5
Chapter 2: Planning Your Wireless Antenna Coverage
High Gain 9dBi Omni-Directional Antenna
How to Achieve Optimal Gain
Wireless coverage depends on several factors, including power and transmission. You can calculate exact
coverage distance by gathering the specifications of the access point and the Antenna and using the equation
below.
Using this equation is not needed in order to place the Antenna and the access point, but it may be beneficial in
optimizing use of your Antenna and access point.
In this formula, everything is in dBm or dB.
S
r
is the received power. Here we plug in the receiver sensitivity to calculate the maximum distance. For
example, -82dBm for 11Mbps.
S
t
is the transmitted power. For example, 18dBm for 11Mbps.
G
t
is the transmitter antenna gain and
G
r
is the receiver antenna gain (9dBi for this Antenna).
λ
is the wavelength of the signal. The product of
λ
and frequency equals to speed of light (c).
d
is the distance.
LinkBudget
is the lumpsum of additional loss (compared to free space) in the path.
Sr
St Gt Gr
20
λ
4
π
⋅
----------
log
⋅
20
d
( )
log
⋅
LinkBudget
–
–
+
+
+
=
