uhf tacsat /dama multi-service tactics, techniques ... - UHF-Satcom.com

I-18
Figure I-9. Waveform Communications for 25-kHz DAMA
d. The OWs transmitted by the PCC are the channel control orderwire (CCOW) and
always start the frame. Every eighth frame is a master frame in which the information
on the frame format is provided to the terminals along with COMSEC information. In
the 25-kHz DAMA frame, the OWs sent from the terminals return channel control
orderwire (RCCOW) are divided into link test, range, and RCCOW slots. The remaining
frame is divided into three user segments, as seen in Figures I-10, I-11, and I-12. Each
segment—A, B, and C—is divided into time-slots for the users based primarily on the
data rate being utilized for communications. The row selected in each user segment
provides the controller the information required to select the frame format for the
channel, normally stated in three-digit format.