ZyXEL Communications N4100 User Manual

Appendix D Wireless LANs
N4100 User’s Guide
327
Antenna Overview
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.
Antenna Characteristics
Frequency
An antenna in the frequency of 2.4GHz (IEEE 802.11b and IEEE 802.11g) or 5GHz
(IEEE 802.11a) is needed to communicate efficiently in a wireless LAN
Radiation Pattern
A radiation pattern is a diagram that allows you to visualize the shape of the
antenna’s coverage area.
Antenna Gain
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
antenna is a theoretical perfect antenna that sends out radio signals equally well
in all directions. dBi represents the true gain that the antenna provides.
Types of Antennas for WLAN
There are two types of antennas used for wireless LAN applications.

ZyXEL Communications N4100 Specifications

General

Number of users	100 user(s)
Ethernet LAN data rates	10, 100 Mbit/s
Maximum data transfer rate	100 Mbit/s
Indoor range	35 ~ 100 m
Outdoor range	100 ~ 300 m
Connectivity LEDs	Yes
Internal	No
Certification	FCC, CE, C-Tick, NCC, RoHS, WEEE
Security algorithms	802.1x RADIUS
Power requirements	100-240 VAC, 50/60 Hz, 0.5 A
Storage temperature (T-T)	-20 - 60 °C
Operating temperature (T-T)	0 - 50 °C
Operating relative humidity (H-H)	10 - 95 %

Weight and Dimensions

Weight	565 g
Dimensions (WxDxH)	222 x 146 x 152 mm