Transcript 802.11 (a,b,g) and Network Interface Cards

© 2003, Cisco Systems, Inc. All rights
© 2003,
reserved.
Cisco Systems, Inc. All rights reserved.
FWL 1.0—2-1
1
Module 2
IEEE 802.11 and Network Interface Cards
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FWL 1.0—2-2
Learning Objectives
•Identify the IEEE 802. standards.
• Identify the IEEE 802.11 standards.
•Understand the MAC and PHY layers of 802.11
•Identify which client operating systems are
supported.
•Determine the status of a client card by
observing the indicator lights.
•Install and configure a Cisco Aironet PC Card.
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FWL 1.0—2-3
Overview
This chapter will cover the IEEE 802.11 WLAN
(WLAN) standards in detail, including data link
and physical layer specifications. Throughout
this module and this course, the terms IEEE and
802 are used often. This module provides a
short overview of IEEE and the 802 committee.
The MAC and physical layer services that have
been standardized will be discussed. Finally,
client adapters, driver types, and client support
will also be discussed.
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FWL 1.0—2-4
Key terms
• IEEE
• MAC
• PHY
• NIC
• STA
• MSDU
• PLCP
• PMD
• BSS
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802.11 Standards
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IEEE 802.11 Standards Activities
802.11a:
802.11b:
802.11d:
802.11e:
802.11f:
802.11g:
802.11h:
802.11i:
802.11j:
802.11k:
802.11m:
802.11n:
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5GHz, 54Mbps
2.4GHz, 11Mbps
Multiple regulatory domains
Quality of Service (QoS)
Inter-Access Point Protocol (IAPP)
2.4GHz, 54Mbps
Dynamic Frequency Selection (DFS) and
Transmit Power Control (TPC)
Security
Japan 5GHz Channels (4.9-5.1 GHz)
Measurement
Maintenance
High-Speed
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802.11a / 5 GHz Band
Data rates supported: 54, 48, 36, 24, 12, and 6 Mbps
•Client will automatically “downshift” to lower data rate when it gets further from AP
23 Countries have approved the use of 802.11a products:
•U.S.
Australia
AustriaDenmark
France
Ireland Japan Singapore
Taiwan Argentina
•U.K.
Germany
Norway
Portugal Canada
Finland Poland Switzerland
Mexico
Sweden New Zealand
Belgium Netherlands
802.11h will ultimately permit worldwide usage of WLANs @ 5 GHz
•Transmit Power Control (TPC)
•Dynamic Frequency Selection (DFS)
5.470-5.725 GHz band being opened up (11 more channels)
•This new 5.47-5.725 GHz band, plus 5.25-5.35 GHz UNII-2 band, will require DFS
•Current UNII-2 products in the market will likely be grandfathered (i.e. no DFS)
5 GHz band has more channels than 2.4 GHz band
•UNII-1 + UNII-2 = 8 channels (plus 11 future channels) vs. 3 channels for 2.4 GHz
•However, depending on distance between AP’s, you may only be able to use half of the 5 GHz
channels due to adjacent channel interference
5 GHz band subject to less interference than 2.4 GHz band
•However, 2.4 GHz interference not a major problem in most business environments
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FWL 1.0—2-8
Three Wireless Technologies
802.11b
802.11a
802.11g
Frequency
Band
2.4 GHz
5 GHz
2.4 GHz
Availability
Worldwide
US/AP
Worldwide
11 Mbps
54 Mbps
54 Mbps
HyperLAN
Devices
Cordless Phones
Microwave Ovens
Wireless Video
Bluetooth Devices
Maximum
Data rate
Other
Services
(Interference)
Cordless Phones
Microwave Ovens
Wireless Video
Bluetooth Devices
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
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FWL 1.0—2-9
IEEE 802.11 Standard
IEEE 802.11 became a standard in July 1997
• 2.4 GHz at 2 Mbps Frequency Hopping Spread Spectrum
(FHSS) and Direct Sequence Spread Spectrum (DSSS)
IEEE 802.11a and 802.11b became standards in
September 1999
• 802.11a – 5 GHz at 54 Mbps OFDM
• 802.11b – 2.4 GHz at 11 Mbps DSSS
IEEE 802.11g is scheduled to be ratified in 2003
• 802.11g – 2.4 GHz at 54 Mbps OFDM
802.11 promises “true” vendor interoperability
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Standards and Organizations
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WLAN Speeds & Frequencies
802.11g
2.4 GHz – OFDM/CCK
54 Mbps
802.11a
5 GHz – OFDM
54 Mbps
802.11b
2.4 GHz – CCK
11 Mbps
Proprietary

Jan’99
IEEE 802.11a/b
Ratified
Jan’00
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Jan’01
Jan’02
Jan’03
Jan’04
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What Is WLAN RF Technology?
Data sent over the air waves
Two-way radio communications (half
duplex)
Same radio frequency for
sending & receiving (transceiver)
No licensing required for Cisco Aironet
Wireless products (in most countries)
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IEEE 802. Standards
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802.11 Architecture
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802.11 Physical (PHY) Layer Modulations
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Stations (STA)
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PHY Protocols
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Basic Service Set (BSS)
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Independent Basic Service Set (IBSS)
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Extended Service Set (ESS) and Distributed
System (DS)
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MAC Layer
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MAC Services
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MAC Architecture
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CSMA
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Interframe Spaces
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PHY Layer
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PHY Functions
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802.11b
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2.4 GHz Channel Sets
Channel
Identifier
Center
Frequency
Regulatory Domain
Americas
Europe, Middle East and Asia
Japan
Israel
1
2412 MHz
X
X
X
2
2417 MHz
X
X
X
3
2422 MHz
X
X
X
X
4
2427 MHz
X
X
X
X
5
2432 MHz
X
X
X
X
6
2437 MHz
X
X
X
X
7
2442 MHz
X
X
X
X
8
2447 MHz
X
X
X
X
9
2452 MHz
X
X
X
X
10
2457 MHz
X
X
X
11
2462 MHz
X
X
X
12
2467 MHz
X
X
13
2472 MHz
X
X
14
2484 MHz
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X
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Channels- 2.4 GHz DSSS
11 Channels – each channel 22 MHz wide
1 set of 3 non-overlapping channels
14 Channels – each channel 22 MHz wide
4 sets of 3 non-overlapping channels, only one set used at a
time
11 “chips per bit” means each bit sent redundantly
11 Mbps data rate
3 access points can occupy same area
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FWL 1.0—2-31
802.11b Access Point Coverage
1 Mbps DSSS
2 Mbps DSSS
5.5 Mbps DSSS
11 Mbps DSSS
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802.11b Scalability
Total Theoretical Bandwidth = 33 Mbps
Blue = 11 Mbps
Green = 11 Mbps
Red = 11 Mbps
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FWL 1.0—2-33
Comparing the Technologies
802.11a Data Rates
Modulation with
Sub Channels
BPSK
Data Rate Per
Total Data Rate
Subchannel
(Mbps)
(Kbps)
125
6
BPSK
187.5
9
QPSK
250
12
QPSK
375
18
16QAM
500
24
16QAM
750
36
64QAM
1000
48
64QAM
1125
54
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FWL 1.0—2-34
802.11a Channel Sets
Australia
New Zealand
Austria
Panama
Brazil
Peru
Canada
Sweden
Chile
Columbia
Denmark
France
United
Kingdom
United States
Venezuela
Channel ID
34
36
38
40
42
44
46
48
52
56
60
64
Frequency
(MHz)
5170
5180
5190
5200
5210
5220
5230
5240
5260
5280
5300
5320
Cisco Maximum Peak Power (mW)*
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Taiwan (-T)
Mexico
Singapore (-S)
Argentina
Japan (-J)
Americas include:
Americas (-A)
Channel Set
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
40
x
40
20
x
x
x
x
40
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802.11a Access Point Coverage
OFDM
54 Mbps
48 Mbps
36 Mbps
24 Mbps
18 Mbps
12 Mbps
09 Mbps
06 Mbps
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FWL 1.0—2-36
802.11a Scalability (Indoor UNII-1 and 2)
Total Theoretical Bandwidth = 432 Mbps
8 non-overlapping
channels
54 Mbps
54 Mbps
54 Mbps
54 Mbps
54 Mbps
54 Mbps
54 Mbps
54 Mbps
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FWL 1.0—2-37
Client Adapters
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Cisco Aironet 802.11b Client Adapters
2.4 GHz
• 802.11b
• 11 Mbps
Include
• PC Card
• PCI Card
• LMC Card
• Mini PCI
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FWL 1.0—2-39
802.11b PC Card
2.4 GHz/802.11b
• 11 Mbps
Rate Shifting
• 1, 2, 5.5, and 11Mbps
Fixed data rates
• User configurable option
Integrated Antenna
PCMCIA interface
Transmit power settings:
• 100 mW, 50 mW, 30 mW, 20 mW,
10 mW, 5 mW, and 1 mW
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FWL 1.0—2-40
802.11b LMC Card
2.4 GHz/802.11b
• 11 Mbps
Rate Shifting
• 1, 2, 5.5, and 11Mbps
Fixed data rates
• User configurable option
PCMCIA interface
Transmit power settings:
• 100 mW, 50 mW, 30 mW, 20 mW,
10 mW, 5 mW, and 1 mW
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FWL 1.0—2-41
802.11b PCI Card
2.4 GHz/802.11b
• 11 Mbps
Rate Shifting
• 1, 2, 5.5, and 11Mbps
Fixed data rates
• User configurable option
RP-TNC Connector
PCMCIA interface
Transmit power settings:
• 100 mW, 50 mW, 30 mW, 20 mW,
10 mW, 5 mW, and 1 mW
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802.11b Mini PCI Adapter
2.4 GHz/802.11b
embedded wireless for
notebooks
100 mW transmit power
Must order through PC
manufactures (not
orderable directly
through Cisco)
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FWL 1.0—2-43
802.11a CardBus2 Client Adapter
5 GHz/802.11a
• 54 Mbps
Rate Shifting
• 6, 9, 12, 18, 24, 36, 48, or 54
Fixed data rates
• User configurable option
5 dBi Patch Antenna
CardBus interface
Transmit power settings:
• 20 mW, 10 mW, and 5 mW
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FWL 1.0—2-44
PC Card LEDs
Dual LED helps
identify the card
status
• Green LED is the
Status LED
• Orange LED is
the RF traffic
LED
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FWL 1.0—2-45
LED Status
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Windows Drivers
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Linux and Macintosh Drivers
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Downloading Drivers and Software
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Ad-Hoc
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Infrastructure
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Aironet Client Utility: Main Screen
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Aironet Client Utility: Loading
Firmware
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Aironet Client Utility: Profile Manager
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Aironet Client Utility: Adding a Profile
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Profile: System Parameters
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Profile: RF Network
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Profile: RF Network
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Profile: Advanced (Infrastructure)
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Profile: Advanced (Ad Hoc)
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Profile: Network Security
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Aironet Client Utility: Status
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Aironet Client Utility: Statistics
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Aironet Client Utility: Link Test
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Aironet Client Utility: Site Survey
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Link Status Meter
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FWL 1.0—2-66
Installing the Client Adapter
Insert the adapter
card into the
PCMCIA slot in the
PC
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Task 4: ACU Install and Setup
From the UTILS
folder on the
driver CD, run
SETUP
SETUP
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Task 4: ACU Install and Setup (cont.)
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Task 4: ACU Install and Setup (cont.)
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Task 4: ACU Install and Setup (cont.)
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Task 4: ACU Install and Setup (cont.)
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Task 4: ACU Install and Setup (cont.)
Aironet Client Utility
(ACU)
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Task 4: ACU Install and Setup (cont.)
Step 13
Step 14
Step 12
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Task 4: ACU Install and Setup (cont.)
Step 16
Step 17
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FWL 1.0—2-75
Summary
• Identify characteristics of Cisco Aironet 802.11a
products.
• Identify characteristics of Cisco Aironet 802.11b
products.
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FWL 1.0—2-76
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