Nkọwa nke GSM (Global System for Mobile Communications)
GSM (akpọ gee-ess-em ) bụ ọkọlọtọ ekwentị kachasị ewu ewu, ma jiri ya na mba ụwa, yabụ na ị nụrịrị banyere ya na ekwentị GSM na netwọk GSM, karịsịa ma e jiri ya tụnyere CDMA .
GSM na-eguzobe maka Group Special Mobile ma ugbu a pụtara Global System for Mobile Communications.
Dị ka GSM Association (GSMA) si kwuo, nke na - anọchite anya mmasị nke ụlọ ọrụ mgbasa ozi zuru ụwa ọnụ, ọ dị ka 80% nke ụwa na - eji teknụzụ GSM mgbe etinye oku oku.
Kedu Netwọk ndị GSM?
Nke a bụ nkwụsị ọsọ nke nanị ndị na-ebugharị ndị na-ebugharị ma jiri GSM ma ọ bụ CDMA:
GSM:
- T-Mobile
- AT & T
- Ala Indigo
- Egwuregwu Cell
- TerreStar
UnlockedShop nwere ndepụta zuru ezu nke netwọk GSM na US.
CDMA:
- Sprint
- Ikuku Verizon
- Virgin Mobile
GSM na CDMA
Maka ebumnuche dị irè na kwa ụbọchị, GSM na-enye ndị ọrụ ntanetịime ike ụwa karịa ndị ọzọ na teknụzụ netwọk ndị ọzọ na United States ma nwee ike ime ka ekwentị bụrụ "ekwentị ụwa." Kedu ihe ọzọ, ihe dị ka ekwentị na-eji ngwa ngwa swapping na iji data mgbe ana-akwado oku GSM netwọk ma ọ bụghị CDMA.
Ndị na-ebu GSM na-agba ụgwọ nkwekọrịta na ndị ọzọ GSM na-ebugharị ma na-ekpuchi ebe ime obodo karia ndi na-ebu CDMA ebubo , na mgbe enweghi ebubo ugbo .
GSM nwekwara uru nke kaadị SIM dị mfe swappable. Igwe GSM jiri kaadị SIM iji chekwaa ozi (ozi onye na - edeba aha) dịka nọmba ekwentị gị na data ndị ọzọ nke gosipụtara na ị bụ onye na - edebanye aha na onye ahụ.
Nke a pụtara na ị nwere ike itinye kaadị SIM n'ime ekwentị GSM iji nọgide na-eji ya na netwọk na ozi niile ịdenyere na mbu (dịka nọmba gị) iji mee oku ekwentị, ederede, wdg.
Na CDMA ekwentị, Otú ọ dị, kaadi SIM adịghị echekwa ozi dị otú ahụ. A na-ejikọta njirimara gị na netwọk CDMA ọ bụghị ekwentị. Nke a pụtara swapping CDMA SIM kaadị adịghị "rụọ ọrụ" ngwaọrụ ahụ n'otu ụzọ ahụ. Kama ịchọrọ ịnwe ihu ọma site na ụgbọelu ahụ tupu ịnwee ike ịrụ ọrụ / gbanwee ngwaọrụ.
Dịka ọmụmaatụ, ọ bụrụ na ị bụ onye ọrụ T-Mobile, ịnwere ike iji ekwentị AT & T na netwọk T-Mobile (maọbụ vice) ma ọ bụrụhaala na ị tinye SIM kaadị SIM n'ime ngwaọrụ AT & T. Nke a bara ezigbo uru ma ọ bụrụ na ekwentị GSM agbajiri ma ọ bụ na ịchọrọ ịnwale ekwentị enyi gị.
Ma, buru n'uche na nke a bụ eziokwu maka ekwentị GSM na netwọk GSM. CDMA abụghị otu.
Ihe ọzọ ị ga-atụle mgbe ị na-atụle CDMA na GSM bụ na netwọk GSM na-akwado ịme oku n'eji data. Nke a pụtara na ị nwere ike ịpụ na banyere na oku ekwentị ma na-eji map igodo gị ma ọ bụ na-achọgharị na ịntanetị. Enweghị ikike dị otú ahụ na ọtụtụ netwọk CDMA.
Lee nkọwa nke CDMA maka nkọwa ndị ọzọ banyere ọdịiche dị n'etiti ụkpụrụ ndị a.
Ozi ndi ozo banyere GSM
Enwere ike ịmaliteghachi na mmalite nke GSM na 1982 mgbe European Group Special Mobile (GSM) guzobere Ụlọ Nzukọ Europe nke Postal na Telecommunications Administrations (CEPT) maka nzube nke ịmepụta teknụzụ nke European European Technology.
GSM amaliteghị iji ya rụọ ọrụ ruo n'afọ 1991, ebe e wuru ya site na iji teknụzụ TDMA .
GSM na-enye njirimara dịka nchikota oku ekwentị, netwọk data, nchịkọta oku, oku ezigara, nkwụsị oku, SMS, na mkparịta ụka.
Teknụzụ ekwentị nka na-arụ ọrụ na band 1900 MHz na US na band 900 MHz na Europe na Eshia. A na-ejikọta data na digitized, wee zipụ ya site na ọwa nwere eriri mmiri abụọ ọzọ, onye ọ bụla na-eji oghere nke aka ha.