User manual

Chapter 2 - Managing a Single Device/Cell Air Interface General Page
AlvariCRAFT Device Manager 38 User Manual
2.3.3 Link Distance Parameters (BreezeNET B)
The higher the distance between the RB and the BU that is serving it, the higher
the time it takes for messages sent by one of them to reach the other. The time
that a unit waits for a response message before retransmission (acknowledge time
delay) should take into account the round trip propagation delay between the two
units (the one-way propagation delay at 5 GHz is 3.3 microseconds per km/5
microseconds per mile). The higher the distance between the BU and the RB, the
higher the acknowledge time delay used by both units should be. The ACK
timeout in microseconds is: 20+Distance (km)*2*3.3 or 20+Distance (miles)*2*5.
The distance between the BU and the RB can be determined either manually or
automatically. In manual mode, the estimated distance between the two units is
Fairness Factor (%) Applicable only for AU. The Fairness Factor enables to define the
level of fairness in providing services to different SUs. When set to
100%, all SUs have the same probability of getting services when
competing for bandwidth. If set to X%, then SUs located up to X% of
the maximum distance from the AU will have an advantage in getting
services over SUs located farther than this distance.
The range is from 0 to 100 (%).
Measured Max Cell
Distance (Km)
A read-only display of the measured distance from the AU of the
farthest unit served by it.
Max Cell Distance (Km) Applicable only for AU. The Maximum Cell Distance parameter allows
configuring the maximum distance when the Cell Distance Option is
set to Manual.
The range is from 0 to 54 (Km). The value of 0 has a special meaning
of No Compensation: Acknowledge Time Out is set to a value
representing the maximum distance of 54 km. The time slot size is set
to its minimal value of 9 microseconds.
The default is 0 (No Compensation).
Most Distant Unit Applicable only for AU. A read-only display of the MAC Address of the
most distant unit served by the AU
Per SU Distance
Learning
Applicable only for AU. Available only when the Cell Distance Mode is
set to Automatic. The Per SU Distance Learning option defines the
mode in which SUs calculate the ACK timeout: based on the
maximum cell distance or on the actual distance from the AU.
When this feature is disabled, all SUs in the cell use for the
calculation of the ACK timeout the maximum cell distance; when
enabled, each SU uses instead its actual distance from the AU.
The options are Disable or Enable.