Wireless Adapters That Periodically Disconnect on UMPCs

In the UMPC realm, a number of people have commented about their wifi connections periodically disconnecting. Apparently, owners of the Asus R2H and some owners of Samsung Q1s have had a lot of problems with their wireless connections periodically dropping. I’ve had my TabletKiosk eo i7210 for almost 4 months now and have noticed occasionally that the wifi connection would drop and reconnect occasionally. It never seemed to cause any inconveniences to me, so I ignored it. But when I read DanDar3’s story on the issue and how he upgraded the Intel drivers in his UMPC and improved his situation, I decided to look into the issue further.

It turned out that I was only seeing wifi disconnects when my eo was docked on it’s docking cradle in my home office. When it’s there it gets power and is connected over the Marvel Yukon LAN connection in the cradle which is blazing fast and great for copying videos and other large files to my eo from the other machines on my LAN. When the eo wasn’t on the cradle, it didn’t seem to be disconnecting the wifi at all.

I was able confirm this by observing it over the part of the day today both on and off of the cradle, and checking the System events in the Windows Event Viewer application. What I found is that, when the eo’s on the cradle, it would disconnect almost exactly every 10 minutes and then reconnect within about 5-30 seconds.

For kicks, I upgraded all the Intel drivers that were available in the version executable found at Intel’s driver download site. After a reboot, I was seeing the same behavior. So the driver update didn’t make the wifi disconnect problem go away.

After a little more googling around, I found a number of sites that said that the Window’s Wireless Zero Configuration service is responsble for the problem; that it will periodically, every 10 minutes actually, scan for stronger network signals to see if it can get a better connection. In doing so, it will often cause your wifi connection to be dropped and reconnected.

So I disabled the zero configuration service and configured the adapter using Winbond UI and service. Voila, the periodic disconnects went away!

But I was still intrigued by why, when using Window’s Wireless Zero Configuration to manage the wireless adapter, it would only drop the connection when the eo is on its cradle. So I spend a few hours with the zero configuration service running, enabling, disabling adapters in different orders, rebooting with the eo on the cradle then off of the cradle, removing and replugging in the hard-wired LAN cable and gathering my observations.

My Observations

My eo will only experience periodic drops/reconnects under the following conditions:

  • Window’s Wireless Zero Configuration service is used to manage the wireless adapter, AND
  • it is on the cradle, AND
  • the cradle’s LAN cable is connected, AND
  • the cradle’s LAN adapter is enabled prior to the wireless LAN adapter

The last item on the list is the important one. When your network adapters are enabled and you boot with the eo on the cradle, the cradle’s LAN is always enabled first (apparently). However, if you reboot the system off of the cradle, the wireless adapter is enabled first; and then if you put it on the cradle, you don’t experience disconnects.

I simulated this theory without reboots by disabling both adapters, restarting the Wireless Zero Configuration service, enabling the wireless adapter first, and then the cradle’s LAN adapter, and saw no more disconnecting. Do the same no-reboot experiment but enable the cradle’s LAN adapter before the wireless adapter and the disconnecting starts up again!

My Conclusions

I can only speculate that when Window’s Wireless Zero Configuration service sees the wired LAN adapter start first, it feels that the wired LAN is the primary adapter and it’s safe to periodically disconnect your wifi while looking for a stronger network signal. And that if the wireless adapter is started first, it’s opting not to do this periodic scan. At least on my eo i7210.

I decided to just avoid the issue altogether from now on by disabling Wireless Zero Configuration and using the Winbond configuration utility.

How does this relate to the wifi problems on the R2H and Q1? I really don’t know. If you have one, do the experiments and let me know what you find out.

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2 Responses to Wireless Adapters That Periodically Disconnect on UMPCs

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