User's Manual Part 1
Release8PlanningGuide
Issue2,November2007 Draft5forRegulatoryReview 147
To use English standard units to find the angle of elevation, use the following formula:
tan b =
B
5280A
where
B is expressed in feet
A is expressed in miles.
The angle of depression from the higher module is identical to the angle of elevation from
the lower module.
12.7 COLLOCATINGCYCLONEMODULES
A BH and an AP or AP cluster on the same tower require a CMM. The CMM properly
synchronizes the transmit start times of all Cyclone modules to prevent interference and
desensing of the modules. At closer distances without sync from a CMM, the frame
structures cause self interference.
Furthermore, a BH and an AP on the same tower require that the effects of their differing
receive start times be mitigated by either
◦ 100 vertical feet (30 meters) or more and as much spectral separation as
possible within the same frequency band range.
◦ the use of the frame calculator to tune the Downlink Data parameter in each,
so that the receive start time in each is the same. See
Using the Frame
Calculator Tool (All)
on Page 444.
Cyclone APs and a BHS can be collocated at the same site only if they operate in
different frequency band ranges.
Where a single BH air link is insufficient to cover the distance from an AP cluster to your
point of presence (POP), you can deploy two BHSs, connected to one another by
Ethernet, on a tower that is between a BHM collocated with the AP cluster and another
BHM collocated with the POP. This deployment is illustrated in
Figure 35.
CMM
BH
-M-
AP
BH
-S-
CMM
BH
-S-
CMM
BH
-M-
CMM
POP
Figure 35: Double-hop backhaul links