Broadcom BCM43225 802.11b/g/n (rev 01) WiFi sees neighbours Wifi but not my own

[kulturedyobbo]

Recently in my home we had the Australian NBN (National Broadband Network) installed. This is part of the plan to bring Australia's internet out of the Paleolithic (early Stone Age). Initially my WiFi worked fine with the new NBN modem, btu earlier this week while using Sparky, for some seemingly inexplicable reason, I suddenly could not connect to my WiFi but I could see my neighbour's wifi! The same thing was happening when I booted into Neptune Linux. I then booted up my wife's laptop, and guess what? I could see our WiFi connection on it! It uses Linux Mint 13 Maya which in this instance does not mean much, but as will become clear later, it uses an Atheros Wifi card.

After switching off and turning on my new NBN modem (NetComm Wireless N300 WiFi Gigabit Router) several times, I could finally see my WiFi connection. But in the evening when I turned my modem off, I had the same problem again in the morning when I booted my laptop up and turned my modem back on. I could see my neighbour's wifi, but not my own. Coming home for lunch, the same problem but my wife said she had no problem with the WiFi on her one year older Acer laptop.

After buying a long ethernet cable, I hooked up to modem and tried to find a solution to this problem. Some gave the suggestion of deleting the connection in Network Manager, and recreate it. This I tried the afternoon before and it had worked but as you will soon see, this was pure coincidence. It had absolutely nothing to do with me deleting and recreating my Wifi connection.

I finally found the solution at this link:

http://unix.stackexchange.com/questions/167009/broadcom-not-able-to-see-my-wifi

"broadcom-not-able-to-see-my-wifi" appearing in the link was most relevant to me!

The problem was this. My Broadcom Wifi card only operates on channels 1 to 11. However, the Atheros Wifi card on my wife's slightly older laptop operates on channels 1 to 13. This you can find out with the command: "iwlist chan".

The article recommended trying to change the channel setting on the modem from "Auto" to somewhere between 1 and 11 inclusive. I chose 10, and yes, suddenly my Broadcom WiFi adapter saw my Wifi network. I then executed the "iwlist chan" on my laptop and found it only had the range of channels from 1 to 11, with it operating on channel 10, the channel I had selected on my modem.

I then out of curiosity executed "iwlist chan" on my wife's laptop, and found the channels ranged from 1 to 13, two more than my own. I am now 99.9% certain that what was happening the day before and earlier the following day was that the modem was randomly choosing channels 12 or 13 which my wifi adapter could not accommodate. When I did connect the evening before, that was only because the modem happened to choose a channel between 1 and 11. However, when I turned my modem off in the evening, I then could not connect the next day, because it kept insisting on channels 12 or 13. The modem I checked does have channels from 1 to 13, as does my wife's Atheros wifi adapter, but not my Broadcom adapter.

Since setting my modem's channel setting from "Auto" to "10", my Broadcom wifi adapter has no problem seeing my wifi network.

Cheers