TLMN CLASS Fall by benbenzhou


									TLMN645 CLASS 10
  US -Wide Wireless
    Data Systems
          Wireless Data System
•   Field Service
•   Transportation and Dispatch
•   Point of sale
•   Public Safety
•   Healthcare
•   Wireless Telemetry
•   Electronic Message (wireless email)
•   Wireless Internet (WiFi)

Field Service                    Point of Sale

     Source: Bell South Mobile Data
• Narrowband -low throughput- under 19.2
• Best for file sizes under10 -20 kB
• Charge by the packet
• Have store and forward capabilities
Wireless Data, PDAs
 CDPD (Cellular Digital Packet
• Concept : Utilize idle cellular channels to
  send bursts of data at 19.2 kb/s (real data
  9.6 kb/s
• Concept: Transmitter hops around finding
  idle channels and leaves channels when
  they become active
• Operation sometimes on dedicated channels
• Data Rate 19.2 Kbits/ second
• CDPD also supports IP multicast (one-to-many)
• CDPD packets use forward error correction
  methods that reduce the effects of noise and
  interference on the airlink.
• CDPD incorporates authentication and encryption
  to all packet transmissions over the airlink.
      CDPD Exploits Idle Time
• Find a space and fill it.
   – The transmission across cellular telephone
     channels are more than 30% idle, even during
     heavy traffic times. CDPD exploits this idle
     time by detecting these times and utilize the
     otherwise wasted moment. It packages data in
     small packets and sends it in short bursts during
     idle time. This allows CDPD to not only
     enhance the efficiency of the cellular network
     but remain completely transparent within it.
       CDPD Infrastructure
         (two networks)
     CDPD is a separate overlay

Source: Northwestern University
          CDPD Operations
• Mobile Data Base Station (MDBS) is sited
  within the cell site and utilizes the same
  antenna structure as the cellular system
• Each channel can be accessed by up to 30
  CDPD users at a time since packet data
• access by CSMA- all listen- no dedicated
  time slot for each user
• Utilizes IP protocol
  Source: Northwestern University

Parts of CDPD Network
CDPD Coverage 2001
Verizon Mobile IP (CDPD)
$55/ month unlimited
(CDPD) -Maryland National
   Capitol Park Police

     Source: Wireless Data Forum
                   CDPD from PDA
Minstrel m500

Fits Palm m500 series
       Cingular Interactive
  (Previously Bell South Mobile
              Data )
• 1000 base stations in US, NJ control center
• Focuses on airports, transportation
  corridors, hotels, i.e. business travelers
• Operates on 12.5 kHz channels in 800/900
• 8kb/s raw data rate, user throughput 4 kb/s
• Packet data with FEC capable of repairing
  up to 20 consecutive errors
Wireless Data Terminal
(Cingular Interactive )
  Wireless Data Infrastructure
 (example: Cingular Interactive
        Wireless Data)

                           Local               Control Center
                           Switch              New Jersey

Base Station
           User Terminal
Cingular Interactive Data
   National Coverage
Cingular (Bell South) Mobitex
Palm VII
    • Provides Internet
      Connectivity via
      Cingular Interactive
    • 260 cities
    • Web clippings rather
      than whole pages
    • Costing issues:
       – per byte charge
Security for Cingular Interactive
            Motient History
• Initially 1990 for field service IBM
• Covers 430 markets & Puerto Rico, Vir. Is.
•  25 kHz chs. in 800 MHz, 1600 base stns.
• User throughput about 2 kb/s moving to
  12.8 kb/s. Good indoor coverage (Explain)
• Combined with American Mobile Satellite
  to form integrated network. Path chosen is
  the shortest delay (terrestrial, satellite)
Motient Coverage
                Motient Coverage   ARDIS

       Source: American Mobile
• . AT&T Wireless has an aggressive schedule for
  it, intending to create a nationwide GPRS network
  by year's end (2002).
• AT&T is about 60 percent done. It's already
  launched services using the network,
  offering a version of the wildly popular I-mode
  wireless Web service of NTT DoCoMo in Japan.
  NTT DoCoMo owns about 16 percent of AT&T
• Peak data rates for its GPRS service should
  reach 115 kilobits per second, though early
  results in launched markets have yielded
  between 20 kbps and 40 kbps at
  customer's handsets.
           GPRS Technology
• GPRS currently supports an average data rate of
  115 Kbps, but this speed is only achieved by
  dedicating all eight time slots to GPRS.3 Instead,
  carriers and terminal devices will typically be
  configured to handle a specific number of time
  slots for upstream and downstream data. For
  example, a GPRS device might be set to handle
• a maximum of four slots downstream and two
  slots upstream. Under good radio conditions, this
  yields speeds of approximately 50 Kbps
  downstream and 20 Kbps upstream.
    ATT GPRS Network (2002)
• The network, which will cover 6,000 cities, will
  allow users to access services at up to 56 kilobits
  per second Available handsets (Motorola T193)
  sell for $50
• Add-on pricing plans for the T193 will start at $3
  per month for 1 megabyte of data and 300 of the
  carriers Ping Pong text messages, and $10 for each
  additional megabyte. 1-megabyte of data is equal
  to about 500 phone screen pages
          GPRS Technology
• The aggregate cell site bandwidth is shared
  by voice and data traffic. GPRS operators
  will vary in how they allocate the
  bandwidth. Typically, they will configure
  the networks to give precedence to voice
• Uses CDMA 2000 with bit rate 50-70 kbs
• You pay $10 a month on top of most Sprint PCS
  voice plans for 2 megabytes (MB) of data sent or
  received; for $20 a month you get 8 MB. You pay
  an additional 2 cents for each kilobyte of data sent
  or received in excess of your monthly limit.
• Picture sharing. Sprint is selling a $99 digital
  camera -- $69 out and plugged directly into the
  Samsung A500 or N400 phones. You can see the
  pictures on the phone's screen, and send them to
  friends -- either as e-mail or directly to the screens
  of other PCS Vision subscribers.
• PCS Vision made good use of the A500's color
  screen for features including:
• Web access. PCS Vision phones can display Web
• Messaging. Electronic mail and short-text
  messages are easier to read on backlit color
  screens than the unlighted monochrome screens on
  older phones.
• PCS Vision also supportslive text chat among its
  subscribers.instant messaging between computers.
• Games. For a one-time fee of $1 to $4, PCS
  Vision subscribers can download simplified
Blackberry Handhelds
        Blackberry Networks
      Use on GPRS and Mobitex
• RIM 1902G™ OEM Radio Modem - Operates in
  the 850/1900 MHz frequency range in North
  America and is compatible with GSM/GPRS
  wide-area wireless data and voice communications

•        RIM 902M™ OEM Radio Modem -
    Operates in the 900 MHz frequency range and is
    compatible with Mobitex wide-area wireless data
    communications networks.
         Wireless Data Future
• Fresh out of bankruptcy (July 2002) wireless data
  company Motient Corp. is starting business anew
  hoping not to be overtaken by wireless 3G.
• Motient's advantages include: covers all U.S.
  metropolitan service areas
• Always-on packet data network; in-building
• United Parcel Service's delivery personnel
  nationwide use Motient services when they log
  package pickup and delivery information via their
  specialized handheld devices.

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