User guide
Release9.5ReleaseNotes
Issue2,October2009 Page54
− Set identical range, downlink data %, and slot settings
− Use the Frame Calculator (see Using the Frame Calculator below) to ensure
compatible receive start times.
This ensures that at any one instant the collocated modules are either all receiving or all
transmitting. This avoids, for example, the issue of one AP attempting to receive a signal from a
distant SM, while a nearby AP is transmitting and overpowering the signal from the distant SM.
8.3.1 UsingtheFrameCalculator
Parameters that affect receive start times include range, slots, downlink data percentage, and
high priority uplink percentage (with software scheduling only). A frame calculator is included in
every module as a helper application to help calculate compatible settings. The frame calculator
does not itself configure or change any settings on the module.
The frame calculator in a module can be used to perform all frame calculations. The operator
enters settings into the calculator, and the calculator outputs details on the frame including an
Uplink Rcv SQ Start value. This calculation should be done for each AP that has different
settings. Then the operator varies the Downlink Data % in each calculation until the calculated
values of Uplink Rcv SQ Start for all collocated APs are within 150 time bits.
For more details on using the frame calculator, refer to the Canopy Release 8 User Guide,
available at http://motorola.wirelessbroadbandsupport.com/software
.
8.3.2 EstablishingVerticalSeparation
If you do not use the Frame Calculator
provide 100 ft (30 m) of vertical separation between same-band modules.
if 100 ft (30 m) of vertical separation is not possible, alternatively provide as
much vertical separation as possible, and choose frequencies far apart within
the band. The physical and spectral separation and local RF conditions
(influenced by tower geometries, layout and position of modules, and use of
reflectors on BHs, among other variables) may support good performance,
but testing and monitoring will be required to confirm that they do.
A system that is under no load with SMs registered and is able to communicate indicates basic
connectivity, but does not indicate that the system will function well under heavy load. The more
conservatively you design collocation, the less you will see interference issues, which may be
hidden under light loads, but cause problems when the system becomes heavily loaded.