Physical Layer

1
Physical Layer

• Computer Networks

2
Numbering Systems

• Binary
• Hexadecimal
• Decimal

3
Transmission of Information

• From Physics
• Energy
• Electromagnetic wave propogation
• From Mathematics
• Coding Theory

4
Analog and Digital Signaling
5
Amplitude Modulation
6
Frequency Modulation
7
Baseband and Broadband
8
Phase Modulation
9
Modems
10
Digital Encoding
11
CSU/DSU
12
Undesirable Effects and Limitations

• Propagation Delay
• Bandwidth
• Noise
• Interference
• Distortion
• Attenuation

13
Sampling and Nyquists Theorem
14
Shannons Limit

• Corrects for SNR
• Encoding more bits per cycle time helps, but you
  cannot overcome the fundamental physical limits
  of a real transmission system.

15
Timing

• Asynchronous
• bit level
• Synchronous
• character level
• Isochronous
• timing coordination must be successful

16
Transmission Media
17
Connectors
18
Media Test and Measurement

• Hands-on Demo

19
Repeaters

• Signal Regeneration
• Clean up
• Amplifly
• Distance Extension

20
Hubs

• Repeater functionality, plus...
• Concentration Point
• Signal Distribution Device
• Management Functions

21
Throughput versus Bandwidth

• Usable capacity
• Determined by engineering

• Electrical Property
• Determined by physics