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© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-1
Wireless LANIntroduction
Olga Torstensson
Halmstad University
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-2
Wireless LAN
• WLAN
• Bridging
• Access Point
• Bridge
• Antenna
• Wi-Fi™
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-3
Major Factors
There are four major factors to consider before implementing a wireless network:
• High availability
• Scalability
• Manageability
• Open architecture
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-4
Wireless Technologies
PAN(Personal Area
Network)
PAN(Personal Area
Network)
LAN(Local Area Network)
LAN(Local Area Network)
WAN(Wide Area Network)
WAN(Wide Area Network)
MAN(Metropolitan Area Network)
MAN(Metropolitan Area Network)
PANPAN LANLAN MANMAN WANWAN
BluetoothBluetooth
Peer-to-PeerDevice-to-Device
Peer-to-PeerDevice-to-Device
ShortShort
<1 Mbps<1 Mbps
802.11a, 11b, 11gHiperLAN2
802.11a, 11b, 11gHiperLAN2
Enterprise Networks
Enterprise Networks
MediumMedium
2–54+ Mbps2–54+ Mbps
802.11MMDS, LMDS
802.11MMDS, LMDS
Fixed, LastMile AccessFixed, LastMile Access
Medium–LongMedium–Long
22+ Mbps22+ Mbps
GSM, GPRS,CDMA, 2.5–3GGSM, GPRS,
CDMA, 2.5–3G
PDAs, MobilePhones, Cellular
Access
PDAs, MobilePhones, Cellular
Access
LongLong
10–384 Kbps10–384 Kbps
StandardsStandards
SpeedSpeed
RangeRange
ApplicationsApplications
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-5
Wireless Technologies
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-6
In Building WLAN
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-7
Site to Site WLAN
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-8
WLAN Markets
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-9
Radio Signal Interference
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-10
Power Consumption
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-11
Interoperability
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-12
Wireless LAN Security:Lessons
“War Driving”
Hacking into WEP
Lessons:
• Security must be turned on (part of the installation process)
• Employees will install WLAN equipment on their own (compromises security of your entire network)
• WEP keys can be easily broken (businesses need better security)
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-13
Reliability and Connectivity
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-14
Installation and Site Design Issues—Bridging
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-15
Installation and Site Design Issues—WLAN
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-16
Health Issues
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-17
IEEE 802.11 Standards Activities
802.11a: 5GHz, 54Mbps
802.11b: 2.4GHz, 11Mbps
802.11d: Multiple regulatory domains
802.11e: Quality of Service (QoS)
802.11f: Inter-Access Point Protocol (IAPP)
802.11g: 2.4GHz, 54Mbps
802.11h: Dynamic Frequency Selection (DFS) and Transmit Power Control (TPC)
802.11i: Security
802.11j: Japan 5GHz Channels (4.9-5.1 GHz)
802.11k: Measurement
© 2003, Cisco Systems, Inc. All rights reserved. FWL 1.0—1-18
WLAN Speeds & Frequencies
802.11g2.4 GHz – OFDM/CCK
54 Mbps
Proprietary IEEE 802.11a/b Ratified
802.11a5 GHz – OFDM
54 Mbps
802.11b2.4 GHz – CCK
11 Mbps
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