24-02-2011, 11:39 AM
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Wireless LAN Security
Uses
Key drivers are mobility and accessibility
Easily change work locations in the office
Internet access at airports, cafes, conferences, etc.
Benefits
Increased productivity
– Improved collaboration
– No need to reconnect to the network
– Ability to work in more areas
Reduced costs
– No need to wire hard-to-reach areas
Standards
IEEE 802.11
IEEE 802.11b
IEEE 802.11a
IEEE 802.11e
HiperLAN/2
Interoperability
802.11
Published in June 1997
2.4GHz operating frequency
1 to 2 Mbps throughput
Can choose between frequency hopping or direct sequence spread modulation
802.11b
Published in late 1999 as supplement to 802.11
Still operates in 2.4GHz band
Data rates can be as high as 11 Mbps
Only direct sequence modulation is specified
Most widely deployed today
802.11a
Also published in late 1999 as a supplement to 802.11
Operates in 5GHz band (less RF interference than 2.4GHz range)
Users Orthogonal Frequency Division Multiplexing (OFDM)
Supports data rates up to 54 Mbps
Currently no products available, expected in fourth quarter
802.11e
Currently under development
Working to improve security issues
Extensions to MAC layer, longer keys, and key management systems
Adds 128-bit AES encryption
HiperLAN/2
Development led by the European Telecommunications Standards Institute (ETSI)
Operates in the 5 GHz range, uses OFDM technology, and support data rates over 50Mbps like 802.11a
Interoperability
802.11a and 802.11b work on different frequencies, so little chance for interoperability
Can coexist in one network
HiperLAN/2 is not interoperable with 802.11a or 802.11b