Telecom, Wireless

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Telecom, Wireless Networks
Chapter 5

• Fundamentals
• Media, Devices, and Software
• Wireless Telecommunications
• Networks and Distributed Computing

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Telecommunications

• Telecommunications The electronic transmission
  of signals over a medium for communications.

(cables or air)
Sender and Receiver must speak the same
language.
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Voice Communication

• It has been said that only about 16 of spoken
  communication is verbal
• Sound waves
• demo
• demo
• Wave characteristics
• Frequency
• Amplitude
• Phase

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Types of Signals
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Modulation

• More about waves
• Different waves
• Electromagnetic waves
• Analog modulation
• AM
• FM

Examples
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Digital Modulation
What might FSK Look like?
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Signal Frequency

• Frequency the speed at which a signal changes
  from high to low.
• Bandwidth the range of signal frequencies that
  can be sent over a given medium at the same time.
• Often expressed as bits per second
• Broadband typically 2 5 Mbps

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5.2 Networking Media, Devices, and Software

• The fundamental components of telecommunications
  networks

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Networking Media
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Radio Waves

• Radio waves use differing frequencies to carry
  many types of information
• AM FM Radio
• Short Wave CB Radio
• Television Broadcasts
• Garage Doors Openers
• Baby Monitors
• Cordless Phones
• Cell Phones
• Radio Controlled Cars and Airplanes
• Global Positioning Systems
• Wireless Computer Networks
• Microwave Communications

http//electronics.howstuffworks.com/radio-spectru
m1.htm
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300 GHz
EHF
SHF
UHF
VHF
HF
MF
LF
VLF
30 GHz
2.9 GHz
Deep space radio communications (2.29-2.3 GHz)
Wi-fi Wireless Networks (2.4 GHz)
Global Positioning System 1.23 and 1.58 GHz
Air traffic Control (960-1,215 MHz)
900-MHz cordless phones
Cell Phones (824-849 MHz)
328.6 MHz
TV CH 7-13 (174-220 MHz)
FM Radio (88-108 MHz)
TV CH 2-6 (54-88 MHz)
Cordless Phones (40-50 MHz)
30 MHz
CB Radio (26.96-27.41 MHz)
3 MHz
AM Radio (535-1700 kHz)
300kHz
30 kHz
The complete picture
10 kHz
The Radio Spectrum
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Networking Devices

• Modem modulates and demodulates signals from one
  form to another.
• Network Adapter Expansion card, or external
  device installed on a computing device used to
  connect to a network.

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Networking Devices

• Network Control Devices
• Hub/Switch
• Controls flow of data between devices on a
  network
• Router
• Routs packets to destinations and connects one
  network to another
• Wireless Access Point
• Allows devices to connect wirelessly to a wired
  network

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Microwave Communications
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Microwave Communications
!
Line-of-sight communications
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Microwave Communications
Line-of-sight required
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5.3 Wireless Telecommunications Technologies
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Cell Phone Technologies

• A cellular network is a radio network in which a
  geographic area is divided into cells, with a
  transmission tower and station at the center of
  each cell, to support mobile communications.

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Cell Phone Technologies

• A cellular carrier is a company that builds and
  maintains a cellular network and provides cell
  phone service to the public.

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GSM and CDMA
GSM CDMA
ATT T-Mobile Verizon Sprint

• Digital networking standards for cell phone
  networks are GSM and CDMA.
• GSM is the most popular global standard for
  mobile phones
• The CDMA networking standard is predominantly
  used in the United States where it is in equal
  competition with GSM.

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GSM and CDMA
GSM CDMA
ATT T-Mobile Verizon Sprint

• GSM Phones include a subscriber identity module
  (SIM) for security and convenient data transfer
  between phones.

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Wireless Technologies

• The Global Positioning System (GPS) uses
  satellites to pinpoint the location of receivers
  on earth.

Aircraft Navigation
How GPS works
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Wireless Technologies

• Wireless Fidelity (IEEE 802.11s), or Wi-fi, is
  wireless networking technology that makes use of
  access points to connect devices to networks.

• 250-1,000 ft range
• 802.11b 4.5 Mbps
• 802.11g 11 Mbps
• 802.11n 74 Mbps
• www.boingo.com

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Wireless Technologies

• WiMAX (IEEE 802.16) is the next generation
  broadband technology that is both faster and has
  a longer range than Wi-fi 31 miles!

Seattles Space Needle To Become WiMax Antenna
http//en.wikipedia.org/wiki/WiMAX
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Wireless Technologies

• Bluetooth is wireless technology that enables a
  wide variety of digital devices to communicate
  directly.

• 33 ft range
• 1 Mbps
• www.bluetooth.com

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Bluetooth
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Wireless Technologies

• Infrared (IrDA) technology utilizes infrared rays
  to send data over a short distance wirelessly.

• 14 ft range
• Narrow-angle cone (30o)
• Line-of-sight
• 4-16 Mbps
• www.mzoop.com

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Wireless Comparison
Wi-fi Access point centered LAN Omni-direction Through obstructions 250 ft range indoors 11 Mbps
Bluetooth Point-to-point Omni-direction Through obstructions 33 ft 1 Mbps
Infrared Point-to-point Narrow-angle Line-of-sight 14 ft 4 Mbps