Hi,

Today I’ll be sharing some basic knowledge about WLAN planning, helping understand the WLAN planning principles and efficiently perform WLAN planning.

A WLAN can be planned in terms of the network coverage, network capacity, and AP deployment.

• Plan the network coverage to ensure that the signal strength in the coverage areas meets user requirements and co-channel interference is minimized.

• Plan the network capacity to ensure that the network bandwidth meets Internet access requirements and offers smooth Internet access experience.

• After the network coverage and capacity are guaranteed, plan the AP deployment to make sure that APs are deployed, installed, and cabled smoothly on site.

During the network capacity design, AP performance must be considered. In the following sections, I’ll try to explain wireless network coverage concept in bit detail:

Wireless Network Coverage

The network coverage design involves planning for the blanket network coverage areas and signal strength within these areas. Let’s go through each concept in bit detail:

Coverage Area

An AP transmits radio signals through an antenna and generates a wireless network coverage area around the antenna. The signal strength becomes weaker as radio signals are transmitted further. Generally, the area where the signal strength around an antenna is greater than the edge field strength is called wireless network coverage area, as shown below. The field strength of radio signals at the edge of a network coverage area is called edge field strength. For example, if the signal strength indicator value in a common coverage area is -65 dBm, the edge field strength must be greater than or equal to -65 dBm.

Figure: Network coverage area from the top view (omnidirectional antenna)

Coverage Radius

The coverage area of omnidirectional antennas is measured by coverage radius. An AP with an omnidirectional antenna installed on a ceiling is used as an example, as shown below in the figure. The AP's installation height is determined according to the site survey. The maximum transmission distance of radio signals can be calculated based on the edge field strength. After the installation height and maximum transmission distance are determined, the coverage radius of the antenna can be calculated, thereby the effective coverage area of radio signals can be obtained.

Figure: Coverage radius

Coverage Distance

The coverage area of a directional antenna is measured by coverage distance. An AP with a directional antenna installed against a pole outdoors is used as an example, as shown below in the figure. The maximum transmission distance from the antenna to the coverage area edge can be calculated using a formula. The antenna height can be obtained according to the site survey.

Figure: Coverage distance

As shown in the preceding figures, the coverage radius and coverage distance can be calculated when the maximum transmission distance is determined.

I hope you've learnt something new today. In case of any queries, do let me know in the comment section below.

Source for further reading.

Thank you.