Turning off wireless network on SIEMENS speedstreams 6520 aDSL modem/router

Hi,
I received a wireless aDSL modem/router SIEMENS speedstreams 6520
from bell for my sympatico HSE. I use BELL's firmware (I don't remember
which version). I do not need the wireless option so I choose NO I WILL
CONFIGURE IT LATER in the wireless configuration dialog (in basic
setup).

At first I was not sure if the wireless network was disabled or
simply not protected by encryption and configured completly. So I was a
little concerned about the security. The wireless led is always off,
and I wanted to know if the LED is supposed to be on only when someone
is connected to the network or when it's configured correctly and up.
So I configured the wireless network and the led was always on. So I
thought that choosing the NO I WILL CONFIGURE IT LATER was what I
should do to turn off the wireless network.

I would just know if anyone knows this modem and if I'm doing the
right thing to turn off the wireless network and be safe. I just want
to be sure.

Thanks