WIRELESS COMMUNICATIONS

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• WIRELESS COMMUNICATIONS

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Timeline of Major Developments

• Mobile Telephone System (MTS)
• Introduced in 1946
• Simplex (one-way transmission) and manual
  operation
• Improved Mobile Telephone System (IMTS)
• Introduced in 1969 using a 450 MHz band
• Advanced Mobile Phone Service (AMPS)
• Introduced in 1983
• First system to employ a cellular concept

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Cellular Topology

• Cellular network
• Series of overlapping hexagonal cells in a
  honeycomb pattern
• Cellular network components
• Base StationTransmitter, Receiver, Controller,
  Antenna
• Cell Base stations span of coverage
• Mobile Switching Center Contains all of the
  control and switching elements to connect the
  caller to the receiver, even as the receiver
  moves from one cell to another

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Digital Access

• D-AMPS (Digital-AMPS)
• TDMA (Time Division Multiple Access)
• CDMA (Code Division Multiple Access)
• Digital wireless technologies provide greater
  system capacity.

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CDMA

• CDMA
• Third generation system
• Separates users by assigning them digital codes
  within a broad range of the radio frequency
• First technology to use soft-handoff
• Employs spread spectrum technique
• Advantages
• Improved capacity, coverage, voice quality, and
  immunity from interference

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An Overview of Cellular Technologies
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Wireless Applications

• Cellular Phone
• High mobility and narrow bandwidth (20 to 30 kHz)
  
• Cordless Phone
• Low mobility and narrow bandwidth (20 to 30 kHz)
• Wireless LAN
• Low mobility and high bandwidth (typically 10
  Mbps)
• Wireless Application Protocol (WAP) is a standard
  for wireless data delivery, loading web pages,
  and navigation

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The Wireless Spectrum
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Cellular Communications

• Mobile telephone service - a system for providing
  telephone services to multiple, mobile receivers
  using two-way radio communication over a limited
  number of frequencies.
• Mobile wireless evolution
• First generation
• Second generation
• Third generation

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Global System for Mobile Communications (GSM)

• A version of time division multiple access (TDMA)
  technology, because it divides frequency bands
  into channels and assigns signals time slots
  within each channel.
• Makes more efficient use of limited bandwidth
  than the IS-136 TDMA standard common in the
  United States.
• Makes use of silences in a phone call to increase
  its signal compression, leaving more open time
  slots in the channel.

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Contact Us at -

• Address -
• c2mTech1313 Valwood Suite 320 Carrollton,
  Texas 75006
• Phone No -
• (P) 972-881-2268 Dallas(P) 817-442-2268
  Ft. Worth(F) 972-221-9366
• Website - http//www.c2mtech.com/
• Sales Representative - sales_at_c2mtech.com