Introduction to Wireless Networking Module-01

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					       Introduction to Wireless Networking

                      Module-01
    Overview of Wireless Standards, Organizations and
                       Technology


                    Jerry Bernardini
             Community College of Rhode Island




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           Presentation Reference Material
• CWNA Certified Wireless Network
  Administration Official Study Guide, Fourth
  Edition, Tom Carpenter, Joel Barrett
  Chapter-1 (Good but out of print)


• CWNA Certified Wireless Network
  Administration Official Study Guide
  (PWO-104), David Coleman, David Westcott,
  2009, Chapter-1
(There is an earlier edition of this book and it has only 16
   chapters-Don’t get this book)


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     Abbreviated Wireless Network History ??dates

• 1830: Professor Joseph Henry transmitted the first practical
  electrical signal.
• 1880: Maxwell’s Equations
• 1905: Marconi
• 1920: Radio Receivers
• 1935: Television
• 1941: Radar
• 1958: Satellite
• 1970: ALOHAnet
• 1990: Internet
• 1998: WLAN

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      Why Study Wireless Networks? A Partial List

•   Cordless phones
•   Wireless Voice over IP phones
•   Wireless print servers
•   Wireless access points, routers, and bridges
•   Radio Frequency Identification devices
•   Wireless presentation gateways
•   Wireless conferencing systems
•   Laptop computers, PDAs, and other mobile wireless client
•   device


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      Wireless Industry Guided by Three Categories
                   of Organizations
• Regulation- Boundaries of Operation
      – Federal Communications Commission (FCC)
      – European Telecommunications Standards Institute (ETSI)
           • Power limits and Frequencies

• Standardization- How systems work together
      – Institute of Electrical and Electronics Engineers (IEEE)
           • 802.11 a, b, g, n

• Compatibility – Tests for interoperability
      – Wi-Fi Alliance
           • If you buy Wi-Fi certified gear it work with other Wi-Fi gear



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       FCC - Federal Communications Commission

• Regulatory Bodies – City, State, Country
• FCC- Born in 1934 to regulate radio, television, cable,
  satellite and wire communications
• FCC regulates
      – Radio frequencies
      – Output power levels
      – Indoor and Outdoor usage
• Every country has regulatory bodies



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                       FCC Wireless Bands
• 1985:Industry, Scientific and Medical Industrial
  License-Free Bands – ISM Bands
      – 900 MHz band, (900 to 928 MHz range)
      – 2.4 GHz band, (2.4 to 2.483 GHz range)
      – 5 GHz band, (5.725 to 5.850 GHz range)
• 1997: Unlicensed National Information Infrastructure
  U-NII bands
      – 5.15 to 5.25 GHz
      – 5.25 to 5.35 GHz
      – 5.725 to 5.825 GHz




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               FCC Unlicensed Bands

        Advantages                         Disadvantages
•No licenses required               •Everyone can use the
•No Fees                            bands
•No Permits                         •Interference between
•Comply with rules and              users
build anything                      •Bandwidth Contention
                                    •First-come-first –serve
                                    •Interference from late-
                                    comers


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                  FCC Regulates Frequencies

• Frequencies are grouped into bands
      – Wireless LAN bands include: (Hz = Hertz)

            Frequency Band      Total Bandwidth              License-Free Band

            2400–2500 MHz             100 MHz                      ISM

             5.15–5.25 GHz            100 MHz                      U-NII

             5.25–5.35 GHz            100 MHz                      U-NII

            5.470–5.725 GHz           255 MHz                      U-NII

            5.725–5.825 GHz           100 MHz                      U-NII

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           FCC Power Output Limits-U-NI Bands
           Band            Power Output                          Limits Area Usage

    U-NII 5.15–5.25 GHz        40 mW                Restricted to indoor operations


    U-NII 5.25–5.35 GHz       200 mW                              Indoor/outdoor


  U-NII 5.470–5.725 GHz       200 mW                              Indoor/outdoor

  U-NII 5.725–5.825 GHz       800 mW                 Higher output power assumes
                                                          outdoor operations



                          mw = 1/1000 watt


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           Non-USA Standard Organizations

• OfCom-Office of Communication –United Kingdom
• MIC- Ministry of Internal Affairs and
  Communications-Japan
• ARIB-Association of Radio and Businesses – Japan
• ACMA-Australian Communications and Media
  Authority




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           International Telecommunications Union
             Radiocommunications Sector (ITU-R)
• 1947: United Nations creates ITU-R to:
      – Promote cooperation and technical development
• ITU-R maintains a database of frequencies with five
  administrative regions
      –    Region A: The Americas
      –    Region B: Western Europe
      –    Region C: Eastern Europe
      –    Region D: Africa
      –    Region E: Asia and Australia




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           Institute of Electrical and Electronics
               Engineers - IEEE (Eye-triple-E)
• World’s leading non-profit professional organization
  for the advancement of technology
• Mission –
      – promote “the engineering process of creating, developing, integrating,
        sharing, and applying knowledge about electronics and information
        technologies and sciences for the benefit of humanity and the
        profession.”
• 350,000 individual members in 150 countries.
• Nearly 900 active standards with 700 under
  development.


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                      IEEE Wireless Standards

• IEEE 802 project is the most important with multiple
  working groups
      –    IEEE 802.3 (Ethernet)
      –    IEEE 802.11 Wireless LAN (WLAN)
      –    IEEE 802.16 WiMAX
      –     IEEE 802.16 Mobile Broadband
• Most of this course will deal with IEEE 802.11




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                     IEEE 802.11 Standards

• 1997: First 802.11 ratified (802.11-1997)
• Three ways of implementing a physical
  communications layer (PHY)
      – Frequency-hopping spread spectrum (FHSS)
      – Direct-sequence spread spectrum (DSSS)
      – Infrared communications (not implemented extensively)
• All operate at 1Mbps and 2Mbps
• To be covered in depth is subsequence lessons



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             IEEE 802.11 Amendments


•   IEEE 802.11a – OFDM, 5 GHz U-NII, 54 Mbps
•   IEEE 802.11b – DSSS, 2.4 Mhz ISM band, 11 Mbps
•   IEEE 802.11c – Bridging operation
•   IEEE 802.11d – regularity specifications
•   IEEE 802.11e – Quality of Service (QoS)
•   IEEE 802.11F- access point re-association
•   IEEE 802.11g – DSSS/OFDM, 2.4 Mhz, 54 Mbps
•   IEEE 802.11h – Dynamic frequency, power control
•   IEEE 802.11i – important security enhancements
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            IEEE 802.11 Amendments

•   IEEE 802.11j – 4.9-5 Mhz band in Japan
•   IEEE 802.11k – channel management above 5 Mhz
•   IEEE 802.11n –Important 100 Mbps plus WLAN
•   IEEE 802.11p –Intelligent Transportation Systems
•   IEEE 802.11r – Roaming amendment
•   IEEE 802.11s – Extended Mesh network interoperate
•   IEEE 802.11T – measurement and test conditions
•   IEEE 802.11u – handoffs between WiMax and WLAN
•   IEEE 802.11v – device management
•   IEEE 802.11w – improved management frames
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               More IEEE Standards

• IEEE 802.1X – port-based authentication for security
• IEEE 802.3-2005 Clause 33 – defines power over
  Ethernet (PoE)
• IEEE 802.1D – bridging priority
• IEEE 802.1Q – priority tagging and VLAN FOR QoS




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       IETF – International Engineering Task Force
• Primarily a volunteer organization
• The most important standards organization for the
  Internet operation
• Operates on the basis of the Request-For-Comment
  (RFC)
      – IETF issues an RFC in a technical issue
      – After a period of time all responses to the RFC are gather and voted on
• WLAN RFC 3748, RFC 2865 are important for wireless
      – RFC 3748 - WLAN security
      – RFC 2865 -security and the use of RADIUS server



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                    Wi-Fi Alliance
• Certification organization for testing and
  interoperability
• Eight basic Wi-Fi CERTIFIEDTM programs
• Wi-Fi is just a marketing name; it does not stand for
  anything
• Before October 2002 know as the Wireless Ethernet
  Compatibility Alliance (WECA)
• Most commercial products will have a Wi-Fi logo
• www.wi-fi.org for more information


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           Wi-Fi CERTIFIEDTM Programs
• IEEE 802.11 baseline – meets up to IEEE 802.11n
• Wi-Fi Protected Access 2 (WPA2) – based upon IEEE 802.11i
• Wi-Fi Multimedia (WMM)- QoS for various applications
• WMM Power Save(WMM-PS) – specifications to save battery
  power
• Wi-Fi- Protection -Security – Simplified and automated WPA
  and WPA2 security setup
• CWG-RF multimedia- defines performance for cellular radios
  and handsets
• Voice Personal-application – support for personal and
  business voice applications

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           Communications Models

• Models are design, management, interoperability
  and learning
• OSI Model - seven layers- can be abstract but is very
  commonly used
• Core-Distribution-Access Model – a useful model for
  wireless networking
• TCP/IP Model - Four layers – good for networks built
  around TCP/IP


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              OSI Model




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                Core – Distribution - Access

• Core Layer – Does not route or manipulate traffic
      – High speed traffic – think superhighway
      – Backbone of network
      – High speed switches and routers
• Distribution Layer – Routes or directs traffic other
  nodes
      – Medium speed traffic – think city traffic
      – Routers and Bridges
• Access Layer – directs traffic to end user
      – Relative slower traffic – think local street traffic
      – Access Points and Switches

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           Core – Distribution – Access Details




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                    TCP/IP Model




      (Transport)




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           TCP/IP and OSI Model Maping




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                           Modulation

• Carrier signal is a continuous electrical signal
   – Carries no information
• Three types of modulations enable carrier signals to
  carry information
   – Height of signal
   – Frequency of signal
   – Relative starting point
• Modulation can be done on analog or digital
  transmissions


                          CWNA Guide to Wireless LANs, Second
                                                                28
                              EditionCCRI J. Bernardini
          Analog and Digital Modulation

• Analog Transmission use analog carrier signals and
  analog modulation.
• Digital Transmission use analog carrier signals and
  digital modulation.
• Modem (MOdulator/DEModulator): Used when
  digital signals must be transmitted over analog
  medium
   – On originating end, converts distinct digital signals into continuous
     analog signal for transmission
   – On receiving end, reverse process performed
• WLANs use digital modulation of analog signals
                   CWNA Guide to Wireless LANs, Second
  (carrier signal)     EditionCCRI J. Bernardini
                                                                             29
            Analog vs. Digital Transmissions



Analog Signal = A signal that has continuously varying voltages, frequencies, or
phases. All amplitude values are present from minimum to maximum signal levels.




 Digital Signal = A signal in which information is carried in a limited number of
 different discrete states or levels; High/Low, One/Zero, 1/0


                               CWNA Guide to Wireless LANs, Second
                                                                                    30
                                   EditionCCRI J. Bernardini
          Analog and Digital Modulation

• Analog Transmission use analog carrier signals and
  analog modulation.
• Digital Transmission use analog carrier signals and
  digital modulation.
• Modem (MOdulator/DEModulator): Used when
  digital signals must be transmitted over analog
  medium
   – On originating end, converts distinct digital signals into continuous
     analog signal for transmission
   – On receiving end, reverse process performed
• WLANs use digital modulation of analog signals
                   CWNA Guide to Wireless LANs, Second
  (carrier signal)     EditionCCRI J. Bernardini
                                                                             31
Frequency and Period




    CWNA Guide to Wireless LANs, Second
                                          32
        EditionCCRI J. Bernardini
                    Analog Modulation

• Amplitude: Height of carrier wave
• Amplitude modulation (AM): Changes amplitude so
  that highest peaks of carrier wave represent 1 bit
  while lower waves represent 0 bit
• Frequency modulation (FM): Changes number of
  waves representing one cycle
   – Number of waves to represent 1 bit more than number of waves to
     represent 0 bit
• Phase modulation (PM): Changes starting point of
  cycle
   – When bits change from 1 to 0 bit or vice versa

                         CWNA Guide to Wireless LANs, Second
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                             EditionCCRI J. Bernardini
                     Digital Modulation
• Advantages over analog modulation:
   –   Better use of bandwidth
   –   Requires less power
   –   Better handling of interference from other signals
   –   Error-correcting techniques more compatible with other digital
       systems
• Unlike analog modulation, changes occur in discrete
  steps using binary signals
   – Uses same three basic types of modulation as analog



                  Amplitude shift keying (ASK)


                          CWNA Guide to Wireless LANs, Second
                                                                        34
                              EditionCCRI J. Bernardini
                  Digital Modulation




 Frequency shift keying (FSK)




Phase shift keying (PSK)




                       CWNA Guide to Wireless LANs, Second
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                           EditionCCRI J. Bernardini
            Spread Spectrum Technology Uses
• Spread spectrum is a technique of transmitting radio
  signals over multiple frequencies
      – The common method of transmitting WLAN signals
      – Spread Spectrum will be explained in depth in chapter-3
• Spread spectrum is used by
      – Wireless LANs (WLANs)
      – Wireless PANs (WPANs)
      – Wireless MANs (WMANs)
  Use                    Examples                 Range           Speeds
  WLAN /Backhaul         IEEE 802.11              375 ft/ miles   > 2Mbps
  WPAN                   Bluetooth                1-3 meters      .723 – 3 Mbps
  WMAN/ Backhaul         WiMax and EDGE 10 km                     ~ 40 Mbps
  WWAN / backhaul        AT&T microwave            variable       ~75-135 kbps

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                     Wireless LANs (WLANs)

• The major application of IEEE 802.11
• WLANs provide mobility and unwired fixed
  connectivity
• Three primarily roles of WLANs
      – Access role
      – Distribution role
      – Core role




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                   Wireless PANs (WPAN)

• Wireless Personal Area Networks
• 10 meter radius connectivity
• Primarily Bluetooth Applications
      – headsets
      – mouse
      – PDA
• Uses 2.4 GHz ISM band which can interfere with
  802.11 WLAN



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               Wireless MANs (WMAN)

•   Wireless Metropolitan Area Network
•   Uses both Point-to-Point and Point-to-Multipoint
•   WiMAX and IEEE802.16
•   Leased networks covering multiple miles
•   Provide QoS mechanisms




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                Wireless WANs (WWANs)

• Expansion of WAN technology
      – DSL
      – ISDN
      – Cable
• WWANs connect LANs to backbone
• Uses both Point-to-Point and Point-to-Multipoint
• WWANs provide multi-channel communications




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                          Last-Mile Delivery
• Last mile is the connection between the ISP and the
  end user
      – Example: home and telephone central office
      – Example: Office and Cable provider hub
• Last mile comes from the old telephone network
  design;
      – max of 18000 ft to central office
• Last mile can be expensive
• Wireless Internet Service Provider (WISP)
• WISP use WiMAX (IEEE 802.16)

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                 Major Wireless Applications

• SOHO – Small Office / Home Office
      – Less than 25 computers
      – Router connections
• Mobile Office Network
      – Similar the SOHO but mobile
      – Mobile IP usage
•   Educational/Classroom Use
•   Hotspots
•   Warehousing and Manufacturing
•   Health Care
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                  Wireless Hotspots

•   Hotspots often use Wi-Fi
•   Free and wide open
•   Free and secure
•   Subscription based
•   Pay-as-you-go
•   Mixed




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