Understanding cellular data networks on iPhone 3G

Q: Why does original iPhone show a different number of bars than iPhone 3G in the same location?

A: The original iPhone uses 2G only (EDGE and GPRS), iPhone 3G uses 3G and 2G and will use the best network available at the time. Note that most carriers have greater 2G network coverage than 3G, but 3G network coverage continues to grow.

Q: My carrier's coverage map indicates that I should have 3G coverage, but I am not getting it. What should I do?

A: The coverage maps presented by carriers such as AT&T typically represent an approximation. Contact your carrier if you are experiencing any coverage related issues.

Q: When on a call, why does my iPhone 3G work better at 1 bar than an original iPhone?

A: This is because when on a 3G network, you can communicate with more than one cell tower at a time. By design, 3G is supposed to work better than 2G in weak signal conditions. Signal bars for 2G are not directly comparable to 3G bars. The bars an estimate of how good the signal conditions are.

Q: Why does my iPhone 3G show 1 bar while another 3G phone shows 2 bars.

A: No standard exists for mapping signal levels to actual bars. The bars are an estimate of how good the signal conditions are.

Q: Is 3G voice quality better than 2G?

A: Yes because 3G can communicate with more cell towers simultaneously and process more data than 2G.

Q: What does turning off 3G do on iPhone 3G?

A: This will turn off the 3G network and limits you to 2G. With 3G turned off, you will not be able to use voice and data at the same time except when using data over a Wi-Fi connection. Note that you may get additional talk time by turning off 3G. See the iPhone 3G specifications for more information.