The Network Layer _ Routing by sofiaie


									WPAN &
        Wireless Technologies
                              (Wide Area Network)
                        (Metropolitan Area Network)
                              (Local Area Network)
                                  (Personal Area

                    PAN                LAN               MAN            WAN
                                  802.11a, 11b, 11g     802.11        GSM, GPRS,
Standards         Bluetooth          HiperLAN2        MMDS, LMDS     CDMA, 2.5–3G
Speed             <1 Mbps           2–54+ Mbps         22+ Mbps      10–384 Kbps

Range               Short             Medium          Medium–Long        Long
                                                                     PDAs, Mobile
                 Peer-to-Peer        Enterprise       Fixed, Last
Applications   Device-to-Device      Networks         Mile Access
                                                                    Phones, Cellular
               Wireless Data Networks
              50 Mbps
                                                                             802.11 is WiFi
              10 Mbps
                                  Spectrum                                   WAP is small
                         Infrared Wireless                                   handhelds
               2 Mbps    Wireless   LANs
Data Rates

               1 Mbps
                                                   2.5 GHz
                                                          Broadband PCS
              56 Kbps
                                             Circuit and Packet Data
             19.6 Kbps                    Cellular, CDPD, Mobitex, DataTac
                          Narrow Band
              9.6 Kbps    Wireless LANs                                          Satellite
                                                   Narrowband PCS

                                 Local                                             Wide
                                               Coverage Area
 WPAN (Wireless Personal Area Network)
•   Is a computer network used for communication amongst
    computer devices (including telephones and personal digital
    assistants) close to one person.
•   The reach of a PAN is typically a few meters.
•   PANs can be used for communication among the personal
    devices themselves or for connecting to a higher level
    network and the Internet.
•   A Wireless Personal Area Network (WPAN) can also be made
    possible with network technologies such as IrDA, Bluetooth
    and UWB
       WPANs Technologies

 Infrared Wireless LAN
 Bluetooth
     • Also an IEEE standard 802.15
       Infrared Wireless LAN
      – Require line of sight (LOS) to work (less flexible)
      – Main advantage: reduced wiring

            usually mounted in fixed positions to
            ensure they will hit their targets

•New version: diffuse infrared,
  – Operates without a direct LOS by bouncing the infrared
    signal off of walls
  – Only able to operate within a single room and at distances of
    only about 50-75 feet
 A Bluetooth WPAN is also called a piconet, and is
  composed of up to 8 active devices in a master-
  slave relationship
      The first Bluetooth device in the piconet is the master,
       and all other devices are slaves that communicate with
       the master
      A piconet typically has a range of 10 meters, although
       ranges of up to 100 meters can be reached under ideal
      WPAN characteristics
 Short Range (at least 10m, up to 70m
 Data rates (currently up to 55 Mb/s)
 Short time to connect (<1s)
 Peer to peer connectivity
 Designed to support low power portable
 Easy to use
        WPAN Applications
 Personal home storage
 Printers & scanners
 Interactive video gaming
 Home theater
 Exchanging information directly between
 Connecting a keyboard or mouse wirelessly
  to a desktop computer
Advantages and Disadvantages
         of WPAN
    Advantages:
         Dynamic network setup
         Usually quick and relatively simple to set up
         WPAN enabled devices are usually portable
         Needs less technical skills to deploy than LANs or WLANs.

    Disadvantages:
         Typically have a limited range
         Currently limited to relatively slow data rates when compared with WLAN
         Compatibility and interoperability issues (WPAN technologies are not usually
          compatible with each other. Some WPAN technologies such as Bluetooth are
          known to have had interoperability issues between devices from different
         As small devices that are often associated with WPANs often have limited
          potential for adding extra hardware it is sometimes difficult to find suitable
          upgrade equipment.
         Devices with inbuilt WPAN technologies can be considerably more expensive than
          devices without WPAN technologies.
Ad Hoc Topology

         Peer-to-Peer (Ad Hoc)
            Can consist of 2 or
            more PCs with wireless
            network adapters.
            Sometimes called an
            Independent BSS (IBSS).
            Limited range.
  Bluetooth – Ad hoc Network
 Consortium
    Ericsson, Intel, IBM, Nokia, Toshiba - many
 Scenarios
   connection of peripheral devices
        • loudspeaker, joystick, headset
      support of ad-hoc networking
        • small devices, low-cost
      bridging of networks
        • e.g., GSM via mobile phone - Bluetooth – laptop
 It does not need any IP infrastructure
      Bluetooth wireless technology is a short-
       range radio technology.
      Bluetooth wireless technology makes it
       possible to transmit signals over short
       distances between telephones, computers
       and other devices and thereby simplify
       communication and synchronization
       between devices.
      The Bluetooth wireless technology
       comprises hardware, software and
       interoperability requirements.
      Transmits at up to 1 Mbps over a distance
       of 33 feet and is not impeded by physical
         Bluetooth – Blue Snarfing
                         Blue-snarfing, the technique leaves no trace of
                          intrusion, steals the contents of a cellphone's
                          address book , or even gain access to a user's
                         "Bluejacking" allows a user to send an anonymous
                          and unauthorized message to another cell user.
                          It has become primarily a means of
                          entertainment for some individuals in crowded
                          places - who'll send anonymous comments like "I
                          like your tie" to people nearby.

Bluetooth was named after the 10th
century Danish King Harold Bluetooth,
who unified Scandinavia
       Bluetooth (IEEE 802.15)
 A standard for Wireless Personal Area Network
     Provides networking in a very small area
       • Up to 10 meters (current generation)
       • Up to 100 meters (next generation)
     Includes small (1/3 of an inch square) and cheap devices
      designed to
       • Replace short distance cabling between devices
           – Keyboards, mouse, handsets, PDAs, etc
     Provides a basic data rate of 1 Mbps
       • Can be divided into several voice and data channels
     Uses Frequency Shift Keying (FSK) for data transmission
      (1 bit per symbol)
            Bluetooth Topology
 Uses the term “piconet” to refer to a
  Bluetooth network
     Consists of 8 devices
       • A “master” device controlling other devices, “slaves”
           – Acts like an AP
           – Selects frequencies and controls access
           – All devices in a piconet share the same frequency range
        Bluetooth Media Access
 Uses Frequency Hopping Spread Spectrum (FHSS)
    Available frequency range (2.4000-2.4835) divided into 79
     separate 1-MHz channels
    A data burst transmitted using one channel, next data
     burst uses the next channel, and so on.
    Channels changed based on a sequence and established by
     the slave and the master prior to the data transfers
        • 1,600 channel change per second
      Also used to minimize interference
        • A noisy channel avoided eventually
 Not compatible with 802.11b
   Potential interference problems (especially if many
    Bluetooth devices present close to .11b devices)

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