Installation Instructions

Ensemble Communications Inc.
3-6 Operator’s Guide to the Fiberless System
Multiple Antenna Configuration
In multiple antenna configurations, each sector must be separated
by a prescribed space to prevent interference from adjacent sectors.
The size of this space depends primarily on the amount of
interference a sector’s receiver can tolerate and whether the sectors
are operating synchronously or nonsynchronously.
Antenna Separation
for Synchronous
Transmission
For configurations using synchronous transmission (that is, each
sector associated with a base station transmits at the same time and
receives at the same time), multiple sectors must be separated by at
least 0.5 meters (1.65 feet) vertically and horizontally (see
Figure 3-1 and Figure 3-2).
Antenna Separation
for Asynchronous
Transmission
For configurations using asynchronous transmission (that is, some
sectors may be transmitting simultaneously while others are
receiving), multiple sectors must be attenuated so the receiver’s
SNR does not fall below the minimum level required to
demodulate the signal. Based on the horizontal antenna patterns
for the Andrew BCA Mark II antenna, Table 3-1 provides minimal
horizontal spacing to isolate sectors that are separated by one, two,
three, and four channels from each other. For distances within the
near field range, the antennas act as radiating point sources
Table 3-1: Minimum Horizontal Spacing for Nonsynchonous Sectors
Antenna
Beam
Width in
Degrees
Angular
Separation
in Degrees
N+1
Spacing
(Meters/
Feet)
N+2
Spacing
(Meters/
Feet)
N+3
Spacing
(Meters/
Feet)
N+4
Spacing
(Meters/
Feet)
45 0 20.33 3.57 0.36 0.36
45 45 20.33 3.57 0.36 0.36
45 90 20.33 3.57 0.36 0.36
45 180 20.33 3.57 0.36 0.36
60 0 20.33 3.57 0.36 0.36
60 60 20.33 3.57 0.36 0.36
60 90 20.33 3.57 0.36 0.36
60 120 20.33 3.57 0.36 0.36
60 180 20.33 3.57 0.36 0.36
90 0 79.80 3.57 0.36 0.36
90 45 20.33 3.57 0.36 0.36
90 60 20.33 3.57 0.36 0.36
90 90 20.33 3.57 0.36 0.36