Wireless LAN Standards (802.11a/b/g) Comparison

Name 802.11a
(Wireless A)
802.11b
(Wireless B)
802.11g
(Wireless G)
Year of standard approval by the IEEE 1999 1999 2003
Operating Frequency UNII band :
5.15 - 5.35 GHz
5.425 - 5.675 GHz
5.725 - 5.875 GHz
ISM band :
2.4 - 2.497 GHz
ISM band :
2.4 - 2.497 GHz
Physical Layer OFDM DSSS (CCK) OFDM and CCK
Supported data rates 6, 9, 12, 18, 24, 36, 48, 54 Mbps 1, 2, 5.5, 11 Mbps (CCK) 1, 2, 5.5, 11 Mbps (CCK)
6, 9, 12, 18, 24, 36, 48, 54 Mbps (OFDM)
Theoretical Maximum Speed 54 Mbps 11 Mbps 54 Mbps
Real speed 15 - 20 Mbps 4 - 6 Mbps 15 - 20 Mbps
Indoor coverage 50 - 75 feet 100 - 150 feet 100 - 150 feet
Compatible with - 802.11g 802.11b
Best Use When user density is high Home
SOHO
Home
SOHO

Notes:

- IEEE: Institute of Electrical and Electronics Engineers
- UNII (or U-NII): Unlicensed National Information Infrastructure
- ISM: Industrial, Scientific, and Medical
- OFDM : Orthogonal Frequency Division Multiplexing
- DSSS: Direct Sequence Spread Spectrum
- CCK: Complementary Code Keying (modulation)
- SOHO: Small Office Home Office