Continuous wave
Abbreviated "CW."
"A continuous wave or continuous waveform (CW) is an electromagnetic wave of constant amplitude and frequency. ... Continuous-wave radio was called radiotelegraphy because like the telegraph, it worked by means of a simple switch to transmit Morse code. However, instead of controlling the electricity in a cross-country wire, the switch controlled the power sent to a radio transmitter. This mode is still in common use by amateur radio operators."[1]
In the discussion of the final flight, references to CW effectively mean "Morse code communications."