MULTIPLEXING 2

MULTIPLEXING 2

1. INVERSE MULTIPLEXING

   • Opposite of multiplexing
   • takes the data stream from one high-speed line and breaks it into portions that can be sent lower speed lines simultaneously, with no loss in the collective data rate
   • Application
     • sending data , voice and video
   • signal can be broken up with a different rate into multiple lines and inversely multiplexed over multiple lines

2. SPREAD SPECTRUM

   • design to be used in wireless applications (LANs and WANs)
   • The expanded bandwidth allow source to wrap it message in a protective envelope for more secure transmission
   • TECHNIQUES
     • Frequency Hopping Spread Spectrum (FHSS)
       • uses M different carrier frequencies that are modulated by the source signal
     • Direct Sequence Spread Spectrum (DSSS)
       • each data bit will be replaced by with n bits using a spreading code