Operating instructions
Appendix I DMD50 Universal Satellite Modem
I-2 TM118 – Rev. 1.1
I.2 Efficient Drop & Insert Mode
With Efficient Drop & Insert, the terrestrial interface selections, terrestrial framing modes,
terrestrial to satellite mapping, ES to ES channel, satellite and terrestrial backward alarm
functionality, and the In Station Prompt and Deferred Service alarm operation are identical to that
of the Drop & Insert Open Network standard. In addition, the selection and operation of
Enhanced Async and AUPC are identical to their closed network IBS counterparts. For more
information on these selections, refer to the appropriate section of the User’s manual.
The following menu selections are utilized for controlling the additional functionality available with
efficient Drop and Insert:
MODULATOR or DEMODULATOR
NETWORK SPEC
CLOSED NET Efficient Drop & Insert is a Closed Network selection
SAT FRAMING
EFFICIENT D&I The satellite frame type is Efficient Drop & Insert
DATA
DATA RATE (bps)
N x 64000 The data rate can be set to any N x 64 kbps rate based on the
desired number of drop or insert slots. The following values of N
are allowed based on the terrestrial interface and terrestrial
framing types shown
T1 Any framing Any N from 1 to 24
E1 Any PCM31 Any N from 1 to 31
E1 Any PCM30 Any N from 1 to 30 as TS 16 is
automatically transmitted
SCRAMBLER CTRL
DISABLED The Efficient Drop & Insert mode utilizes a frame synchronous
energy dispersal technique that is always on, thus there is no
need for any additional scrambling
INBAND RATE
150 This menu is available when enhanced async is enabled. This
300 field allows the operator to select a desired Earth Station to Earth
600 Station in-band rate. This allows the user to optimize the In-
Band
1200 Rate based on the amount of traffic that will pass over the.
2400 satellite. In most cases, this should be set to the same rate or
4800 higher than the TX & RX Async/ ES port baud rate. When this
9600 rate is set lower than the ES port baud rate, the user must insure
19200 that the actual ES to ES transmission rate does not exceed the
In-Band Rate, otherwise characters will be dropped.