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Why LTE (4G) drains battery faster than 2G/3G?


#1

Hello experts.

When i access the Settings for my phone, in the ‘Preferred Network Type’ i see a ‘4G (recommended)’ option.

But if I use this option (and put my phone in LTE), it drains a lot of battery. It is really annoying.

I want to use 4G because of its great speed (vs 3G), unfortunately it drains battery much faster than 3G.

So, i would like to know:Why LTE has such high power comsumption compared to 3G/2G? Is there any settings that i can configure to avoid this huge problem? Or am i bound to use 3G forever?

BR,
Rafael.


#2

Hello @rafaeldamasio

Yes, you’re right, LTE uses more energy from battery, as you can see in the ‘Battery drain tests (3G vs 4G vs screen vs idle)’ http://androidforums.com/threads/battery-drain-tests-3g-vs-4g-vs-screen-vs-idle.502036/

In the author conclusions, there are also a lot of considerations to take into account.

From a more technical point of view, we can list some other reasons:

LTE networks uses 2G/3G for voice (unless we have VoLTE enabled). So it should remain in constant contact with those legacy networks to make/receive vocie calls/text messages when needed.

LTE devices periodically do searches to determine which cell it should be. With a typical combination 2G/3G/4G in different bands, it have a lot of networks to go.

LTE are not fully deployed everywhere, so chances are you’re more distant from the cell, and needs boost you transmission power.

LTE devices uses MIMO for multiple parallel transmissions. So, we have 2 RX/TX antennas (each with its own PA).

LTE technology has more complex - QAM and OFDM(A) requires more computing power/processors for modulating/demodulating the RF.

BR,
Carlos


#3

Hello @rafaeldamasio,

The handset makers and network vendors are doing a big ‘task force’, a ‘work in progress’ to maximize the power efficiency of LTE devices (and avoid battery drastic drain). These efforts are very important, mainly because future technologies like LTE-Advanced will also have an even bigger hunger for power.

One big advance was the development of Envelope Tracking technology, that help a lot in this battle (although many improvements ‘needs to’ and ‘can be’ still made).

Here you can find an explanation of Envelope Tracking:
http://www.telecomhall.com/what-is-envelope-tracking.aspx

BR,
Leo


#4

LTE is actually more battery efficient. Where you run into problems is many carriers only upgrade a certain number of their towers to LTE. That means a lot of the time your signal is lower than if you were on [3G] mode. Lower signal means your phone has to pump more power into the radio for it to keep a live signal. Generally there isn’t a huge amount of difference though so it just depends on if you want that extra couple percent. I personally would just leave it on LTE. The extra speed is worth any possible minor battery drain.