3Com AirConnect User Manual - page 14

14

C

HAPTER

 1: O

VERVIEW

OF

 D

IGITAL

 W

IRELESS

 N

ETWORKING

For details concerning the installation of your PowerBASE-T, see “Using the 

PowerBASE-T”.

Radio Basics

AirConnect devices use radio signals to transmit and receive data without wires. 

You can communicate with the network by establishing radio links between 

wireless clients and APs.

AirConnect uses Quadative Phase Shift layered modulation (QPSK)to transmit 

digital data from one device to another. Using QPSK, a radio signal begins with a 

carrier signal that provides the base or center frequency. The digital data signal is 

superimposed on the carrier signalin process called “modulation.” The radio 

signal then travels through the air as electromagnetic waves. A receiving antenna 

in the path of the waves absorbs them as electrical signals. The receiving device 

“demodulates” the signal by removing the carrier signal. This demodulation 

results in the original digital data.

AirConnect uses its environment (the air and certain other objects) as the 

transmission medium. AirConnect radio devices transmit in the 2.4-2.5 GHz 

frequency range, a license-free range throughout most of the world. The actual 

range your AirConnect network operates at is country-dependent.