Navnath chinchore nanded

Slide 1:

WEL-COME

Transmission Media:

Transmission Media

Transmission media:

Transmission media “Transmission media is a 'Medium' through which we send the data over the network”. While concerning with media data transfer rate is most important and it is measured in BPS (Bits Per Second) .It is also called as baud. Following are the types of transmission media:- Guided Medium Unguided Medium

Transmission Media:

Transmission Media Guided Media (Wired) Twisted-Pair Cable Coaxial Cable Fiber-Optic Cable Unguided Media (Wireless) Radio Waves Microwaves Infrared

Slide 5:

Classes of transmission media

Slide 6:

GUIDED MEDIA “Guided media which are those which provide conduit from one device to another” Following are the some examples of guided medium twisted-pair cable coaxial cable fiber-optic cable.

Data Rate and Bandwidth:

Data Rate and Bandwidth Any transmission system has a limited band of frequencies This limits the data rate that can be carried

Guided Media – Twisted-pair Cable:

Guided Media – Twisted-pair Cable Twisted-pair cable

Twisted Pair:

Twisted Pair

Twisted pair(UTP):

Twisted pair(UTP) One of the wires carries signal, the other is used only as a ground reference. The receiver uses the difference b/w the two levels. Twisting increases the probability that both wires are effected by the noise in the same manner, thus the difference at the receiver remains same. Therefore, number of twists per unit length determines the quality of the cable.

Twisted Pair - Transmission Characteristics:

Twisted Pair - Transmission Characteristics Analog needs amplifiers every 5km to 6km Digital can use either analog or digital signals needs a repeater every 2-3km Disadvantages limited distance limited bandwidth (1MHz) limited data rate (100MHz) susceptible to interference and noise

Unshielded Versus Shielded Twisted-Pair Cable:

Unshielded Versus Shielded Twisted-Pair Cable UTP and STP cables

Unshielded Twisted Pair (UTP):

Unshielded Twisted Pair (UTP) Ordinary telephone wire Cheapest Easiest to install Suffers from external EM interference

Shielded Twisted Pair (STP):

Shielded Twisted Pair (STP) Metal braid or sheathing that reduces interference More expensive Harder to handle (thick, heavy)

Guided Media – UTP:

UTP Connector Guided Media – UTP

Guided Media - UTP:

Guided Media - UTP Applications: Telephone lines connecting subscribers to the central office DSL lines LAN – 10Base-T and 100Base-T

Twisted Pair - Applications:

Twisted Pair - Applications Most common medium Telephone network Within buildings For local area networks (LAN)

Guided Media – Coaxial Cable:

Coaxial Cable Guided Media – Coaxial Cable

Coaxial Cable:

Coaxial Cable

Coaxial cable:

Coaxial cable Inner conductor is a solid wire outer conductor serves both as a shield against noise and a second conductor

Coaxial Cable Applications:

Coaxial Cable Applications Most versatile medium Television distribution Long distance telephone transmission Can carry 10,000 voice calls simultaneously Short distance computer systems links Local area networks

Coaxial Cable - Transmission Characteristics:

Coaxial Cable - Transmission Characteristics analog signals amplifiers every few km closer if higher frequency up to 500MHz digital signals repeater every 1km closer for higher data rates

Guided Media – Coaxial Cable:

BNC Connectors Guided Media – Coaxial Cable

BNC connectors:

BNC connectors BNC = Bayone-Neill-Concelman BNC Connector is used to connect the end of the cable to a device BNC T is used in networks to branch out a cable for connection to a computer or other device BNC Terminator is used at the end of the cable to prevent the reflection of signal.

Guided Media – Coaxial Cable:

Guided Media – Coaxial Cable Applications: Analog telephone networks Cable TV networks Traditional Ethernet LAN – 10Base2, 10Base5

Guided Media – Fiber-Optic Cable:

Optic Fiber Guided Media – Fiber-Optic Cable

Optical Fiber - Benefits:

Optical Fiber - Benefits greater capacity data rates of hundreds of Gbps smaller size & weight lower attenuation electromagnetic isolation greater repeater spacing 10s of km at least

Optical Fiber - Transmission Characteristics:

Optical Fiber - Transmission Characteristics uses total internal reflection to transmit light can use several different light sources Light Emitting Diode (LED) cheaper, wider operating temp range, lasts longer Laser Diode (LD) more efficient, has greater data rate

Guided Media – Fiber-Optic Cable:

Fiber-optic Cable Connectors Guided Media – Fiber-Optic Cable

Guided Media – Optical Fiber Cable:

Guided Media – Optical Fiber Cable Applications: Backbone networks – SONET Cable TV – backbone LAN

Unguided Media:

Wireless transmission waves Unguided Media

Microwave:

Microwave used for long haul telecommunications and short point-to-point links requires fewer repeaters but line of sight use a parabolic dish to focus a narrow beam onto a receiver antenna 1-40GHz frequencies higher frequencies give higher data rates main source of loss is attenuation distance, rainfall also interference

Microwaves:

Microwaves Unidirectional Antenna

Satellite Microwave:

Satellite Microwave satellite is relay station receives on one frequency, amplifies or repeats signal and transmits on another frequency eg. uplink 5.925-6.425 GHz & downlink 3.7-4.2 GHz typically requires geo-stationary orbit height of 35,784km spaced at least 3-4° apart typical uses television long distance telephone private business networks global positioning

Satellite Point to Point Link:

Satellite Point to Point Link

Satellite Broadcast Link:

Satellite Broadcast Link

Wireless Propagation Ground Wave:

Wireless Propagation Ground Wave

Wireless Propagation Line of Sight:

Wireless Propagation Line of Sight

Unguided Media – Infrared:

Unguided Media – Infrared Frequencies between 300 GHz to 400 THz. Can not penetrate walls. Used for short-range communication in a closed area using line-of-sight propagation.

Infrared:

Infrared modulate noncoherent infrared light end line of sight (or reflection) are blocked by walls no licenses required typical uses TV remote control IRD port