User's Manual Part 3
Release8OperationsGuide
Issue2,November2007 Draft5forRegula toryReview 444
NumDLHalfSlots
This is the number of downlink half slots in this AP or BHM’s frame. To get slots, just
divide by 2.
NumULContSlots
This field displays how many control slots are being used in the uplink portion of the
frame.
The AP Evaluation tab also provides the following buttons.
Rescan APs
You can click this button to force the SM or BHS to rescan the frequencies that are
selected in the Radio tab of the Configuration page. (See Custom Radio Frequency Scan
Selection List on Page 276.) This module will then register to the AP or BHM that
provides the best results for power level, jitter, and—in an SM—the number of registered
SMs.
Update Display
You can click this button to gather updated data without causing the SM or BHS to
rescan and re-register.
27.5 USINGTHEFRAMECALCULATORTOOL(ALL)
Cyclone avoids self-interference by syncing collocated APs (so they begin each
transmission cycle at the same time) and requiring that collocated APs have the same
transmit/receive ratio (so they stop transmitting and start receiving at the same time).
This ensures that, at any instant, they are either all receiving or all transmitting.
This avoids, for example, the problem of one AP attempting to receive from a distant SM,
while a nearby AP is transmitting and overpowering the signal from the distant SM.
Parameters that affect transmit/receive ratio include range, slots, downlink data
percentage, and high priority uplink percentage. All collocated APs must have the same
transmit/receive ratio. Additional engineering is needed for setting the parameters in a
mixed cluster – one with APs on hardware scheduler and APs on software scheduler.
A frame calculator helps to do this. The operator inputs various AP settings into the
calculator, and the calculator outputs many details on the frame including the Uplink Rcv
SQ Start. This calculation should be done for each AP that has different settings. Then
the operator varies the Downlink Data percentage in each calculation until the calculated
Uplink Rcv SQ Start for all collocated APs is within 300 time bits. The frame calculator is
accessed by clicking on Expanded Stats in the navigation column, then clicking on Frame
Calculator (at the bottom of the expanded navigation column).
The calculator does not use data on the module or populate new data. It is merely a
convenience application running on the module. For this reason, you can use any module
to do the calculations for any AP. Running the calculator on the AP in question is not
necessary.
IMPORTANT!
APs with slightly mismatched transmit/receive ratios and low levels of data traffic
may see little effect on throughput. As the data traffic increases, the impact of
mismatched transmit/receive ratios will increase. This means that a system that
was not tuned for collocation may work fine at low traffic levels, but encounter