LEARNING OUTCOME 2

Identify the different types of Transmission Media

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Read Information Sheet 2.1 Transmission Media

Transmission Frequencies

Transmission Media Characteristics Cost Installation Requirements Bandwidth Band Usage Attenuation Electromagnetic Inteference

Guided/Cable Media Coaxial Cable Twisted Pair Cable Fiber Optics

Unguided/Wireless Media Reasons for wireless network Wireless Communication with LANs Comparison of Different Wireless Media

Transmission Frequencies

Transmission Media Characteristics Cost Installation Requirements Bandwidth Band Usage Attenuation Electromagnetic Inteference

Guided/Cable Media Coaxial Cable Twisted Pair Cable Fiber Optics

Unguided/Wireless Media Reasons for wireless network Wireless Communication with LANs Comparison of Different Wireless Media Perform Activity Sheet 2.1 Crimping Cat5/Cat5e

Answer Self Check 2.1Evaluation: Match Answer your answer to Model 2.1

Information Sheet 2.1

Self Check 2.1

Activity 2.1

Model Answer to Self Check 2.1

INFORMATION SHEET 2.1

Transmission Media

Transmission - transfers of dataMedia - the medium through which data is transferred from one place to anotherSignals - information is transmitted in the form of electromagnetic signals

Two Types of Signal1. Analog Signal Continuous signal in which the signal intensity varies smoothly over time2. Digital SignalDiscrete signal in which the signal intensity maintains a constant level for some period and then changes to another constant level.

Characteristic of Analog signal1. Amplitude: intensity of signal at any given time2. Frequency: no of cycles/periods in one second, measured in HzFrequency = 1/Period

Digital Signals1. Digital signals can be better described by two terms Bit interval: time required to send a single bit Bit rate: number of bit intervals in one second2. A digital signal is a composite signal having an infinite number of frequencies i.e. infinite bandwidth The digital BW is bits per sec (bps)

Transmission Media Frequency

TRANSMISSION MEDIA CHARACTERISTICS1. Cost2. Installation requirements3. Bandwidth 4. Band usage (baseband or broadband)5. Attenuation 6. Immunity from electromagnetic interference

Band Usage

a. Baseband - devotes the entire capacity of the medium to one communication channelb. Broadband - enables two or more communication channels to share the bandwidth of the communications medium.

Multiplexing - technique that enables broadband media to support multiple data channels

Bandwidth - refers to the measure of the capacity of a medium to transmit data.

Baseband and broadband transmission modes

Attenuation - a measure of how much a signal weakens as it travels through a medium

Electromagnetic Interference - consists of outside electromagnetic noise that distorts the signal in a medium.

Classes of Transmission Media

1. Guided Media - provides a conduit from one device to another2. Unguided Media - transports electromagnetic waves without using a physical conductor called Wireless Communication

Guided Media1. Twisted Pair2. Coaxial Cable3. Fiber Optics

Twisted PairTWO TYPES OF TWISTED PAIR Unshielded Twisted Pair (UTP) Shielded Twisted Pair (STP)

Unshielded Twisted Pair - is considered the fastest copper-based media.

UTP CATEGORY

SHIELDED TWISTED PAIR

Twisted pair connections1. Common in business applications2. Delivers both voice and data3. Select proper cable type based on Cables electrical characteristics Conductor size Ability to resist crosstalk4. 3-4 pairs of wire for networking5. Twisted to prevent crosstalk6. More twists equal less crosstalk, but greater attenuation

Stranded versus solid1. Solid a. Thicker, more protective covering b. Less flexiblec. Best for longer network runs and fixed wiring2. Stranded a. Thinner protective coveringb. More pliable c. Useful for shorter-distances and movable wiring

Twisted pair connectors

1. Four types for UTPa. RJ-11

b. RJ-14

c. RJ-25

d. RJ-45

RJ-45 connector

1. Attaches to 8 wires2. Two connection standards for Etherneta. T568A mostly residential useb. T568B mostly commercial use

PIN NUMBERING OF RJ-45

COAXIAL CABLE

Coaxial connections

1. Found in older networks2. RG-8, RG-11, RG-58 used in Ethernet3. Stranded or solid4. Impedance in ohms

TYPES OF COAX CABLING

Thinnet connectors

F TYPE CONNECTOR AND BNC CONNECTOR

BNC CABLE CONNECTOR

A BNC CONNECTOR CONNECTING TO A WORKSTATION

BNC-T CONNECTOR USED ON THINNET COAX CABLE

CONNECTING WITH THICKNETAUI PORT

Thicknet vampire tap

Coaxial cable wiring configuration

Thicknet Cable with Vampire Taps and Transceiver cable to connect to a computer

FIBER OPTICSCarries digital signals in the form of pulses of light

BENEFITS1. Thinner and lighter weight 5. Less signal degradation 2. Higher carrying capacity 6. Less interference 3. Use of digital signals 7. Non-flammable 4. More secure

Fiber optic connectors1. Straight Tip (ST)2. Subscriber Connector (SC): 3. Fiber Local Connector (LC) and Mechanical Transfer-Registered Jack (MT-RJ)

FIBER OPTIC CABLE TYPES1. Multimode Fiber (MMF) a. Typically has a 62.5 micron coreb. Light travels down the core in many raysc. Works with LED light sources of different wavelengths2. Single Mode Fiber (SMF)a. Very small core of about 9 micronsb. Light travels down the cable in one rayc. Optimal for very fast transmissions

COMPARISON OF CABLE MEDIA

UNGUIDED MEDIA

Unguided MediaIt transports electromagnetic waves without using a physical conductor called Wireless Communication

Reasons for Wireless Networks1. Spaces where cabling would be impossible or inconvenient.2. People who move around a lot within their work environment.3. Temporary installations.4. People who travel outside of the work environment and need instantaneous access to network resources.5. Satellite offices or branches, ships in the ocean, or teams in remote field locations that need to be connected to a main office or location.

Types of Unguided Media Satellite Communication Terrestrial Microwave Radio Communication Infrared

Satellite CommunicationSatellite provides communication over longer distance compared to normal radio

Terrestrial Microwave communication used extensively in situations when physical transmission media is impractical or difficult to install used for only short distance up to 50km

Radio Communication used for the purpose of wireless communication used for private communication with devices like portable phones used for sending and receiving computer data.

Infrared communication allows computing devices to communicate via short-range wireless signals requires line-of-sight transmissions Infrared transmissions are typically limited to within 100 feet. Infrareds high bandwidth supports transmission speeds of up to 10Mbps

Four varieties of infrared communication Broadband optical telepoint Line-of-sight infrared Reflective infrared Scatter infrared

SELF CHECK 2.1Encircle the letter of the correct answer.1. Which of the following is not a common type of medium used in networking?A. Coaxial cableC. Fiber-optic cableB. Twisted-pair cableD. RJ-45

2. What is the distance limitation of thinnet?A. 100 metersC. 250 metersB. 185 metersD. 500 meters

3. Which cable type sends the signal as pulses of light through a glass core?A. ThinnetC. Fiber opticB. ThicknetD. CAT 5e

4. What is the maximum distance of CAT 3 UTP cabling?A. 100 metersC. 250 metersB. 185 metersD. 500 meters5. Connector of coaxial cable?A. RJ-11C. SCB. BNC-TD. All of the above

6. You want to create a crossover cable to connect two systems directly together. Which wireswould you have to switch at one end of the cable?A. Wires 1 and 2 with wires 3 and 6C. Wires 1 and 2 with wires 3 and 4 B. Wires 2 and 3 with wires 6 and 8D. Wires 2 and 3 with wires 3 and 6

7. Fiber-optic cabling uses which two types of connectors (select two)?A. SCC. BNCB. RJ-45D. ST

8. Two types of fiber opticsA. MMF and SMFC. RJ-14 and RJ-11B. BNC and BNC-TD. All of the above

9. Which cable type is immune to outside interference and crosstalk?A. ThinnetC. Twisted pairB. ThicknetD. Fiber optic

10. Wireless media that used extensively in situations when physical transmission media is impractical or difficult to install. A. Radio waveC. Infrared B. Terrestial Microwave D. BluetoothMODEL ANSWER TO SELF CHECK 2.11. Which of the following is not a common type of medium used in networking?A. Coaxial cableC. Fiber-optic cableB. Twisted-pair cableD. RJ-45

2. What is the distance limitation of thinnet?A. 100 metersC. 250 metersB. 185 metersD. 500 meters

3. Which cable type sends the signal as pulses of light through a glass core?A. ThinnetC. Fiber opticB. ThicknetD. CAT 5e

4. What is the maximum distance of CAT 3 UTP cabling?A. 100 metersC. 250 metersB. 185 metersD. 500 meters5. Connector of coaxial cable?A. RJ-11C. SCB. BNC-TD. All of the above

6. You want to create a crossover cable to connect two systems directly together. Which wireswould you have to switch at one end of the cable?A. Wires 1 and 2 with wires 3 and 6C. Wires 1 and 2 with wires 3 and 4B. Wires 2 and 3 with wires 6 and 8D. Wires 2 and 3 with wires 3 and 6

7. Fiber-optic cabling uses which two types of connectors (select two)?A. SCC. BNCB. RJ-45D. ST

8. Two types of fiber opticsA. MMF and SMFC. RJ-14 and RJ-11B. BNC and BNC-TD. All of the above

9. Which cable type is immune to outside interference and crosstalk?A. ThinnetC. Twisted pairB. ThicknetD. Fiber optic

10. Wireless media that used extensively in situations when physical transmission media is impractical or difficult to install. A. Radio waveC. Infrared B. Terrestial Microwave D. Bluetooth

ACTIVITY 2.1

CRIMPING A CATEGORY 5/5e CABLE

In this exercise, you will learn how to crimp your own CAT 5 cable. To complete this exercise, you will need to have a crimping tool, a piece of CAT 5 cabling, some RJ-45 connectors, and a little bit of patience! To create a CAT 5 cable, do the following:

568B WIRING STANDARD FOR A CROSSOVER CABLE

PIN OUT DIAGRAM OF A CROSSOVER CABLE

568B WIRING STANDARD FOR A STRAIGHT-THROUGH CABLE

PIN OUT DIAGRAM OF STRAIGHT-THROUGH CABLE

1. Ensure that you have a clean-cut end on the cable by using your wire cutters to cut a little off the end of the CAT 5 cable.

2. Once you have cut a clean end on the cable, strip about an inch off the outer jacket from the cable using the wire-stripper portion of your crimping tool, as shown in the next illustration. After stripping the outer jacket off, make sure that you have not cut into any of the individual wires. If you have, cut a clean end off the cable again and start from the beginning.

3. Once you have stripped the outer jacket off the cable, order the wires from left to right to follow the 568B standard. This is where your patience will come in, because it will take some time to get the wires in the correct order and placed tightly together so that they will go inside the RJ-45 connector.

4. Once you have the wires aligned in the correct order and you have them all nice and snug together so they will fi t inside the RJ-45 connector, you are ready to insert them into the connector. Before inserting the wires into the connector, make sure that their ends are of equal length; if they are not, just cut the tips a bit with your wire cutters, as shown in the following illustration, to be certain that they will fi t nicely into the RJ-45 connector.

5. Slide the wires into the RJ-45 connector, as shown in the next illustration, and make sure that all wires have made contact with the metal contacts inside the RJ-45 connector by looking at the end of the connector. This is where mistakes happen frequently; there is usually one wire in the middle that is not pushed up to the end of the connector.

6. Once you are certain that all wires have made contact, you can crimp the wire, which will enclose the RJ-45 connector on the wires, creating a permanent fi t. Insert the connector into the crimping tool and squeeze the handle tight, as seen in the following illustration.