hello lengogiang,
what seems to be your problem is that you do not know HOW TO connect to a wireless AP.
You were at the correct place and in fact, your broadcom driver WAS connected to the ZyXEL AP. Look right here:
[root@localhost ~]# iwconfig
lo no wireless extensions.
eth0 no wireless extensions.
wmaster0 no wireless extensions.
wlan0 IEEE 802.11g ESSID:"ZyXEL".........................................<<< connected!!
Mode:Managed Frequency:2.437 GHz Access Point: 00:13:49:3D:27:27
Tx-Power=27 dBm
Retry min limit:7 RTS thr

ff Fragment thr=2346 B
Encryption key

ff
Link Quality:0 Signal level:0 Noise level:0
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0
You were connected to this AP: ZyXEL and you just gave up and walked off and messed that all up by installing ndiswrapper. You don't need ndiswrapper. The broadcom driver works just fine.
What you SHOULD HAVE done next is to make a DHCP lease request to acquire an IP address.
Like so:
dhclient wlan0
and then, when that works, you will need to set your default gateway route.
Perhaps if you go do some reading on how Linux networkworking for wireless works, you would understand better how to recognize a connection when one exists!