Appendix J. Ita Operation; Information Throughput Adaptation (Ita Operation - Comtech EF Data DMD-2050E Installation And Operation Manual

Appendix J. ITA Operation
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Information Throughput Adaptation (ITA Operation)

Information Throughput Adaptation (ITA) also known as Adaptive Coding and
Modulation (ACM), allows the DMD2050E to mitigate downlink rain-fades by means of adapting
the throughput of the modem effectively decreasing the modulation and coding by fixing the
symbol rate and changing data rate to keep a constant power spectral density. When ITA is
operating using the DMD2050E partner modem indicates the highest possible data rate
constrained to a fixed symbol rate.
ITA turns fade margin into increased link capacity – gains of 100% or more are possible,
compared to traditional static FDMA links. This is accomplished by automatically adapting the
modulation type and FEC code rate to give highest possible information throughput. ITA
maximizes throughput regardless of link conditions (noise or other impairments, clear sky, rain
fade, etc). Initial setup is easy, and then requires no further user intervention. With a static
traditional FDMA system, severe rain fading can cause the total loss of the link, and zero
throughput. ITA keeps the link up (with lower information throughput) – and can yield much
higher system availability. ITA in the DMD2050E used in conjunction with the EBEM framing unit
adjusting the IP traffic in either IP Only or mixed serial IP mode.
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