Re: 3G off fixed my battery life!
 

one thing to keep in mind about 2g/gsm is that it may or may not be able to handle a incoming call while the data connection is in use, depending on the way the operator have their network configured...

Re: 3G off fixed my battery life!
 

I'm one of those with great battery life, and my SIM doesn't allow 3G - so I'm on 2.5G all the time. You could be on to something here. Unfortunately (due to the SIM) I can't switch to 3G to verify that not using 3G is what gives me the good battery time.

EDIT: Typo: on -> on to

Re: 3G off fixed my battery life!
 

I have had mine on GSM (its says 2G on display) now for a few days.. its a big difference for me. But Im also in a place where it switched alot before. Ususally for me 2G is fine as Im online on IM and I get email, rss updates.. and thats most often what I need. I think I can get 12 hours with no problem now.

Re: 3G off fixed my battery life!
 

I have 3g activated (though it uses wifi in the house)...and I get a full days' (read: about 24 hours) worth of battery life in moderate use with weather, news, and email apps going. The biggest change I made that seemed to have a dramatic impact on battery life was logging off of skype (and I never set up any other IM accounts). The constant traffic needed for the keepalives in IM protocols really sucks the juice.

Re: 3G off fixed my battery life!
 

One question, Can I use the N900 always in 3G ? (only 3G) ?

Personaly, and in my company, all employees use xmpp in n85 / n95 / n86 througt nimbuzz client. I offen drain my battery in 12hs with 1200mah working only in 3G. (dual mode or 2.5g is painfull=cant talk)

Remaind that we always call over VoIP xmpp (across many domains)

For us, for my friends and for me, XMPP is crucial, specially jingle-xmpp support.

Best regards,

PS: by the way, Who want a full featured phone in gsm to use with MSN propietary protocol=closed network without calling over IP capabilities ?

Hope N900 have a MUCH bigger battery to last at least a day in 3G.

Re: 3G off fixed my battery life!
 

Common opinion is that 3G has worse sound quality than GSM. Don't have the technical reasoning behind this, sry.

Re: 3G off fixed my battery life!
 

GSM is TDMA based...so each "circuit" is assigned a time slice on the tower and a guaranteed swathe of bandwidth to use. The upside is that the bitrate is constant for constant quality (assuming you aren't losing packets). The downside is that there is a very definite "falling off the cliff" effect on the number of clients a tower can service since each one needs a dedicated time slice.

3G is CDMA based...so as more clients connect to the tower, the tower can assign a dynamically shrinking bitrate to all in order to share the available bandwidth and "fail gracefully" as the tower gets more and more clients which leads to more efficient use of bandwidth overall and can handle more clients in general. So, on busy towers, 3G clients will have a downgraded bitrate which will affect the perceived voice quality, but are less likely to get a "service busy" error.

Re: 3G off fixed my battery life!
 

I tend to think the issue is not so much 2g vs 3g, but the drain in switching/looking for 3g.

At my home in San Diego, my 2g signal is weak, but I have a pretty strong 3g signal (tmobile).

I get better battery life on 3g only than dual mode. Can't say if I'd get better battery life on 2g only though.

Re: 3G off fixed my battery life!
 

No networks use a single frequency for both. In AT&T's case, both frequency's happen to be in same *band* but are different frequencies. However, point taken that the different bands could use more physical resources (ie multiple radios) whereas a single band send/receive could get away with one..thus there is a power difference. That said, it's the transmitting that kills it more than anything (and it's transmitting while searching for a 3G signal as it has to register with a prospective tower). That's why turning off 3G is a battery saver in areas that cause it to constantly hunt for a new lock...and why turning off applications that transmit a lot is also a battery saver (eg Skype)..and why doing both is a really really big battery saver ;)

Re: 3G off fixed my battery life!
 

That's exactly what I have: a T-mobile data only plan, $39.95 a month (actually a little less due to a corporate discount). I have disabled 3G for better battery life.

Have you tested Skype on 2.5G? I have not tested it yet, but EDGE speeds should be enough for at least some forms of VoIP.