This is very important to know if you are buying a laptop or desktop with Wireless Network Card. These standards vary in terms of frequency and speed from each other.
802.11 - This standard was adopted in 1997 by the Institute of Electrical and Electronics Engineers (IEEE) for wireless devices operating in the 2.4 GHz frequency band. This standard supports three radio technologies:
- Direct Sequence Spread Spectrum (DSSS)
- Frequency Hopping Spread Spectrum (FHSS)
WLAN is different from wired LAN. So, IEEE 802.11 standard also includes issues like access to the network (i.e. addressing), bandwidth, privacy of the wireless traffic and power management as most of the wireless LAN NICs are available in PCMCIA Type II format.
802.11b – The IEEE 802.11 standard was modified in 1999 and that was called 802.11a. The data speed was increased to 11 Mbits/sec and 802.11b devices are backward compatible with IEEE 802.11 – 2.4 GHz devices.
802.11a – IEEE 802.11 standard was further modified in 1999 to support 5GHz frequency band and it was referred 802.11a. Unlike the 802.11b wireless devices, 802.11a wireless device uses Orthogonal Frequency Division Multiplexing radio technology. This increased the data rates to 54 Mbits/sec. The data rate up to 108 Mbits/sec is also possible with the use of 2X Turbo Mode. But 2XTM is not part of the 802.11a standard.
802.11g – IEEE 802.11 was modified again in 2002 to achieve 54 Mbits/sec data speed. 802.11g wireless devices operate in 2.4 GHz frequency band and uses Orthogonal Frequency Division Multiplexing radio technologies. 802.11g wireless devices are backward compatible with 802.11b wireless devices.
Recommendation: When you buy a laptop with built in wireless technologies, always check these standards. I recommend for having 802.11b/g. This is very commonly used.