfenyuro yekuteerera. Mushure mekutanga kunouya ndima yekubatanidza (SYNC), inova analogue yeL-STF/L-LTF. Inoshanda kuita kuti zvikwanise kugadzirisa frequency uye kuwiriranisa inogamuchira mudziyo. Uye panguva ino iyo mudziyo wekutumira unochinja kune imwe chiteshi hupamhi hwe4 MHz. Yechii? Zvese zviri nyore. Izvi zvinodikanwa kuitira kuti simba rideredzwe uye inofananidzwa chiratidzo-kune-ruzha reshiyo (SINR) inogona kuwanikwa. Kana kuti siya simba sezvariri uye uwane yakakura kuwedzera kwekutapurirana renji. Ndingati iyi ndiyo mhinduro yakanakisa, iyo inobvumirawo kuti munhu aderedze zvakanyanya zvinodiwa zvemagetsi. Ngatiyeuke, semuenzaniso, iyo yakakurumbira ESP8266. Mukufambisa modhi uchishandisa bitrate ye54 Mbps uye simba re16dBm, inoshandisa 196 mA, iyo yakakwira zvakanyanya kune chimwe chinhu chakaita seCR2032. Kana tikadzikisa hupamhi hwechiteshi nekashanu uye tikadzikisa simba rekutapurirana kashanu, saka isu hatingarasikirwe muhuwandu hwekutapurirana, asi mashandisirwo azvino anozoderedzwa nechinhu che, toti, kusvika pamakumi mashanu mA. Kwete kuti izvi zvakakosha pachikamu cheAP chinotumira furemu yeWUR, asi hazvina kushata. Asi kune STA izvi zvatove zvine musoro, sezvo kushandiswa kwakaderera kunobvumira kushandiswa kwechimwe chinhu chakaita seCR50 kana mabhatiri akagadzirirwa kuchengetedza simba renguva refu ane yakaderera yakatemerwa kubuda kwemhepo. Ehe, hapana chinouya mahara uye kuderedza hupamhi hwechiteshi kunozotungamira mukudzikira kwekumhanya kwechiteshi nekuwedzera munguva yekufambisa yeimwe furemu, zvichiteerana.
Nenzira, nezve chiteshi kumhanya. Chiyero muchimiro chayo chazvino chinopa sarudzo mbiri: 62.5 Kbps uye 250 Kbps. Unonzwa here kunhuwa kweZigBee? Izvi hazvisi nyore, sezvo iine chiteshi chakafara che2Mhz pachinzvimbo che4Mhz, asi imwe mhando yemodulation ine yakakwirira spectral density. Nekuda kweizvozvo, huwandu hwe802.11ba zvishandiso hunofanira kunge hwakakura, hunobatsira zvakanyanya kune yemukati IoT mamiriro.
Kunyange, kumirira kweminiti ... Kumanikidzira zviteshi zvose munzvimbo yacho kuti zvinyarare, pavanenge vachishandisa 4 MHz chete ye20 MHz band ... "IKO KUSVIRA!" - iwe uchataura uye iwe uchave wakarurama. Asi kwete, IYI NDIYO KURAMBA CHAIKO!
Iyo chiyero inopa kugona kushandisa 40 MHz uye 80 MHz subchannel. Muchiitiko ichi, ma bitrate ega ega subchannel anogona kuve akasiyana, uye kuti aenderane nenguva yekutepfenyura, Padding inowedzerwa kumagumo efomati. Kureva, mudziyo unogona kutora airtime pane ese 80 MHz, asi ishandise chete pa16 MHz. Uku kutambisa chaiko.
Nenzira, yakakomberedza Wi-Fi zvishandiso hazvina mukana wekunzwisisa zviri kutepfenyurwa ipapo. Nekuti iyo yakajairwa OFDM haina kushandiswa encode 802.11ba mafuremu. Ehe, saizvozvi, mubatanidzwa wakasiya izvo zvakashanda zvisina mhosva kwemakore mazhinji. Panzvimbo peiyo classic OFDM, Multi-Carrier (MC) -OOK modulation inoshandiswa. Iyo 4MHz chiteshi yakakamurwa kuita 16 (?) subcarriers, imwe neimwe inoshandisa Manchester encoding. Panguva imwecheteyo, munda weDATA pachawo wakakamurwa zvine mutsindo muzvikamu zve 4 ΞΌs kana 2 ΞΌs zvichienderana ne bitrate, uye muchikamu chimwe nechimwe chakadaro chikamu chakaderera kana chepamusoro che encoding chinogona kuenderana nechimwe. Iyi ndiyo mhinduro yekudzivisa kutevedzana kwenguva refu kwezero kana imwe. Kutsvanzvadzira pamuhoro wepasi.
Iyo MAC level zvakare yakarerutswa zvakanyanya. Inongova nendima dzinotevera:
- Frame Control
Inogona kutora kukosha Beacon, WUP, Discovery kana chero humwe kukosha kwesarudzo yemutengesi.
Beacon inoshandiswa kuwiriranisa nguva, WUP yakagadzirirwa kumutsa chimwe kana boka remidziyo, uye Discovery inoshanda yakapesana kubva kuSTA kuenda kuAP uye yakagadzirirwa kuwana nzvimbo dzekuwana dzinotsigira 802.11ba. Iyi munda zvakare ine hurefu hwefuremu kana ichipfuura 48 bits. - ID
Zvichienderana nerudzi rwefuremu, inogona kuona AP, kana STA, kana boka remaSTA rinoitirwa furemu iyi. (Ehe, unogona kumutsa zvishandiso mumapoka, inonzi groupcast wake-ups uye inotonhorera).
- Type Dependent (TD)
Munda unochinjika. Iri mairi iyo nguva chaiyo inogona kutumirwa, chiratidzo pamusoro pe firmware / configuration update nenhamba yeshanduro, kana chimwe chinhu chinobatsira icho STA inofanira kuziva nezvazvo.
- Frame Checksum Field (FCS)
Zvose zviri nyore pano. Iyi icheki
Asi kuti tekinoroji ishande, hazvina kukwana kungotumira furemu mune inodiwa fomati. Iyo STA neAP inofanirwa kubvumirana. Iyo STA inoshuma ma paramita ayo, kusanganisira nguva inodiwa kutanga PCR. Kukurukurirana kwese kunoitika uchishandisa yakajairwa 802.11 mafuremu, mushure meizvozvo iyo STA inogona kudzima PCR uye kupinda WUR inogonesa modhi. Kana kuti zvimwe kutorara, kana zvichiita. Nokuti kana iripo, saka zviri nani kuishandisa.
Inotevera inouya zvishoma kudzvanya kweakakosha milliamp maawa anonzi WUR Duty Cycle. Hapana chakaoma, kungoti STA neAP, nekuenzanisa nemabatirwo azvaive zveTWT, vanobvumirana pane chirongwa chekurara. Mushure meizvi, STA kazhinji anorara, achibatidza WUR kuti ateerere "Pane chero chinhu chinobatsira chasvika kwandiri?" Uye chete kana zvichidikanwa, inomutsa main radio module yekutsinhana kwetraffic.
Inoshandura zvakanyanya mamiriro ezvinhu kana ichienzaniswa neTWT neU-APSD, handizvo here?
Uye ikozvino nuance inokosha yausingakurumidzi kufunga nezvazvo. Iyo WUR haifanirwe kushanda panguva imwecheteyo seyo huru module. Pane kudaro, inodiwa uye inokurudzirwa kuti ishande pane imwe nzira. Muchiitiko ichi, iyo 802.11ba mashandiro haapindire chero nzira nekushanda kwetiweki uye, pane zvinopesana, inogona kushandiswa kutumira ruzivo runobatsira. Nzvimbo, Muvakidzani Rondedzero uye zvimwe zvakawanda mukati memamwe 802.11 zviyero, semuenzaniso 802.11k/v. Uye ndeapi mabhenefiti anovhurika kune Mesh network ... Asi iyi ndiyo musoro weimwe chinyorwa chakasiyana.
Kana iri magumo echiyero pachayo segwaro, saka . Kureva, gore rino tinogona kutarisira mwero chaiwo kana kanenge kekutanga kuita. Nguva chete ndiyo icharatidza kupararira kwazvichaitwa.
Zvinhu zvakadaro ... (c) .
Kuverenga kunokurudzirwa:
Source: www.habr.com