Lecture on Fiber Optics and Copper Cables

Fiber Optics

Types of Fiber Optic Connections
- Multimode Fiber
  - Uses multiple paths for light to travel.
  - Common sizes: 50 Micron and 62.5 Micron.
- Single Mode Fiber
  - Uses a single path for light.
  - Diameter: ~9 Microns.
Fiber Structure
- Both multimode and single-mode fibers have cladding bringing the total size to 125 microns.
Importance of Correct Fiber Use
- Mixing fiber types can lead to signal errors.
- Color coding can be unreliable; documentation is essential.

Telecommunications Industry Standards (TIA)
- Set standards for cable construction.
- Cables are categorized (Cat 5, Cat 6, Cat 6A, etc.) based on construction and testing.
Ethernet Standards
- 1000Base-T uses Category 5 cable (up to 100m).
- 10GBase-T uses Category 6 or 6A (depends on distance).
Bandwidth vs Throughput
- Bandwidth: Theoretical maximum data rate.
- Throughput: Actual data rate over time.

Signal Attenuation
- Loss of signal strength over distance.
- Relevant for both copper and fiber optics.
Cross Talk (XT)
- Near-End Cross Talk (NEXT)
  - Signal leakage at the closest end to the testing device.
- Far-End Cross Talk
  - Signal leakage measured at the far end of the cable.
- Alien Cross Talk
  - Interference from other cables.
- Attenuation to Cross Talk Ratio (ACR)
  - Compares signal loss to signal leakage.

Cable Testing
- Essential for verifying category compliance and installation quality.
- Testing reveals errors such as cross talk and signal attenuation.
Best Practices
- Maintain twists in cables to reduce interference.
- Use removable cable ties, avoid staples, and limit sharp bends.
- Avoid EMI sources like power cords and fluorescent lights.

Connector Challenges
- Proper termination crucial for network performance.
- Misaligned pins can cause connection issues.
- Auto-MDIX can sometimes correct pin mismatches, but proper installation is preferred.