In the United States, the FCC defines regulations for unlicensed bands as 902 to 928 MHz and 2400 to 2483.5 MHz.
Licensed Vs. Unlicensed
|License required to be purchased||License is free|
|Medium can be accessed\used only by the owner of the license||Unlicensed spectrum and its medium can be accessed\used by anyone|
|Permission is required for transmission or reception and scheduling||Anyone can access the medium if channel is empty|
|Interference management is carried out by careful frequency planning||Interference management can be done using various techniques such as distributed management|
|Advantages- The benefits of licensed spectrum is known and predictive interference||Advantages- Free or low cost to use, available nearly everywhere, scalable|
|Disadvantages- high costs for network operators, requires central management, low scalability||Disadvantages- Unpredictable interference (due to lack of QoS), Higher load, Lack of protection from interference due to other systems|
For FCC Basics of Unlicensed FCC Basics of Unlicensed
Transmitters click here.
For the National Association of Broadcasters Engineering Handbook, click here.