Point-to-point simplex circuits, Point-to-multipoint simplex circuits – Comtech EF Data MIDAS 4 System and Design User Manual
Page 56
System and Design Manual, Revision 2
3–14
Theory of Operation
The termination sequence is similar to that of a data circuit.
To terminate circuits involving two integrated traffic/control modems, the
NMS transmits an interfering carrier using the LinkSync™ Modem. This
causes the modems/terminals to lose lock and return to the control channels.
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MIDAS supports point-to-point simplex data and video circuits. The
establishment and termination of point-to-point simplex circuits is similar to
that of full duplex circuits except for the following:
• Only one traffic channel is allocated as part of the circuit.
• Only the transmitting traffic node can request a simplex circuit
establishment by specifying the pre-defined circuit ID. The traffic node
cannot request the establishment of a simplex circuit if it is not pre-
defined.
• Since the transmitting traffic modem is not receiving, it will not report
loss of lock.
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MIDAS supports point-to-multipoint simplex data and video circuits for
applications like video conferencing, data broadcast/multicast, etc. Only one
traffic channel is allocated as part of the circuit.
Circuit Setup
A point-to-multipoint simplex circuit setup could be initiated by:
• The MIDAS Controller, due to activation of a pre-defined circuit by
the MIDAS operator
• The traffic node
5
, due to
♦
User port command
5
Only the transmitting traffic node can request the establishment of a point-to-
multipoint circuit.