Hi,

1. Fertig (Ready, the pilot is ready to be launched.)
2. Seil straff (All of the slack is out of the cable)
3. Frei (The glider has cleared the ground)

The official standardized phraseology as laid down in the SBO
(Segelflugbetriebsordnung)[1] is:

0) Inform the winch driver about type of glider, seats taken,
ballast, anything that may affect his choice of power to be
applied. Also information about things like plans for a
simulated cable-break. And on multi-drum winches identification
of the cable being used. "Am Bonner Seil eine ASK-21,
doppelsitzig, startklar."

1) "Seil anziehen".

2) When all slack is taken up: "Seil straff". At this point we
release the brake on our winch but do not apply any power
above idle.

3) When the glider starts rolling: "Fertig". This is the point
where launch power is (smoothely) applied. This is not
necessarily full power, depending on winch, aircraft and
conditions like wind.

4) "Frei" as the glider leaves the ground. After this point
the winch driver can see the glider.

At any time "Halt Stop! Halt Stop! Halt Stop!" to abort.

These commands were relayed to the winch operator via a "field
telephone", the kind where you would turn the little crank to ring the
bell on the other end of the line.

It is also required that there is a _reliable_ (emphasis from the SBO)
voice-link between the launch point and the winch. Using aircraft
radio/frequency is explicitly disallowed.

So it usually is a fixed telephone line.

Ciao, MM

[1] http://www.daec.de/se/downfiles/SBOstand01-11-2008.pdf