ZyXEL Communications NWA-3163 & NWA-3166 User Manual

 Appendix A Wireless LANs

NWA-3160 Series User’s Guide

An antenna couples RF signals onto air. A transmitter within a wireless device 
sends an RF signal to the antenna, which propagates the signal through the air. 
The antenna also operates in reverse by capturing RF signals from the air. 

Positioning the antennas properly increases the range and coverage area of a 
wireless LAN. 

An antenna in the frequency of 2.4GHz (IEEE 802.11b) or 5GHz(IEEE 802.11a) is 
needed to communicate efficiently in a wireless LAN. 

A radiation pattern is a diagram that allows you to visualize the shape of the 
antenna’s coverage area. 

Antenna gain, measured in dB (decibel), is the increase in coverage within the RF 
beam width. Higher antenna gain improves the range of the signal for better 
communications. 

For an indoor site, each 1 dB increase in antenna gain results in a range increase 
of approximately 2.5%. For an unobstructed outdoor site, each 1dB increase in 
gain results in a range increase of approximately 5%. Actual results may vary 
depending on the network environment. 

Antenna gain is sometimes specified in dBi, which is how much the antenna 
increases the signal power compared to using an isotropic antenna. An isotropic 

WPA 

TKIP/AES

No

Enable

WPA-PSK 

TKIP/AES

Yes

Disable

WPA2

TKIP/AES

No

Enable

WPA2-PSK 

TKIP/AES

Yes

Disable

Table 92   Wireless Security Relational Matrix (continued)