New Technologies for Wireless LANs

30 Pages·2001·1.907 MB·English

by  Alexander B.

Presentation_ID © 2001, Cisco Systems, Inc. All rights reserved. 111
New Technologies
for Wireless LANs
Bruce Alexander
Cisco Aironet Wireless Networking Business Unit
Session Number
Presentation_ID © 2001, Cisco Systems, Inc. All rights reserved. 2
The Productivity Paradox
Why is it that the
only location where
employees have
access to all their
productivity tools...
...is the one
location where they
spend the least
amount of time—
their desks
ACC-231
5P05re9s_e0n4t_a2ti0o0n2__IDc1 ©© 22000012,, CCiissccoo SSyysstteemmss,, IInncc.. AAllll rriigghhttss rreesseerrvveedd.. 333333
Technology that is available
TODAY
can help you build a WLAN
that will continue to work for
TOMORROW.
Presentation_ID © 2001, Cisco Systems, Inc. All rights reserved. 444
Seminar Overview
•WLAN Technologies
•802.11a, 802.11b, 802.11h, and 802.11g
•When to use what technology
•Comparing 802.11a and 802.11b
•Combining technologies
•Security (Quick Update)
Presentation_ID © 2001, Cisco Systems, Inc. All rights reserved. 555
Wireless Technologies
WAN
(Wide Area Network)
MAN
(Metropolitan Area Network)
LAN
(Local Area Network)
PAN
(Personal Area
Network)
PPAANN LLAANN MMAANN WWAANN
880022..1111aa,,1111bb,,1111gg 880022..1111 GGSSMM,, GGPPRRSS,,
SSttaannddaarrddss BBlluueettooootthh
HHiippeerrLLAANN22 MMMMDDSS,, LLMMDDSS CCDDMMAA,, 22..55--33GG
SSppeeeedd << 11MMbbppss 22 ttoo 5544++ MMbbppss 2222++ MMbbppss 1100 ttoo 338844KKbbppss
RRaannggee SShhoorrtt MMeeddiiuumm MMeeddiiuumm--LLoonngg LLoonngg
PPDDAAss,, MMoobbiillee
PPeeeerr--ttoo--PPeeeerr EEnntteerrpprriissee FFiixxeedd,, llaasstt mmiillee
AApppplliiccaattiioonnss PPhhoonneess,, cceelllluullaarr
DDeevviiccee--ttoo--DDeevviiccee nneettwwoorrkkss aacccceessss
aacccceessss
Presentation_ID © 2001, Cisco Systems, Inc. All rights reserved. 666
Wireless LAN Technologies
880022..1111bb 880022..1111aa 880022..1111gg
Frequency
22..44 GGHHzz 55 GGHHzz 22..44 GGHHzz
Band
Availability WWoorrllddwwiiddee UUSS//AAPP WWoorrllddwwiiddee
1111 MMbbppss
Maximum 5544 MMbbppss 5544 MMbbppss
Data Rate
The Laws of Radio Dynamics:
Higher data rates = shorter transmission range
Higher power output = increased range, but lower battery life
Higher frequency radios = higher data rates, shorter ranges
Presentation_ID © 2001, Cisco Systems, Inc. All rights reserved. 777
802.11a
• Ratified as Standard in September, 1999
• Provides similar technology to HylerLAN2
• Data rates to 54Mb defined
• Provides 8 indoor WLAN channel
• Regulation differ extensively across
countries
Presentation_ID © 2001, Cisco Systems, Inc. All rights reserved. 888
802.11a Issues
• 8 channels (UNII1 and UNII2 combined)
May not be able to use adjacent channels in
adjacent cells due to sidebands
• Interoperability—Some independent testing has
been completed. Wi-Fi testing expected to start
in late spring, early summer
• Not qualified for Europe
TX power control and Dynamic Frequency
Selection required- not part of 802.11a
Presentation_ID © 2001, Cisco Systems, Inc. All rights reserved. 999
802.11b
11Mb 2.4GHz Direct Sequence
• Ratified as Standard in September, 1999.
• 11Mb 2.4Gz
• 11 US channels
• 13 ETSI channels
• 14 Japan Channels
• Power levels of 36dBm EIRP-FCC
20dBm EIRP- ETSI
• Virtually approved for world wide use.
Presentation_ID © 2001, Cisco Systems, Inc. All rights reserved. 111000