|
IEEE 802.11b |
IEEE 802.11a |
Time
Table |
Standard
in 1997, Products in 2000 |
Standard
in 2001, products in 2002 |
Frequency
Band and bandwidth |
Transmit
at 2.4 GHz - IEEE 802.11g standard increases speed of
802.11b to 22
Mbps in the same 2.4 GHz band |
5
GHz |
Speed |
11 Mbps
(Effective speed - half of rated speed) |
54 Mbps
(Effective speed - 50% rated speed) |
Modulation
Technique |
Spread
Spectrum |
OFDM
(Orthogonal Frequency Division Multiplexing |
Distance
Coverage |
Up to
300 feet |
60 feet
- speed goes down with increased distance |
Number
of access points required |
Every
200 feet in each direction |
Every
50 feet; |
Maturity |
More
matured products |
Less
matured but progressing fast |
Market
Penetration |
Quite
widespread |
Just
starting in 2002 |
Interference
with other devices |
Band is
more polluted - significant interference here |
Less
interference because of few devices in this band |
Interoperability |
Current
problems expected to be resolved in future |
Problems
now but expect resolution soon |
Cost |
Cheaper
- $300 for access point and $75 for adapter |
More
expensive $ (500 in 01/2002 - will come down |
Vendors |
Major
vendors in both camps |
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