This document discusses different types of transmission media used in communications systems. It focuses on guided media, including twisted pair cables, coaxial cables, and fiber optic cables. For twisted pair cables, it describes unshielded twisted pair (UTP) and shielded twisted pair (STP), their types and applications. It also discusses coaxial cables, their types according to RG ratings, advantages of enhanced bandwidth and noise immunity, and disadvantages of limited connections. The document provides details on fiber optic cables in subsequent chapters.
5. Transmission media
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• Transmission media is a pathway that carries the information from sender to receiver.
• Different types of cables or waves are used to transmit data.
• Normally, data is transmitted through electrical or electromagnetic signals.
8. Guided media
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• Guided media can be defined as, the media that provides a channel
from one device to another through cables.
• Types of guided media utilized in communication
1. Twisted – Pair Cables.
2. Coaxial Cables.
3. Fiber – Optic Cables.
9. Twisted Pair cables
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• A twisted pair consists of two conductors, basically copper based, with its own plastic
insulation, twisted together.
• It provide protection against cross talk or interference (noise).
• One of the wires is used to carry signals to the receiver, and the second wire used as a
ground reference.
Advantages
1. Cheap
2. Easy to work
Disadvantages
1. Low data rate
2. Short range
Application
Very common medium that can be use in
1. Telephone network
2. Local Area Networks (LAN)
10. Twisted Pair cables types
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• There are two types for twisted paid cables
1. Unshielded Twisted Pair (UTP)
2. Shielded Twisted Pair (STP).
11. Unshielded Twisted Pair (uTP)
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Description
• Pair of unshielded wires twisted around each other.
Application
• Telephone Networks.
• Local Area Networks (LAN).
UTP Cable Types
UTP are categorized according to the IEEE standards to:
• Cat 1.
• Cat 2.
• Cat 3.
• Cat 4.
• Cat 5.
• Cat 5e.
• Cat 6.
• Cat 7.
Advantages of UTP
• Affordable
• Most compatible cabling for
Major networking system
Disadvantages of UTP
• Suffers from external
Electromagnetic interference
15. shielded Twisted Pair (STP)
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Description
• Pair of unshielded wires wound around each other inside a protective foil wrap, that
is used to reduce the interference.
Application
• Higher transmission rates over longer distance.
STP Cable Types
STP are categorized according to the Telecommunications Industry
Association (TIA) and Electronic Industries Alliance (EIA) standards to:
• IBM Type 1.
• IBM Type 1A.
• IBM Type 2A.
• IBM Type 6A.
Advantages of STP
• More resistance to EMI, i.e. Shielded
• Faster than UTP
Disadvantages of STP
• More expensive than UTP
16. Coaxial cables
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Description
• Co-axial cable carries signal of higher frequency ranges than twisted pair cables.
• The inner conductor is a solid wire, while, the outer conductor
serves as a shield against noise.
Application
• TV broadcasting.
• Short distance computer networks.
• Long distance telephone transmission.
• Can carry 10,000 voice calls simultaneously.
Coaxial Cable Types
Coaxial cables are categorized by Radio Government (RG) ratings:
Advantages of Coaxial cables:
• Enhanced resistance to EMI due to its
better shielding especially compared to
twisted pair cables.
• Hight bandwidth (i.e. up to 1GHz).
• Enhanced noise immunity.
• Cheap installation.
Disadvantages of Coaxial cables:
• Limited number of connections.
• Cable terminals and connectors must be
done properly.
• More expensive when compared to
twisted pairs.
17. Coaxial cables connectors
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• Coaxial connectors are required to connect coaxial cable to other devices.
1. BNC Connector
• Used at the end of the cable to a device, e.g. TV set connection.
2. BNC-T connector
• Used at Ethernet networks to branch out connection to computer or other devices.
3. BNC terminator
• Used at the end of the cable to prevent the reflection of the signal.
