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7.11.11 Why Did Telephone Networks Change From FDM To TDM?

Explore the technological evolution of telephone networks from analog frequency-division multiplexing to digital time-division multiplexing. Learn why advances in digital electronics, pulse-code modulation, and optical transmission made TDM more efficient, scalable, and economical than traditional FDM systems.

  1. Why Was FDM Used First?
  2. How Successful Was FDM?
  3. How Did Analog Telephone Hierarchies Work?
  4. What Were the Limitations of FDM?
  5. What Changed During the 1960s?
  6. What Is Pulse-Code Modulation?
  7. Why Does Digital Speech Favour TDM?
  8. Why Is TDM Simpler?
  9. What Happened to Noise?
  10. Why Was This So Important?
  11. How Did Digital Switching Change Networks?
  12. Why Was TDM Better Suited to Optical Fiber?
  13. Did Digital Systems Use Less Bandwidth?
  14. Why Was Network Management Easier?
  15. What Role Did SONET and SDH Play?
  16. Did FDM Disappear Completely?
  17. Why Was the Transition So Successful?
  18. What Can Engineers Learn from This Transition?
  19. Why Is This Transition Important?