Request: Auto toggle between edge and 3g anteanna for voice vs. data

Can I just point out that is exactly what happens...... 3G is the date element of the connection not the voice. voice still goes over the standard voice channel. This is how you can surf and talk at the same time unlike on the edge network where voice and data are carried over the same channel.

Far be it for me to disagree with you as I only have 15 years working in mobile networks..... But yes it does. 3G is always on and exchanging data with the network. Edge is a reactive protocol and effectively 'dials' the connection every time you make a data demand. That is how edge works over the top of the voice channel.

When the 3G icon disappears it is because you are out of range of a 3G signal but the chip is still hunting for a connection and will consume power.

I suspect this is why Apple went 2G in the first place and only went 3G as a result of market pressure. 3G devices have always had terrible battery requirements.

Not to be argumentative but this isn't correct.

When your iPhone says 3G it means that it is using UMTS (W-CDMA) for both Voice and Data connections. This is a very different protocol and works over different frequencies than GSM.

When your iPhone says EDGE then it is using the GSM network for Voice on a GSM Cell that supports EDGE specific data enhancements to increase data throughput over normal GSM data (GPRS).

Finally when your iPhone doesn't say EDGE or 3G then it is on a GSM Cell that doesn't support the EDGE data enhancements.

So really the 3G iPhone has to choose between two different Cellular technologies, 2G (GSM) or 3G (UMTS) and the device can't communicate on both of these technologies at the same time.

Have a read of the wiki pages for more information:
UMTS (WCDMA): http://en.wikipedia.org/wiki/WCDMA
GSM: http://en.wikipedia.org/wiki/GSM

Hope this clears things up.
-- Colm.

Actually it is correct but depends on where you are based. I am giving the UK angle.

3G networks in general are notorious power drains, but the network type used by AT&T is particularly power-hungry because voice calls use the same mobile broadband network as data tasks. In contrast, the EvDO technology on which Sprint and Verizon base their 3G networks supports data only; voice uses older CDMA networks, which (in theory at least) use less power.