802.11a Wireless LAN
The first wireless LAN (WLAN) standard was created by the IEEE committee
in 1997, and was called 802.11. However, 802.11 standard supported only up
to 2 Mbps of bandwidth, and quickly became obsolete. Subsequently, IEEE
created the 802.11a, and 802.11b standards.
The following are the
advantages of the IEEE 802.11a standard compared to 802.11b:
- 802.11a uses 5GHz frequency band which is less crowded and hence has
relatively smaller interference problem.
- 802.11a supports up to 54Mbps of bandwidth, which is much faster
than the 11Mbps bandwidth provided by 802.11b standard devices.
- 802.11a offers as many as 12 non-overlapping channels. With more
channels, larger number of users can be accommodated with no performance
Some of the disadvantages of using the 802.11a standard are:
- Not many client devices such as note book computers, PDAs support
802.11a standard. Most of these support either 802.11b or Bluetooth
- It is more expensive compared to other contemporary technologies
like 802.11b and Bluetooth.
standards are not compatible with 802.11b. Hence, devices manufactured
complying with 802.11a and 802.11b respectively, are not interoperable.
- The distance covered will be slightly less compared to 802.11b due
to higher operating frequency (5 GHz). Note that, higher the radio
frequency, lower the propagation distance for a given output power.
You may consider using 802.11g in place of 802.11a for reasons of cross