Problems with wireless connectivity on certain laptops
First, some background.
I've got a set of 5 laptops here [Acer Aspire 5552-3680] and they all have an interesting issue with wireless.
We have about 12 access points around the school, all with the same WPA encryption key and SSID so they look like one large wireless network, and......this isn't the way I'd like but on a very very restricted budget, they're consumer routers with DHCP off and a network cable plugged in from a switch/network jack around the school to one of the 4 LAN jacks on the wireless routers. Since some routers are fairly close in proximity to others, what I've done is changed the channels on all of them between channels 1, 6, and 11, and separating the 1's farthest away from each other, 6's farthest away, and 11's farthest away. So for example, a channel 11 router might be in range of a channel 6 router, but not another channel 11 router. Believe it or not, it's worked fairly well. All laptops are on the domain and require authentication to use, there are no local accounts besides the Administrator account.
Now the problem.
These 5 laptops, for whatever reason, in certain areas of the school, won't log in. Domain not available. I log in locally using the Administrator account and I notice that the wireless adapter isn't connected, but can see the wireless network perfectly fine. If I try to connect [I'm using just the built-in Windows wireless manager], I notice the wireless adapter flip from Acquiring IP Address, to Not Connected. Back and forth fairly quickly [1 to 2 seconds between status change usually]. If I move the laptop down the hall about 10 to 15 meters and try reconnecting, boom, connected. Signal strength is good to excellent in both locations. I've noticed 3 particular places in the school that connectivity seems to be an issue, and I'm not sure if it's these particular laptops wireless adapters, or if it's something else. I notice the issue sometimes with my iPhone too. Is it the way I have the routers configured? Something else?
It's been understandably frustrating for the staff that work with student services and lend a student a laptop to use during class only to find out that in some classrooms the domain connectivity isn't available because their laptop isn't connected, thus the student can't log into the laptop in the first place.
What I'm wondering is if certain laptops and wireless adapters are getting confused at having multiple routers in range. But it should work, and has always worked for the majority of our computers here. Not sure what's up with these ones, and they're the newest.
Latest Firmware on the APs, some of them can get a bit stupid with a bunch of clients connected and will trip out just those clients that have connected after its wireless assosiation bit has crashed out. Had that a few times with simmilar setups. It can work alright with quality consumer APs but I know from bitter experience how badly it can go wrong with lower end consumer APs.
Check the wireless cards, we had a batch of either toshiba's or Acer that use a Realtek wireless card that has issues. We changed the wireless cards to other Realtek ones and intel ones and the laptops connected to the wireless straight away.
To be honest, I can't remember the model number of the affected Realtek wireless cards, as it was a while ago (and at work)
These Acers are all Draft N, you really don't want these fighting for connectivity in your unmanaged 12 router wifi fest...
If you can disable the N feature completely you might see an improvement.
You simply can't run N in a multi AP common SSID configuration without N Points and proper Management.
Your in Canada, there are more bears there than there are access points over here...
You can run a 1 watt AP and cover an entire mountain and nobody would complain.
Try reducing the output of your "Routers" wifi if that is a selectable option, in case your new Acers are hearing more beacons than they can handle properly.
You might find the option to disable N in the advanced driver options, you might also try reducing power on the laptops as well.
Everybody on here is going to tell you you need to install a Ruckus system.... Despite the fact that you have no resources or finance to do so!
Wouldn't necessarily be my first choice but the truth is, you need something..... You can't carry on expanding your wireless empire on a network of dampened string.
Last edited by m25man; 30th April 2011 at 09:20 PM.
I have more then 36 'unmanaged' Cisco Access Points and 175 laptop`s running in my building, without having any issues, so you do not have to choose for a managed system if the AP`s can be configured properly.
Like m25man said, look into the output, see if you can reduce it to 1 or 5 mw to keep the signal from each AP inside a classroom.