Database Develop

Galaxy Tab 'forgets' to reconnect to wifi?

I've notice a slight issue with my Tab. Sometimes, when it's been left sleeping for a while it 'forgets' to go back to wifi and stays on 3G connectivity, even though I'm sitting right next to the wlan router. If I check the wifi settings, the network is listed as 'out of range'. If I turn off wifi and then back on again, it connects without any trouble.
Has anyone else noticed this behaviour?

This is most certainly a router issue. The simplest fix is to reserve ip up for the tab and use fixed up settings.
I do this with all my LAN devices anyway because it adds a little security, as well as better interconnectivity.
But really you should investigate the router.

Somehow I doubt that. I'm using DD-WRT running on the classic LinkSys WRT54G, a combo that is widely famed for it reliability. I also have the router set up to serve a fixed IP to the Galaxy Tab, determined by the MAC address of the Tabs wireless interface.
I'm also running quite a few other wifi devices with the router, including three other android devices (G1, milestone, nook), and none of them show the same behavior.

I see... how many of your other devices use a dual band revision n radio? In my experience this can be a headache, even for custom firmware.

None, as far as I know. I'm not entirely sure about my wifes Motorola Milestone, but I'm pretty sure the G1 and the nook use bog standard 802.11g. I think you're right that this might be the problem. Any ideas how to improve that? It's not really a problem, just a slight blemish on the otherwise awesome experience.

This is well known android behavior making wi-fi sleep to preserver battery.
There are some mods to keep it on when sleeping.

Khisha said:
This is well known android behavior making wi-fi sleep to preserver battery.
There are some mods to keep it on when sleeping.
Click to expand...
Click to collapse
Yes, and there's nothing wrong with that. I certainly don't want wifi on all the time, I just want it to reconnect when it wakes up.

Ill look into your router tomorrow, but atm I'd say there wont be much you can do other than force g only on the router. This will stop the tab from sending crc/ plcp overhead on both bands. Crazy as it sounds, the tabs radio is actually interfering with itself in this scenario.

I just replaced my HTC HD2 with the Samsung Galaxy Tab and have the exact same problem. The HD easily picked up my work and home WiFi when I moved between them, but the Tab 'forgets' to reconnect after standby.

I'm having this problem too. Every morning I need to turn off the wifi, then immediately turn it back on, before it will reconnect. This is with an Asus WL520GC running DD-WRT.

Yes, seems to be a router/device compatibility issue.
My tab works fine in my uni network (and it has quite a few dark spots), all of my friend's networks but it intermittingly fails to reconnect to my home wlan. I have a sky router (sagem actually).
Sent from my HTC Vision using Tapatalk

I have seen this on various routers before and encountered it again last night.
There is a discussion on the cause here:
http://forum.xda-developers.com/showthread.php?t=839367&highlight=connect+wifi&page=3
It is due to the lease expiring from the access point and the device requesting the old IP with first sending a discovery message.
One work around - not the best - is to reboot the router. Then the Tab seems able to connect. Also I think if you connect ofter to the router you might not see this as the device will ask for a new lease.
Another - from the above referenced post - is to create a DHCP reservation for the Tab. This will ensure it gets the same IP address every time. I made this change to my router - so we will see.
Hope this helps.

Samsung Galaxy tab won't connect to WEP wireless
I am trying to get my Galaxy tab to connect to my HTC HD2 that is set up as a wi-fi hotspot.
My galaxy tab will connect to all WPA/WP2 networks but not the WEP. Please help.

mine does the same on a SMC Gateway (SMC8014WN) aswell as a D-Link Router (DIR-665)

I am going nuts here because of the same problem. Tab worked flawlessly for the last 4 months, found any router and had no wifi problems until recently. I have a D-Link DGL-4500 gaming router, and my dsl modem router also has a wifi connection. I suspect from the new firmware. Mine is a Euro model. I dont know why I upgraded from JK5 to JMG stock firmware, and wifi issues started. D-link's logs reports that it receives a deauth from the device and the connection ends... and never revives. Sometimes it happens 3-4 times in an hour, sometimes it stays connected for hours. I tried everything, static IP, delete dhcp list, etc. I have reset the device twice to factory defaults. Even then it disconnected the first minute I turned it on and set the wifi. So it should be a firmware issue. I realize that the wifi signal is also weaker now compared to the previous firmware. Congrats SAMSUNG! The Tab is consuming my data plan even when I am home. And I wonder how wifi only Tab is going to handle this problem. DOES ANYONE KNOW IF WE CAN DOWNGRADE FROM JMG?? Help is appreciated.

my tab does the same thing (so does my x10). But when I open my browser, or anything that needs wifi, it reconnects automatically, however the browser usually needs to be refreshed (retry).

elorimer said:
I'm having this problem too. Every morning I need to turn off the wifi, then immediately turn it back on, before it will reconnect. This is with an Asus WL520GC running DD-WRT.
Click to expand...
Click to collapse
exactly the same behaviour. Every morning, I'm connected to my router but nothing works. Turn-OFF->ON and it works again

I should have noticed Roto's entering line. See: http://forum.xda-developers.com/showthread.php?t=939360.
Since JMG has wifi isuues, I jumped onto JMI !

[Q] I9000 different Battery drain rate with different Routers?

I wonder if anyone else has noticed this oddity.....
I use my i9000 with three different wireless routers.
(1) Linksys WRT54G running latest DD-WRT
(2) O2 Thomson TG585-V7 (Wireless Box II)
(3) Belkin F5D7634-4A-H
I've done this testing multiple nights from midnight to 6am. No other apps running. The I9000 is fully charged by midnight.
With (Router 2) I will lose about 1% per hour overnight.
With (Router 3) I will lose about 3% per hour overnight.
But with (Router 1), I will lose (10 to 15%) per hour overnight.
All of the routers are running the same channel and default antenna power. I can't see any difference between the routers, power wise.
I am beginning to wonder if this disparity is responsible for some users having unpredictable battery drain with their Galaxys.
Has anyone come across an app that will let me log all of the wireless connection activity?

I believe that, as for 3g connection, a stronger and cleaner wifi signal reduces battery drain. If it is so it looks to me quite normal that a good quality router (cisco/linksys) gives better results than a cheap device..

I believe you may have mis-read the results. The Linksys gives the worst battery drain. Anywhere from 60 to 80% in six hours.
The O2 Thomson gives the best overall. That or I've mis-read your answer....

finally i found someone with (almost)the same problem as me!!
except i am experiencing the direct opposite - when im using the stock wrt54g my battery only drains 1-2% per hour, but when im using my main router, the dir 615, it can drain up to 10% per hour.
i did almost everything i could to reduce the battery drain with my dir 615 router but it just doesn't work! i removed the security password for the router and even changed the speed mode to wireless B + G only but still it still drains crazily! wtf?
i've searched high and low for this problem but no one else ever posted about this problem. i've even posted this issue on another forum but didn't get any solution.
the problem is my phone doesn't go to sleep ("time spent without sleeping" in battery history is always very high - like a few hours off from "time spent with screen on") whenever i am connected to my home router. BUT when i am using some other connection like one at public or at work the "time spent without sleeping" in battery history is very close to "time spent with screen on". so clearly something is preventing my phone from sleeping whenever i am at home. i just can't figure out what it is.
i posted this issue on hardwarezone as well. link is below
hxxp://forums.hardwarezone.com.sg/showthread.php?p=50910987
if anyone could help id be greatly appreciate it cuz i don't want to change my damn router just to fix this thing.
HELP! AND SORRY IF I AM HIJACKING!

My bad, I read your post too fast thinking the first drain % was about first router and so on. Still I belive connection "quality" (signal strenght & noise absence) does affect battery life.
Btw, assuming that connection configuration is the same (b/g/n, wpa, wpa2, wep or whatever), you should check somehow (even with a laptop, I think) what kind of differences the 3 router wifi signal have (in terms of S/N).

Interesting, I checked and my drain while connected to the router at home is appalling as well - I thought it was just the new firmware getting something wrong. Luckily I just got a new router so I'll try that out and see if there's any improvement.

Barkotron said:
Interesting, I checked and my drain while connected to the router at home is appalling as well - I thought it was just the new firmware getting something wrong. Luckily I just got a new router so I'll try that out and see if there's any improvement.
Click to expand...
Click to collapse
any news on the results? what are the models of the new and old routers?
Sent from my GT-I9000 using XDA App

salivaman said:
finally i found someone with (almost)the same problem as me!!
except i am experiencing the direct opposite - when im using the stock wrt54g my battery only drains 1-2% per hour, but when im using my main router, the dir 615, it can drain up to 10% per hour.
i did almost everything i could to reduce the battery drain with my dir 615 router but it just doesn't work! i removed the security password for the router and even changed the speed mode to wireless B + G only but still it still drains crazily! wtf?
Click to expand...
Click to collapse
Just a thought - the SSID isn't hidden on one of the routers, is it? I've known that to cause strange issues in other wifi situations...

Many routers, specially old ones, don't support the "power save" option that some laptops feature, in this case, probably SGS has problems when entering save mode on the routers which don't support the power saving feautre of the device.
Maybe setting your phones wifi to the never sleep policy might affect in your performance, try it out guys, I hope it helps.

hiroshige said:
Just a thought - the SSID isn't hidden on one of the routers, is it? I've known that to cause strange issues in other wifi situations...
Click to expand...
Click to collapse
SSID is not hidden on both routers.

gtluis said:
Many routers, specially old ones, don't support the "power save" option that some laptops feature, in this case, probably SGS has problems when entering save mode on the routers which don't support the power saving feautre of the device.
Maybe setting your phones wifi to the never sleep policy might affect in your performance, try it out guys, I hope it helps.
Click to expand...
Click to collapse
my results have been tested using the "never sleep" policy. i always have that turned on so that 3g won't be switched over when the screen is off.

Could be the Beacon Interval of the routers.
http://wireless-nets.blogspot.com/2008/07/beacon-interval-impacts-on-battery-life.html
http://www.technologyreview.com/printer_friendly_article.aspx?id=25651

I believe you may be onto something here. I researched Beacon Interval and DD-WRT (Router 1) and found multiple instances of people having connection, latency and speed issues with DD-WRT that were fixed by changing the Beacon Interval on the Access Point.
I will check out the Linksys router later today to see what the default Beacon Interval is set at and report back.

tc80tc80 said:
I wonder if anyone else has noticed this oddity.....
I use my i9000 with three different wireless routers.
(1) Linksys WRT54G running latest DD-WRT
(2) O2 Thomson TG585-V7 (Wireless Box II)
(3) Belkin F5D7634-4A-H
I've done this testing multiple nights from midnight to 6am. No other apps running. The I9000 is fully charged by midnight.
With (Router 2) I will lose about 1% per hour overnight.
With (Router 3) I will lose about 3% per hour overnight.
But with (Router 1), I will lose (10 to 15%) per hour overnight.
All of the routers are running the same channel and default antenna power. I can't see any difference between the routers, power wise.
I am beginning to wonder if this disparity is responsible for some users having unpredictable battery drain with their Galaxys.
Has anyone come across an app that will let me log all of the wireless connection activity?
Click to expand...
Click to collapse
Hi!
This is some interesting facts you have encountered, regarding an app to log wifi activities I would reccomend Shark together with Shark reader, not the native mode version of Shark as it doesn't work on the Galaxy. It's not an easy to use program but it should be able to tell you what goes on in the network of your device.
You are very welcome to present your findings in my YADB - Yet Another Battery Drain thread, hope it's ok that I post a link to this thread from mine.
If you or anyone else want to visit YABD, there is a link in my signature.

Although my phone is a Desire HD I need to share my experience with you guys.
I have the AirTies RT-204 router and since I started using my phone the battery life when wifi was always on had been horendous (about 5-10% per hour on idle).
However, about 5 days ago my router was restarted and my battery has been excellent from that point on (about 1% even less per hour on idle).
Last night the router has been reset again and the big battery drain has come back again.
What this tells me is that the model of a router is not the culprit for the big battery drain. It has something to do with the IP changing when restarting it. Now, I am not an expert on routers etc but I believe this seems as a logical assumption.
Could some of you having this problem try restarting your router and see if it helps? Remember that maybe it will not have an impact the first time you restart and you will have to do this multiple times.
If u have anyhting more on this please post your thoughts.
Thanks

Wifi drops out when not used ?

I am having some issues with my WiFi staying connected to my network. My NC is fully rooted with all current upgrades/tweeks. My network is very strong in my house, I have full reception bars in any room. I can connect to the network just fine and as long as I am using the Wifi on my NC the connection is solid. But if I stop web browsing and do some reading then go back to browse again, my Wifi connection on the NC is off. Or it is on but not connected. As soon as I hit connect or reconnect it is fine again.
Why would my Wifi stop like this ?? I have no problems with my LapTop and its network/Wifi connection.
Thanks for any tips or insight.

Mine does this too, after about 2-3 minutes of not surfing or stuff like that it kicks wifi off.

This is by design, to save battery life. You can install the Spare Parts app from Market to modify the WiFi Sleep Policy.

EugeneKay said:
This is by design, to save battery life. You can install the Spare Parts app from Market to modify the WiFi Sleep Policy.
Click to expand...
Click to collapse
Cheers !

Had that too, more probably a bug since they are fixing that with the 1.10 update -> http://www.barnesandnoble.com/u/noo...igLink-_-k244266-_-j12871747k244266-_-Primary
"NOOKcolor V1.0.1 improves Wi-Fi connectivity and the browser experience. "

mine didn't have this problem out of the box. i did notice this problem after applying a wifi update to allow connection to ad hoc networks (link below).
http://forum.xda-developers.com/showthread.php?t=868354

WIFI slow while cellular connection enabled

I did a search and only found one reference to this in a post. So dont flame on if I missed it.
I can connect to my network fine at home over the WiFi but if I leave the cellular connection on it is terribly slow. If I go into airplane mode and then turn on the WIFI separately its blazing fast. It appears the cellular wants to take priority over the WiFi. Has anyone else experienced this or found what causes it. Below are my phone specs and network.
HD7 with WiFi, Bluetooth, cellular enabled.
Netgear wireless N

I completely agree with this statement btw.
In my basement my "wifi" connection is HORRIBLY slow on my hd7. Many, and I repeat MANY times I feel as though i'm still using my 3G connection instead of the wifi as it should.
Just wanted to comment on this, i'll search later on, maybe i'll find something else.

just turn on cellular connection when you need it , and turn off when don't need.(when u have wifi nearby)

Thats what I do but it shouldn't work like that. There should be WiFi priority when available for data services.

If ur wifi signal is too weak , it can be so.

dougolupski said:
I did a search and only found one reference to this in a post. So dont flame on if I missed it.
I can connect to my network fine at home over the WiFi but if I leave the cellular connection on it is terribly slow. If I go into airplane mode and then turn on the WIFI separately its blazing fast. It appears the cellular wants to take priority over the WiFi. Has anyone else experienced this or found what causes it. Below are my phone specs and network.
HD7 with WiFi, Bluetooth, cellular enabled.
Netgear wireless N
Click to expand...
Click to collapse
I have the same phone as you, from TMOUS, and I have noticed the same effect, cellular over-riding the wifi, and I think that the cellular is just set as the default... and I think that is the way it is intended, by the carrier(s), because then we would use our minutes/data up quicker then otherwise... I have noticed when using wifi, and not on airplane mode, that minutes/data are consumed at a MUCH quicker rate, than when on wifi w/airplane mode on... and thanks for pointing this out, I may not have payed as much attention otherwise... I am leaving TMOUS, maybe going to Simple Mobile, or something like that, and I will be keeping a much closer eye on it now... right now, with no carrier, I am using my phone strictly on wifi and it is pretty damn fast, and I only have an 802.11G router, not an 802.11N router like yours... which only makes me want an N router even worse... I'll post any more info as it appears, and thanks again!...

@ artmodeler At work I can understand a week signal but not at my house. I am about 10 feet away from the router which is located on my desk. Also the connection manager in the settings is showing full bars.
@ mlongue1 Yeah it works amazingly fast on my WiFi under airplane mode. I use Super Tube for my you tube client and theres little if any pausing to buffer large videos. Not so much when the cellular connection is enabled.

Issues with wife's Turbo

My wife and I both have the Turbo on VZW (joint plan, etc). I generally perform any mods on my phone first, before doing the same to hers, so that I know what issues will happen and I can make sure the phone doesn't work any differently for her daily usage. So, aside from apps, we have the same phone in theory. Both phones are stock SU4TL-44, rooted, BL-unlocked (via Sunshine) states.
My wife's has been having rather poor battery life for the past many months. I can get a good 3.5+ hours of screen-on-time on my phone (as reported by GSam) but hers only gets like 1.5 hours on a good day. Her phone radio is what's reported as the largest load, so I started trying things there. We were both on the .49 radio (using the TWRP download by firstEncounter), so I thought maybe her phone doesn't like that radio, and put her back to the .44 radio. (Note, I have checked the hashes on these files, and they match. I also have used the same-exact files on both phones (via dropbox)... so it shouldn't be a radio/corruption issue.) Both
I'm not sure if the battery life has improved or not (only been a few days, but checking just now it looks like her max is now 2.5 hours in GSam, so that's a start I guess) but now another problem has come up - her phone keeps dropping the internet connection. Wifi appears to remain connected, but it shows an "!" which means it has lost internet connectivity. Checking the browser confirms that it is really lost for internet sites. (Next time, I plan to try going to the router IP and seeing if I can get to that, at least...) This drop happens sporadically, and doesn't self-repair... it is only fixed by disabling and then re-enabling Wifi. I "forgot" the wifi (2.4GHz, by the way), re-connected, and re-entered the password... this doesn't seem to fix the dropout either.
The wifi, itself, is working well. My Turbo has none of these issues, my work phone (Turbo2) doesn't appear to have issues, nor do our 2 laptops or wifi-Tivo... every other device works fine, just her phone has been giving issues.
Needless to say, the priority is to fix the dropping internet connectivity... if anyone can help me troubleshoot this further, I would appreciate it.
Longer term, I'd like to figure out the battery issues (health is reported as "good" by various battery apps... is there a way to see what the "real" capacity is, and not just "good/bad"?)... but the wifi is the primary issue. Part of me thinks of doing a factory reset (or maybe flashing SU4TL-49 and then re-rooting)... but I fear this may not fix anything.
Any help/ideas are appreciated. Thank you!
EDIT: One more difference - she has a Tile Gen2 along with the associated app. The app requires Bluetooth to be on, as it does some polling, I expect. I have turned this off for now (further testing) to see if it helps. She's had the Tile for a while, so it's not a new change... but I'm running out of ideas. Battery usage isn't significant, based on what's reported... but I thought maybe it has some effect on the wifi... I simply don't know, so I'm trying anything!

A little more info. I have left her bluetooth off for the past day, thinking that maybe Tile was the problem... it certainly seems to have helped the battery life (weird, since all the battery tools I've used don't seem to identify the app or BT as a large battery sink?)
Things were great for about 24 hours, but now the dreaded exclamation point is back. I tried getting to the router, but I get "ERR_ADDRESS_UNREACHABLE" from Chrome. Weird since I'm giving it an actual IP address (so no DNS should be involved). Phone has a valid IP address (same one it's had for a while now) and claims to have the interface "up" as well.
Any ideas, anyone?
EDIT: I see some UPNP activity in my router... I wonder if that has something to do with it. As a test, I have disabled UPNP to see if that helps (and what it breaks... which shouldn't be much, as I try to keep things explicitly configured)....

A further update in case others run into problems like this.... the issue may be caused by an interaction between my router and the bluetooth Tile app (which isn't on my phone but uses BT relatively often) - note that BT runs on the same 2.4GHz frequency as her wifi. I chose 2.4Ghz wifi (instead of 5Ghz) on her phone because it helps extend the range. Turning off BT on her phone seems to keep the connection stable and without issue... I have a little more testing to do to ensure it's the root cause before I consider it found.
There are a few potential solutions. One is to update the firmware on the router to a newer one which has an option to enable BT coexistence mode (disables some features in 2.4GHz wifi to improve compatibility). Another is to move her to 5GHz. I plan to test the coexistence mode, just to prove it's the problem... but my final solution will likely be to move her to 5GHz as the coexistence mode may reduce performance on 2.4GHz.

schwinn8 said:
A further update in case others run into problems like this.... the issue may be caused by an interaction between my router and the bluetooth Tile app (which isn't on my phone but uses BT relatively often) - note that BT runs on the same 2.4GHz frequency as her wifi. I chose 2.4Ghz wifi (instead of 5Ghz) on her phone because it helps extend the range. Turning off BT on her phone seems to keep the connection stable and without issue... I have a little more testing to do to ensure it's the root cause before I consider it found.
Click to expand...
Click to collapse
What about changing Wi-Fi channels on the router?
I also disable 5GHz on both our Quarks because the 5GHz range is shorter. I set our phones to ONLY connect to 2.4GHz and that's what I use for Wi-Fi router too (even routers with dual bands, I disable the 5GHz band).
But you can change 2.4GHz Wi-Fi router channels to mitigate interference, right?
http://www.goldtouch.com/stop-bluetooth-interference-messing-devices/
How to Stop Bluetooth Interference From Messing With Your Other Devices
Change Router Channel: If you have an Apple router and you’re constantly getting interference with your WiFi, try rebooting it. Upon restart, the station will search for a new channel — specifically, a different channel than the one your Bluetooth devices are using to communicate. If you don’t have an Apple router, you may need to instead go into your router settings and try changing the channel manually. Experiment with different channels to see which one works best.
Click to expand...
Click to collapse
I don't use anything Apple -- I just quoted from that article because it suggested what I was suggesting, changing Wi-Fi channels...

Yeah, I kept testing and found that the BT wasn't the only issue (may have been part of it, but it still dropped internet after a day or two even when BT was off).
Like you said, it's probably a 2.4GHz interference issue... and since I'm in an apartment building the spectrum is rather crowded. Plus, if anyone else bought a new phone/monitor/microwave/router that could be causing the issue, too. Bottom line, there's too much out of my control, so I switched her back onto 5GHz and the problem seems to have gone away (at least for the past few days)... so I'll leave it at that. I can't solve the entire area's problem, after all!
I am on the "cleanest" channel I can find, but that's only based on seeing other routers (via Wifi Analyzer)... interference won't be "seen" there, so we can only guess on those issues.
Bottom line, switching her phone to 5GHz is good enough for now, and solves the issue. I'll flip her phone back to the 49 radio as well.
In fact, this might have also helped her battery issue - when the phone lost internet, it would sit there and suck down power for "phone radio" doing who-knows-what. I don't see why it should do that, but it really killed the battery on one of the days. Putting her on 5Ghz prevents the loss of internet, and the battery drain from that, too... so that's better. Still, she gets much less SOT than I do on my phone, and she uses it less than I do... maybe the battery just needs to be replaced after all.
I wish there was a way to see what the "real capacity" is of the battery, instead of just assuming that 100% = original capacity (which we know it won't be). Do you know of a way to get that info?