1.5.4 Release; New Dpc (Dynamic Power Control) Enhancements; Stdma Power Hunt; Hitless Switching - Comtech EF Data Vipersat CDM-570 User Manual

P r o d u c t D e s c r i p t io n

1.5.4 Release

New DPC (Dynamic Power Control) Enhancements

Higher Order Modulation BER Waterfall Mapping
DPC target Eb/No values are automatically adjusted using the BER waterfall
curves stored in the CDM-570/570L modems. The calculations are based on the
received VMS multi-command message configuration (i.e., bit rate, modulation,
FEC) lookup per BER table and used to modify the target Eb/No to sustain an
acceptable bit performance over all possible waveform configurations.
Delta Rain Fade Power Compensation
DPC offsets in modem power that are necessary during rain fade conditions are
now applied to incoming switch commands from the VMS. This prevents possi-
ble link failures due to power value changes associated with these switch
commands.

STDMA Power Hunt

Should link reception from a Remote be incorrect or impaired (e.g., poor envi-
ronmental conditions), the STDMA Power Hunt feature is an option on the
Remote modem that automatically adjusts the Remote transmit power to ensure
that burst map acknowledgements from that unit are received by the Hub burst
controller.

Hitless Switching

Data outages can occur during transitional switching in the satellite network.
New hitless switching parameters allow for fine tuning the switching process to
account for satellite propagation delay, command processing, and demodulator
re-acquisition.

VMS Registration and Managing Address

The 1.5.4 release introduces new methods for handling the managing address
and modem registration with the VMS. Unless a modem is registered with a
VMS, traffic will not pass either LAN-to-SAT or SAT-to-LAN. Also, Remotes
now receive a periodic update message from the VMS for setting the managing
address. This new message will update any Remote unit that is a new arrival, is
incorrectly set, or following VMS change-overs (redundancy switched).

UDP Port Base Address

It is now possible to change the assigned UDP base port address when an appli-
cation conflicts with the default address.
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