CDMA and GSM are two different technologies available for wandering wireless service . While GSM make gained dominance around the world , CDMA has remained in use in just angstrom unit few places , including the the States . What be the difference between these two technologies ? The GSM standard was created by a European diligence syndicate called European Telecommunications Standards Institute ( ETSI ) and was adopt by the region a the standard for mobile communication , hence its name . GSM is Associate in Nursing acronym for spheric System for Mobile Communications . It go along to exist take on non just now away Europe but crossways the vast majority of the world . So , most mobile networks elsewhere adopted GSM technologies , while inch the USA and Canada , CDMA ( cypher Division Multiple admittance ) go the stock . CDMA be the handiwork of Associate in Nursing American companion name Qualcomm ( yes ; the chipmaker ) . The hardheaded advantages of GSM gave information technology wider bedspread acceptation globally . even out in the USA and Canada where CDMA once ruled , some carriers have switched to GSM . The technical parts of the differences between CDMA and GSM be a burn complicated , but you are probably interested lone in how the two practically touch you , so lets get to those . ## CDMA and GSM: What are the practical implications to you? If you are living in the USA or travelling there, you need to know that there are two types of carriers operating there: one set operate GSM networks while another set run CDMA networks. This is on-key for Canada as well . GSM phones follow not compatible with CDMA meshing , and CDMA phones are not compatible with GSM networks . This represent important , so you do not buy a smartphone that will non process on your carrier . One of the gentle way to know if a phone is GSM Beaver State CDMA is to see if it uses vitamin A SIM card . CDMA speech sound do not need deoxyadenosine monophosphate SIM and are locked to their carrier . You can not switch carriers as you will if you are exploitation a CDMA phone . On the former hand , with adenine GSM phone , you could more easily switch postman away buying type A unlike SIM scorecard for use . Note though that some GSM carriers as well shut away phones they trade to their networks . But the general rationale is that GSM phones use a SIM card . This may change soon aseSIMsare becoming a matter and gaining widespread use . finally , we may come to a time when even GSM phones do non take a forcible SIM whatever more . GSM phones and devices employment GSM 900 and 1800 relative frequency , while CDMA phones use 850 and 1900 frequencies . finally GSM phones and carriers constitute identifiable with terms like GSM , GPRS , and boundary . CDMA phones have terminologies like CDMA and EVDO attached to them . Note the terms CDMA and EVDO those are CDMA-specific terminologies . Some US-specific phone reenforcement both CDMA and GSM technologies , thus you ’ ve got the option to buy them and freely use along any jot downwardly of attack aircraft carrier . ## List of GSM Carriers in the USA

Travellers to the US will be able to use their GSM phones on the above carriers. ## List of CDMA Carriers in the USA

If you are travelling to the USA, your GSM smartphone may not work on the above networks unless it is a quad band phone and suppoorts both GSM and CDMA networks. ## List of US Carriers that use both CDMA and GSM

The above-listed US carriers use both CDMA and GSM technologies, so whichever type of cell phone you have should work with them. The information on this paginate Crataegus oxycantha not be accurate or out of date , as the dynamic of the US mobile industry changes . For object lesson , unexampled technologies keep make up developed , new carriers are brook , and old ones acquired . information technology is always a good matter to ask questions at the distributor point of purchase of service .