DSL, Mobile Telephone System, and Cable


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DSL, Mobile Telephone System, and Cable

  1. 1. CS412 Introduction to Computer Networking & Telecommunication DSL, Cable, and Mobile Telephone System
  2. 2. Topics <ul><li>Digital Subscriber Line </li></ul><ul><li>Cable </li></ul><ul><li>Mobile Telephone System </li></ul>
  3. 3. Digital Subscriber Lines <ul><li>Bandwidth versus distanced over category 3 UTP for DSL. </li></ul>
  4. 4. Digital Subscriber Lines <ul><li>Operation of ADSL using discrete multitone modulation . </li></ul>
  5. 5. Figure 9.1 DMT
  6. 6. Figure 9.2 Bandwidth division
  7. 7. Digital Subscriber Lines <ul><li>A typical ADSL equipment configuration. </li></ul>
  8. 8. Figure 9.3 ADSL modem
  9. 9. Figure 9.4 DSLAM
  10. 10. Wireless Local Loops <ul><li>Architecture of an LMDS system. </li></ul>
  11. 11. Cable Television <ul><li>Community Antenna Television </li></ul><ul><li>Internet over Cable </li></ul><ul><li>Spectrum Allocation </li></ul><ul><li>Cable Modems </li></ul><ul><li>ADSL versus Cable </li></ul>
  12. 12. Community Antenna Television <ul><li>An early cable television system. </li></ul>
  13. 13. Internet over Cable <ul><li>Cable television </li></ul>
  14. 14. Compared to Telephone System <ul><li>The fixed telephone system. </li></ul>
  15. 15. Spectrum Allocation <ul><li>Frequency allocation in a typical cable TV system used for Internet access </li></ul>
  16. 16. Cable Modems <ul><li>Typical details of the upstream and downstream channels in North America. </li></ul>
  17. 17. Figure 9.8 Cable modem
  18. 18. Figure 9.9 CMTS
  19. 19. ADSL versus Cable <ul><li>Discussions … </li></ul>
  20. 20. Mobile Telephone System <ul><li>First-Generation Mobile Phones </li></ul><ul><ul><li>Analog Voice </li></ul></ul><ul><li>Second-Generation Mobile Phones </li></ul><ul><ul><li>Digital Voice </li></ul></ul><ul><li>Third-Generation Mobile Phones </li></ul><ul><ul><li>Digital Voice and Data </li></ul></ul>
  21. 21. Advanced Mobile Phone System <ul><li>Area is divided into cells with an antenna control by a cell office in each cell </li></ul><ul><li>Cell offices communicate with MTSO </li></ul><ul><li>Transmission frequencies cannot be the same in adjacent cells </li></ul><ul><li>Cell size is not fixed </li></ul><ul><ul><li>Smaller cells used in higher populated area </li></ul></ul>
  22. 22. Figure 7-36 WCB/McGraw-Hill  The McGraw-Hill Companies, Inc., 1998 Cellular System
  23. 23. Advanced Mobile Phone System <ul><li>(a) Frequencies are not reused in adjacent cells. </li></ul><ul><li>(b) To add more users, smaller cells can be used. </li></ul>
  24. 24. Figure 17.2 Frequency reuse patterns
  25. 25. Cellular Transmission <ul><li>Traditionally analog </li></ul><ul><ul><li>FM used to minimized noise </li></ul></ul><ul><li>Digital transmission </li></ul><ul><ul><li>CDPD (Cellular Digital Packet Data) </li></ul></ul><ul><ul><ul><li>Low-speed digital service over existing cellular network </li></ul></ul></ul><ul><ul><ul><li>Based on OSI Model </li></ul></ul></ul><ul><ul><ul><li>Modem needed </li></ul></ul></ul>
  26. 26. Cellular System <ul><li>Handoff </li></ul><ul><ul><li>When a mobile telephone leaves a cell </li></ul></ul><ul><ul><li>1. Its base station notices the signal fading out </li></ul></ul><ul><ul><li>2. The base station asks all the surrounding base stations how much power they are getting from it </li></ul></ul><ul><ul><li>3. Ownership is transferred to the neighbor base station that receives strongest power </li></ul></ul><ul><ul><li>4. The telephone is informed of its new boss </li></ul></ul><ul><ul><li>5. If a call is in progress, it will be asked to switch to a new channel </li></ul></ul>
  27. 27. Channels <ul><li>832 full-duplex channels </li></ul><ul><ul><li>Each channel consists of 2 simplex channels </li></ul></ul><ul><ul><li>Transmission channels </li></ul></ul><ul><ul><ul><li>(849-824)MHz/30KHz  832 </li></ul></ul></ul><ul><ul><li>Receiving channels </li></ul></ul><ul><ul><ul><li>(894-869)MHz/30KHz  832 </li></ul></ul></ul><ul><li>Typically, actual number of voice channel per cell  45 </li></ul>
  28. 28. Channel Categories <ul><li>The 832 channels are divided into four categories </li></ul><ul><ul><li>Control (base to mobile) to manage the system </li></ul></ul><ul><ul><li>Paging (base to mobile) to alert users to calls for them </li></ul></ul><ul><ul><li>Access (bidirectional) for call setup and channel assignment </li></ul></ul><ul><ul><li>Data (bidirectional) for voice, fax, or data </li></ul></ul>
  29. 29. Second-Generation Mobile Phones <ul><li>D-AMP </li></ul><ul><li>GSM </li></ul><ul><li>CDMA </li></ul>
  30. 30. D-AMPS Digital Advanced Mobile Phone System <ul><li>(a) A D-AMPS channel with three users. </li></ul><ul><li>(b) A D-AMPS channel with six users. </li></ul>
  31. 31. GSM Global System for Mobile Communications <ul><li>GSM uses 124 frequency channels, each of which uses an eight-slot TDM system </li></ul>
  32. 32. GSM <ul><li>A portion of the GSM framing structure. </li></ul>
  33. 33. Third-Generation Mobile Phones: Digital Voice and Data <ul><li>Basic services an IMT-2000 network should provide </li></ul><ul><ul><li>High-quality voice transmission </li></ul></ul><ul><ul><li>Messaging </li></ul></ul><ul><ul><ul><li>Replace e-mail, fax, SMS, chat, etc. </li></ul></ul></ul><ul><ul><li>Multimedia </li></ul></ul><ul><ul><ul><li>Music, videos, films, TV, etc. </li></ul></ul></ul><ul><ul><li>Internet access </li></ul></ul><ul><ul><ul><li>Web surfing, w/multimedia </li></ul></ul></ul><ul><li>2.5G, 4G, … </li></ul>