If I buy a GSM phone with Sprint will it work if necessary on other networks like ATT verizon etc... meaning if signal strenght is low the phone automatically will pick any network??
A GSM phone will not work on Sprint as Sprint uses CDMA technology. A GSM phone with 850/1900 Mhz capabilities will, in the U.S. work on carriers like T-Mobile and AT&T, while a CDMA phone will work on/roam on carriers like ALLTEL, U.S. Cellular, Verizon and Sprint. If you have Sprint service and you go into a No Service area, the phone will automatically switch over to a roaming partner.
I agree with Ryan, well said Andy. There's got to be a way of posting a thread that can be stickied so hopefully we could avoid endless threads about this very issue. GSM is AT&T and T-Mobile, CDMA is Verizon, Sprint, Alltel, US Cellular, and MetroPCS/Cricket. GSM and CDMA are NOT compatible with each other
If you are thinking about one of the phones from Sprint that has GSM (BlackBerry 8830 or the Samsung IP830w) that will not work with any GSM carriers in the U.S. Sprint has those phones so people that travel out of the country often can take their phone with them and put in a prepaid SIM from a foreign carrier. The bands for GSM elsewhere in the world are different than the bands we use. (900MHz and 1800MHz while we use 850MHz and 1900MHz.) Sprint's network is 1900MHz CDMA only. All Sprint phones are 1900MHz CDMA with 800MHz CDMA for roaming because many CDMA carriers use 800MHz, or a combination depending on what area you are in. The two Sprint phones that have GSM have the dual band CDMA radio plus a GSM radio for 900MHz and 1800MHz. This will not work with any U.S. carriers. If the OP is just talking about buying an unlocked GSM phone and activating it with Sprint that will never happen as Mike and Andy mentioned. GSM and CDMA are different technologies.
