ADSL & VDSL TECHNOLOGY

J.SWAMY BABU

A.JAGAN MOHAN KRISHNA

G.HEMANTH BABU

M.SHYAM PRAKASH

INTRODUCTIONWhat is broadband?A communications network in which the bandwidth

can be divided and shared by multiple simultaneous signals (as for voice or data or video)

Broadband NetworkBroadband Switch Network (eg. ATM)

Service Providers

Servers&

Billing

Access Network

OperationalSupport System

New OpticalCable

ADSL

Local Exchange

VDSL

POTS

High-Capacity Backbone Links

TYPES OF BROADBANDBROAD BAND IS MAINLY CLASSIFIED IN TO TWO

TYPESADSL(ASYMMETRIC DIGITAL SUBSCRIBER LINE)VDSL(VERY HIGH SPEED DIGITAL SUBSCRIBER

LINE)

WHAT DOES ADSL MEANS??Asymmetric - The data can flow faster in one

direction than the other. Data transmission has faster downstream to the subscriber than upstream

Digital - No type of communication is transferred in an analog method. All data is purely digital, and only at the end, modulated to be carried over the line.

Subscriber Line - The data is carried over a single twisted pair copper loop to the subscriber premises

Market Status of ADSL TechnologyADSL is a form of DSL, a data communications

technology that enables faster data transmission over copper telephone lines

ADSL is the #1 Broadband Choice in the WorldADSL is available in every region of the worldADSL is capable of providing up to 50Mbps, and

supports voice, video and data.

ISDN

ADSL

FTTx, VDSL2,ADSL2plus

EnhancedCopper

Hybrid Fibre/Copper

Pure Fibre

ADSL Speed Comparison

Voice bandModem

FTTH

ADSL Equipment

ResidentialCustomer

Remote ADSLUnit

Customer Premises

Equipment

Central Office Building

ADSL Rackof Line Cards

Standard Telephone Lines

ADSL Applications

Internet Access & File Sharing. LAN Access (Teleworking) Broadcast TV Online Education & Shopping Video On Demand Online Gaming

ADSL RangeIn general, the maximum range for DSL without a repeater is 5.5

km As distance decreases toward the telephone company office, the

data rate increases

For larger distances, you may be able to have DSL if your phone company has extended the local loop with optical fiber cable

Data Rate Wire gauge Wire size Distance

1.5 or 2 Mbps 24 AWG 0.5 mm 5.5 km

1.5 or 2 Mbps 26 AWG 0.4 mm 4.6 km

6.1 Mbps 24 AWG 0.5 mm 3.7 km

1.5 or 2 Mbps 26 AWG 0.4 mm 2.7

Advantages

Doesn’t need new wiringConnection open and still use the phone line for voice

callsYou can talk on the phone and use the Internet at

the same time on a single phone lineYou can connect to the Internet at up to 140 times

faster than analog modemsYour home has its own dedicated connection

Disadvantages

Better connection if closer to the provider’sFaster receiving than sending dataNot available everywhereIt is possible to download things faster if they are

downloaded one after the other instead of all at the same time

What is vdsl??

Very High Speed Digital Subscriber Line transmits data in the 13 Mbps - 55 Mbps range over short distances, usually between 1000 and 4500 feet (300 - 1500 meters), of twisted pair copper wire.

BLOCK DIAGRAM OF VDSL

Early versions of VDSL will use FDM to separate downstream from upstream channels and both of them from basic telephone service and ISDN.

ADSL and VDSL Market Growth Projections

Describing VDSL specifications

• Runs over single pair copper wire

• VDSL provides 1.5 Mbps to 2.3 Mbps speed for upstream

traffic

• VDSL provides up to 52 Mbps speed for downstream traffic

• Symmetric bandwidth up to 26Mbps

Vdsl conclusionVDSL is a well developed technology at

the last stages of standardization in Europe, North America and internationally

VDSL is spectrally compatible with other xDSL and designed to operate in the presence of all kinds of impairments in copper pairs

VDSL is a flexible technology and may be adopted for different environments and deployment scenarios

Differences between adsl and vdsl Vdsl is significantly faster than adslVdsl is able to support HDTV while adsl

cannotVdsl suffers from attenuation much quicker

compared to adslVdsl is better for homes