Shaady1,
The radio link method chosen by GSM is a combination of Time and FrequencyDivision Multiple Access (TDMA/FDMA).
Pacific Bell/Cingular ONLY operates on 1900mhz frequency. GSM phones sold in the United States ONLY transmit and receive via 1900mhz GSM frequency unless otherwise stated, such as world phones, such as the Ericsson T28World (NOT to be mistaken for the T28z), the Nokia 8890, there are some others... The T28World and the 8890 both offer compatibility with 900, 1800, and 1900mhz GSM networks - almost the entire world.
Pacific Bell/Cingular offers no CDMA/AMPS coverage whatsoever.
Technicalities aside, I drive to work sometimes across the Bay Bridge, other times I take the Bart. I admit that the T28 and 8890 that I have both offer MUCH better reception than the 5190 I had initially when I signed up my contract, especially the 8890, however the multi-band features are of no use unless you travel to a different GSM network.
The radio link method chosen by GSM is a combination of Time and FrequencyDivision Multiple Access (TDMA/FDMA).
Pacific Bell/Cingular ONLY operates on 1900mhz frequency. GSM phones sold in the United States ONLY transmit and receive via 1900mhz GSM frequency unless otherwise stated, such as world phones, such as the Ericsson T28World (NOT to be mistaken for the T28z), the Nokia 8890, there are some others... The T28World and the 8890 both offer compatibility with 900, 1800, and 1900mhz GSM networks - almost the entire world.
Pacific Bell/Cingular offers no CDMA/AMPS coverage whatsoever.
Technicalities aside, I drive to work sometimes across the Bay Bridge, other times I take the Bart. I admit that the T28 and 8890 that I have both offer MUCH better reception than the 5190 I had initially when I signed up my contract, especially the 8890, however the multi-band features are of no use unless you travel to a different GSM network.