What is 802.11a | Wireless-A: 802.11a is the first wireless model which was available to the public build under the 802.11 family. 802.11a was first introduced in the world in October 1999. The Wireless 802.11a was initially designed to support the wireless communication in the U-NII bands (Unlicensed National Information Infrastructure). The frequency range of Wireless-A or 802.11 A is between the frequency 5 to 6 GHz. The frequency range is regulated in the US by the code of Federation Regulations.

What is 802.11a? | Wireless-A | Wireless Standards

What is 802.11a? | Wireless-A | Wireless Standards

The 802.11 a was initially described as the clause 17 of 1999 specification but now it is written in clause 18 of 2012. The Wireless-A / 802.11a provides us the protocol which allows data transmission and reception at rates of 1.5 to 54Mbit/S. The Wireless-A has a widespread implementation and most particularly within the corporate office workspace. The Term “802.11a” is used by the wireless cards and router manufacturers to mention interoperability of their systems at 54Mbit/s and 5.8GHz.

What is 802.11a?

IEEE 802.11 a standard uses the original core standard and operates in the 5.8 GHz frequency band. The 802.11a uses a 52 subcarrier OFDM (Orthogonal Frequency-Division Multiplexing) with a maximum raw data rate of 54Mbit/S. The data is then reduced to 48, 36, 24, 18, 12, 9 then 6 Mbit/s depending on the distance the individual stand from the router. Initially, 802.11a had 12/13 non-overlapping channels. 802.11 a doesn’t interfere with 802.11b as they operate on the different frequency range.

What is 802.11a? | Wireless-A | Wireless Standards

802.11-a Carriers per Channel

By using the 5GHz band, 802.11 a has an advantage which is lagged by 802.11b as it operates on 2.4GHz which is crowded and causes interference in the signal. The degradation caused by such interference can result in loss of connection and sometimes degradation of the carriers as well. 802.11 a operates in a 5GHz band which is not crowded as the signal is available for a shorter distance only which itself acts as a disadvantage for the 802.11-a cards.

802.11a and Wireless Signalling

The United States Government opened three specific wireless frequency ranges for public use in the year 1980.

  1. 900 MHz (0.9 GHz)
  2. 2.4 GHz
  3. 5.8 GHz (Ofter referred 5Ghz)

Among the three bands, 900 MHz is neglected as the frequency was very low and it won’t suit data transferring. (But many cordless phones use 0.9 GHz most widely). The 802.11-a uses 5.8 GHz for wireless radio signals while 802.11b uses 2.4GHz. The 2.4GHz is subject to many radio interference causing the slow down of data transmission. But the 802.11-a uses 5.8 GHz which is not affected by any signal interference. The Wireless-A Networks are neither affected by any transmitting devices.

What is 802.11a? | Wireless-A | Wireless Standards

2.4GHz VS 5GHz

802.11-a Pros

The below are the various advantages of  Wireless-A

  • Fast and High Speed
  • Regulated frequencies prevent interference from other devices

802.11-a Cons

The below are the various disadvantages of Wireless-A

  • Cost is high. (Manufacturing an 802.11a device for 5GHz frequency band is high)
  • It works for a shorter range only.

The above are the various pros and cons about Wireless-A.

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