I am also suffering from this problem with my wireless. I think that this is related to the wireless connection when connected in 801.11n-mode. When I use the 801.11g the connection is stable (at least using up to 4 wireless routers). You write that your problem is fixed? Did Dell replace the Atheros (I also live in NL)?
Just wanted to share my experience. I have purchased an XPS 13 recently. Since it had Ubuntu 12.04 I immediately upgraded to 14.04 (by doing a fresh install, no sputnik i think). It was then when i ran into all the wifi problems reported on this thread. The device kept trying to reconnect constantly esp. in battery mode.
I tried the disabling of 802.11 (options iwlwifi 11n_disable=1 into /etc/modprobe.d/iwlwifi.conf ). That did *not* help at all.
What I had found odd was that usually the connection would be stable for about ten minutes after reboot. Then the adapter would disconnect and try reconnect for several times. Eventually the connection would come back (not every time though) but then be very very slow. So why always about 10mins? It was then when I remembered someone mentioning a potential problem with power management. So does the adapter go to sleep after minutes? I don't know.
So I tried that fix (disabling the power management). And that did help! The wifi is much more stable now. No more disconnects and the speed is as expected. So again, all that I did to fix this issue was to create a file /etc/pm/power.d/wireless and put in the following content:
/sbin/iwconfig wlan0 power off
I really hope that this helps someone.
P.S.: Btw, here are the details on my adapter (lshw -C network):
description: Wireless interface
product: Wireless 7260
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:02:00.0
logical name: wlan0
width: 64 bits
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=iwlwifi driverversion=3.13.0-32-generic firmware=18.104.22.168 ip=192.168.1.22 latency=0 link=yes multicast=yes wireless=IEEE 802.11abg
resources: irq:59 memory:f0400000-f0401fff
Thank you Soren!
I also recently purchased the Dell XPS 13 developer edition that came with the Intel 7260 wireless adapter. I noticed straight out of the box that it was having connectivity issues. When I tried using "sudo apt-get update" and "sudo apt-get upgrade" the downloads would slow to crawl and pretty much time out regardless of my distance from the access point. So I cancelled that and tried doing an upgrade to 14.04, which was also timing out during the download phase. I decided to use a USB thumb drive to upgrade the OS to 14.04. However, the problems didn't go away. After upgrading, I noticed the adapter would frequently disconnect from my WLAN (within 5-10 minutes of booting) and would not automatically re-establish the connection. I had to keep restarting the network manager service. Eventually, after reading through several forums, I found your post and tried disabling power management on the wlan0 interface and it seems to have solved all the network issues! No more disconnects, and the apt-get update/install is quick like it should be.
Don't forget to make the /etc/pm/power.d/wireless script executable, so that it runs when the laptop gets rebooted.
sudo chmod +x /etc/pm/power.d/wireless
P.S. There is still an annoying squealing noise that comes from the keyboard when the back light is on, but I'll post about that in a different forum.
nice to hear that disabling the power management helped. I've been working with that fix for quite a while now. Even though it fixed the continuous disconnects, some of the the problems seem to remain. I am running the 3.13.0-36-generic kernel I am still experiencing slow connection to the AP. I have been monitoring the connection (watch iwconfig) for the last couple of days and noticed that at some point (typically after 20min of work) the bit-rate starts jumping from ~72 Mbit/s to 1Mbit/s. And that's regardless of the distance to the AP. The only way to sort of handle this is to disconnect manually and then reconnect.
I still couldn't figure out what might be the cause. I've heard people saying that one should try to switch to 5Ghz, but unfortunately my AP doesn't allow that. So that's still very annoying.
Again, I experienced that disabling the 802.11n (options iwlwifi 11n_disable=1) didn't help at all. I am curious as of other experience that behavior too.
P.S.: Yeah I get that squeaking noise too, but I have had the old XPS M1330 for many years and got used to these kind of noises i guess 😉
I received my shiny new Xmas present to myself today (XPS 13 Developer Edition with the 7260 wireless adapter), and I'm also having a beast of a time with the wireless - disconnects after about 3 minutes, then reconnects fairly quickly, and repeats the disconnect/reconnect cycle intermittently. Has anyone tried Soren's solution on the shipped Ubuntu 12.04 install with the 7260 wireless card? I tried it, with a little help from the Ubuntu forums as well, and I've had no luck. I'm wondering now if I might have to update to a newer kernel, since the card appears to be supported in 3.10+.
I can't believe people are still dealing with this issue over ONE YEAR later.
I was considering buying another Developers Edition once I need a new one but the lack of support for such a major annoyance is disheartening. I'll be looking elsewhere unless Dell gets their act together.
Interesting development - I brought the laptop to work with me today just to do a quick test of an alternate WiFi setup, and it hasn't disconnected on me once. So, upgrading to 14.04 is still on the table, but I'm thinking I need to wrestle with my router at home a little bit first.
Oops, I meant to provide the following link that contains some of my notes and a co-workers notes for the XPS 13. We each have different wifi cards which required a different solution.