The wireless calculator is for outdoor wireless deployment reference only and contains the following functions:

Wi-Fi Link Budget Calculation the reference of WLAN Backbone System or WLAN Surveillance System (PtP link)
Fresnel Zone Calculation the reference of WLAN Backbone System or WLAN Surveillance System (PtP link)
Antenna Downtilt Calculation the reference of WLAN Internet Surfing Coverage System.
Downtilt Coverage Calculation the reference of WLAN Internet Surfing Coverage System.

The calculated results provided are based on the assumption of radio Line-of-Sight (LoS) and thus it only takes into account the free space path loss and cable loss based on your input values. If you have a long radio link, you will need to take all effects (e.g. earth's curvature, refractive index, and more) into account. The final value represents a first order approximation and should only be used as a guide. No guarantees or warranties are implied accordingly.

Note:
The Line-of-Sight (LoS) between radios is required and at least 80% clear of any obstruction in the Fresnel Zone is recommended.

The path between two antennas is referred to as the Line-of-Sight (LoS).
The Fresnel Zone referenced in the diagrams below is an electromagnetic phenomenon, where radio signals get diffracted or bent from solid objects near their path.

There are three main categories of Line of Sight for reference:

  1. Line of Sight (LoS): No obstacles reside between the two antennas; the link can be established and is reliable.
  2. Near Line of Sight (nLoS): Partial obstructions such as tree tops between the two antennas are included. The link may be established with lower performance, but may not be stable.
  3. Non Line of Sight (NLoS): Where full obstructions exist between the two antennas, the link is difficult to establish.

Description:
The Wi-Fi Link Budget is a way of quantifying a communication link's performance while accounting for the system's power, gains, and losses for both the transmitter (Tx) and receiver (Rx).
The Free Space Loss is the transmission loss between two antennas, separated by a distance.
The System Operating Margin is a measure in dB of the signal loss your system can withstand before it degrades to the error rate specified at your Receiver Sensitivity threshold.

Frequency of Site A is not equal to Site B DataRate of Site A is not equal to Site B
Site A Site B
AP Model
Frequency
Tx Power
Data Rate
(Rx Sensitivity)
Antenna Gain
RF Cable Loss
Environment
Distance Between Antennas
miles, or
km
Result
Free Space Loss

Predicted RX signal Strength
Site A: (from Site B)
Site B: (from Site A)

Link should work properly if sites are in clear line of sight. Link may not work or not stable!
System Operating Margin

Maximum Transmission Distance , or
Note:
  1. The following Rx Signal Level is recommended:
    • For WLAN Backbone System: -50dBm ~ -30dBm
    • For WLAN Surveillance System: -55dBm ~ -35dBm
    • For WLAN Internet Surfing Coverage System: -60dBm ~ -40dBm
  2. A minimum 20 dB System Operating Margin is recommended for a reliable link.
  3. Considering the winds to the offset of the antenna, ground shaking (e.g. windmills, wind generators and etc), air temperature and humidity changes (e.g. rain, haze, dust), the link distance over 25miles or 40km are very difficult to align and install.
  4. The Maximum Transmission Distance provided is based on theory and only for design reference. For actual values, field trial is required.

The estimated distance shown in the table is generated based on the above input values of both sites.

Data Rate Estimated Distance
{{item.dataRate}} {{item.dist}}

Description:
The radio frequency line of sight is defined by Fresnel Zones which are ellipse-shaped areas between any two radios. The primary Fresnel zone is required to be at least 80% clear of any obstruction to ensure the highest performance of wireless link.

Signal Frequency
Frequency MHz (between 2400 to 6000)
Environment
Distance between Antennas meters, or miles
Result
Fresnel Zone Radius (r) , or

80% of Fresnel Zone Radius (r) , or

Note:
The final value represents a first order approximation and should only be used as a guide. No guarantees or warranties are implied accordingly.

Description:
The Antenna Downtilt is used to determine the approximate downward angle, measured in degrees, which the transmitting antenna is to be positioned for optimal signal strength and coverage.

Site A Site B
Antenna Base Antenna Height (Hb)
meters, or feet
Remote Antenna Height (Hr)
meters, or feet
Environment
1. Distance meters, or miles

2. Downtilt Angle degrees
Result
1. Result in downtilt angle

2. Result in distance , or

Note:
The final value represents a first order approximation and should only be used as a guide. No guarantees or warranties are implied accordingly.

Description:
Besides the Antenna Downtilt, the Downtilt Coverage Calculator will also give you the inner and outer radius of coverage given the antenna's beamwidth.
Inner Cell Radius: When clients in this area are difficult to connect to the AP
Outer Cell Radius: The maximum antenna radius coverage
Vertical Beamwidth: The perpendicular to the ground as to antenna orientation.

Antenna
Antenna Height (H) meters, or feet

Downtilt Angle degrees

Vertical Beamwidth degrees
Result
Inner Radius Distance , or

Outer Radius Distance , or

Note:

  1. The final value represents a first order approximation and should only be used as a guide. No guarantees or warranties are implied accordingly.
  2. Outer Radius Distance: The value should be “positive”; the "negative" value means the radiation lobe does not touch the ground.