If you're using bcm43xx, you need to install firmware. See here: https://wiki.ubuntu.com/WifiDocs/Driver/bcm43xx?highlight=%28bcm43xx%29#head-cf3f0ec9146ae9441b39c4bed74e5d044ef78d2f for the really simple method.
If you're using bcm43xx, you need to install firmware. See here: https:/ /wiki.ubuntu. com/WifiDocs/ Driver/ bcm43xx? highlight= %28bcm43xx% 29#head- cf3f0ec9146ae94 41b39c4bed74e5d 044ef78d2f for the really simple method.