[ltp] Re: Thinkpad T60 Wireless LED on Ubuntu 8.10 (Intrepid Ibex)

[Micha Feigin]

On Tue, 20 Jan 2009 22:40:47 -0500
Stefan Monnier <monnier@iro.umontreal.ca> wrote:

> > That's the way I like it, because it tells you if the transceiver is on.
> > For example on planes this way you know you are safe.
> 
> I cannot relate to this sentiment:
> - the rfkill switch works better for that.
> - if the plane's safety depends on you taking such measures, then all
>   passengers (and populations underneath) are in deep trouble.
> 

I've heard of dvd players driving the plain sensors wild. Personally I'd rather
not play with it.

> > Unassociated doesn't mean that it's not transmeeting either I'm here,
> > does anyone want to connect, or is there anybody out there, which is
> > not the same as antena off.
> 

Unassociated means you don't have an IP but the antenna is still sucking power
(maybe not full power, depending on the power saving controls, but power all the
less). If you have network manager or wicd they still scan periodically even
when not associated so you antenna is transmitting every 2 seconds or so.

> As mentioned, I don't actually care about the antenna's status, as long as:
> - it doesn't suck up my battery.

If I understood your description correctly, the iwl4965 behaviour tells you if
the antenna is sucking power (the transceiver is on), with iwl3965 or what was
it, it tells you if you are associated, but even if you are not associated then
antenna is still on = sucking power. People can't hack in but you are paying
the power penalty.

> - nobody can hack into my system or capture valuable data.
> I guess having the antenna really off is good to make sure nobody can
> detect my presence, but I don't care that much about it, and when that's
> really needed, the rfkill does that job better than any LED can.
> 

The led is an indication to the rfkill state. Led off == rfkill enabled ==
at least some power waste.

With my atheros I see a different of about 0.5W between not associated (but
rfkill disabled) and removing the module (the equivalent of using rfkill which
doesn't work with my atheros).

> > Usually if you are associated there is at least some blinking.
> 
> There's also blinking when you're trying to associate.  So it really
> doesn't tell me anything about the association state, which is the only
> thing I really care about.
> 
> > What madwifi did is blink when there is traffic and otherwise stay off
> > which I liked less.
> 
> Indeed, I'd find it completely useless.
> 
> 
>         Stefan
>