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Chapter 1

Chapter 1. Overview of Wireless Standards, Organizations, and Fundamentals. Exam Essentials. Know the three industry organizations Understand the roles and responsibilities of the regulatory domain authorities, the IEE, and the Wi-Fi Alliance. Understand Core, Distribution and Access

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Chapter 1

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  1. Chapter 1 • Overview of Wireless Standards, Organizations, and Fundamentals

  2. Exam Essentials • Know the three industry organizations • Understand the roles and responsibilities of the regulatory domain authorities, the IEE, and the Wi-Fi Alliance. • 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

  3. 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 Pg 2

  4. Standards Organizations • FCC • IEEE • Wi-Fi Alliance • ISO Pg 3

  5. 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) Pg 3

  6. 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) Pg 3

  7. 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 Pg 5

  8. ITU-R • Manages global spectrum of RF Pg 6

  9. IEEE • Defines the 802 series standards • 802.3 Ethernet • 802.11 Wireless • Document the technical and equipment basics • Can be different interpretations Pg 7

  10. Wi-Fi Alliance • Starting with 802.11b manufacturers formed WECA • Promote technology • Support interoperability • In 2000, WECA became WiFi Alliance Pg 8

  11. Interoperability Certifications • Addressed the issue of standards • Help growth and progression • Allow interoperability Pg 8

  12. 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) Pg 8

  13. 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 Pg 8

  14. Wi-Fi Protected Access 2 (WPA 2.0) Certification Overview Pg 8

  15. 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 Pg 8

  16. 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 Pg 8

  17. 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 Pg 8

  18. ISO • Identifies standards for business, government and society • Created the OSI model for computers networking • Not implemented, but often referenced • Should understand the layers Pg 11

  19. 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 Pg 11

  20. 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 Pg 12

  21. Communications Fundamentals • Most people have a basic idea about transfer of data • This section gives more background on fundamental communications for wireless Pg 14

  22. Carrier Signals • Need to be able to transmit two states: • 1 or 0 • AC or DC alone wont do it, need to alternate or modulate • The base signal that is modified is called the Carrier Signal • The method of adjusting it is the modulation technique Pg 13

  23. Amplitude and Wavelength Pg 14

  24. 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 length between peaks. • Frequency is how often the peaks come in a period 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. Pg 15

  25. Amplitude and Wavelength Pg 15

  26. Phase Pg 15

  27. Keying Methods • Signal transmitted from the transceiver has to be manipulated to let receiver distinguish between 1 and 0 • This is the keying method • Also known as modulation techniques • Amplitude Shift Keying • Frequency Shift Keying • Phase Shift Keying Pg 16

  28. 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 Pg 16

  29. 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 Pg 16

  30. 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 Pg 17

  31. Frequency-Shift Keying • Uses the frequency, or number of cycles per second to indicate change. • Current state technique • A shift indicates a change from current signal • Used in legacy (older) 802.11 technologies Pg 17

  32. Phase-Shift Keying • Varies the phase of a signal to represent data • State Transition technique Pg 17

  33. Phase-Shift Keying-Advanced • Can encode multiple bits per symbol as well • Use four different phases • Multiple Phase shift Keying Pg 17

  34. Exam Essentials • Know the three industry organizations • Understand the roles and responsibilities of the regulatory domain authorities, the IEE, and the Wi-Fi Alliance. • 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 Pg 21

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