what are cdma and gsm phones?
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Two basic technologies in mobile phones, CDMA and GSM, represent a gap you can't cross. They're the reason you can't use older AT&T phones on Verizon's network and vice versa. ... CDMA (Code Division Multiple Access) and GSM (Global System for Mobiles) are shorthand for two older radio systems used in cell phones.
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To summarize, unlocked GSM phones can be used with any compatible carrier across the globe. Some CDMA phone will come internationally unlocked but will find it more difficult to find a compatible CDMA carrier worldwide. Always check with your carrier and speak to them before you travel.
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The Philippines operates on a GSM phone network, and T-Mobile and AT&T are the only U.S. carriers using the GSM network, according to CNET. Other U.S. providers use the CDMA network and may have less extensive roaming capabilities overseas than AT&T and T-Mobile.
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In general, an unlocked GSM phone from AT&T and T-Mobile will work on each other's networks. ... Older phones from Verizon and Sprint, on the CDMA network, don't operate with a SIM card. That basically means that those phones are restricted and can't be used on another CDMA networks.
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Check your phone's "About" settings. If you see an MEID or an ESN category, your phone requires CDMA; if you see an IMEI category, your phone is GSM. If you see both (e.g., Verizon phones), your phone supports both CDMA and GSM, and may be either one.
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A CDMA phone cannot be used on a GSM network and vice-versa. However, newer phones may support either network. You will need to check the phone's specifications. The answer to your question will depend on the specific iphone model you were planning on buying.
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In the US, Sprint, Verizon, and US Cellular use CDMA. AT&T and T-Mobile use GSM. Most of the rest of the world uses GSM. The global spread of GSM came about because in 1987, Europe mandated the technology by law, and because GSM comes from an industry consortium.
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For most of them, CDMA is the network offered by MTS India, Reliance and TATA Indicom, while GSM is the network provided by major companies like Airtel, Idea, Vodafone, Reliance, BSNL, Tata, Aircel and a few others.
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CDMA: The American Contender The other well-travelled cellular technology is CDMA. CDMA was developed by Qualcomm. The CDMA brand name encompasses two different standards: IS-95 aka CDMA One, a 2G digital service, and its modern 3G successor CDMA-2000.
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A GSM carrier doesn't care what phone a SIM card is in. ... Because of this, there is no need for CDMA networks to lock phones, so in that sense, every CDMA phone is unlocked, but it doesn't matter because the blocking is done on the carrier end.
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GSM is the most secured cellular telecommunications system available today. GSM has its security methods standardized. ... The privacy of the communication is maintained by applying encryption algorithms and frequency hopping that can be enabled using digital systems and signalling.
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GSM handsets came with a SIM card slot, while CDMA phones did not. ... On the other hand, with GSM devices, the phone number is linked to the SIM card, so when switching devices, all you have to do is pop the SIM card into a new phone and you are good to go.
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Past 2G networks. 2G, understood as GSM and CDMA, has been superseded by newer technologies such as 3G (UMTS / CDMA2000), 4G (LTE) and 5G; however, 2G networks are still used in most parts of Europe, Africa, Central America and South America. ... No plan to shut down 2G.
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2G, understood as GSM and CDMA, has been superseded by newer technologies such as 3G (UMTS / CDMA2000), 4G (LTE) and 5G; however, 2G networks are still used in most parts of Europe, Africa, Central America and South America. ... No plan to shut down 2G.
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All GSM devices are designed so that service is provisioned using a SIM card. With an unlocked device, a GSM smartphone can be reprovisioned and used on another network simply by popping out the old SIM card and putting in a new one from the new carrier. ... CDMA devices do not have SIM cards.
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In CDMA technology, More security is provided as compared with the GSM technology because encryption is inbuilt in the CDMA. ... The signal cannot be traced easily in CDMA as compared to the signals of GSM, which are concentrated in the narrow bandwidth. Therefore, CDMA phone calls are more secure than GSM calls.
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CDMA (Code Division Multiple Access) and GSM (Global System for Mobiles) are shorthand for two older radio systems (2G and 3G) used in cell phones. ... Verizon will turn off its CDMA network and T-Mobile will turn off its 2G GSM network by the end of 2020.