WiFi mysteries resolved once and for all — Power saving is clearly the culprit!


kaitosan

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Now I checked at my workplace on the TP-LINK router before mentioned, with power saving off (from Pandora System Info GUI!). The only change I noticed the connection speed went up from 5,5Mbit/s to 54Mbit/sec as for the Sys Info screen stated. But for anything else it didn't do a thing. Ping still fails ("Destination host ureachable...") to the wifi point i connect to. Heck it even gets the IP from the DHCP server what runs on the same router, but afaik this is a different story due to different protocols and bandwith usage... On the sys info's Network screen I do see some traffic up/down, but i think those are only little packets trying to desperately extablish connection. Hmm maybe I do some logging and post it here. See you!
 

kaitosan

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Breaking News! I tried to connect to a different router (works as WiFi AP) at work and SUPRISE! It WORKS FLAWLESSLY! I did ping and upgraded the packages from PNDStore, during this I checked SysInfo Network screen and power saving was ON all the time. Bit rate varied from 1Mb/s to 54Mb/s and also the ping response time went from 18ms to 4-500ms. Aside from some sudden stops, which were about 1-2 sec but happened several times as data was written to SD, it worked! I also would like to check net speed but speedtest needed the newest flash plugin in Firefox (seems i have to install the 11.1.. ).

JFYI the router it worked on was the following type:

 TP-LINK TL-WR740N Ver.: 4.2 (S/N: 11979209098)

 Stock Firmware, DHCP off

 It has 4 other clients connected to it through wifi(aside from my Pandora)

That's all for now! If I happen to know anything new I'll post it here.

I already ordered a WiFi dongle :p (checked up in compatibility list!)

Thanks!
 

PowerGod

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@kaitosan: as far as I see from your description, you have exactly the issue I have, and the problem is not related to the firmware, but to the wifi load the router is processing.

If your other devices connected are doing nothing with wifi, the Pandora works well, but if them start some heavy upload/download the Pandora goes to "Destination host unreachable", and you can resolve this  connecting them through ethernet cable, so the Pandora has a clear wifi band.

EDIT: I made a PND a year ago to make the pandora reconnecting automatically in this situation

http://boards.openpandora.org/index.php/topic/8690-wifi-reconnector/

It will not create a stable connection, but it detect the problem and reconnect automatically. This is useful mainly just for internet browsing, not heavy download because until the wifi is busy the Pandora will still lose the router address after little time.
 
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ZXDunny

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Anyone noticed that the Pandora tends to steal all your bandwidth? Mine does.

My connection is capable of about 512KB/Sec.

The Pandora, when connected, downloads on average at about 60KB/Sec.

No other devices in the house can get on the internet at all when the Pandora is downloading; at best they get 1 - 2 KB/Sec download speed.

This is with a BT router (v3).

D.
 

TrashyMG

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^ Never noticed that, generally I can stream video from the internet and use the Pandora at the same time without issues.
 

WizardStan

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I have not noticed this myself. I've got a Pandora, BeagleBoard, two laptops, and a roku box all going at the same time and I can netflix without a hitch.
 

PowerGod

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Anyone noticed that the Pandora tends to steal all your bandwidth? Mine does.


My connection is capable of about 512KB/Sec.


The Pandora, when connected, downloads on average at about 60KB/Sec.


No other devices in the house can get on the internet at all when the Pandora is downloading; at best they get 1 - 2 KB/Sec download speed.


This is with a BT router (v3).


D.
I noticed this, but this happens even when using a dongle, so I think it's a router limit

EDIT: no, wait, when this happens to me the Pandora is using the "entire" band, not just 60K...
 
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porg

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I also would like to check net speed but speedtest needed the newest flash plugin in Firefox (seems i have to install the 11.1.. ).
No need to do the speedtest in the webbrowser.

Pandora System Info, among many other monitoring capabilities, can also monitor, log & graph your network speed accurately to the byte!
 
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porg

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Concerning the router specific problems you encounter, some investigation happened around 2013-05 in our thread:

That's actually wifi powersaving in action, the chip only turns on it's radios every 300ms to see if anyone wants to send anything, and this timing is negotiated with the router so the router knows when to send all data that accumulated during radio silence. I'm not sure where this 300ms setting comes from, mac80211 (Linux wifi stack) provides it over it's API to the driver, but it might be actually received earlier from the router itself. Some material  about it here:

http://wireless.kernel.org/en/developers/Documentation/ieee80211/power-savings

Clearly this mechanism isn't working for zapman, maybe wifi firmware gets out of sync from the router or maybe something is wrong with negotiation.
 

kaitosan

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@PowerGod: Ah, I understand this and thank you for the info and the link. I will try that and see how it turns out.

BUT! One more thing still bugs me.

Yesterday when I tried it at home there was no other device on the WiFi than my laptop, and I can assure you that I didn't do mass down or upload from anywhere. In fact the laptop was on Windows desktop no progs running but with wifi connected! This was tha case bot in the first time with 1.54 SZ and later on with the 1.55 SZ. And of course I did not change anything on the router in the meantime. TP-LINK TL-WR542G and this is the same in my workplace on this router with 40 or so clients. But with the TL-WR740N with 4 clients over wifi the Pandora connects and works fine! And last but not least: Both of the 542G routers are in 802.11g (54Mbit)mode selected (only this or the "b" mode can be selected on their stock FW), BUT the 740N router is in 802.11b/g/n (mixed) mode. All routers use WPA-PSK (TKIP) encryption and only the TP-LINK WR542G at my workplace offers DHCP! At home I use a different dhcp server than my wifi router.

I wrote all this to be clear with the situation!

Thanks for all!
 

kaitosan

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@porg: I see. Maybe the different kind of routers use different modes to handle power saving mode using stations (clients). For example I can set these advanced options on the webinterface of the WR740N router (beacon interval, DTIM, etc.), but I cannot do the same on the other router WR542G (this is the older model) it's firmware and/or interface cannot make it possible to do this, since there is no option for it at all.

All in all: Every routers i tried uses the factory default settings for this (beacon interval, and so on...) and I did not try to change it, but it tells me maybe these valuesare different (and of course the hardware is weaker) on the older WR542G routers and those can not be changed.
 

WizardStan

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So I did an update to pndmanager and then did an update all: 3 simultaneous downloads at about 300-400K each, everything finished in very short time.

After these finished, with the Shumway Flash extension installed, I went to speedtest.net: 3.54 Mbps. This is hardly blazing fast, but that's still 440KB/second sustained, and local connections (and multiple local connections) are even faster, blazing along at almost 1MB/s combined with 4 simultaneous tranfsers.

I used to get 300KB/s sustained, maybe hitting 500KB/s if my router was feeling strong. I wish I could do more than brag but I have no idea what I did to improve it so much. :(
 
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Rockthesmurf

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My internal wifi always seems to die after using it for 10 minutes or so, on this particular occasion I had a SSH session from my desktop PC connected with top running, the Wifi started to die (goes really slow briefly before connection is completely dropped), I noticed that during this stage, top shows irq/181-w11251 and watchdog/0 and kworker/0:1 taking up a good chunk of CPU. This doesn't really mean much to me, but just posting it here 'for fun'.

 
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