WiFi or Internet Disconnection: Strange Issue

[aimo3]

For a long time I had this small shop with a Sonic Wall wireless router having this problem. Toshiba laptops have no problem. Some Dell and Lenovo (in addition to some mobile phones) have it, and this is it:

Sometimes (it could be a few times a day or too frequently to allow users to work) the WiFi disconnects by itself, and sometimes the WiFi remains connected but the internet is lost. All these laptops work fine in other sites.

And I've done the following so far.

1. Updating the WiFi drivers more than once on each laptop.
2. Replacing the WiFi adapter on one of the laptops on warranty.
3. Putting the routers adapter on another power socket.
4. Replacing the power adapter of the router.
5. Replacing the the router with another of the same model.

Nothing changed. WTF!!

Appreciate you help..

 

[PP Mguire]

Replace the router?

 

[aimo3]

I said I had.

 

[PP Mguire]

You replaced it with another of the same model, by replace I meant upgrade. If the same machines aren't having issues at another location utilizing the same router model, then it's going to be something at that location causing interference with that router model.