Summary And Examples - Radyne DMD20 Installation And Operation Manual

DMD20/20LBST Universal Satellite Modem
I.3.4.1

Summary and Examples:

These examples illustrate how to calculate the Efficient D&I rate, which can be summarized for N
timeslots as:
With E1 signaling add
With Enhanced Async add
Example 1a:
5 Drop Slots with T1-D4 framing, standard ES to ES overhead
The Drop & Insert Open Network rate is over 20,000 bps higher at 341333 bps.
Example 1b:
Change to E1-PCM30 framing (E1 Signaling), standard ES to ES overhead
Still saving over 10,000 bps compared to the open network standard.
Example 1c:
Change to Enhanced Async with In-Band Baud Rate of 1200
An increase of 625 bps to carry 1200 baud
MN-DMD20-20LBST Revision 14
Efficient D&I Rate
N * 2000 bps
(Truncation (In-Band Baud / (N * 125))) * (N * 125) bps
For 5 Drop Slots, the Data Rate would be 5 * 64000 or 320000 bps
The Efficient D&I Rate would be 320000 + (5 * 250) bps = 321250 bps
Add 5 * 2000 bps to our previous calculation gives 331250 bps
X = Truncation of (1200 / (5 * 125)
X = Truncation of (1.92)
X = 1
Add 1 * 5 * 125 bps to our previous calculation gives 331875 bps
= Data Rate + (N * 250 bps)
Efficient Drop & Insert
I–4