Turn wifi down to 10mW
 

Hi guys it looks like I need your help again, i heard people saying that if you Turn wifi down to 10mW the battery should last longer, the problem is I really cant find where I could do that, could any one post step by step how to do that please.

And i got another question some people been saying after you use wi-fi there is a bug which is going to drain your batter if you doing restart your phone is this true? and also if it is do you have to restart it, or could go to offline mode then back to the normal mode ?

Thanks :)

Re: Turn wifi down to 10mW
 

Settings -> internet connection -> any Wi-Fi connection -> edit -> next ... advanced just before clicking finished. There you can find the power setting on 'Other' tab.

As for the bug. Some people have problem with Wi-Fi usage triggering battery drainage bug. Offline mode won't help. Only reboot helps in my case. For more info, see:
http://talk.maemo.org/showthread.php?t=36438

Re: Turn wifi down to 10mW
 

Thanks mate

Re: Turn wifi down to 10mW
 

is there any disadvantage of turning it down to 10mW ?

Re: Turn wifi down to 10mW
 

You won't have the range you'd have with it at full power (100mw?). That means you'll have to get closer to the WiFi router you're bouncing off of.

Re: Turn wifi down to 10mW
 

For the earlier devices it was said (from Nokia IIRC) that the 10mW setting wouldn't really make any difference for the power consumption, because the data is sent in bursts anyway. The reason there's a 10mW setting is because of legal issues in certain countries (where only 10mW is allowed).

EDIT: Maybe I should add that with the lower setting you risk that your wi-fi connection negotiates a lower data rate (you may be aware of the fact that a wi-fi connection can select different data rates due to signal strenght and quality, e.g. 54/22/11/5/2 Mb/s). So, the lower effect may force a lower data rate, which means longer data bursts and thus more battery usage. Even when taking into account the lower TX effect.

Re: Turn wifi down to 10mW
 

I turned it down to 10mW as soon as i saw the setting on the phone was available, never had connection or speed problems with my home wi-fi.. skype and browsning seems just as smooth as with 100mW settings.

And battery lasts alot better since i changed to 10mW

Re: Turn wifi down to 10mW
 

Well, for a little calculation... The power usage of the pure transmission power of the Wi-Fi... Considering the change from 100 mW to 10 mW is 90 mW, and the nominal battery voltage is 3.7 V (varies from 4.2 at fully charged to around 3 V when empty). So, 90 mW will on average take 90 mW / 3.7 V = 24 mA. Given the battery real full capacity is about 1260 mAh when new, this gives a time of a bit over 2 days. Of course everything else piles up, so if a random browsing etc on 100 mW Wi-Fi uses the full battery down in 8 hours of active time, it uses about 160 mA. So, in ideal case that the Wi-Fi were transmitting at 100 mW continuously, which probably isn't the case ever, you might increase the time to 9 hours. Or perhaps if you transfer data at full speed on Wi-Fi it will use that. But then the whole thing will probably use much more battery in any case lowered the real benefit of lower transmission power in ideal conditions to more like half an hour.

The extra consumption of using 100 mW transmission power on Wi-Fi is quite small in the worst case scenario of continuous full power usage. And while it may cause lowering of signal quality when further away from the router etc. Those might account to lower transfer rates and more usage elsewhere on longer bursts etc. All in all, you might as well be losing battery time with 10 mW change in addition to possible problems with Wi-Fi connection alltogether and likely lower transfer speeds unless you are close to the Wi-Fi router.

As of now with the Wi-Fi bug I am experiencing (using about 180 mA no matter if Wi-Fi is on or off after having used it even once - only to go back to normal with reboot) there is no way for me to test the real outcome of the settings. And at least for that bug, there is no effect for that setting.

Re: Turn wifi down to 10mW
 

The wi-fi chip isn't transmitting continously, quite the opposite. It's not like it's transmitting just because you're connected. It makes no sense to do that kind of calculation.

That is with a normally functioning setup. However, the problem you have reported (that the wi-fi chip consumes lots of power after disconnect) is not normal behaviour and a very interesting possible cause of battery drain. If confirmed, it should be possible to fix by a firmware upgrade.

When that problem has been fixed I for one won't bother with dropping my TX power to 10mW. It makes no difference on the N800 (except making things worse in some cases), there's no reason it should be needed on a fully functional N900 either.

Re: Turn wifi down to 10mW
 

cool, I used lots of nseries device, all has this setting.
I have been never thought N900 has this too! :-)

Re: Turn wifi down to 10mW
 

Yes, what TA-t3 said. This is a regulatory setting only!

Setting you WiFi to 10mW will not measurably improve your battery life!

In certain situations it may actually reduce it. :)

Re: Turn wifi down to 10mW
 

Thats weird, first day i got it, i managed to go from full battery to half in like 1-2 hours. Now since i switched to 10mW.. i hardly notice any battery drain at all...

Re: Turn wifi down to 10mW
 

Okay, so some people are saying it shouldn't matter, some people say it does.
a) Whom do I trust?
b) Would the people who say it shouldn't matter explain why it does seem to matter substantially for some people?

Re: Turn wifi down to 10mW
 

Try it for yourself? The power saving might also be affected by the wlan acces point people are using and it's settings. So different effects to different people.

Re: Turn wifi down to 10mW
 

what does 10mw-wifi means in real life? how far is "too far" on this setting?

for example, when i'm in my room, the router is around 10-12 meters away from me, in the next room.
will it still connect?

Re: Turn wifi down to 10mW
 

The N900, like the N810 before it, has a great WiFi radio and seems to connect at greater distances than my other WiFi devices. But just try it and see if it works for you.

Regarding the power setting, I seem to get my best battery life on 10mW with the intermediate power saving setting. If I use 10mW and maximum power saving, it discharges the battery quickly (oddly enough).

But WiFi depends on your device AND your WiFi router, so each person's optimum solution may be different.

Regards,
Roger

Re: Turn wifi down to 10mW
 

Yes, but you must not forget to take into account the problem user Phantasm reported: It looks like the wi-fi chip may be left in a weird mode after you disconnect. There may be other problems too for all we know. All this could make the 10mW/100mW setting affect the battery drain. But with a proper functioning wi-fi chip it shouldn't. So, all we have to do is wait for a firmware fix for this, and then we can go back to proper 100mW (except in countries which must use 10mW).

Re: Turn wifi down to 10mW
 

It depends what your walls are made of and how much loss there is in them. However, on the basis that the construction of your wall isn't changing, its down to the link budget. 10mW is 10dB less than 100mW. 6dB less signal will halve your range. With 12dB less, the range will be 1/4 of the original range.

So my guess is that with all else being equal, the maximum range with 10mW will be a little bit more than one quarter of the range with 100mW.

Re: Turn wifi down to 10mW
 

I would trust the people saying that it's a regulatory issue. Good WiFi hardware will adapted their transmission power as the current situation warrants. The battery life and WIFI problem which plagues somebut not all people seems to be depends on the Access Points that people are using. And also it seems to be a firmware bug which prevents the WIFI in teh N900 from gracefully loosing contect with access points.

At work we use very highend Cisco WIFI access points. I can stay connected with e-mail, SIP and IM connections running all day with very little power drain. At home, I use a lowend Linksys access point. Last night I got bit by WIFI/batter problem. I had an almost fully charged battery. I less the E-mail app running before I went to bed. My battery was drained in only a few hours. My phone powering down woke me out of a sound sleep. :mad: (Probalby going to upgrade my Access Point to something decent running a Linux image :) ).

Re: Turn wifi down to 10mW
 

ok.. so you convinced me i might have been mistaken when i saw wi-fi at 100mW drain my battery.. so i switched back to that... in 40min my battery dropped 30%!!! switched it back to 10mW and it haven't dropped since.. thats 30min. ago now...

theres no doubt that 100mW setting kills my battery.. fast. i have never seen my battery go down so fast in the week i had this phone. and i spent alot of time on wi-fi and on 3G/edge.

Re: Turn wifi down to 10mW
 

you meant setting the Wifi signal strength on the router save your n900 battery? that is insanely busted. How can wifi signal strength effect your battery power? I dont get it lol..

Please explain more. I'll try it out when mine arrives

Re: Turn wifi down to 10mW
 

I'm going to try cutting down to 10mw. I'm sure it makes a difference. The other thing is the option to connect whenever wi-fi is available option. This will cause the N900 to search every few minutes ( you can set the rate) for a wi-fi network. This in my opinion, similar to cell tower searches (*) cause significant battery drains. I noticed that today. I put off the option, and the battery lasted a lot longer. Now I will try with the 10mw option and post when/if I notice a difference.

* - Cell-tower search. I have noticed this with different phones. When you are in an area with no phone network connectivity, I have noticed that the battery drains in a matter of hours. Upon searching on the issue I found that phones tend to increase power to search and connect to a network. When there are no networks around, it continues searching every few minutes. This causes rapid power drains even though you're not even talking or using the cellphone.

I suspect its similar with Wi-Fi searches. So the solution I think would be to simply turn it off and choose your network (Carrier or Wifi) when you need it.

Re: Turn wifi down to 10mW
 

Its not a router setting. you can set 100mW/10mW on your n900.. thats what i'm talking about anyway.

Re: Turn wifi down to 10mW
 

All those arguing why, despite what some of us says, 10mW does seem to make a difference: Please read the thread better! We already know (from another poster) that there's currently a bug in the N900 which would make this a difference (wi-fi doesn't shut down properly).

So, for now, if the 10mW setting does make a difference to your battery time, feel free to use that setting. Nobody will call you names. However, when this bug gets fixed you would be better off setting it back to 100mW. See http://talk.maemo.org/showpost.php?p...3&postcount=18 above.

Re: Turn wifi down to 10mW
 

3dB is a factor 2
6dB is a factor 4
10dB is a factor 10

In radio we define that 6dB is one 'S' point, doubling the 'range'.

And yes, of course, if you lower the output power by a factor 10, the amount of power needed to generate that output is also lower (not by a factor of 10, as it depends on how the amplifier works etc).

PH7Wim

Re: Turn wifi down to 10mW
 

Any prove ?

Re: Turn wifi down to 10mW
 

Exactly the same test result !

Agree with you !

Re: Turn wifi down to 10mW
 

holy macaroni! tried the 10mw and yes it does make the battery last longer! with wifi enabled and email set to check every 15 mins, after 7 hrs i with 100mW i had 1 bar left. using 10mW same condition only 1 bar was consumed.

Re: Turn wifi down to 10mW
 

Most 802.11 devices use between 1 & 100 mW of power

1 mW(milliwatt) = 0.001 Watt
10mW = 0.01W
100mW = 0.1W

http://en.wikipedia.org/wiki/DBm

Re: Turn wifi down to 10mW
 

Can you reproduce it? File that on the bug report.

I personally cannot reproduce any of the Wi-Fi bugs, and my battery lasts around 4 days (with or without 100mW which as many people have said it's very much useless to idle times). Note that the biggest improvements in Wi-Fi battery life can usually be accomplished by selecting a proper AP... or careful configuration of the router, not the N900.

Re: Turn wifi down to 10mW
 

can we have the ideal router configuration, please?

Re: Turn wifi down to 10mW
 

4 DAYS OF USE !!?!??!!?!?!? WAT R U SMOKIN??? oh, thats right im smashed

Re: Turn wifi down to 10mW
 

I dont have any pics to show but if im near the router, or has strong signal, i have less battery consumption

Re: Turn wifi down to 10mW
 

im only ever within 10m of my router, never get 4 days use

OMG, Ill swap you N900'z

XD

Re: Turn wifi down to 10mW
 

Of idling, with Wi-Fi on, yes.

Re: Turn wifi down to 10mW
 

In my experience, the WiFi module works as intended but the applications are not up to par.

I also have automatic updates on my IMAP email account and the one night that our email server was having problems, I ended up with an empty battery because the client was spending all its time in the CPU trying to get what it couldn't get.

And when it comes to kernel modules, if there really is a bug in the WiFi kernel module that causes this, unloading and loading it should take care of most problems.

Re: Turn wifi down to 10mW
 

haha
lol
go check the transfer speed..
i got around about 25kbps with 10mw
and the modem is in my room
unless ure willing to sit on the modem while surfing, bad idea
besides, even with wifi disconnected, my mobile jus lasts 24 hours batters with rare use :S

edit : titans default kernel with 500 - 805
*500 undervolt to 33*