Battery life on GPRS, 3G and 4G

[kiddingguy]

Just a question... when 3G/4G is enabled in the settings of iOS 7, which technology is consuming more battery power: GPRS, 3G or 4G?

I know the speed difference can be huge, but how does this affect battery life? I can imagine that it takes longer on GPRS to surf the web, download apps and -thus?- requiring more battery power in the long run than a shorter amount of time (less battery) on 3G/4G.

And is there a difference in standby mode?

As well as the bullets/percentage network coverage? Is more better for your battery life?

[Roger H. Veteran]

In usage LTE uses more power. LTE because it's not as optimized yet will suck use more power in the short bursts and as a result cause the CPUs to spike as well too to process all that data right away. Also because of the bandwidth requirements for LTE (5Mhz chunks vs 200Khz chunks for 3G) it requires more power as well to monitor that.

During idle, 3G uses more since LTE now is a DATA only application. They are working on VoLTE (Voice over LTE) but it murders battery life. Dropping back to 2G for voice uses less power.

Obviously the more solid network coverage is the better your signal will be which means your phone doesn't have to power up the amplifiers all the way to send a signal back to the tower. So if we built all brand new LTE/UMTS/GSM networks today with GSM being less propogated, it would be the worse regarding battery life. We have the opposite today because GSM is the oldest so it's been built out to cover everything and everywhere (even though they are slowly stripping it away to shut it down by 2017).

This is why we still have the same or less battery life in all these years. All the tech improves but just battery doesn't improve enough to compensate for the higher demands to give us MORE than we had before. We basically end up with the same amount of battery life even if we do much more now on our devices vs 5yrs ago.

[kiddingguy]

Thx for the explanation!

[kiddingguy]

Real life question on battery usage. What uses more power:

1) 1-2 bars (of 5 bars) on GPRS vs.

2) 3-4 bars (of 5 bars) on 3G

3) 3-4 bars (of 5 bars) on GPRS vs.

4) 1-2 bars (of 5 bars) on 3G

[Nick H. Supervisor]

Explanation.

That was very fascinating to read, thanks for the information. If it weren't for the follow-up question, I'd have gone ahead and marked this as solved.

[Roger H. Veteran]

Real life question on battery usage. What uses more power:

1) 1-2 bars (of 5 bars) on GPRS vs.

2) 3-4 bars (of 5 bars) on 3G

3) 3-4 bars (of 5 bars) on GPRS vs.

4) 1-2 bars (of 5 bars) on 3G

I would attempt to answer but since bars are meaningless because they don't show SNR (Signal to noise ratio) and that I don't have specifics of hardware used in any particular phone, my answers would be just as meaningless.

What bars don't show is quality of signal, they only show signal strength. So you can have 4 bars but not able to make a call (think AT&T in NYC/San Francisco during early iPhone 3GS days). The phone was showing it had a strong signal but because of noise the amplifiers had to jack up power to fight through the noise on the channel (because of all the other idle or active phones). As a result with 4 bars you could still easily get crappy 3G battery life vs 1-2bars on LTE or GSM.

Then there is ASU to take into consideration.

So there's plenty to go into it. One phone may behave better with 3G as well compared to 2G depending on antenna design as well (some just more efficient to certain frequencies). The iPhone (original) famously lacked 3G because they deemed 3G chipsets at the time not mature enough. While that's not the case now they still aren't created equally.