transmission media by jawad ahmed
DESCRIPTION
Transmission media and their typesTRANSCRIPT
TRANSMISSION MEDIA
TRANSMISSION MEDIAThe transmission media is the physical path between transmitter and receiver in a data transmission system.
TRANSMISSION IPMPAIRMENTS
RESISTANCE
CROSSTALK
NOISE
TRANSMISSION MEDIA
GUIDED MEDIA
TWISTED PAIR
CO-AXIAL
CABLES
OPTIC FIBRES
UNGUIDED MEDIA
INFRARED
MICROWAVES
BLUTOOTH
GUIDED TRANSMISSION MEDIA
The waves are guided along a solid medium such as
Fiber optic COAXIAL Twisted pair
TWISTED PAIR
Made up of pairs of solid copper Insulating materialThe copper core of the cable is usually 22-AWG or 24-AWG
TWISTED PAIR
Information is transmitted by sending electrical current through the wires.The twisting tends to decrease the cross-talk interference between adjacent pairs.Pairs in the cable depends on the type.
TWO TYPES
UTP •Unshielded twisted pair
STP •Shielded twisted pair
UTP
UTP) is ordinary telephone wire. UTP costs less
than (STP).
UTPCategories of (UTP)
Category 3 16 MHz 100 ohm unshielded twisted pair
Category 4 20 MHz 100 ohm unshielded twisted pair
Category 5 100 MHz 100 ohm unshielded twisted pair
ADVANTAGES
Low cost
Capable of high speeds for LANs.
Easy installation
DISADVANTAGES
EMIeffect
100 meter limit
UTP &
RJ-45
STP
ADVANTAGESThe biggest difference between UTP and STP is the reduction of EMIYou can have a higher bandwidths rates, than UTP.
DISADVANTAGES
More expensive than UTP and thin coaxial cable.
Installation of STP is also harder than that of UTP.
Also suffers from EMI and attenuation but less than UTP.
APPLICATIONS
Transmit both analog and digital signalsTelephone network, with in building for LAN
COAXIAL CABLE
Plastic like material, used to separate the inner conductor from the outer the conductor.The outer conductor is a fine cylindrical mesh made from copper.DIAMETER 0.4 to about 1-inch.
APPLICATIONS
Television.
Long distance telephone transmission
Local Area Networks.
Characteristics of Coaxial Cable
Coaxial cable is used to transmit both analog and digital signalscarry higher frequencies and much data rates.Less interference and cross-talk than twisted pairFor long distance transmission of analog signals, amplifiers are needed every few kilometers
The following are some coaxial cables commonly used in networking.
Coaxial cables are split and joined using metal connectors known
as T-Pieces and I-Pieces
ADVANTAGES OF COAXIAL CABLE
Inexpensive
much better resistance to EMI’s effects.
Much faster than twisted
pair
Easy to wire or install
High costExpensive connector
Effective by EMI.
OPTICAL FIBER
Transmits light signalsInner core of glass or plastic thatThe outer most layer is the jacket.This jacket is composed of plastic50 microns in diameter
Principal of Optical-Fiber
The light source, the transmission medium, and the detector. Pulse of light indicates 1-bit and the absence of light indicates a 0-bit.
WORKING
Applications
Long-haul Trunks: 900 miles in length and offer high capacity (typically 20,000 to 60,000 voice channels).Metropolitan Trunks: This type has an average length of 8 miles and may have as many as 100,000 voice channels in a trunk group.Rural-exchange Trunks :Rural-exchange trunks have circuit length ranging from 25 to 100 miles that link towns and villages and can support 5,000 voice channelsLocal Area Networks: A final important application of optical fiber is for local area networks.
Characteristics of Optical Fiber
It uses light
Data rates from 100 Mbps to 2Gbps
Data rate of 3.5 Gbps over a distance of 318 km without repeaters
Less errors
ADVANTAGES
Extreme speed NO! EMI Smaller size
One thousands twisted pairs 1km long weight 8000Kg. Two fibers have more capacity and weight only 100Kg.
DISADVANTAGES
EXPENSIVE !
Hard to install
UNGUIDEDTRANSMISSION
MEDIUM
INFRARED
Infrared (IR) light is electromagnetic radiation with a wavelength longer than that of visible light
INFRARED
Employed in short-range communication among computers & personal electronic devices
INFRARED devices
LED (Light Emitting Diode) •wider transmission beam•suitable for diffuse configuration•more widely used
LD (Laser Diode)•have more focused beam•are more efficient
APPLICATIONS
Available in mobiles/computers
Now a days using in few medical fields
In night vision cameras
For climate reading
ADVANTAGES
SIMPLE CIRCUITCHEAP
LOW POWER CONSUMPTION
HIGHER SECURITY
PORTABLE
NO LISENCE NEDEED
DISADVANTAGES
SHORTRANGE
LOW SPEED
Blocked by common materials
LOW BANDWIDTH
BLUETOOTHBluetooth is a wireless protocol for exchanging data over short distances from fixed and mobile devices, creating personal area networks (PAN)
CLASSES
We have 2 classes of Bluetooth
2nd class range of up to 10 m
1st class range of up to 100 feet
APPLICATIONS
OBEX (Object Exchange) which allows transfer of files, contacts, multimedia etc.
Hands-free profiles (HFP)
A2DP AVRC
Wi-FiIt provides short-range wireless high-speed data connections between mobile data devices (such as laptops, PDAs or phones)
TABLE
FEW +POINTS OF Wi-Fi
Wi-Fi is much faster than any data technologies operating through the cellular network like GPRS, EDGE and even UMTS and HSDPA.INDOOR range 30-100 metersOUTDOOR range ~650 meters
HOT-SPOTS
Access Wi-Fi services to access the Internet Hot spots vary in area of coverageThey are usually public and many charge users by the day or month. However, some are free
Wi-MAX WiMAX comes from "Worldwide Interoperability for Microwave Access“ It's an another way of calling the 802.16e protocol.
Wi-MAX WiMAX provides broadband speeds without the need for cables
WORLD CITY, REGION & COUNTRY
Wi-MAXWiMAX technology allows for data transfer speeds of up to 75Mbps
MICROWAVESMicrowaves - electromagnetic waves with a frequency between 1GHz (wavelength 30cm)12GHz (wavelength 1mm)
CATEGORIESmicrowaves frequency are further categorized into frequency bands:
MICROWAVES
L (1-2 GHz)
S (2-4 GHz) C (4-8 GHz)
X (8-12 GHz)
MICROWAVESMicrowaves are ideal when large areas need to be covered and there are no obstacles in the path
MICROWAVES ADVANTAGES
GREATER TRANSMISSION RATE
GREATER BANDWIDTH
HIGHER SPEED
SHORT WAVE LENGHT SMALLER ANTENA
DAILY LIFE & MICROWAVES
SATELLITE COMMUNICATION
CELLULAR COMMUNICATION
BLUETOOTH
Wi-MAX
GPSGLOBAL POSITIONING
RADIO WAVES
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light
Radio waves travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space
RADIO WAVES
Broadcasting & Uni-casting
USES of RADIO WAVES
Audio
Radar
Video
Navigation
Telephony
Simple CircuitCheapNo Licenses NeededHigh Speed/BandwidthCovers Large Areas (Penetrates through walls)
Limited number of free frequency bands
Shielding is difficult
Interference with other electrical devices
Greater Power Consumption
The first rule of any technology used in a business is that automation applied to an
efficient operation will magnify the efficiency. The second is that automation
applied to an inefficient operation will magnify the inefficiency.
THANK YOU!!