1. Asymmetric Digital Subscriber Line
ADSL
Asymmetric Digital Subscriber Line
Manoj Kumar
Piyush Mishra

2. What Is ADSL
ADSL – Asymmetrical Digital Subscriber Line, is a broadband communication technology that creates high-speed access to the Internet and remote networks using the phone lines that are already present in your home. ADSL is superior to analog modems in many respects.

3. Introduction
ADSL is a form of DSL, a data communications technology that enables faster data transmission over copper telephone lines
ADSL is capable of providing up to 50 Mbps, and supports voice, video and data.
ADSL is the #1 Broadband Choice in the World with over 60% market share
ADSL is now available in every region of the world

4. Total Subscribers Middle East & Africa 0.25% North America 29.5%
Latin America
2.0%
Western Europe
22.7%
Eastern Europe
0.28%
South East Asia
2.7%
Asia Pacific
42.5%

5. What does ADSL mean?
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

6. Simultaneous Connections
Talk on the phone and surf the Internet at the same time on the same phone line!
You do not have to disable call waiting to connect to the Internet.

7. ADSL standards : Standard name Common name Downstream rate
Upstream rate
ITU G.992.1
ADSL (G.DMT)
8 Mbit/s
1.0 Mbit/s
ITU G.992.2
ADSL Lite (G.Lite)
1.5 Mbit/s
0.5 Mbit/s
ITU G.992.3/4
ADSL2
12 Mbit/s
ITU G.992.3/4 Annex J
3.5 Mbit/s
ITU G.992.3/4 Annex L
RE-ADSL2
5 Mbit/s
0.8 Mbit/s
ITU G.992.5
ADSL2+
24 Mbit/s
ITU G Annex L
RE-ADSL2+
ITU G Annex M
28 Mbit/s

8. ADSL Speed Comparison Pure Fibre Hybrid Fibre/Copper FTTH Enhanced
FTTx, VDSL2,
ADSL2plus
ADSL
ISDN
Voice band Modem

9. OPTICAL FIBRE

10. What is fiber optics?
We're used to the idea of information travelling in different ways. When we speak into a landline telephone, a wire cable carries the sounds from our voice into a socket in the wall, where another cable takes it to the local telephone exchange. Cellphones work a different way: they send and receive information using invisible radio waves—a technology called wireless because it uses no cables. Fiber optics works a third way. It sends information coded in a beam of light down a glass or plastic pipe. It was originally developed for endoscopes in the 1950s to help doctors see inside the human body without having to cut it open first. In the 1960s, engineers found a way of using the same technology to transmit telephone calls at the speed of light (186,000 miles or 300,000 km per second).

11. ISDN
Integrated Services Digital Network: the CCITT standard that defines a completely digital telephone/telecommunications network which carries voice, data, and video over existing telephone network infrastructure. ISDN provides two 64 Kbit/s channels, which can be combined or used independently for both voice and data. It is designed to provide a single interface for hooking up a phone, fax machine, PC, etc.

12. The ISDN subscriber will have full connectivity, nationally, to other analog telephone subscribers. At present ISDN services are available to and from India for the following countries:
Australia
Austria Belgium 
Canada 
Denmark 
France 
Germany 
Ireland 
Italy 
Israel 
Japan 
Malaysia 
Netherland 
Norway 
Phillipines 
Singapore
Switzerland 
Thailand 
U.A.E 
United Kingdom 
U.S.A

13. Variety of supplementary Services supported by ISDN.
Calling Line Identification Presentation(CLIP)
Calling Line Identification Restriction(CLIR) 
Multiple Subscriber Number(MSN)
Terminal Portability(TP)
Call Hold(CH)
Call Waiting(CW)

14. DIAL-UP
Dial-up Internet access is a type of Internet connectivity that operates through a standard telephone line.

15. ADSL Range
In 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

16. ADSL Speed Factors The distance from the 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.

17. ADSL hardware equipments
DSLAM (Digital Subscriber Line Access Multiplexer) - DSL Access Multiplexer, a mechanism at a phone company's central location that links many customer DSL connections to a single high-speed ATM line.
CPE (Customer Premise Equipment) - communications equipment that resides on the customer's premises. For example, DSL modem is Customer Premise Equipment (CPE).

18. ADSL Requirements Phone-line, activated by your phone company for ADSL
Filter to separate the phone signal from the Internet signal
ADSL modem
Subscription with an ISP supporting ADSL

19. ADSL-based Reference Diagram

20. ADSL Loop Architecture
Voice Switch
ISP
Central Office
Subscriber premises

21. The role of the DSLAM
The path of data along the ADSL from its commercial or residential source, via the local loop, to the CO (Central Office).
The local loop here terminates at the Main Distribution Frame (MDF), to be picked up by one of the CO's many ADSL modems. If the form of ADSL allows for the carrying of both analog and digital signals, a POTS splitter will separate out the signals.
The analog signal will follow its time-honored path along the copper-wire infrastructure.
For the digital signal, however, one step before the signal can be shot along to its destination.

22. Using DSLAM

23. Splitter
Full-rate ADSL requires that a device, known as a splitter, be installed on your phone line where it enters your home in order to separate the voice service from the data service

25. RJ 45 CABLE

26. STRAIGHT CONNECTIONS

27. ADSL Modem Connections
RJ 45
RJ11
Power Supply
CAT 5

28. PPPoE Connection
The Point-to-Point Protocol over Ethernet (PPPoE) is a network protocol for encapsulating Point-to-Point Protocol (PPP) frames inside Ethernet frames. It is used mainly with ADSL services where individual users connect to the ADSL modem over Ethernet.

29. PPPoE - How it works
PPPoE - enables establishing PPP sessions and encapsulating PPP packets over Ethernet.
It has two distinct stages - A discovery stage and a Session stage.
The discovery stage identifies the Ethernet MAC address of the peer with which the PPP session is to be established.
The session stage gets a PPPoE session ID for the PPP session and encapsulates PPP packets.

30. To make an PPPoE connection Configuration

31. To open Network Connections
Click Start,
Click Control Panel,
Click Network and Internet Connections,
Click Network Connections. 

32. Under Network Tasks,
Click Create a new connection,
Click Next.
Click Connect to the Internet,

33. If you already have an account with an Internet service provider (ISP), click Set up my connection manually and then click Next.
If you have a CD from an ISP, click Use the CD I got from an ISP and then click Next. 
If you do not have an Internet account, click Choose from a list of Internet service providers (ISPs) and then click Next.

34. Set up my connection manually
•If you are connecting to your ISP using a standard 28.8 Kbps, 56 Kbps, or ISDN modem, click Connect using a dial-up modem, click Next, and follow the instructions in the wizard.
If your DSL or cable modem ISP connection requires a user name and password, click Connect using a broadband modem that requires a user name and password, click Next, and then follow the instructions in the wizard.
If your DSL or cable modem ISP connection is always on and does not require you to type a user name and password, click Connect using a broadband connection that is always on,
Click Next, and then click Finish.

40. How does ADSL work?
One phone line delivers voice and a high-speed Internet connection
Voice/fax calls only use the frequencies below 4 kHz
Frequencies above 4 kHz are reserved for data transmission
ADSL
Voice/Fax
0 kHz
25 kHz
3.4 kHz
1100 kHz

41. How DSL divide bandwidth

42. Observations Three Channels: VOICE channel
Voice channel is split off from the digital modem by filters, thus guaranteeing uninterrupted POTS.
High speed downstream channel
Its data rate depends on length of the copper line, its wire gauge, presence of bridged taps, cross talk, etc.
Medium speed upstream channel

43. Modulations Used in ADSL
Modulation is the key of ADSL technology; it is a process in which one signal modifies properties of another.
Several modulation technologies are used by various kinds of ADSL.

44. ADSL Modulation
Modulation is the overlaying of information (or the signal) onto an electronic or optical carrier waveform
There are two competing and incompatible standards for modulating the ADSL signal:
Carrierless Amplitude Phase (CAP)
Discrete Multi-Tone (DMT)

45. Carrierless Amplitude Phase
CAP used for ADSL divides the available space into three bands. The range from 0 to 4 kHz is allocated for POTS transmissions. The range of 25 kHz to 160 kHz is allocated for upstream data traffic and the range of 240 kHz to 1.5 MHz is allocated for downstream data traffic.

46. Carrierless Amplitude Phase
Carrierless Amplitude Phase (CAP) is an encoding method that divides the signals into two distinct bands:
The upstream data channel (to the service provider), which is carried in the band between 25 and 160kHz
The downstream data channel (to the user), which is carried in the band from 200kHz to 1.1MHz .
These channels are widely separated in order to minimize the possibility of interference between the channels.

47. How does ADSL work
ADSL exploits the unused analogue bandwidth available in the wires
ADSL works by using a frequency splitter device to split a traditional voice telephone line into two frequencies 4
25,875
138
1104
KHz
VOICE
Downstream
Upstream

48. Discrete Multi-tone (DMT)
high-bit rate services carried by ADSL must not interfere with other services, particularly plain old telephone service , that are being transported simultaneously over the same lines.

49. Discrete Multi-tone (DMT)
Discrete Multi-Tone (DMT) separates the DSL signal so that the usable frequency range is separated into 256 channels of kHz each.
DMT has 224 downstream frequency bins (or carriers) and 32 upstream frequency bins.
DMT constantly shifts signals between different channels to ensure that the best channels are used for transmission and reception.

50. How does ADSL work
ADSL exploits the unused analogue bandwidth available in the wires
ADSL works by using a frequency splitter device to split a traditional voice telephone line into two frequencies 4
25,875
138
1104
KHz
VOICE
Downstream
Upstream

51. Point-to-Point Protocol over Ethernet over ATM (PPPoEoA)

52. Features Appropriate for Internet requirement Convenient
downstream data rate of up to 6-8Mbps
upstream data rate of up to 640kbps to 1Mbps
Convenient
always on
Parallel with voice service
no need to unplug telephone line
Secure access to Internet
no need to worry about your noisy neighbors

53. Pros & Cons Why ADSL? ADSL disadvantages:
Simultaneous Internet and voice/fax capabilities over a single telephone line
Uninterrupted, high-speed Internet access that's always on-line
Cost-effective solution for society
Data Security that exceeds other technologies
Fast download speeds
ADSL disadvantages:
Distance-sensitive
Slower upload speeds
Phone line required

54. Conclusion
ADSL was born of the need for speed coupled with the desire for low cost dedicated remote network access. It will revolutionize the way we see the World Wide Web. ADSL emerge heralding the coming of a new age of remote multimedia. With the internet influencing our lives more and more each day, it will be high speed ADSL connections that power the revolution. In the future people will view ADSL like they view cable TV. That such a small object as an ADSL card may wield such an influence over our lives.

55. Thank you
Now Questions Time