Transcript Transmission Media - Computing Science

Part II. Physical Layer and
Media
Chapter 7. Transmission Media
COMP 3270 Computer Networks
Computing Science
Thompson Rivers University
Learning Objectives


List the three types of guided media.
State the reason why higher frequency radio band can transfer more
data.
Transmission medium and physical layer
Classes of transmission media
1. GUIDED MEDIA
Guided media, which are those that provide a conduit
from one device to another, include twisted-pair
cable, coaxial cable, and fiber-optic cable.
Topics discussed in this section:
• Twisted-Pair Cable
• Coaxial Cable
• Fiber-Optic Cable
Twisted-pair cable
Twisting: to reduce the mutual interference
UTP and STP cables
Unshielded Twisted Pair
Shielded Twisted Pair
Categories of UTP cables
Coaxial cable
Categories of coaxial cables
BNC connectors
Optical Fiber
Bending of light ray
Optical fiber
Propagation modes
Using reflection
Using refraction
These days
Fiber-optic cable connectors
2. UNGUIDED MEDIA: WIRELESS
Unguided media transport electromagnetic waves
without using a physical conductor. This type of
communication is often referred to as wireless
communication.
Topics discussed in this section:
• Radio Waves
• Microwaves
• Infrared
Electromagnetic spectrum for wireless communication
Microwave
30
GHz
Propagation methods
Diffraction
Reflection
Bands
Wireless transmission waves
~ 30 G
~ 300 G
~ 400 THz
Omnidirectional antenna
Unidirectional antennas