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Modem Technologies ADSL Modem

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Outline of the PresentationModem Technologies.DSL

ADSL ModemUpstream/Downstream Bands and Frequency

Bandwidth notationSetup Properties of ADSL Modem

Routing and Security

Wireless ADSLCable ModemComparison of ADSL and Cable Modem

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What does modem mean?The word " modem " comes from

"mo dulator- dem odulator“

Modulation: digital information toanalog signals

Demodulation: analog signals backinto useful digital information

Settled device for computers.

Allows 2 computers to communicateover standard phone lines.

They have many different shapesand sizes to correspond all kind of needs.

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Conversion of Digital Informationto Analog Information

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What is DSL?

Digital Subscriber Line.

New modem technology.

Data transmission is based on digital encoding (digital).

Uses phone line so for the customer wiring (subscribers’

line).

Use digital coding techniques to provide more capacity. Allows high-speed Internet access over existing twisted-

pair and ordinary copper telephone wires.

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Provides "always-on" connection.

To transport high-bandwidth data.

A special hardware attached to both the user and switch

ends of line.

What is DSL?

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Advantages of DSL

High-speed.Secure connection.

No dial-up, waiting or dropped connections.

It's always on connection.

Saves both money and time.

Provides large file transfers.

Multiple workers on a network can connect to a single

DSL.

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What is ADSL?

Asymmetric Digital Subscriber Line.

Is a form of DSL.

A high-speed Internet access service.

Speed depends on the length and the diameter of the

cable and the type of the mode

Requires a special ADSL modem and an Internetservice provider (ISP) .

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It is asymmetric since the data coming to your computer

from the Internet (download) is faster than the data

traveling from your computer to the Internet (upload).

Uses standard telephone lines.

Telephone can be used normally, even when surfing in

the Web with ADSL service. An "always on" service.

Not available to everyone.

What is ADSL?

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ADSL Splitter separates the analogue voice (phone)

traffic from data (adsl) traffic.

ADSL Modem converts digital signals from your PC into

analog signals that can be transmitted over telephone

cable in the local loop.

Local Loop is the path your telephone line will take from

your house to the local exchange.Service Provider.

The cable consists of a "copper pair" .

How does ADSL work?

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How does ADSL work?

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How does ADSL work?

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How does ADSL work?

•DSLAM - DSL A ccess Multiplexer •BRAS – Broadband Remote Access S erver •ISP - Internet S ervice P rovider

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How does ADSL work?

The DSLAM associates a

number of ADSL user

connections as many as

several hundred into a single

fiber connection.

This fiber will normally be

connected to a BroadbandRemote Access Server or

BRAS.

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How does ADSL work?BRAS routes traffic to and from

the digital subscriber line access

multiplexers (DSLAM) on an

Internet service provider’s (ISP)network.

A single BRAS will probably

handle connections from several

DSLAMs.

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How does ADSL work?

This is the place where your

connection to the Internet is

made.

The ISP usually provides other

services like mail and news

servers, and frequently-used

pages from the Internet so thatyou can access them more

quickly.

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How does ADSL work?

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ISP

I nternet S ervice P rovider

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ISP A company.

Access to the internet.

Monthly fee.

Software package.

User name, password and access phone

number.

Modem.

Log-on.

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Individuals and large companies.Connected to one another through Network

Access Points (NAPs).

Examples:

Superonline

E-kolay. Atlas On-Line.

Tr-Net.

ISP

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ADVANTAGES of ADSLQuick connection.

Fast.

Use phone connection when connected to the internet.

No need for second phone line.No dropped connections.

Always on connection.

Ability to download large files.

Save time.

Cost efficiency.

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Upstream/Downstream Bands and

Frequency ADSL Communication is Full Duplex.

Full duplex ADSL communication is usually providing

with a wire pair by either frequency division multiplex

(FDM).

FDM uses two separate frequency bands, these are

the upstream and downstream bands.

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Downstream data.

Upstream data.

ADSL transmit upstream and downstream data on a

digital frequency

Upstream/Downstream Bands and

Frequency

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Upstream/Downstream Bands andFrequency

PSTN(Plain OldTelephoneService )

UPSTREAM DOWNSTREAM

Frequency plan for ADSL. The red area is the frequencyrange used by normal voice telephony (PSTN), the green(upstream) and blue (downstream) areas are used for ADSL.

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BANWIDTH NOTATION

Monthly quota of data.

Upload/download.

Monthly bandwidth allowance will be measured inMegabytes or Gigabytes .

The amount of bandwidth you need depends on how

frequently use the internet.

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SETUP PROPERTIES of ADSL

Physical connections.

Modem synchronization.

Computer networkconfigurations.

Modem Configuration.

Ip Control.

Connection Control

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ROUTING and SECURITY

Device.

A router allows you to connect one

or more computers or one or more

networks onto the ADSL service.

Many routers have built in

switches that allow you to plug

your computer directly into them

Sharing an Internet connection.

ROUTING

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Change the user name and password after first

configuration.

Change the port which is used for access to modem

settings. Activate the firewall applications.

Use Ethernet+Router+USB Adsl modems.

Do not use USB Adsl modems.

Use antivirus software programs.

Update the antivirus programs.

ROUTING and SECURITYSECURITY

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WIRELESS ADSLWithout any cable it provides broadband data transfer.

This service using at hotspots such as airports, hotels,

shopping centers, universities, conference halls etc.

If you have WLAN technology in your laptop, phone or

etc. You can use this service.

If you don not have this technology in your pc you can

take a card that has the wi-fi (wireless fidelity ) capabilityand fix it to your pc than you can use this service.

Uses access point which is a wireless access device to

spread the adsl connections.

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VDSL

Very high bit-rate Digital Line Subscriber.

Next generation DSL.

Entire home-entertainment package .

Very high bandwidth.Shorter distance, faster connection.

Coding based on Discrete Multitone (DMT) and

Quadature Amplitude Modulation (QAM).

Is not literally deployed yet

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CABLE MODEM

CMTS : Cable Modem Termination System

CATV: Community Antenna Television or Cable TV system. Can be

all coaxial or HFC (Hybrid Fiber Coax) based.

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Provides high-speed Internet access through a cable

television network.

TV cables provide much higher bandwidth.

Upstream/downstream.

Asymmetric.

Coaxial cable line.

It can be external devices nearly computer or integratedwithin a computer .

“Always on” connection.

CABLE MODEM

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ADSL vs CABLE MODEMSpeed.

Availability.

Bandwidth.

Time for getting the service.

Installation.

Service.

Cost.

Hardware requirements.

Security.

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WAP/GPRSWAP ( Wireless Application Protocol ).

Allows users to access information instantly with

handheld wireless devices.

Internet content in special text format.

Low-bandwidth.

Uses WML format for small screens and one-hand

navigation without a keyboard .

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GPRS (General Packet Radio Service).

Uses existing GSM network.

Transmit and receive data from GPRS mobile devices.

Runs at speeds up to 115 kilobits per second.

Supports a wide range of bandwidths.

Efficient use of limited bandwidth.

Provides “always online” connection.

GPRS

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GPRS

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Thank you for Listening.

QUESTIONS?