BROADBAND TECHNOLOGY

PRESENTED BY: RAMAKANT TYAGI

Introduction

Advantages

ADSL technology

Types of DSL modulation

Various components and their arrangement

Cable Modem

ECHO Cancellation

Services through broadband

CONTENTS

Bharat Sanchar Nigam Limited

BSNL is fourth largest Telecommunication Company in Asia and seventh in world today.

It is the largest provider of fixed telephony and fourth largest mobile telephony provider in India, and is also a provider of broadband services.

At present BSNL enjoys around 60% of market share of ISP services.

2007 was declared as "Year of Broadband" in India.

.Broadband refers to high internet access.

.It provides services more than 256 kbps to several mbps.

.There are many different technologies both wired and wireless(WIMAX).

.BSNL’ s broadband working under the brand name “cell one” and MTNL ’s brand name under “tri band”.

INTRODUCTION

ADVANTAGES • Always on

• Fast speed ranging from 256kbps to 2mbps

• No disconnection

• No additional charge access

• Telephone and data simultaneously

ADSL TECHNOLGY• ASYMMERTIC-indicates downstream and upstream capacity is not

same

• DIGITAL-means BINARY “0” AND “1”

• SUBSCRIBER LINE-means both data and voice are send over twisted copper cable to the subscriber

FEATURES OF ADSL TECHNOLOGYDistance sensitive technologyInternet connection is always onSimultaneous use of phone lines for voice as well as

data.It is highly reliable and secure.High speed in mbps.

VARIOUS XDSL TECHNOLOGIES

ADSL(Asymmetric digital subscriber line)VDSL(Very high speed digital subscriber line)RADSL(Rate adaptive digital subscriber line)HDSL(High data rate digital subscriber line)SDSL(symmetric digital subscriber line)

WORKING OF ADSLADSL works by splitting the available bandwidth on twisted copper wire(telephone lines)into three different channel:A high speed download stream channelA medium speed upstream channel POTS-Plain Old Telephone service channel25.875khz to 138 kHz → upstream communication138 kHz to 1104 kHz → downstream communication0-4 kHz → PSTN

DSL MODULATION• CAP(Carrier less amplitude phase modulation)• DMT(Discrete multi tone)modulationCAP is now an old technique, now a days we prefer DMT

• DMT (DISCRETE MULTI TONE MODULATION)Bandwidth ranging from 26 kHz -1.1 MHz is splitted into two bands using FDM(frequency division multiplexing) and echo cancellation technique

1.Upsteam band(26khz-138khz)2.Downsteam band(138khz-1.1mhz)

Now using FFT(fast Fourier transform) we divide them further in to 256 discrete sub channels each of band

width 4khz.

ECHO CANCELLATIONIt is used so that downstream channel overlaps upstream channel so that upstream channel and downstream channel are sent simultaneously over same telephone wire.

BROADBAND COMPONENTS

• DSLAM(Digital Subscriber Line Access multiplexer)• BRAS(Broadband Remote Access Server)• SSSS(Subscriber Service Selection System)• LAN switch• CPE(customer premises Exchange)

• DSL CPE: At customer premises. On one end it connects telephone cable coming from exchange via splitter. At the other end, it connects to PC through Ethernet / USB Port.

• DSLAM: called as DSL Access Multiplexer. It has a built in splitter which splits voice and data. It is a technique to send both voice and data over same twisted telephone wire.

• LAN SWITCH: For aggregating multiple DSLAM and providing a common uplink to the core.

• BRAS: called as Broadband Remote Access Server. First intelligent device in the whole chain. It terminates the customer session, authenticates, allot IP addresses and keeps track of user session for billing .

• SSSS: Called as Subscriber Service Selection System. When customer logs in he will be welcomed with this customized screen from where he can select various range of service.

High speed internet access.Bandwidth on demand.

MulticastingDial vpn serviceAudio on demand

Video on demandBilling and IPTV

SERVICES THROUGH BROADBAND

CONCLUSION Broadband helps in bridging the digital division between rural and urban regions and hence uniting the world.

“One key to strengthen education , innovation in communities is to harness the full power of internet and that means faster and more widely available broadband” as mentioned by Mr. Obama (The U.S President)

‘High speed internet connection is the need of the hour and Broadband is a solution to it!’

THANK YOU