Transmission Media

Adapted from lecture slides by Behrouz A. Forouzan© The McGraw-Hill Companies, Inc. All rights reserved

Asst. Prof. Mahdi Abbasiabbasi@basu.ac.ir

http://profs.basu.ac.ir/abbasiComputer Engineering Department

Bu-Ali Sina University, Hamedan, Iran.

Data Communication and Computer Networks

2

Physical Layer

3

Classes of Transmission Media

4

Guided Media

Provide a conduit from one device to another

Include

twisted-pair cables

coaxial cables

fiber-optic cables

Guided Media:Copper Media

6

Twisted-Pair Cable

7

UTP – Unshielded Twisted Pair STP –Shielded Twisted Pair

UTP and STP Cables

8

Categories of UTP/STP Cables

9

Categories of UTP/STP Cables

Category Bandwidth Digital/Analog Use

1 very low Analog Telephone

2 < 2 MHz Analog/digital 4Mbps token ring

3 16 MHz Digital 10-100 Mbps Ethernet

4 20 MHz Digital 16 Mbps token ring

5 100 MHz Digital 100 – 1000 Mbps Ethernet

5E 100 MHz Digital 100 – 1000 Mbps Ethernet

6 250 MHz Digital 1 – 10 Gbps Ethernet

6A 500 MHz Digital 1 – 10 Gbps Ethernet

7 600 MHz Digital 10 Gbps Ethernet

7A 1000 MHz Digital 40-100 Gbps Ethernet

10

RJ – Registered Jack

UTP Connectors

11

UTP Performance

12

Coaxial Cable

13

RG – Radio Government

Categories of Coaxial Cables

14

BNC Connectors

Bayonet Network Connector

aka. Bayonet Neil-Concelman

Used with coaxial cables

15

Performance of Coaxial Cables

Guided Media: Optical Media

17

Optical Fiber

Based on physics of light

18

Optical Fiber

19

Propagation Modes

20

Fiber Types

21

Fiber Construction

22

Fiber-Optic Cable Connectors

23

Optical Fiber Performance

Unguided Media

25

Unguided Media: Wireless

Transport electromagnetic waves without using a physical conductor

Radio Waves

Microwaves

Infrared

Often referred to as wireless communication

26

Electromagnetic Spectrum

27

Propagation Methods

28

Bands

29

Antennas

Omni-directional Antenna Unidirectional Antennas

30

Wireless Transmission Waves

used for multicast/broadcast communications, such as radio and television

used for unicast communication such as cellular telephones, satellite networks,and wireless LANs

used for short-range communication in a closed area using line-of-sight propagation