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1.1.2 Product Evolution

1.1.2 Product Evolution. TELEPHONE. Telegraph. Inventor: Samuel B. Morse (1837) Transmits messages over long distance Messages received are audible signals Earlier telegraphs experiments in Germany used bubbles in a glass of water. Morse Code.

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1.1.2 Product Evolution

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  1. 1.1.2 Product Evolution

  2. TELEPHONE

  3. Telegraph • Inventor: Samuel B. Morse (1837) • Transmits messages over long distance • Messages received are audible signals • Earlier telegraphs experiments in Germany used bubbles in a glass of water

  4. Morse Code • Language made up of dots and dashes in a pattern to represents letters and numbers • Receiver hears short audible signals for dots and long audible signals for dashes

  5. Telephone • Inventor: Alexander Graham Bell (1870s) • Microphone converts sound waves into electrical signals • Earphone converts electrical waves into sound waves

  6. Landlines • Plain Old Telephone Service (Post Office Telephone System) - POTS • 2-twisted wire path of bi-directional, full duplex, voiceband • avoids electromagnetic interference & cross talk • Frequency: 300 to 3400 Hz • Subscriber Loop • 40 volts DC and 300 ohms • From central office to subscribers home • Analog lines carries control and audio signals

  7. Landline Telephones • Hand Cranked Magneto Generator • Direct connection to an operator that will connect the call • Candlestick • Direct connection to an operator that will connect the call • Constantly powered

  8. Rotary Dial Telephone • Rotary movement’s sends electrical pulses – length represents a number • Pulse dialing – sounds like a series of clicks

  9. DTMF Telephone • Dual-Tone Multi-Frequency • Touch Tone dialing over analog lines • An established tone’s frequency with distinct sine waves represents a number or symbol (* or #)

  10. Analog Signals & Digital Signals Analog Signals Digital Signals Large signal fluctuations any continuous signal for which the time varying feature (variable) of the signal is a representation of some other time varying quantity Small signal fluctuations each point in time, the value of the signal must be above or below some discrete threshold Not subject to electronic noise

  11. Cordless Telephone • Uses and RF (radio frequency signal) • Handset communicates with base station • Handset contains rechargeable batteries

  12. Cellular • RF digital signals • Sites are spaced apart in hexagonal pattern with 120 degree directional antennas • CDMA (Code Division Multiple Access): encoding signals • Alcalet-Lucent’s Lightradio, size of Rubix Cube, has same technology and power as a large cell tower

  13. Cellular Telephone • Transmits and receives signals over a radio link • Connects to cellular network and public telephone network

  14. Satellite Telephone • Geosynchronous Satellites (4 at 22,000 miles) • Fixed orbital position • Transmits and receives RF digital signals

  15. Mobile Computing(Smartphone) • A.K.A Personal Digital Assistant (PDA) • Contains a Mobile Operating System • iOS • Android (Linux) • Windows • Blackberry

  16. TELEPHONE FUTURE Video: Apple's iPhone Concept Video: Sixth Sense Technology

  17. References "Telephone - Wikipedia, the free encyclopedia." Wikipedia, the free encyclopedia. N.p., n.d. Web. 24 May 2012. <http://en.wikipedia.org/wiki/Telephone>.

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