Transmission Media Sharing

1
Transmission Media Sharing

• When can you share?
• High Medium capacity
• Why share ?
• Less transmission costs
• More cost-effective transmissions
• How would you share?
• Multiplexing

2
Multiplexing vs. No Multiplexing
3
Multiplexer
4
Types of Multiplexing

• Frequency Division Multiplexing (FDM)
• Wave Division Multiplexing (WDM)
• Time Division Multiplexing (TDM)
• Synchronous
• Asynchronous (Statistical TDM)

5
Frequency Division Multiplexing

• Analog signaling transmission.
• Total bandwidth sum of input bandwidths guard
  bands.
• Modulates signals to different frequency
• Uses
• Radio broadcasting and television

6
FDM - Multiplexer
7
FDM - Demultiplexer
8
TDM - Synchronous
9
TDM - Asynchronous
10
Inverse Multiplexing

• Takes data stream from one high speed line
  breaks it into portions that can be sent over
  multiple lower speed lines simultaneously.

11
Multiplexing and Inverse Multiplexing
12
Analog Services

• Analog switched
• Dial- up, voice networks
• PSTN Public Switched Telephone Network
• Analog Leased
• Conditioned Lines

13
Multiplexing Efficiency

• Multiplex signals from lower bandwidth into high
  bandwidth lines
• Many analog lines into fewer bigger channels
• FDM used
• Hierarchical structure

14
Analog Hierarchy
15
Digital Service

• Less sensitive to interference
• 3 Types Digital Service
• Switched/56 Service
• DDS - Digital Data Service
• DS Digital Signal Service

16
DS Hierarchy
17
DS

• T Lines are Digital Lines for Digital
  Transmission to deliver DS Service.
• T1 DS-1 1.544Mbps
• T2 DS-2 6.312Mbps
• T3 DS-3 44.736Mbps
• T4 DS-4 274.176Mbps