Asymmetric Digital Subscriber Line

1. WELCOME TO THE
RISING TECHNOLOGY
“ASYMMETRIC DIGITAL
SUBSCRIBER LINE”
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2.  CHAPTER 1
 INTRODUCTION
 1.1 DIFFERENT VARIANTS OF DSL
 1.2 WHAT IS ADSL
 1.3 WHAT ARE THE BENEFITS
 CHAPTER 2
 FUTURE OF ADSL 2

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4. CHAPTER 6
ADSL EQUIPMENT
6.1 DSL EQUIPMENT DSLAM
CHAPTER 7
DISTANCE LIMITATIONS
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5. CHAPTER 8
INSTALLATION ISSUES
CHAPTER 9
APPLICATIONS
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6. REFERENCES
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7. PASTDECADE HAS SEEN EXTENSIVE GROWTH IN THE
TELECOMMUNOCATION INDUSTRY
POPULARITY
OF INTERNET & OTHER DATA
COMMUNICATION SERVICES HAS INCREASED
MAJORITYOF INTERNET USERS ACCESS THEIR SERVICE
VIA MODEMS CONNECTED TO P.O.T.S.
P.O.T.S.
WAS DESIGNED FOR VOICE TRANSMISSION AT
FREQUENCIES BELOW 3 KHz
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8. TOINCREASE PERFORMANCE OF NEW ONLINE
SERVICES, THE BANDWIDTH HUNGRY PUBLIC MUST
CONSIDER OTHER OPTIONS
TECHNOLOGIES,SUCH AS I.S.D.N. OR CABLE
CONNECTIONS, REQUIRE SPECIAL CABLING
AP.O.T.S. CONNECTION PROVIDED AN ADEQUATE
MEDIUM FOR RELATIVELY SMALL AMOUNTS OF DATA
THAT REQUIRED TO BE TRANSMITTED
SOTHE EXISTING SYSTEM WAS THE LOGICAL CHOICE
OVER SPECIAL CABLING
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9. H.D.S.L.
IT IS THE PIONEERING HIGH SPEED FORMAT,
BUT NOT COMMERCIALLY VIABLE OPTION DUE TO ITS NEED FOR
2 TWISTED PAIRS &
DOESN’T HAVE SUPPORT FOR NORMAL TELE PHONE SERVICES
S.D.S.L.
IT IS SYMMETRIC DSL
OPERATES OVER A SINGLE TWISTED PAIR
LIMITED TO SHORT DISTANCES
SUFFERS N.E.X.T.
I.S.D.L.
STANDS FOR I.S.D.N. DSL 9

10. SIMILAR TO I.S.D.N. TECHNOLOGY
LACKS SUPPORT FOR ANALOG VOICE
V.D.S.L.
VERY HIGH BIT RATE D.S.L.
REQUIRES
SHORTER CONNECTIONS THAN ARE GENERALLY
PRACTICAL
A.D.S.L.
MOST PROMISING TECHNOLOGY
SUITABLE FOR PERSONAL BROADBAND REQUREMENTS
ALLOWS SAME CHANNEL TO STILL ACT AS A TRADITIONAL
SERVICE 10

11. A MODEM TECHNOLOGY
CONVERTS EXISTING TWISTED PAIR TELEPHONE LINES
INTO ACCESS PATHS FOR MULTIMEDIA & HIGH SPEED
DATA COMMUNICATIONS
CAN TRANSMIT UPTO 6Mbps TO SUBSCRIBER
832 Kbps IN BOTH DIRECTIONS
EXPANDS ACCESS CAPACITY BY A FACTOR OF 50 OR
MORE
ITALLOWS MORE BANDWIDTH DOWNSTREAM THAN
FOR UPSTREAM
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13. PROVIDESHIGH SPEED INTERNET ACCESS USING
REGULAR TELEPHONE LINES
CONNECTIVITY-ALWAYS ON
DATA SECURITY
EASE OF USE
NO DIAL-UP IS REQUIRED
SPEED
IS UPTO 25 TIMES FASTER THAN ANALOG
MODEMS
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14. ADSL will play a crucial role over the next decade or more as
telephone companies enter new
markets for delivering information in video and multimedia
formats. New broadband cabling will
take decades to reach all prospective subscribers. Success of
these new services will depend on
reaching as many subscribers as possible during the first few
years. By bringing movies, television,
video catalogs, remote CD-ROMs, corporate LANs, and the
Internet into homes and small
businesses, ADSL will make these markets viable and
profitable for telephone companies and
application suppliers alike.
ADSL Capabilities

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16. oADSLMODEM CONNECTED TO EACH END OF TWISTED PAIR
TELEPHONE LINE
o3 INFORMATION CHANNELS ARE CREATED :-
o1). HIGH SPEED DOWNSTREAM CHANNEL
o2). A MEDIUM SPEED DUPLEX CHANNEL
o3). A BASIC TELEPHONE SERVICE CHANNEL
oADSL GUARANTEES UNINTERRUPTED TELEPHONE SERVICE EVEN
IF ADSL FAILS
oDOWMSTREAM RATES DEPEND ON :-
o1). LENGTH OF COPPER LINE 16

18. POTS & A.D.S.L. DATA 18

19.  DEPENDS UPON ADVANCED DIGITAL SIGNAL PROCESSING
TECHNOLOGY & ALGORITHMS
 OUTSIDE - ADSL LOOKS SIMPLE
 INSIDE- MIRACLE OF MODERN TECHNOLOGY
 IT CONSISTS OF :- TRANSMITTER & RECEIVER…..
 1).TELEPHONE EXCHANGE
 2). SPLITTER
 3). DSLAM , ISP
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21. 21

22. FREQUENCY RESPONSE OF ADSL
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23. 1). CARRIERLESS AMPLITUDE / PHASE (CAP)
TELEPHONE SIGNAL DIVIDED IN 3 PARTS
i. VOICE CONVERSATIONS- 0 TO 4 KHz (POTS CKT)
ii. UPSTREAM CHANNEL-25 TO 160 KHz (FROM USER BACK
TO SERVER)
iii. DOWNSTREAM CHANNEL- BEGINS AT 240 KHz (FROM
SERVER TO USER)
 INTERFERENCE MINIMISED

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25. BLOCK SIGNALS ABOVE CERTAIN FREQUENCY
ALL CONVERSATIONS- BELOW 4 KHz
LPF’s DESIGNED TO BLOCK SIGNALS ABOVE 4KHz
PREVENT DATA SIGNALS FROM INTERFERING WITH
STANDARD TELEPHONE CALLS
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26. It uses two pc’s of equipments one at the customer end and one at
the internet services provider
Atthe customer location there is DSL transceiver also called as
“DSL MODEM” and ATU-R too.
DSL service provider has a DSL access
multiplexer(DSLAM ) to receive customer connection.
The transceiver can connect to the customer equipment by using
USB or 10 base –T Ethernet connections.
The devices used by businesses may combine network routers
network switches or other networking equipments

27. It really allows DSL to happen
It takes connection from many customers and
aggregates them on to a single high capacity connection
to the internet
It is flexible and able to support multiple types of DSL
in a single central office.

29.  IT IS A DISTANCE SENSITIVE TECHNOLOGY.
 LIMIT FOR ADSL service is 18000 feet.
 Maximum downstream speed is 8 mbps at a
distance of about 6000 feet.
 Maximum upstream speed is 640 kbps.
 ADSL cant be received using bridge tapes , fiber
optic cables and loading coils. .

30. DSL ADSL
 It do not uses the  It uses the frequency
spectrum
frequency spectrum
 Splitter or micro filter  Frequency filters are used at
are used near the customers premises to
avoid interference
demarcation point  This do not require
 This requires a technician
technician for
installation purposes  Less costlier than DSL
 More costlier
 DSL signal is separated  DSL signal is filtered at each
phone outlet by use of LPF
at demarcation point for voice and HPF for data

31.  Maximum range for DSL without a
repeater is 5.5 km
 As distance decreases towards the telephone
company office , the data rate increases
 For larger distances , DSL service is provided
only when phone company has extended the
local loop with optical fiber cable

32.  The distance from local exchange
 The type and thickness of wires used
 The number and type of joins in the wire
The proximity of the wire to other wires carrying
ADSL ,ISDN and other non voice signals
 The proximity of the wires to radio transmitters

33. Phone line , activation by your phone company
for it
Filter to separate the phone signal from the internet
signal
ADSL modem
Subscription with an ISP supporting ADSL

34.  1.HIGH SPEED INTERNET ACCESS
 2. E-COMMERCE
 3.DISTANCE LEARNING
 4.VIDEO CONFERENCING
 5.ENTERTAINTMENT-ONLINE GAMING

36.  IT IS ASYMMRTRIC.
 ALLOWS MORE BANDWIDTH FOR
DOWNSTREAM THAN UPSREAM
DATA FLOW.
 ADSL modems create multiple channels
using FDM or echo cancellation.
 It is ideal for those who download
much more data than they send.