Page 52
NewS
tream
User Guide and Technical Manual
Microwave Status Page
[Continued]
Modulation Status
The Modulation Status
fi
elds present
NewS
tream
’s microwave settings for the selected
preset.
Modulation Mode
This
fi
eld displays one of the following modulation classes for each microwave preset:
• COFDM-DVB-T
— Coded Orthogonal Frequency - Division Multiplexing - Digital
Video Broadcasting — Terrestrial
• LMS-T
— Link Modulation Scheme —Terrestrial
• DVB - S
—
Digital Video Broadcasting — Satellite Mode
• DVB - S2
—
Digital Video Broadcasting —Satellite Mode
Modulation
This
fi
eld displays the following modulation classes for each microwave preset in the
Microwave Settings page. Moving up the scale of modulations allows higher throughput
but at the cost of robustness:
• QPSK
— Quadrature phase-shift keying
• 16-QAM
— Quadrature amplitude modulation
• APSK
— Amplitude Phase-shift Keying [for both 16 and 32-APSK]
• 64 - QAM
— Quadrature amplitude modulation
FEC
Forward Error Correction [FEC] or channel coding is a technique used for controlling
errors in data transmission over unreliable or noisy communication channels. This
fi
eld
displays the FEC for the existing microwave preset. Lower fractions are more robust
to noise and fading but at the cost of reduced information bandwidth. Common FEC
values include:
• 1/4
• 1/2
• 1/3
• 2/3
• 3/4
• 5/6
• 7/8
Guard Interval
The Guard Interval is a method used to prevent interference within distinct
transmissions. The Guard Interval con
fi
gured for the microwave preset is displayed in
this
fi
eld. The Guard Interval values include:
• 1/32
• 1/16
• 1/8
• 1/4
