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!!