Rooftop Antenna Placement Tool - Cisco BWX 8305 Installation And Commissioning Manual

BWX 8305 Basestation Antenna Installation

6.3.5 Rooftop Antenna Placement Tool

Reference: Rooftop Antenna Placement Tool
This is a picture of the worksheet in the Antenna Placement Tool for a quick visual identification
Figure
datafill the site information. This form can be found on the following LiveLink site:
https://tools.cisco.com/cws/livelink?func=ll&objid=4353291&objaction=browse
The Tool is updated periodically. If you are not sure that you have the latest version, please contact Cisco
Technical Services and request that the latest version of the tool be sent to you.
Figure 6-13
Legend
User input required
Calculated Value
Cisco Antenna Beam Widths (3 dB point)
Cisco Antenna Fixed Electrical Downtilt (@ 0 degrees mechanical tilt)
BWX 2305 Basestation Installation and Commissioning Guide
6-12
6-13); this appendix does not include the entire tool. Please use the electronic copy of the tool to
Rooftop Antenna Placement Tool
V er tical Be a mwidth
2 X half th e V erti ca l Be am width
M ai n B eam
Cen te r Po int
a1
ht
Side View
h1
d1
Antenna Azimuth top view
Sector RFS
Horizont al Beamwidth = 120°
(+/ - 60°) from the antenna Azimuth
d1 = the distance to
the farthest edge of
the roof
Lower Roof
Upper Roof
Vertical Horizontal
RFS8 Panel 5° 120°
RFS2 7° 120°
RFS8 Panel -6°
RFS2 0°
BWX Rooftop Antenna Placement Tool
1). Are the measurements in feet or meters?
2). What type of antenna is being used?
3). How many sectors are being used?
4). What is farthest distance (d1) on the roof within the sector antenna's
horizontal beamwidth?
For a single sector antenna on a rooftop the actual antenna pattern will
extend to ~90° to the left / right of the antenna centerline, although at a
reduced signal level relative to the 3dB beam width, If more than 120° of
coverage is desired, then d1 should be the farthest distance to the roof edge
within +/- 90° of the antenna centerline.
3). What is the height of the obstruction or parapet wall ( h1 ) ?
4). What is the built-in electrical downtilt of the antenna in degrees?
[See electrical downtilt choices for Cisco supplied antennas]
(Use a negative number for all entries)
4). What is the planned mechanical tilt of the antenna in degrees ?
[See RF Planning documents] (+ = uptilt and - = downtilt)
(Net Downtilt = Fixed Electrical Downtilt + Mechanical Up/Down Tilt)
(Negative for a net downtilt and positive for a net uptilt)
5). What is the 3dB vertical beam width of the antenna?
[See Vertical Beam width choices for Cisco supplied antennas]
6). The Required Clearance Angle ( a1 ) is the sum of the downtilt + two
times half the vertical beam width + 3 extra degrees to allow for any
additional downtilt for future network optimization.
7). This is the minimum required antenna height from the rooftop ( ht )
necessary to provide sufficient signal clearance
Chapter 6 Installation
Feet
RFS8
1
55.0
10.0
-6
0
-6
5
8
17.73 ft
OL-16336-02