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Wireless Telecommunication Facilities Master Plan - Town of Morrisville, NC – Adopted July 23, 2013
B-13
Signal strength
The theoretical maps to this point in the master plan illustrate general coverage area from
identified sites. Propagation mapping is a process that illustrates the level of coverage from an
individual antenna site. Signal strength, in this application, is a term used to describe the level of
operability of a wireless phone. The stronger the signal between the elevated antenna and the
wireless phone, the more likely the wireless phone and all the built-in features will work. A
reduced signal decreases the opportunity for satisfactory service caused by dropped calls or
failed calls on the wireless device. Distance between the wireless phone and the elevated
antennas, in addition to existing obstructions such as topography, buildings, and the physical
location of the person using the handset (indoors or outdoors) are variables that affect signal
strength.
The level of propagation signal strength is shown through the gradation of colors from yellow to
blue. The geographic areas in yellow identify superior signal strength; green equates to areas
with average signal strength; shades of blue symbolize acceptable signal strength; and gray
shades show marginal or no signal strength. Generally, the closer the proximity to the antenna,
the brighter shades of yellow within the geographic service area; which means the better quality
of wireless service between the elevated antenna and the wireless handset. As distance increases
between the handset and the antenna the green, blue, and gray shades appear indicating
geographic service areas with average, acceptable, and no signal strength, respectively. Table 4
below provides further explanation of the color coding relative to propagation signals.
Signal Strength Color
Signal Strength Title
Signal Strength Description
Yellow
Superior
Signal strength strong enough to receive signal in
many buildings
Green
Average
Signal strength strong enough to receive signal in a
car, but not inside most buildings
Blue
Acceptable
Signal strength strong enough to receive signal
outside for many handsets, but no expectation of
receiving a signal in a car or building
Gray
No Service
Signal strength is marginal or no service
Table 4: Signal strength
Using the same random antenna locations identified in Figure 1 and Figure 2 Figures 7 and 8
illustrate the various levels of signal coverage from the theoretical antenna locations including
terrain, network capacity and environmental variables. The areas in yellow identify geographic
areas with superior signal strength; green equates to areas with average signal strength; shades of
blue symbolize acceptable signal strength; and gray shades show marginal or no signal strength.
While the industry standards identify green and blue shades as “average” and “acceptable”
coverage; customers tend to indicate otherwise. Most early twenty-first century wireless
subscribers are demanding superior signal strength (yellow) in their residences, schools, offices,
and places frequented for shopping and entertainment. As consumers continue the trend of