Telecommunications & The Internet Basic Telecom Model



Download 298.5 Kb.
Page1/7
Date25.03.2024
Size298.5 Kb.
#63930
  1   2   3   4   5   6   7
Network-Internet

Telecommunications & The Internet

Basic Telecom Model

  • Computer
  • Computer
  • Channel
  • interface
  • Channel
  • interface
  • Communication
  • Channel

Typical Home Telecom Model

  • Computer
  • Computer
  • Modem
  • Modem
  • Digital
  • signals
  • Digital
  • signals
  • Analog signals

Channels

  • Twisted wire (twisted pair)
  • Coaxial Cable
  • Fiber Optics
  • Microwave
  • Newer Wireless

Twisted Pair

  • Low cost
  • easy to work with
  • installed infrastructure
  • crosstalk
  • 300bps to 100Mbps
  • “This modem is 56Kbps capable. However, current regulations limit download speeds to 53Kbps,” the fine print from a typical modem advertisement.

DSL

  • Uses existing twisted pair
  • 256Kbps to 40Mbps
  • Loop length max about 18,000 ft.
  • More correctly ADSL (Asymmetric Digital Subscriber Line) with download speeds different from upload speeds.

Coaxial Cable

  • More expensive
  • harder to work with
  • not as extensive an existing infrastructure
    • cable TV companies are changing this
  • 56Kbps to 550Mbps

Fiber Optics

  • Very expensive
  • difficult to work with
  • existing infrastructure limit to backbones
  • 500Kbps to 30Gbps

Microwave

  • Not as expensive as land lines
  • Limited to line of site, (towers)
    • reasonable infrastructure
  • Satellite bounce, increases expense
    • geo-synchronous (22,000 miles)
    • low earth orbit (cheaper, lower power)
  • 256Kbps to 100Mbps

Newer Wireless

    • Cellular
    • mobile data networks
    • personal communications services (PCS)
    • note: pagers & PDAs are not channels, they would be nodes on one end of a channel

Download 298.5 Kb.

Share with your friends:
  1   2   3   4   5   6   7




The database is protected by copyright ©ua.originaldll.com 2024
send message

    Main page