Comtech EF Data DMD-2050E - Manual (Page 48)

DMD2050E Universal Satellite Modem Theory of Operation
MN-DMD2050E Revision 2 3–6
Figure 3-4. DMD2050E Universal Satellite Modem Functional Block Diagram
3.2.3 Tx Baseband Processing
The Tx Data and Clock enters the Baseband Processor, passes through a Rate Adapting FIFO
and enters the Framer/Drop Processor. In Closed-Net Mode, the data passes through the framer
unaltered. In IDR, IBS, and D&I Modes, the framer adds the appropriate framing and ESC as
defined in IESS-308 and 309. In D&I Mode, the framer acquires the terrestrial framing structure,
E1 or T1, and synchronizes the Drop Processor. The Drop Processor extracts the desired time
slots from the terrestrial data stream and feeds these channels back to the framer. The framer
then places the ‘dropped’ terrestrial time slots into the desired satellite channel slots. The data is
then sent to the Reed-Solomon Encoder.