Kumadivayisi e-IoT esikole angagadiwe ngqo ngumuntu—amamitha ageleza amanzi emithonjeni (boreholes), iziteshi zesimo sezulu, ama-alamu ezokuphepha ekhempasini, noma amamitha e-greenhouse—ama-SIM card ajwayelekile akhokhelwa kusengaphambili ayiphutha elibizayo. Ayacisha nakanjani ngamaholide kaZibandlela lapho imithetho yokungasebenzi kwezinombolo idala ukuthi inombolo ibuyiselwe emuva, noma aqede i-airtime yethemu yonke emahoreni amane ngenxa yamanani aphezulu angaphandle kwenqwaba yedatha (out-of-bundle rates) noma izingibe ze-SMS zabahlinzeki bezokuxhumana.

Uma ufuna inzwa yesikole ekude ithumele i-telemetry ethembekile kumanethiwekhi omakhalekhukhwini aseNingizimu Afrika, awudingi inqwaba yamagigabhayithi ajwayelekile. Umthamo ojwayelekile we-telemetry usebenzisa ngaphansi kwama-megabyte angu-5 ngenyanga. Okudingayo yisakhiwo esingazicishi uma singagadiwe: ikakhulukazi, i-SIM yedatha ehlanganyelwe ephethwe yohlobo lwe-machine-to-machine (M2M), ukubhalisela i-Narrowband IoT (NB-IoT) ezinikele, noma i-gateway yendawo engasebenzisi inethiwekhi yamaselula.

Izindlela Ezine Ama-SIM Akhokhelwa Kusengaphambili Ashiya Ngazo Izikole Phansi

Iningi lamakilabhu erobhothiki ezikoleni neminyango yezesayensi liqala ngokuthuma othile esitolo sendawo enemali esandleni kanye ne-ID kathisha ukuze bathenge i-SIM evamile ekhokhelwa kusengaphambili kwa-Vodacom, MTN, noma Telkom. Izinkinga ezintathu ezilindelekile zilandela phakathi kwezinsuku ezingamashumi ayisishiyagalolunye.

• Ukuvalwa ngenxa yokungasebenzi ngamaholide: Abahlinzeki bamanethiwekhi omakhalekhukhwini eNingizimu Afrika kumele babuyise izinombolo ezingangenisi imali. Uma i-SIM ingaqali isenzo esikhokhelwayo nesingenisa imali (njengekholi ekhokhelwayo, i-SMS ekhokhelwayo, noma ukusetshenziswa kwedatha ekhokhelwayo) phakathi nesikhathi esibekiwe—imvamisa phakathi kwezinsuku ezingama-90 n蝴蝶e-120 kuye ngenethiwekhi—inombolo imakwa njengengasebenzi, icishwe, iphinde ibuyiselwe ohlwini lwezinombolo ezidayiswayo. Lapho izikole zivala amasonto amane ngoNhlangulana noma amasonto amahlanu ngoZibandlela, idivayisi ethumela amaphakethe amancane ingadlula kalula lo mngcele noma ife buthule uma inqwaba yedatha ehlala izivuselela iphelelwa yisikhathi.
• Ukushabalala kwe-airtime namanani angaphandle kwenqwaba yedatha: Isikole sifaka u-R50 we-airtime ku-SIM ekhokhelwa kusengaphambili. Iphutha elincane le-firmware, ukuphinda kokuqinisekisa kwe-TLS (TLS handshake retry storm) okungalindelekile, noma ukuvumelanisa isikhathi senethiwekhi okuzenzakalelayo (NTP sync) kuqeda inqwaba yokuqala yephromoshini engu-50MB. Uma inqwaba ifika kuqanda, amanethiwekhi ashintshela kumanani angaphandle kwenqwaba (out-of-bundle) angadla i-airtime ngamanani aphindaphindwe kamashumi amabili kuya kamashumi amahlanu ngemegabhayithi ngayinye. Ibhalansi ifika ku-R0.00, ukuxhumana kwedatha kuyanqamuka, bese imonitha yendlu yamaphampu iyayeka ukubika.
• Ubunzima bokuphatha be-RICA: Ukuthobela umthetho we-Regulation of Interception of Communications and Provision of Communication-Related Information Act (RICA) kudinga ubufakazi bekheli kanye nomazisi. Uma ibhaliswe ngaphansi kwegama lothisha oyedwa, ukunakekelwa kwayo kuyaphela ngokushesha lapho lowo thisha eshintsha isikole noma ethatha ikhefu. Uma ibhaliswe ngaphansi kwegama lesikole, ukuthenga amanye ama-SIM ayisihlanu kubandakanya umsebenzi omude wokuphatha onezincwadi zomkhandlu olawula isikole (SGB), izikweletu zikamasipala, nezimvume zabasunguli abagunyaziwe.
• Ukuphelelwa yisikhathi kwenqwaba yedatha yezinsuku ezingama-30: Ukuthenga inqwaba yedatha evamile engu-1GB ngo-R85 kubonakala kushibhile, kodwa izinqwaba zedatha kuma-SIM akhokhelwa kusengaphambili aseNingizimu Afrika ziphelelwa yisikhathi ngqo ezinsukwini ezingama-30 ngemuva kokuvulwa. Ngenxa yokuthi inzwa eyodwa yezemvelo ayivamile ukusebenzisa ngaphezu kwe-3MB ngenyanga, isikole sikhokhela amamegabhayithi ayi-1 000 bese silahla ayi-997 njalo ngemva kwamasonto amane.

Izibalo Zangempela Zedatha Yenzwa Ye-IoT

Ukuze ukhethe indlela efanele yedatha, bala lokho okuthunyelwa ngempela yi-microcontroller ye-IoT. Umthamo wedatha ye-telemetry owakhiwe kahle—obika izinga lokushisa lomoya, umswakama womoya, amandla kagesi ebhethri (voltage), amandla ephansi lelanga (solar current), nomswakama wenhlabathi—udinga umkhawulokudonsa (bandwidth) omncane kakhulu.

I-JSON ehlangene noma idatha ye-binary equkethe izilinganiso zezinzwa ezinhlanu ngokwesilinganiso iba ngama-byte ayi-128. Ukuthumela leyo datha kanye njalo ngemizuzu eyishumi kusho ukuthumela kasithupha ngehora, noma amaphakethe ayi-144 ngosuku. Uma wengeza i-TCP/IP kanye nesisindo sepholothokholi yokuthutha (njenge-MQTT noma i-HTTPS elula), isamba sansuku zonke cishe singamakhilobhayithi angama-70. Enyangeni yezinsuku ezingama-30, lokho kulingana cishe namamegabhayithi ayi-2.1 edatha.

Izibalo zisobala: ukuthenga inqwaba yanyanga zonke engu-1GB ngo-R85 yesiteshi sesimo sezulu kusho ukuthi ukhokha inani eligcwele lomthamo ongasetshenziswanga ongu-99.8% oshabalala njalo ezinsukwini ezingamashumi amathathu.

Okukhethwa Kukho 1: Ama-SIM E-M2M Aphethwe Anedatha Ehlanganyelwe

Isixazululo esijwayelekile ku-telemetry yezimboni yi-SIM ephethwe ye-Machine-to-Machine (M2M). Esikhundleni sokugcina ama-akhawunti azimele, wonke amadivayisi esikole adonsa echibini elilodwa ledatha elihlanganyelwe eliphethwe ngeplathifomu eku-inthanethi (njenge-SIMcontrol noma amakhonsoli ebhizinisi abahlinzeki bezokuxhumana).

Ngaphansi kwenqubo yedatha ehlanganyelwe ye-M2M:

• I-SIM ngayinye inemali yokuqashwa kwentambo noma imali yeplathifomu yanyanga zonke ephakathi kuka-R8 no-R15.
• Idatha ibalwa ngemegabhayithi ngayinye kusuka ebhalansini eyodwa ye-akhawunti ehlanganyelwe, imvamisa ephakathi kuka-R0.15 no-R0.30 nge-MB ngayinye, ngaphandle kokuphelelwa yisikhathi ezinsukwini ezingama-30 ngasohlangothini lwedivayisi.
• Izivikelo zokuvimbela ukusetshenziswa ngaphandle kwenqwaba (out-of-bundle locks) zingabekwa ezingeni lokuphathwa kwe-SIM, okuvimbela ukukhula ngokweqile kwezindleko.
• I-SIM ayilokothi icishwe ngenxa yokungafakwa kwe-airtime ngesandla, inqobo nje uma i-akhawunti enkulu ihlala isebenza.

Esikoleni esisebenzisa imithombo yamanzi emithathu, isiteshi sesimo sezulu, kanye nesiqophi se-telemetry yelanga (amadivayisi amahlanu esewonke), isamba sezindleko ezihlangene sihlala ngokunethezeka ngaphansi kuka-R100 ngenyanga kuwo wonke amadivayisi.

Okukhethwa Kukho 2: Amanani E-NB-IoT Ne-LTE-M

Lapho izinzwa zisebenza ezindaweni ezingaphansi komhlaba (basements), ezivalweni zamapompo zensimbi, noma emaphethelweni amakhempasi asemakhaya, i-Narrowband IoT (NB-IoT) ingcono kakhulu ngokwezobuchwepheshe kune-4G/LTE evamile. Bobabili o-Vodacom no-MTN baqhuba amanethiwekhi asebenzayo e-NB-IoT ezindaweni ezinkulu zasemadolobheni kanye nasemigwaqweni emikhulu yezwe eNingizimu Afrika.

I-NB-IoT isebenza ngaphakathi kwesiphekitramu selayisensi yamaselula isebenzisa izingxenye ezincane ze-bandwidth ezingama-200 kHz. Lokhu kuyinikeza amandla aphezulu kakhulu okuxhumana (link budgets)—ingena ezindongeni zikakhonkolo futhi ifinyelele ekujuleni komhlaba lapho omakhalekhukhwini abavamile be-4G bengakhombisi amabha okuxhumana—kuyilapho isebenzisa amandla kagesi amancane kakhulu. Amandla e-standby aphansi kangangokuba amamitha ageleza amanzi asebenza ngamabhethri angahlala iminyaka eminingana esebenzisa amabhethri e-lithium angashajwa kabusha.

Abahlinzeki bezokuxhumana banikeza amanani e-NB-IoT azinikele ahlelwe ngokwenani lemiyalezo esikhundleni samagigabhayithi amaningi. Izinga elijwayelekile livumela inani elinqunyiwe lamaphakethe ngosuku ngemali engashintshi yonyaka noma yanyanga zonke, evame ukuba phakathi kuka-R10 no-R18 ngenyanga ngedivayisi ngayinye. Inkinga ekhona ukuhambisana kwe-hardware: i-microcontroller yakho kufanele ihlanganiswe nemodemu ekwazi ukusebenza nge-NB-IoT (njenge-Quectel BG95, SIM7020E, noma i-Nordic nRF9160) esikhundleni semodemu endala engabizi ye-2G/3G.

Okukhethwa Kukho 3: Enye Indlela Engenazo Izindleko (LoRaWAN)

Ngaphambi kokuthenga noma iyiphi i-SIM card, qinisekisa ukuthi ngabe idatha yamaselula iyadingeka ngempela yini. Uma izinzwa zakho ziqhele ngamakhilomitha aphakathi kuka-1 no-2 ukusuka esakhiweni sesikole esivele sinoxhumano lwe-inthanethi lwentambo, awuyidingi nhlobo i-SIM card kuleyo nzwa.

I-gateway eyodwa ye-LoRaWAN yasendlini noma yangaphandle eneziteshi eziyi-8 efakwe eceleni kwehholo lesikole ixhuma ngqo kunethiwekhi yendawo yesikole nge-Ethernet noma nge-Wi-Fi yekhempasi. Ama-node asendle angaphandle axhumana ne-gateway kusetshenziswa amaza omsakazo angadingi layisensi (868 MHz eNingizimu Afrika). Izindleko zokusebenza kudatha azikho, impilo yebhethri kuma-node yande kakhulu, futhi ugwema ngokuphelele ukuphathwa kwezinkampani zokuxhumana zikamakhalekhukhwini. Lapho kuhlanganiswa amanethiwekhi ezinzwa aphelele ekhempasini, izakhiwo ze-IoT zakwa-Sheen zivamise ukuxhuma i-gateway emaphakathi exhunywe nge-Ethernet nama-node asendle angaxhumekile kugridi ukuze kuqedwe ngokuphelele izindleko eziphindaphindwayo ze-SIM.

Ukuqhathanisa Kwezabelomali Zezikole

Yini Okufanele Uyisebenzise NgoMsombuluko

Uma ufaka idivayisi eyodwa noma ezimbili zokuqapha ezihambayo noma ezikude—njengedamu elikude elingamakhilomitha ayi-10 ukusuka emagcekeni amakhulu—sebenzisa i-SIM ye-M2M ephethwe ngomhlinzeki ohlinzeka ngokusebenzisa amanethiwekhi amaningi (roaming) kanye nokuhlanganisa idatha ye-telemetry okukhululekile. Vala i-SIM ukuze ingavumeli ukuthunyelwa kwama-SMS, vimba idatha engaphandle kwenqwaba kudeshibhodi yomhlinzeki, futhi uhlele idivayisi ukuthi ithumele i-telemetry ye-binary noma i-JSON emfushane.

Uma wethula uhlelo lokuqapha imvelo noma izinsiza ekhempasini yonke ezindaweni zesikole, yeka ukuthengela izivande ngazinye nezivalo zemithombo yamanzi ama-SIM card. Beka ibhodi le-NB-IoT ezindaweni ezikude, noma umise i-gateway yendawo ye-LoRaWAN exhunywe kungqalasizinda yokuphatha yesikole. Uma isifunda sakho noma umkhandlu olawulayo udinga ukuqaliswa okuphethwe kwe-telemetry yekhempasi yonke okugwema izindleko ezingalindelekile eziqhubekayo, hlola izinhlaka zethu eziklanyelwe lokhu kokuthi amasevisi ezikole akwa-Sheen.