We are currently on our third wireless base station. First was a Netgear, next came a Linksys and now we have an Apple Airport Express. There are three laptops on the network, not all of them on at the same time. One is an HP Pavilion running XP, and the two others are Apple Laptops. The problem has been the same with any of the three base stations. With no rhyme or reason the connection to the internet is dropped. The broadcast signal from the base station is fine. The Motorola Surf Board cable modem seems fine and the cable company says everything tests out fine. When the connection drops sometimes a reset of the modem and base station gets us back online but sometimes it does not. Sometimes we have to actually wait hours to get back online. Hard wiring to the back of the modem always works perfectly. I have changed the channel that the base station uses. While we have a cordless phone and microwave oven there is no correlation with them and the problem and the base station is far from them. I know there are other wireless networks in the neighborhood but I doubt any of them are broadcasting on channel three. I have changed the channels around and there doesn't seem to be any affect regardless of the channel. this is becoming a major frustration and problem because we are trying to work from home and rely on the internet to work. Any ideas?? Thanks!
Beware of your cordless phone. Some of them will transmit signal even when they are not actually being used to let its base know it is there and available. Being very local to the users computer and wifi, it very effectively "blocks" the wifi signal, even though it may seemingly be on a different channel set. Sometimes the wifi can take a while to resync again.
Alternatively you may well have another source of interference as yet not identified, wireless doorbell, AV sender, even some security devices and any of these devices could just as easily be at your neighbours!
Try reducing the distance between the AP and the client computer to only a few feet if possible and see if there is a point where the connection becomes more stable. If you get a good reliable connection when really close, it is most likely that you do have an interference problem.
This problem is not that bizarre, it only seems that way!
All are good wireless routers. All have model numbers. What are you currently using for a wireless router?
OK, it's a fair assumption that it's not the wireless routers or the laptops. What's left?
Hint: Are you using the same ethernet cables between the modem and the wireless routers de jure for each test? A bad connector or crappy cable could easily be the culprit. Same with everything else that's in common such as the power strip or UPS that the wall warts plug into.
Is there anything common in the timing of the disconnects? Does it coincide with the power saving features of the laptops? Do the laptops go into standby or hibernate and not recover?
How close are the laptops to the wireless router? Too close (less than about 2 ft) is sometimes a problem.
Are you using encryption? If so, try it temporarily without any encryption to eliminate one possible variable (re-keying interval).
How do you know it's fine? Hint: Assumption is the mother of all screwups.
Both the modem and the wireless router? That's fine but doesn't tell you which is the culprit. Try power cycling one, retest, and if that doesn't help, power cycle the other.
When you get disconnected, try pinging the wireless router or connecting to it with a web browser. If that works, but you can't surf the internet, then it's either the router section or the cable modem (or the cable ISP). Ping is your best diagnostic tool.
Ping the router IP.
Ping the cable ISP gateway address.
Ping something on the internet by IP address.
Ping something on the internet by DNS name.
Works perfectly for how long? A quick test doesn't count.
Also, did you try plugging an ethernet cable into the LAN ports on the back of the wireless router de jure? If that works, then it's probably something related to the wireless section. If that fails, it could be the router section or the cable modem.
It would help if you determined the nature of the disconnect failure. Does the client laptops show a "disconnect" symbol for the wireless? Or is it that you just can't surf the internet? Describe the exact symptoms.
Note that if you simply can't surf, it might be something like DNS lookup failure. Find the IP address of something obvious like Yahoo or Google (just ping it by name and ping will give you the IP address). When it fails, ping it first by IP and then by name. If IP works, but ping by name does not, your DNS lookup has a problem.
How far in feet or meters?
Don't use channel 3. Use 1, 6, or 11. If you use 3, you will get interference from other users on BOTH channels 1 and 6.
Well, it sure sounds like interference, but that's difficult to determine without a spectrum analyzer. Check if you have one of the sources of RF interference listed in the FAQ:
out the window and check if there are any municipal networks or rooftops with possible WISP installations. Municipal WLAN's tend to hang from street lights. Meanwhile, try moving your wireless router and laptops away from windows with views of the city. Try putting some obstructions between your wireless devices and the likely direction of any interference.