User manual

AN-80i User Manual
70-00072-01-10 Proprietary Redline Communications © 2011 Page 53 of 152 March 2, 2011
Adaptive Modulation: Select the adaptive modulation mode.
The adaptive modulation feature provides automatic adjustments to maintain wireless
link operation during periods of transient interference, power variations (fade), and
reflections. This feature is enabled and disabled individually for each Subscriber Link.
Enabled (
):Automatically adjust the modulation and coding to achieve the highest
throughput where packet error rates (PER) are lower than a pre-set value. When
packet error rates exceed the threshold, the modulation/code combination is
adjusted to maintain the connection at a lower throughput rate (graceful
degradation).
Automatic adjustments to the modulation/coding result in relative changes to the PIR
of all connections on that wireless link. This ensures the degradation of any single
link does not affect the throughput of other links in the sector.
When adaptive modulation adjusts the uplink or downlink modulation/coding settings
of a wireless link to below the desired minimum burst rate setting, the burst rates are
displayed in red, and the PIR values for all Services and Service Groups are
temporarily proportionally reduced.
Example: In a link operating at 16 QAM 3/4, transient interference may result in a
temporary change from to 16 QAM 1/2 to maintain the required PER. The AN-80i will
periodically test transmission at a higher rate and resume operation at the normal
rate after the interference has cleared.
Disabled (
): Modulation and coding values are fixed at settings required to
achieve the operator selected UBR (Max. UL Burst Rate / Max. DL Burst Rate).
Note: Adaptive modulation is 'disabled' by default when upgrading from PMP
versions earlier than v12.00.
4Gon www.4Gon.co.uk [e-mail] Tel: [phone] Fax: [phone]