What is IEEE 802.11a? - Explained


After the very first initial release of the core specification to the IEEE 802.11 legacy wireless network communication, IEEE released the amended version of 802.11 wireless network standard as IEEE 802.11a which is also known as IEEE 802.11a-1999.

Technology

The amendment which made into the IEEE 802.11 wireless network is to operate the IEEE 802.11 wireless network in OFDM communication system also known as Orthogonal Frequency Division Multiplexing. In addition the original design of the specification is to support wireless communication by using the Unlicensed National Information Infrafucture in USA also known as U-NII bands which operates in 5GHz to 6GHz.

The data transfer rate of the wireless network got higher speed from 1Mbit/s - 2Mbit/s to 1.5Mbit/s - 54Mbit/s. Because of the higher speed and the wireless connectivity, version 802.11a implemented in many corporate office environments in the world. The most popular wireless network was which operated at the frequency 5.8GHz and capable enough to deliver 54Mbit/s theoretically. But the realistic achievement by using the OFDM was 20Mbit/s.

Using the 802.11a was a huge advantage to the general public because in the early days, the 2.4GHz frequency was crowded due to heavy usage in the channels. Due to crowded network channels, the wireless network wasn't capable enough to deliver the highest speeds due to interference made by the other networks in the same 2.4GHz frequency levels and in the same channels.

There were multiple modulation types which used in the 802.11a wireless networks and each wireless network provided different types of strengths to the wireless network.


RATE bitsModulation TypeCoding RateData Rate in Mbit/s
1101BPSK1/26
1111BPSK3/49
0101QPSK1/212
0111QPSK3/418
100116-QAM1/224
101116-QAM3/436
001164-QAM2/348
001164-QAM3/454