Lesson 4 Flashcards
carries the data in the form of signals between two or more computers
network media
signals can be in the form of
electronic current, microwave, radio or light spectrum energy
provides the path for sending and receiving information between computers
network media
2 major classification of network media
wired media and wireless media
also known as cabled, bounded, or conducted media
wired network media
two strands of copper wire twisted around each other
twisted pair cable (tp cable)
used for telephone communications, not for transmitting data
cat1
4 mbps > 10 mbps > 16 mbps > 100 mbps > 1000 mbps/1gbps
cat 2-5e
consists of a center wire surrounded by insulation then a grounded shield of braided wire
coaxial cable
type of wired media carries data in the form of modulated pulses of light
fiber optic cable
Factors to consider in choosing the network media
Cost, ease of installation, flexibility, resistance to interference or EMI, speed or capacity or bandwidth, attenuation
EMI meaning
Electromagnetic Interference
refers to the amount of data that can be transmitted in a fixed amount of
time
Bandwidth
capacity of the cable to transfer signal from one point to another
Attenuation
capacity of the cable to transfer signal from one point to another
Attenuation
Wired Media
○ Twisted pair cable
○ Coaxial Cable
○ Fiber Optic Cable
Wired Media
○ Twisted pair cable
○ Coaxial Cable
○ Fiber Optic Cable
Wireless Media
○ Wireless LAN
○ Extended LAN
○ Mobile Computing
○ Wireless PAN
carries data in the form of electronic signals
twisted pair cables and coaxial cables
carries data in the form of electronic signals
twisted pair cables
two types of twisted pair cable
shielded twisted pair and unshielded twisted pair
two types of twisted pair cable
shielded twisted pair and unshielded twisted pair
consists of
four pairs of 24 American Wire Gauge
(AWG) copper wires.
Cat6
Comparison between STP and UTP
STP:
10 to 100mbps
moderately expensive
medium to large connector
100m (short)
UTP
10 to 1000mbs
least expensive
small
100m (short)
advantages of tp cable
- Availability and relatively low cost
- Ease of installation
- Excellent spatial efficiency
(high transmission capacity in very small
cable) - Good information-carrying capacity
(transmission rates of 1 Gigabit per second at
100
meters for Category 6 twisted pair cable) - Application independent cabling
disadvantages of tp cable
•Relatively low transmission rates it
provides
for long-distance links
•Unsuitable for very high-speed data
transmission
•Susceptibility to signal distortion or
error due
to interferences
Thin Coaxial Cable (RG-58)
○ Diameter is about 0.64 cm
○ Attenuation is 185 m (sometimes rounded of to 200 m)
● Thick Coaxial Cable(RG-8)
○ Diameter is about 1.27 cm
○ Attenuation is 500 m
● Thick Coaxial Cable(RG-8)
○ Diameter is about 1.27 cm
○ Attenuation is 500 m
advantages of coaxial cable
○Immunity to interference such as noise or
signal distortion better than twisted pair
cables
○Reasonable cost over short distances
○Standards and technology are mature which
promotes compatibility and interoperability of
different vendor’s equipment
○Heavier coaxial cable is relatively strong and
resists rough treatment
Disadvantages of coaxial cable
○Lack of security
○Low data transmission rates compared to
twisted pair and fiber optic cable
○Must be kept dry to prevent excessive
leakage between the two conductors
Single mode fiber optic cable
Fastest fiber optic technique; the
lights is guided down the center of an
extremely narrow core
multimode fiber optic cable
Refracts the light toward the center
of the fiber by variations in the
density of the core
advantages of fiber optic cable
○Very low error rates
○Faster transmission rate
○Immunity to environmental interference
○High attenuation
disadvantages of fiber optic cable
○Costly for short distances
○Complex to configure and install
○Needs specialized training/education in
order to install
○Possesses the inability to add new nodes
while other nodes are active
