EVO LTE drops wifi when hibernating?

[smorcy11]

So I've noticed that when my phone screen is turned off for a while, that when I turn it back on and unlock it, it usually has ended the wifi connection, or at least the screen says it does, and then it automatically reconnects after a few seconds.

 

Anyone know why it does this? I would think it would be more economical for the battery to just remain connected to wifi.

[WiWavelength]

Anyone know why it does this? I would think it would be more economical for the battery to just remain connected to wifi.

 

Nope, just the opposite. It does so to conserve battery power.

 

AJ

[smorcy11]

Nope, just the opposite. It does so to conserve battery power.

 

AJ

 

So, it takes MORE battery to stay connected to wifi, than to connect to a low 3g signal?

[WiWavelength]

So, it takes MORE battery to stay connected to wifi, than to connect to a low 3g signal?

 

Wi-Fi or not, unless you enable airplane mode, you stay connected to the mobile network. So, no, that battery drain is basically the same, regardless.

 

AJ

[smorcy11]

Wi-Fi or not, unless you enable airplane mode, you stay connected to the mobile network. So, no, that battery drain is basically the same, regardless.

 

AJ

 

Interesting... thanks for the info

[koiulpoi]

Check the advanced settings for Wi-Fi, to see if it's disabling it during sleep.

 

Personally, I noticed (back when I had the EVO LTE) that it would drop WiFi while sleeping no matter what, reconnecting every so often. It lead to delayed notifications while connected.

 

And AJ, what do you say about Sprint's claims that WiFi improves battery life? They claim certain devices can see upwards of 50-100% improvement in battery life during heavy usage, compared to using EV-DO. Anecdotally, I have noticed similar findings.

[Dkoellerwx]

Check the advanced settings for Wi-Fi, to see if it's disabling it during sleep.

 

Personally, I noticed (back when I had the EVO LTE) that it would drop WiFi while sleeping no matter what, reconnecting every so often. It lead to delayed notifications while connected.

 

And AJ, what do you say about Sprint's claims that WiFi improves battery life? They claim certain devices can see upwards of 50-100% improvement in battery life during heavy usage, compared to using EV-DO. Anecdotally, I have noticed similar findings.

 

Compared to EVDO, yes. But your phone is always connected to 1x, so whether or not it's connected to WiFi, it's still using a mobile network.

[koiulpoi]

Compared to EVDO, yes. But your phone is always connected to 1x, so whether or not it's connected to WiFi, it's still using a mobile network.

Oh, naturally, that's why I said EV-DO and not "mobile network". AJ said that battery drain was the same on WiFi vs low-signal EV-DO, which is why I questioned it.

[Dkoellerwx]

Oh, naturally, that's why I said EV-DO and not "mobile network". AJ said that battery drain was the same on WiFi vs low-signal EV-DO, which is why I questioned it.

 

A low 3G signal, still means low 1x, so it would drain the battery.

 

I see AJ lurking... better explanation likely pending.

[WiWavelength]

Oh, naturally, that's why I said EV-DO and not "mobile network". AJ said that battery drain was the same on WiFi vs low-signal EV-DO, which is why I questioned it.

 

No, I said "mobile network." I never said EV-DO. Different handsets seem to handle Wi-Fi vs EV-DO differently. My experience has been that SVDO capable handsets shut down EV-DO when connected to Wi-Fi, but non SVDO handsets do not. However, do not quote me on that.

 

Regardless, we are talking about power management during a hibernation period, not during "heavy usage." If you are not using the handset for long periods of time -- say, you are asleep -- then you want it to shut down as much connectivity and conserve as much power as possible because, after all, you are not using the handset. Timely notifications do not matter until you actually start to use the handset again.

 

AJ

[MacinJosh]

No, I said "mobile network." I never said EV-DO. Different handsets seem to handle Wi-Fi vs EV-DO differently. My experience has been that SVDO capable handsets shut down EV-DO when connected to Wi-Fi, but non SVDO handsets do not. However, do not quote me on that.

 

Regardless, we are talking about power management during a hibernation period, not during "heavy usage." If you are not using the handset for long periods of time -- say, you are asleep -- then you want it to shut down as much connectivity and conserve as much power as possible because, after all, you are not using the handset. Timely notifications do not matter until you actually start to use the handset again.

 

AJ

 

The Galaxy Nexus also disconnects EVDO when on Wi-Fi.

 

[WiWavelength]

The Galaxy Nexus also disconnects EVDO when on Wi-Fi.

 

Possibly. But I would not take the regular old user accessible status screen as gospel. I would have to see the EV-DO engineering screen to know for certain.

 

AJ

[MacinJosh]

Possibly. But I would not take the regular old user accessible status screen as gospel. I would have to see the EV-DO engineering screen to know for certain.

 

AJ

 

 

I'm going to say I was wrong. But you tell me for sure.

[koiulpoi]

Ah, went back and glanced at that again. Yes, you did say mobile network.

 

What should one be looking for in the engineering screens to determine if EV-DO has been disconnected? I have access to an S3, a Note II, a Photon Q, an Optimus G, an iPhone 4S, and an iPhone 5. I'll check 'em all!

 

Edit: And, at any rate, the lack of "timely notifications" on the EVO LTE was actually one of the most annoying parts of it to me. While connected to WiFi, all notifications would be delayed by upwards of 10 minutes. As I use Google Voice for SMS, this got rather annoying quickly. The nice side was the great battery life due to the phone almost instantly dropping in to Deep Sleep...

[WiWavelength]

I'm going to say I was wrong. But you tell me for sure.

 

Yep, you were wrong.

 

 

AJ

[MacinJosh]

Yep, you were wrong.

 

 

AJ

 

It wouldn't be the first time. Thanks for correcting me.

[WiWavelength]

While the EVO LTE is connected to Wi-Fi, here is the EV-DO engineering screen:

 

 

Note the difference? The Galaxy Nexus may be disconnected, but it continues to monitor the EV-DO carrier. The EVO LTE does not. I surmise that is due to SVDO, but I am not sure.

 

AJ

[koiulpoi]

Odd, the EVO LTE I just checked is in "State 2 = Idle".

 

The Note II, SIII, Photon Q, and Optimus G all showed various non-zero connection numbers and non-disconnected states in the EVDO Engineering screens. All are connected to WiFi.

[WiWavelength]

You know what? Scratch that. I forgot that I also had LTE signal. It was LTE, not Wi-Fi, that fully shut down EV-DO.

 

Now, with the EVO LTE set to CDMA1X/EV-DO only and connected to Wi-Fi, here is the EV-DO engineering screen:

 

 

AJ

[WiWavelength]

Nevertheless, the above actually furthers my point that shutting down Wi-Fi during long periods of hibernation is a power conservation measure because the handset continues to monitor to the mobile network regardless of Wi-Fi state.

 

AJ

[koiulpoi]

Nevertheless, the above actually furthers my point that shutting down Wi-Fi during long periods of hibernation is a power conservation measure because the handset continues to monitor to the mobile network regardless of Wi-Fi state.

 

AJ

This is super interesting to me, by the way. Sadly, I do not have LTE at our location (tower is in progress!), so I can't see if LTE shuts down EVDO on other devices.

 

Interestingly, the iPhone 4S and 5 appear to shut down EVDO completely while connected to WiFi. Engineering screens for EVDO are blank or zeroed out, while 1X stays connected.

 

Also, I had no idea that you used the EVO LTE. You apparently use a "N/A".

 

That being said, I suppose I cannot comment further, as I have no idea the average power usage of e.g. a low-signal active EV-DO data session, versus authenticating and connecting to WiFi. It does make sense to power as few radios as possible, and yet...

[WiWavelength]

This is super interesting to me, by the way. Sadly, I do not have LTE at our location (tower is in progress!), so I can't see if LTE shuts down EVDO on other devices.

 

Yes, I suppose this comes as no shock, but this is all interesting to me, too. And I have had to figure out a lot on the fly the last nine months as LTE, SVDO, and SVLTE devices have become available.

 

What I have learned is this: any device in which EV-DO and LTE share a path -- and I believe this covers all SVDO capable devices that we have detailed in our series of articles -- will be able to operate on either EV-DO or LTE, exclusive. In other words, if EV-DO is active, then LTE is shut down and vice versa.

 

The Galaxy Nexus could be another case, however. For better and mostly for worse, it has two separate CDMA1X/EV-DO and LTE chipsets. So, it might be able to do EV-DO and LTE at the same time, but I doubt it.

 

AJ

[irev210]

My experience with the EVO is at night it shuts off EVDO, LTE, and WIFI and stops serving data unless you power on the phone.

 

Phone calls still come through just fine, as the 1x network is still active, but is not used for data.

 

It's an awesome power saving feature, I love it. Sometimes it's annoying when you are waiting for an email or a text and your phone is hibernating but that rarely happened to me.

[puch96]

..interesting... I believe my EVO LTE will still get notifications (like email etc) while in sleep (hybernating) overnight....

When I wake up the phone in the morning, I can actually see in the battery usage status that the phone wakes up every now and then, and probably wakes up network data connection, downloads and email, etc, then goes back down to sleep...and I can actually see email message pending as soon as I push the power button....

 

??

[kckid]

There is a setting Keep Wi-Fi on during sleep. It is in the advanced menu of the Wi-Fi settings. Mine was set to never and I've changed it to Always.