Specifications
Chapter 4 - Operation and Administration Menus and Parameters
BreezeACCESS 4900 180 System Manual
The default value is 5 (milliseconds), enabling a maximum burst of (0.005 X CIR)
Kbps after a period of inactivity of 5 milliseconds or more.
4.2.6.6.2.6 Maximum Delay (SU only)
Sets the maximum permitted delay in the buffers system. As certain applications
are very sensitive to delay, if relatively high delays are permitted, these
applications may suffer from poor performance due to data accumulation in the
buffers from other applications, such as FTP. The Maximum Delay parameter
limits the number of available buffers. Data that is delayed more than the
permitted maximum delay is discarded. If the SU supports applications that are
very sensitive to delay, the value of the Maximum Delay should be decreased.
Valid values range from 300 to 10000 (milliseconds).
The default value is 5000 (milliseconds).
4.2.6.6.2.7 Proportional IR Factor Parameters (SU only)
When an SU operates at low modulations, the MIR values may become irrelevant.
A device that, due to environment limitations, always transmits at lower
modulations needs more time to reach the MIR values than devices that transmit
at high modulations. In this situations, the MIR/CIR algorithm is not able to
deliver an adequate level of fairness. The Proportional IR Factor (PIF) addresses
this issue.
Using this factor, the MIR/CIR values used by the device will be adjusted.
Depending on the average rate (modulation) used and the Proportional IR Factor,
the MIR/CIR values employed by the MIR algorithm will be calculated as an
average.
The average rates (for uplink and downlink) are calculated periodically. If the
difference between the current average rate and the previous average rate exceeds
a predefined percentage (Threshold Percentage) from the configured rate and the
current average rate is lower than a specific threshold (Threshold Rate), then the
respective MIR/CIR values for uplink or downlink will be recalculated.
Since the used MIR/CIR values must be calculated for both uplink and downlink,
there will be two values for MIR (Used Uplink MIR and Used Downlink MIR) and
two values for CIR (Used Uplink CIR and Used Downlink CIR). If at least one of
these four MIR/CIR values is updated, a reassociation is required in order to
inform the AU about the new MIR/CIR values. After reassociation, both units (AU
and SU) will work with synchronized values for MIR/CIR.
The following formula is used for calculating the applicable rates:
UsedRate
PIF AvgRate 100 IFF–ThrRate+
ThrRate 100
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ConfiguredRate=