to the use of orthogonal frequency-division multiple access
The multiple access connection and collision avoidance is achieved by the Orthogonal Frequency-Division Multiple Access
(OFDMA)  , OFDMA  is a multi-user version of OFDM which provides multiplexing operation of user data stream onto the wireless link carriers.
The conventional orthogonal multiple access (OMA) schemes, such as frequency-division multiple access
(FDMA), time-division multiple access (TDMA), code-division multiple access (CDMA) and orthogonal frequency-division multiple access
(OFDMA) deploy reserved and limited resources for dedicated users which are orthogonal and uniquely allocated.
Although, there are various MAC protocols such as Time division multiple access (TDMA), carrier sense multiple access (CSMA), Frequency-division multiple access
(FDMA), Wireless Sensor MAC (Wise MAC) and Code division multiple access (CDMA) which have already proposed for sensor networks, there is no protocol accepted as a standard     and so designing a MAC protocol is always a challenging research space.
It also offers a more flexible and lower deployment cost compared with previous mobile-broadcast options, by leveraging OFDMA (Orthogonal Frequency-Division Multiple Access
) and wider bandwidths available in LTE.
WiMAX uses scalable frequency-division multiple access
(SOFDMA) which is spectrally very efficient and satisfies the needs of 4G networks.
* Scalable orthogonal frequency-division multiple access
and support for MIMO communications technology for increased coverage, lower power consumption, and more efficient spectrum and bandwidth utilization.
called Frequency-Division Multiple Access
In smart antenna systems, an antenna array is used at the base station to receive information from users of wireless networks operating under the same or different multiple access schemes, such as frequency-division multiple access
(FDMA), time-division multiple access (TDMA) and code-division multiple access (CDMA).
Analog systems, such as the Advanced Mobile Phone Service (AMPS) and the Total Access Communication System, use frequency-division multiple access
in which each user is assigned a unique carrier frequency or channel for the duration of the telephone call.
Both access methods offer advantages over analog frequency-division multiple access