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Chapter 1 Overview of Wireless Standards,
Organizations, and Fundamentals
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Exam Essentials Know the three industry organizations Understand the roles and responsibilities of the
regulatory domain authorities, the IEE, and the Wi-FiAlliance.
Understand Core, Distribution and Access Know where 802.11 technology is deployed in
fundamental network design
Understand wavelength, frequency, amplitude,
and phase Know the definitions of each RF characteristics
Understand the concepts of modulation ASK, FSK, PSK are three carrier signal modulation
techniques
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History of WLAN Trace back to 19th century scientists
Radio Frequency
WWII
Tramsitting encrypted plans over RF
Spread Spectrum Technology created
1970s-Aloha Net
1990s-Early commercial development
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Standards Organizations FCC
IEEE
Wi-Fi Alliance
ISO
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FCC Regulates Communication in the US
Regulate Licensed and Unlicensed
Wireless LAN mostly in unlicensed Regulates:
Frequency
Bandwidth
Maximum Power of the intentional Radiator Maximum equivalent isotropically radiated power
(EIRP)
Use (indoor and/or outdoor)
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FCC Regulates Communication in the US
Regulate Licensed and Unlicensed
Wireless LAN mostly in unlicensed Regulates:
Frequency
Bandwidth
Maximum Power of the intentional Radiator Maximum equivalent isotropically radiated power
(EIRP)
Use (indoor and/or outdoor)
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Federal Communications
Commission Manage RF for USA
802.11 wireless can use both licensed and
unlicensed frequencies Unlicensed means no cost to users
2.4 Ghz industrial, scientific and Medical
(ISM) 5 Ghz Unlicensed National Inforamtion
Infrastructure (UNII) band
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ITU-R Manages global spectrum of RF
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IEEE Defines the 802 series standards
802.3 Ethernet
802.11 Wireless Document the technical and equipment
basics
Can be different interpretations
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Wi-Fi Alliance Starting with 802.11b manufacturers
formed WECA
Promote technology Support interoperability
In 2000, WECA became WiFi Alliance
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Interoperability Certifications Addressed the issue of standards
Help growth and progression
Allow interoperability
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Wi-Fi Protected Access (WPA)
Certification Overview Created due to weak security in initial standards
Interim solution before 802.11i
Temporal Key Integrity Protocol (TKIP) Passphrase
802.1X/EAP
Two Modes
Personal Home Office
Enterprise
Larger Deployment (Servers)
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Wi-Fi Protected Access 2 (WPA
2.0) Certification Overview Post 802.11i
WPA 2.0
Personal and Enterprise
More advanced security
Personal mode security uses a passphrase
Generates a 256 bit preshared key Enterprise mode uses 802.1X/EAP
Port based authentication designed for enterprises
Strong security and external authentication
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Wi-Fi Protected Access 2 (WPA
2.0) Certification Overview
WiFi Alliance Security
Mechanism
Authentication
Mechanism
Cipher Suite/Encryption
Mechanism
WPA-Personal Passphrase TKIP/RC4
WPA_Enterprise 802.1x/EAP TKIP/RC4
WPA2.0 Personal Passphrase CCM/AES or TKIP/RC4
802.1x/EAP CCM/AES or TKIP/RC4
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Wi-Fi Multimedia (WMM)
Certification Overview Proactive certification for 802.1e
Address QOS for wireless networks
WMM Validates the features of 802.11e Vendor neutral QOS approach
Ciritical for interoperability
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Wi-Fi Multimedia Power Save (WMM-PS)
Certification Overview Designed for Mobile devices with battery issues
VoIP Phones
Notebooks
PDAs
Headsets
Mice
Keyboards Allow dozing to save battery
May affect performance
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Wi-Fi Protected Setup (WPS)
Certification Overview Designed for simple set up of wireless for SOHO
networks
Requires support for two types of authentication
Push Button Config (PBC)
PIN based config
Enables automatic configuration of network
names and WPA2 security Both methods need to be supported
Near Field Communications also supported
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ISO Identifies standards for business,
government and society
Created the OSI model for computersnetworking
Not implemented, but often referenced
Should understand the layers
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OSI Model Layer 7- Application Layer 6-Presentation
Layer 5- Session
Layer 4- Transport Layer 3-Network
Layer 2-Data Link LLC
MAC Layer 1-Physical
Please Do Not Throw Sausage Pizza Away
All People Seem To Need Data Processing
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Core, Distribution, Access Core No routing-High Speed Switching
Redundant Solutions
Distribution Router Traffic between LANS/VLANS
Wireless Bridges can operate here
Access Slower delivery to end user devices
To the desktop
802.11 Mostly implemented at access layer Access points
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Communications Fundamentals Most people have a basic idea about
transfer of data
This section gives more background onfundamental communications for wireless
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Carrier Signals Need to be able to transmit twostates:
1 or 0
AC or DC alone wont do it,need to alternate or modulate
The base signal that is
modified is called the CarrierSignal
The method of adjusting it isthe modulationtechnique
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Amplitude and Wavelength
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Key wave terms Amplitude is a measure of the height of a wave.The higher the amplitude, the higher the power.
Wavelength is the measure of the lengthbetween peaks.
Frequency is how often the peaks come in aperiod of time, usually measured in Hertz (times
per second). Phase is usually used to refer to the relationship
between two waveforms of the same frequency.Phase is measured in degrees.
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Amplitude and Wavelength
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Phase
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Keying Methods Signal transmitted from the transceiver
has to be manipulated to let receiver
distinguish between 1 and 0 This is the keyingmethod
Also known as modulation techniques
Amplitude Shift Keying Frequency Shift Keying
Phase Shift Keying
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Current State Keying Uses the current (in time) value to show a 1 or 0 Whatever the current state is is the binary 0
Other state is 1
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State Transition Keying The change, or lack of change will signify
a 0 or 1
0 is a change in state 1 is no change in state of signal
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Amplitude-Shift Keying Uses the height, or amplitude of the wave
to signal change.
Current state technique A shift indicates a change from current signal
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Frequency-Shift Keying Uses the frequency, or number of cycles persecond to indicate change.
Current state technique
A shift indicates a change from current signal
Used in legacy (older) 802.11 technologies
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Phase-Shift Keying Varies the phase of a signal to representdata
State Transition technique
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Phase-Shift Keying-Advanced Can encode multiple bits per symbol aswell
Use four different phases Multiple Phase shift Keying
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Exam Essentials Know the three industry organizations Understand the roles and responsibilities of the
regulatory domain authorities, the IEE, and the Wi-FiAlliance.
Understand Core, Distribution and Access Know where 802.11 technology is deployed in
fundamental network design
Understand wavelength, frequency, amplitude,
and phase Know the definitions of each RF characteristics
Understand the concepts of modulation ASK, FSK, PSK are three carrier signal modulation
techniques