Nexus 7 wlan0 DOWN

[david...@gmail.com]

I have installed this kernel https://github.com/monk-dot/SPAN/tree/master/kernels/ASUS%20Nexus%207 on the stock Android ROM. I have also rooted the device. When I tap the Manet Manager logo to start ad-hoc mode, it seems to work (it turns green and says "press to stop Ad-hoc mode". However, when I go to Routing Info, it says "wlan0 DOWN" under "Table interfaces".

/data/data/org.span/bin/iwconfig tells me:

wlan0 IEEE 802.11bgn ESSID:"AndroidAdhoc"
Mode:Ad-Hoc Frequency:2.412 GHz Cell: DE:90:D9:01:6F:E4
Tx-Power=1496 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Encryption key:off
Power Management:on

(and of course I have wlan0 selected as the interface in Manet Manager settings).

Any suggestions?

Thanks,

David

[Jeffrey Robble]

Under the Settings app, does it show your Wi-Fi as off? It should be once you've started ad-hoc mode. It's possible that there's some conflict between what the device is trying to do with Wi-Fi normally and what the Manet Manager is trying to do.

Maybe you should try running "/data/data/org.span/bin/ifconfig wlan0 up" and see what happens.

--
You received this message because you are subscribed to the Google Groups "Smart Phone Ad-Hoc Networks" group.
To unsubscribe from this group and stop receiving emails from it, send an email to spandev+u...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

[david...@gmail.com]

Yes, in the Settings app, Wi-Fi is OFF. I have also rebooted after ensuring it was OFF as I read to do this in some instructions.

I have tried 'ifconfig wlan0 up', but nothing seems to happen:

root@grouper:/ # /data/data/org.span/bin/ifconfig wlan0 up
root@grouper:/ #

After doing that, wlan0 is still DOWN in the Manet Manager Routing Info.

David

[Jeffrey Robble]

What version of Android are you running? Is it CyanogenMod?

Although I haven't experienced your problem, the solution to these kinds of issues is usually to tinker with the iwconfig, ifconfig, load_wifi(), etc., operations for your device in the following file:

https://github.com/ProjectSPAN/android-manet-manager/blob/master/AndroidManetManager/res/raw/adhoc_edify

[david...@gmail.com]

> What version of Android are you running? Is it CyanogenMod?

Android 4.3. It is not CyanogenMod, it is the stock Android with the Nexus 7 modified kernel.

> Although I haven't experienced your problem, the solution to these kinds of issues is usually to tinker with the iwconfig, ifconfig, load_wifi(), etc., operations for your device in the following file:
https://github.com/ProjectSPAN/android-manet-manager/blob/master

I notice when I'm looking around in the settings menu in LogCat it says:

/AndroidManetManager/res/raw/adhoc_edify
System.out(20987): wlan0 UP 192.168.1.100/24

which seems promising (although then immediately checking the Routing Info it still says DOWN). Then I disabled and reenabled ad-hoc mode, and in the LogCat I see:

wpa_supplicant(514): wlan0: No network configuration found for the current AP

wpa_supplicant(514): wlan0: CTRL-EVENT-DISCONNECTED bssid=46:5a:8a:52:5a:d8 reason=3 locally_generated=1

Does that mean anything to you guys?

Thanks,

David

[Jeffrey Robble]

Ah, the issue is most likely related to running Android 4.3. I believe I tested it on the Nexus 7 running Android 4.2.

The wpa_supplicant process seems to be trying to take over control of the Wi-Fi. Try doing a "kill -9" on it and then starting ad-hoc mode.

[david...@gmail.com]

> Ah, the issue is most likely related to running Android 4.3. I believe I tested it on the Nexus 7 running Android 4.2.

I tried it with Android 4.2.2 and it seems to work (better). The wlan0 is now UP, but I have 4 devices and none of them can see each other (the Routing Info shows no routes on all of them, and they all have the same SSID).

> The wpa_supplicant process seems to be trying to take over control of the Wi-Fi. Try doing a "kill -9" on it and then starting ad-hoc mode.

Before I tried 4.2.2 as mentioned above, I tried this and it did not work (wlan0 was still DOWN). If you need a guinea pig for any other thoughts you have on 4.3 in the future, please let me know and we can try it for you.

[Jeffrey Robble]

Did you assign your four devices the same IP address in the same /24 subnet? Only the last octet of each address should be different.

[David Doria]

They are all 192.168.1.x. Explicitly, 192.168.1.100, 192.168.1.101,
192.168.1.102, 192.168.1.103.

David

> You received this message because you are subscribed to a topic in the

> Google Groups "Smart Phone Ad-Hoc Networks" group.

> To unsubscribe from this topic, visit
> https://groups.google.com/d/topic/spandev/FdHDoz45bu4/unsubscribe.
> To unsubscribe from this group and all its topics, send an email to

[Jeffrey Robble]

You may be experiencing the Nexus 7 cell-splitting issue mentioned previously on this forum. It has to do with the different devices trying to associate with different cells. Do an iwconfig on the devices and see what's printed out for the BSSIDs.

[David Doria]

When I first tried (working with only two devices on at the moment),
one of them says:

Cell: Not-Associated

while the other says:

Cell: C6:B9:7B:91:B9:18

What would cause one to be "not associated"?

When I restarted ad-hoc mode, the "not associated" one got a different
cell: Cell: 52:02:DF:DA:FD:A3. If these cells are different, that is
the "cell splitting" problem (and they hence won't be able to see each
other)? I searched the archives but didn't really see any information
about this. Is there some way to prevent it? Or perhaps force a static
cell BSSID?

Thanks for your help so far!

David

[Jeffrey Robble]

You are correct. If the BSSIDs are different they won't be able to see each other. More specifically, they'll filter out each other's broadcast packets. In the past I've got the mesh up and running with the "not associated" status on each device. I believe that's actually desirable because then the device won't filter out packets.

Setting the BSSID is somewhat difficult because the command doesn't seem to be fully supported on some devices. See this thread:

https://groups.google.com/d/msg/spandev/iYFhBhjXhqQ/djwUMHIGlcwJ

[Martin Kennedy]

Apologies for dredging up the old thread but I wanted to share how to get MANET running on Nexus 7 with Android 4.3 or higher.

I was having the same issues described in this thread "wlan0 DOWN". I remembered that Android 4.3 introduced a new setting which enables the device to scan for WiFi APs even when WiFi is turned off. This is used to calculate the device location. I had enabled this option, which meant that Android wouldn't let the device go into ad hoc mode successfully. Once I disabled this option (Settings - WiFi - Menu - Advanced - Scanning Always Available) I was able to connect to the network normally after reboot. Make sure to have WiFi turned off before reboot too.

I hope this helps,
Martin

[Martin Kennedy]

Tested with Android 4.4.2, by the way.

[Jeffrey Robble]

Thanks for the info Martin! I wasn't aware of the scanning issue.

--

You received this message because you are subscribed to the Google Groups "Smart Phone Ad-Hoc Networks" group.
To unsubscribe from this group and stop receiving emails from it, send an email to spandev+u...@googlegroups.com.

For more options, visit https://groups.google.com/d/optout.

[MC]

Hi Martin,

I disabled the Scanning Always Available, still wlan0 is down. When I am installing the app form the play store adhoc mode is running and its working fine. When I run the source code in eclipse and execute on the Nexus 7 by connecting the same device using USB, adhoc mode is not running. When I debugged the issue, I can see that the wlan0 is down.

Please let me know your suggestion, if any.

Thanks.
MC

[Martin Kennedy]

Hi MC,

I'm afraid I only ever installed from the Play Store so never noticed this issue. Sorry I can't be of more help but maybe someone from the project could suggest something?

Kind regards,

Martin

--
You received this message because you are subscribed to a topic in the Google Groups "Smart Phone Ad-Hoc Networks" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/spandev/FdHDoz45bu4/unsubscribe.
To unsubscribe from this group and all its topics, send an email to spandev+u...@googlegroups.com.