Modem TechnologiesModem Technologies ADSL ModemADSL Modem

Outline of the PresentationOutline of the PresentationModem Technologies.Modem Technologies.

DSLDSL

ADSL ModemADSL Modem Upstream/Downstream BandsUpstream/Downstream Bands and Frequency and Frequency Bandwidth notationBandwidth notation

Setup Properties of ADSL ModemSetup Properties of ADSL Modem Routing and SecurityRouting and Security

Wireless ADSLWireless ADSL

Cable ModemCable Modem

Comparison of ADSL and Cable ModemComparison of ADSL and Cable Modem

What does modem mean?What does modem mean?The word "The word "modemmodem" comes from " comes from ""momodulator-dulator-demdemodulator“odulator“

Modulation: digital information to Modulation: digital information to analog signals analog signals

Demodulation:Demodulation: analog signals back analog signals back into useful digital information into useful digital information

Settled device for computers. Settled device for computers.

Allows 2 computers to communicate Allows 2 computers to communicate over standard phone lines. over standard phone lines.

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

Conversion of Digital Information Conversion of Digital Information to Analog Informationto Analog Information

What is DSL?What is DSL?

Digital Subscriber Line.Digital Subscriber Line.

New modem technology. New modem technology.

Data transmission is based on digital encoding (digital).Data transmission is based on digital encoding (digital).

UseUsess phone line so for the customer wiring (subscribers’ line). phone line so for the customer wiring (subscribers’ line).

Use digital coding techniques to provide more capacity. Use digital coding techniques to provide more capacity.

Allows high-speed Internet access over existing twisted-pair Allows high-speed Internet access over existing twisted-pair

and ordinary copper telephone wires.and ordinary copper telephone wires.

Provides "always-on" connection.Provides "always-on" connection.

To transport high-bandwidth data.To transport high-bandwidth data.

A special hardware attached to both the user and switch ends of A special hardware attached to both the user and switch ends of

line.line.

What is DSL?What is DSL?

Advantages of DSLAdvantages of DSL

High-speedHigh-speed..

Secure connectionSecure connection..

No dial-up, waiting or dropped connections.No dial-up, waiting or dropped connections.

It's always on connection.It's always on connection.

Saves both money and time.Saves both money and time.

Provides large file transfers.Provides large file transfers.

Multiple workers on a network can connect to a single Multiple workers on a network can connect to a single

DSL. DSL.

What is ADSL?What is ADSL?

Asymmetric Digital Subscriber Line.Asymmetric Digital Subscriber Line.

Is a form of DSL.Is a form of DSL.

A high-speed Internet access service. A high-speed Internet access service.

Speed depends on the length and the diameter of the Speed depends on the length and the diameter of the

cable and the type of the mode cable and the type of the mode

Requires a special ADSL modem and an Internet Requires a special ADSL modem and an Internet

service provider (ISP) .service provider (ISP) .

It is asymmetric since the data coming to your computer It is asymmetric since the data coming to your computer

from the Internet (download) is faster than the data from the Internet (download) is faster than the data

traveling from your computer to the Internet (upload). traveling from your computer to the Internet (upload).

Uses standard telephone lines. Uses standard telephone lines.

Telephone can be used normally, even when surfing in Telephone can be used normally, even when surfing in

the Web with ADSL service. the Web with ADSL service.

An "always on" service. An "always on" service.

Not available to everyone. Not available to everyone.

What is ADSL?What is ADSL?

ADSL SplitterADSL Splitter separates the analogue voice (phone) separates the analogue voice (phone)

traffic from data (adsl) traffictraffic from data (adsl) traffic..

ADSL ModemADSL Modem converts digital signals from your PC into converts digital signals from your PC into

analog signals that can be transmitted over telephone analog signals that can be transmitted over telephone

cable in the local loop.cable in the local loop.

Local LoopLocal Loop is the path your telephone line will take from is the path your telephone line will take from

your house to the local exchange.your house to the local exchange.

Service Provider.Service Provider.

The cable The cable consists of a "copper pair" . consists of a "copper pair" .

How does ADSL work?How does ADSL work?

How does ADSL work?How does ADSL work?

How does ADSL work?How does ADSL work?

How does ADSL work?How does ADSL work?

•DSLAM - DSL Access Multiplexer•BRAS – Broadband Remote Access Server•ISP - Internet Service Provider

How does ADSL work?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 Broadband

Remote Access Server or

BRAS.

How does ADSL work?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.

How does ADSL work?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 that

you can access them more

quickly.

How does ADSL work?How does ADSL work?

ISPISPIInternet nternet SService ervice PProviderrovider

ISPISP

A company.A company.

Access to the internet.Access to the internet.

Monthly fee.Monthly fee.

Software package.Software package.

User name, password and access phone User name, password and access phone

number.number.

Modem.Modem.

Log-on. Log-on.

Individuals and large companies.Individuals and large companies.

Connected to one another through Network Connected to one another through Network

Access Points (NAPs). Access Points (NAPs).

Examples: Examples:

Superonline Superonline

E-kolay.E-kolay.

Atlas On-LineAtlas On-Line..

Tr-NetTr-Net..

ISPISP

ADVANTAGES of ADSLADVANTAGES of ADSL

Quick connection.Quick connection.

Fast.Fast.

Use phone connection when connected to the internet.Use phone connection when connected to the internet.

No need for second phone line.No need for second phone line.

No dropped connections.No dropped connections.

Always on connection.Always on connection.

Ability to download large files.Ability to download large files.

Save time.Save time.

Cost efficiency.Cost efficiency.

Upstream/Downstream BandsUpstream/Downstream Bands and and FrequencyFrequency

ADSL Communication is Full Duplex.ADSL Communication is Full Duplex.

Full duplex ADSL communication is usually Full duplex ADSL communication is usually providing providing

withwith a wire pair by either frequency division multiplex a wire pair by either frequency division multiplex

(FDM).(FDM).

FDM uses two separate frequency bandsFDM uses two separate frequency bands, these are, these are

the upstream and downstream bands.the upstream and downstream bands.

Downstream data. Downstream data.

Upstream data.Upstream data.

ADSL transmit upstream and downstream data on a ADSL transmit upstream and downstream data on a

digital frequencydigital frequency

Upstream/Downstream BandsUpstream/Downstream Bands and and FrequencyFrequency

Upstream/Downstream BandsUpstream/Downstream Bands and and FrequencyFrequency

PSTN(Plain Old Telephone Service )

UPSTREAM DOWNSTREAM

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

BANWIDTH NOTATIONBANWIDTH NOTATION

Monthly quota of data.Monthly quota of data.

Upload/download.Upload/download.

Monthly bandwidth allowance will beMonthly bandwidth allowance will be measured in measured in MegabytesMegabytes or or

GigabytesGigabytes..

The amount of bandwidth you need depends on how frequently The amount of bandwidth you need depends on how frequently

use the internet. use the internet.

SETUP PROPERTIES of ADSLSETUP PROPERTIES of ADSL

Physical connections.Physical connections.

Modem synchronization.Modem synchronization.

Computer network Computer network

configurations.configurations.

Modem Configuration.Modem Configuration.

Ip Control.Ip Control.

Connection ControlConnection Control

ROUTING and SECURITYROUTING and SECURITY

Device.Device.

A router allows you to connect one A router allows you to connect one

or more computers or one or more or more computers or one or more

networks networks oonto the ADSL service. nto the ADSL service.

Many routers have built in Many routers have built in

switches that allow you to plug switches that allow you to plug

your computer directly into themyour computer directly into them

Sharing an Internet connection.Sharing an Internet connection.

ROUTING

Change the user name and password after first Change the user name and password after first

configuration.configuration.

Change the port which is used for access to modem Change the port which is used for access to modem

settings.settings.

Activate the firewall applications.Activate the firewall applications.

Use Ethernet+Router+USB Adsl modems.Use Ethernet+Router+USB Adsl modems.

Do not use USB Adsl modems.Do not use USB Adsl modems.

Use antivirus software programs.Use antivirus software programs.

Update the antivirus programs.Update the antivirus programs.

ROUTING and SECURITYROUTING and SECURITYSECURITY

WIRELESS ADSLWIRELESS ADSLWithout any cable it provides broadband data transfer.Without any cable it provides broadband data transfer.

This service using at hotspots such as airports, hotels, This service using at hotspots such as airports, hotels,

shopping centers, universities, conference halls etc.shopping centers, universities, conference halls etc.

If you have WLAN technology in your laptop, phone or If you have WLAN technology in your laptop, phone or

etc. You can use this service.etc. You can use this service.

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

take a card that has the wi-fi (wireless fidelity ) capability take a card that has the wi-fi (wireless fidelity ) capability

and fix it to your pc than you can use this service.and fix it to your pc than you can use this service.

Uses access point which is a wireless access device to Uses access point which is a wireless access device to

spread the adsl connections.spread the adsl connections.

VDSLVDSL

Very high bit-rate Digital Line Subscriber.Very high bit-rate Digital Line Subscriber.

Next generation DSL.Next generation DSL.

Entire home-entertainment package .Entire home-entertainment package .

Very high bandwidth.Very high bandwidth.

Shorter distance, faster connection.Shorter distance, faster connection.

Coding based on Discrete Multitone (DMT) and Coding based on Discrete Multitone (DMT) and

Quadature Amplitude Modulation (QAM).Quadature Amplitude Modulation (QAM).

Is not literally deployed yetIs not literally deployed yet

CABLE MODEMCABLE MODEM

CMTS: Cable Modem Termination System

CATV: Community Antenna Television or Cable TV system. Can be all coaxial or HFC (Hybrid Fiber Coax) based.

Provides high-speed Internet access through a cable Provides high-speed Internet access through a cable

television network. television network.

TV cablesTV cables provide much higher bandwidth provide much higher bandwidth..

Upstream/downstream.Upstream/downstream.

Asymmetric.Asymmetric.

Coaxial cable line. Coaxial cable line.

It can be external devices nearly computer or integrated It can be external devices nearly computer or integrated

within a computer .within a computer .

“ “Always on” connection.Always on” connection.

CABLE MODEMCABLE MODEM

ADSL vs CABLE MODEMADSL vs CABLE MODEMSpeed.Speed.

AvailabilityAvailability..

Bandwidth.Bandwidth.

Time for getting the service.Time for getting the service.

Installation.Installation.

Service.Service.

Cost.Cost.

Hardware requirements.Hardware requirements.

Security.Security.

WAP/GPRS WAP/GPRS WAPWAP ((Wireless Application ProtocolWireless Application Protocol ). ).

Allows users to access information instantly with Allows users to access information instantly with

handheld wireless devices.handheld wireless devices.

Internet content in special text format.Internet content in special text format.

Low-bandwidth. Low-bandwidth.

Uses Uses WML WML format for small screens and one-hand format for small screens and one-hand

navigation without a keyboard .navigation without a keyboard .

GPRSGPRS (General Packet Radio Service). (General Packet Radio Service).

Uses existing GSM network.Uses existing GSM network.

Transmit and receive data from GPRS mobile devices.Transmit and receive data from GPRS mobile devices.

Runs at speeds up to 115 kilobits per second.Runs at speeds up to 115 kilobits per second.

Supports a wide range of bandwidths.Supports a wide range of bandwidths.

Efficient use of limited bandwidth.Efficient use of limited bandwidth.

Provides “always online” connection. Provides “always online” connection.

GPRSGPRS

GPRSGPRS

Thank you for Listening. Thank you for Listening.

QUESTIONS?QUESTIONS?