Difference between Licensed Band and Unlicensed Band
This page compares licensed band vs Unlicensed Band and mentions major difference between Licensed and Unlicensed (i.e. License Exempt) Bands.
Introduction: The systems deployed within both licensed and unlicensed bands operate as per national or regional regulations. Cellular systems follow 3GPP technical specifications. In unlicensed or license exempt bands, local variations are higher. In USA, FCC defines regulations for unlicensed bands viz. 902 to 928 MHz and 2400 to 2483.5 MHz. In Europe, ETSI publishes standards for unlicensed bands such as 863 to 870 MHz and 2400 to 2483.5 MHz.
➤License is required to be purchased for spectrum use and it is not free.
➤The medium can be accessed or used only by the owner of the license (e.g. MNO)
➤Medium can be accessed via scheduling. Permission is required for transmission or reception.
➤Interference management is carried out by careful frequency planning.
➤Advantages: The benefits of licensed spectrum is known and predictive interference, possibly to use QoS.
➤Disadvantages: • It incurs high costs for network operators. • It is not in use most of the time. • It requires central management. • Low scalability. ➤Examples (licensed frequency bands) : 700 MHz, 800 MHz, 1.8 GHz, 2.6 GHz, 3.5 GHz etc.
➤Examples (Systems): GSM, UMS, LTE, TV broadcasting, Military etc.
➤License is free.
➤Anyone can use the unlicensed spectrum and its medium.
➤Anyone can access the medium via listening if channel is empty.
➤Interference management is carried out using various techniques such as listen before talk, good neighbour behaviour, distributed management etc.
➤Advantages:• Free or low cost to use• It is available everywhere• Scalable
➤Disadvantages:• Unpredictable interference (due to lack of QoS), Higher load, Lack of protection from interference due to other systems.
➤Examples (Unlicensed frequency bands) : 2.4 GHz, 5.8 GHz, 60 GHz
➤Examples (Systems) : WiFi, Bluetooth, LAA etc.
WLAN 802.11n, 802.11ac and 802.11ax related links
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advantages and disadvantages of 802.11ax
Difference between 802.11ac Wave1 and Wave2
Difference between 802.11n,11ac,11ad
WLAN 802.11ac tutorial
WLAN 802.11ax tutorial
WLAN 802.11ac frame structure
WLAN 802.11ac Physical Layer
802.11ac MAC Layer
WLAN 11a,11b,11n,11ac frame structures