8/14/2019 Nave Ed Khan
1/32
7.1
Chapter 7Transmission Media
Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
8/14/2019 Nave Ed Khan
2/32
7.2
Figure 7.1 Transmission medium and physical layer
8/14/2019 Nave Ed Khan
3/32
7.3
Figure 7.2 Classes of transmission media
8/14/2019 Nave Ed Khan
4/32
7.4
7-1 GUIDED MEDIA7-1 GUIDED MEDIA
Guided media, which are those that provide a conduitGuided media, which are those that provide a conduit
from one device to another, include twisted-pair cable,from one device to another, include twisted-pair cable,
coaxial cable, and fiber-optic cable.coaxial cable, and fiber-optic cable.
Twisted-Pair Cable
Coaxial Cable
Fiber-Optic Cable
Topics discussed in this section:Top
ics discussed in this section:
8/14/2019 Nave Ed Khan
5/32
7.5
Figure 7.3 Twisted-pair cable
8/14/2019 Nave Ed Khan
6/32
7.6
Figure 7.4 UTP and STP cables
8/14/2019 Nave Ed Khan
7/327.7
Table 7.1 Categories of unshielded twisted-pair cables
8/14/2019 Nave Ed Khan
8/327.8
Figure 7.5 UTP connector
8/14/2019 Nave Ed Khan
9/327.9
Figure 7.6 UTP performance
8/14/2019 Nave Ed Khan
10/327.10
Figure 7.7 Coaxial cable
8/14/2019 Nave Ed Khan
11/327.11
Table 7.2 Categories of coaxial cables
8/14/2019 Nave Ed Khan
12/327.12
Figure 7.8 BNC connectors
8/14/2019 Nave Ed Khan
13/327.13
Figure 7.9 Coaxial cable performance
8/14/2019 Nave Ed Khan
14/327.14
Figure 7.10 Fiber optics:Bending of light ray
8/14/2019 Nave Ed Khan
15/327.15
Figure 7.11 Optical fiber
8/14/2019 Nave Ed Khan
16/327.16
Figure 7.12 Propagation modes
8/14/2019 Nave Ed Khan
17/327.17
Figure 7.13 Modes
8/14/2019 Nave Ed Khan
18/327.18
Table 7.3 Fiber types
8/14/2019 Nave Ed Khan
19/327.19
Figure 7.14 Fiber construction
8/14/2019 Nave Ed Khan
20/32
7.20
Figure 7.15 Fiber-optic cable connectors
8/14/2019 Nave Ed Khan
21/32
7.21
Figure 7.16 Optical fiber performance
8/14/2019 Nave Ed Khan
22/32
8/14/2019 Nave Ed Khan
23/32
7.23
Figure 7.17 Electromagnetic spectrum for wireless communication
8/14/2019 Nave Ed Khan
24/32
7.24
Figure 7.18 Propagation methods
8/14/2019 Nave Ed Khan
25/32
7.25
Table 7.4 Bands
8/14/2019 Nave Ed Khan
26/32
7.26
Figure 7.19 Wireless transmission waves
8/14/2019 Nave Ed Khan
27/32
7.27
Radio waves are used for multicastcommunications, such as radio and
television, and paging systems. They
can penetrate through walls.
Highly regulated. Use omni directional
antennas
Note
8/14/2019 Nave Ed Khan
28/32
7.28
Figure 7.20 Omnidirectional antenna
8/14/2019 Nave Ed Khan
29/32
7.29
Microwaves are used for unicast
communication such as cellulartelephones, satellite networks,
and wireless LANs.
Higher frequency ranges cannotpenetrate walls.
Use directional antennas - point to point
line of sight communications.
Note
8/14/2019 Nave Ed Khan
30/32
7.30
Figure 7.21 Unidirectional antennas
8/14/2019 Nave Ed Khan
31/32
7.31
Infrared signals can be used for short-
range communication in a closed area
using line-of-sight propagation.
Note
8/14/2019 Nave Ed Khan
32/32
7 32
Wireless Channels
Are subject to a lot more errors thanguided media channels.
Interference is one cause for errors, canbe circumvented with high SNR.
The higher the SNR the less capacity isavailable for transmission due to the
broadcast nature of the channel. Channel also subject to fading and nocoverage holes.
Top Related