Ged Haywood
2005-03-21 13:44:46 UTC
Hello all,
The network in Grampian that I mentioned is up and running now. Once
I got up there it took about three days to install all the antennae,
cables, radio devices and the OpenWRT software. Unfortunately the BT
line went down so we have a couple of radio links and no ADSL, but
hopefully BT will soon be getting one of those round tuit thingies.
Zetnet IRC support was good but they're at the mercy of BT for the
line of course.
I'll post some documentation about the OpenWRT experience soon. It
wasn't entirely straightforward but it seems easy enough once you get
the hang of it and the software has performed well so far.
...oooOOOooo...
Question: Does anyone know of the mapping between the byte value that
controls the transmit power on the WRT54GS V2.0 and the actual output
power transmitted?
I've been Googling all morning but failed to come up with anything
that makes sense. I'm pretty sure that the output power is limited
by the hardware devices to a range of 1mW to 84mW. The single byte
value which controls it has (er, obviously:) a range of 0 to 255 but
I believe that it might be a two's complement number (the mapping of
2's complement to decimal is 127=127; 0=0; 255=-1; 128=-127). There
seems to be very little information about the mapping of this value
to actual output power whether it be in dBm or mW, and there's a lot
of confusion with some people saying that a byte value of 255 means
a transmit power of 255mW which I am sure is not the case. Finally
I don't know if this value represents a fixed power output or if it's
just a limit to the power output and the device can reduce the power
further if it so chooses, I'd like to know more about that and about
anything the receiver might be doing with its gain.
73,
Ged.
The network in Grampian that I mentioned is up and running now. Once
I got up there it took about three days to install all the antennae,
cables, radio devices and the OpenWRT software. Unfortunately the BT
line went down so we have a couple of radio links and no ADSL, but
hopefully BT will soon be getting one of those round tuit thingies.
Zetnet IRC support was good but they're at the mercy of BT for the
line of course.
I'll post some documentation about the OpenWRT experience soon. It
wasn't entirely straightforward but it seems easy enough once you get
the hang of it and the software has performed well so far.
...oooOOOooo...
Question: Does anyone know of the mapping between the byte value that
controls the transmit power on the WRT54GS V2.0 and the actual output
power transmitted?
I've been Googling all morning but failed to come up with anything
that makes sense. I'm pretty sure that the output power is limited
by the hardware devices to a range of 1mW to 84mW. The single byte
value which controls it has (er, obviously:) a range of 0 to 255 but
I believe that it might be a two's complement number (the mapping of
2's complement to decimal is 127=127; 0=0; 255=-1; 128=-127). There
seems to be very little information about the mapping of this value
to actual output power whether it be in dBm or mW, and there's a lot
of confusion with some people saying that a byte value of 255 means
a transmit power of 255mW which I am sure is not the case. Finally
I don't know if this value represents a fixed power output or if it's
just a limit to the power output and the device can reduce the power
further if it so chooses, I'd like to know more about that and about
anything the receiver might be doing with its gain.
73,
Ged.