Broad Band technology, Next generation network (NGN),DSLAM

1. BroadBand Telecom.
Networks Workshop
1

2. Objectives of Workshop
• After this session, you will learn:
– How to reuse the existing Access Networks for Broadband
Services ?
– One practical Broad Band Access System DSL
– About Upcoming Broadband Systems e.g NGN.
– Connectivity of IP Network for DSL
and other Broadband Services (Access & Core)
– Configuration of IP Network for DSL
• and other Broadband Services
2

3. About this Session
• Background Of Telecommunication Networks ?
• Requirements of new Access Technology ?
• Broadband Technologies
• Digital Subscriber Lines-DSL
• DSL-What ?
• DSL-When ?
• DSL-Why ?
• DSL-Flavors
• DSL Architecture
3

4. Background Of Telecommunication
Network s?
4

5. Building Blocks of Telecommunication Network Model
• Three Basic layers of Telecommunication Network
Model are:
1. Access Layer
2. Switching and Services Layer (Core Layer)
3. Transport Layer
5

6. Building Blocks of Telecommunication Network Model
Contd…
…
1. Access Layer
Represents the network that links the customers to the Switch and
Services Layer.
2. Switching and Services Layer (Core)
Consists of all the Switching Nodes (Local Exchange ,Transit
Exchange etc.)
1. Transport Layer
Represents the links among the nodes and provides the medium and
systems to carry the information from one node to the other.
6

7. Building Blocks of Telecommunication Network Model
Contd…
7

8. What is an Access Network (AN) ?
The access network refers to the part of the
network, connecting the subscriber to the
telecommunication service providing point /
exchange.
It is the last link /last Mile in a network between
the customer premises and the first point of
connection to the Network infrastructure
8

9. Typical Network Construction
9

10. Requirements of new Access Technology
• Changes in Trends
– Technological Evolution
• Demand for High Speed Access
– Broad Band Services
– Increase in Internet Usage
– Increase in demand of bandwidth
10

11. What is broadband ?
• Broader, wider – more bandwidth
• More bandwidth than narrow band dial up (56 kbps)
• Greater than 128 kbps
• Definitions vary from country to country
• Higher bandwidths of 256, 512, 1024 kbps and above
• Always on
• Uses various mediums:
– Copper
– Coaxial
– Wireless (Microwave ,Satellite etc.)
– Optical Fiber

12. Broadband Technologies
12

13. Why Broadband ?
• In a Telecommunication Network , last mile or first
mile is most important. It creats bottleneck
• Development of bandwidth hungry applications
• Convergence of Voice, data and video at one
delivery mechanism
• Need for Speed

14. Why Broadband ?

15. Narrow band Services & Broad band Services
• Narrow band Services
– Voice
– Limited Data
• Broadband Services
– Band width Hungry
– Multimedia Services ……..Voice + Video + Data
15

16. Narrow band Services & Broad band Services
SPEED !

17. Broad band Access
17

18. Broad band Access
18

19. Broadband access technologies
• Optical Access Network
– FTTH: Fiber To The Home
– FTTC: Fiber To The Curb
– Passive Optical Networks
– HFC (Hybrid Fiber Coaxial)
• xDSL
– HDSL (High rate digital subscriber line)
– SDSL (Symmetric digital subscriber line)
– ADSL (Asymmetric digital subscriber line)
– VDSL (Very high bit rate DSL)
– IDSL (ISDN DSL)
– UDSL (Ultrahigh bit rate DSL)
19

20. Broadband access technologies
• Wireless broadband access
– Wireless LAN
– WLL (Wireless Local Loop
– Microwave Radio Access (WiMax)
– GPRS (General Packet Radio Service)
– EDGE ( Enhanced Data GSM or Global Evolution )
– CDMA
– EVDO
• And many many more........
20

21. Requirement of new Access Technology
21

22. Requirement of new Access Technology
• Limitations of Conventional Telecomm. Network
(PSTN,ISDN) in terms of Broadband services
– Bandwidth Limitation
• Analog Modem Connections are limited to 56K.
• Basic Rate ISDN limited to 144 Kbps
– Switch Congestion
• Voice calls are usually short (say 5 min)
• Data calls are usually long (may be 120 mins.)
• Flat Charge /Low Charging by ISPs intends users for long
internet usage.
22

23. Requirement of new Access Technology
• Applicable to Existing Network
– xDSL
– Digital Cross Connect (DXX)
– ISDN
• Requiring new Installations
– Optical Fiber
– Wireless Local Loop
– CATV
23

24. xDIGITAL SUBSCRIBER LINE-
xDSL ?
24

25. x Digital Subscriber Lines (x DSL)
• Digital Subscriber Line is an Access technology
that enables broadband data over twisted copper
pairs, opening the most crucial bottleneck in the
today’s data stream.
25

26. x Digital Subscriber Lines (x DSL)
The three Ws
– What ?
– Why ?
– When ?
26

27. x Digital Subscriber Lines (x DSL) What ?
• DSL uses existing telephone lines
– Millions of telephone lines around the world.
– DSL can provide data and voice over the same phone line
– Users don’t need a second line.
– DSL provides service providers with the capability to
leverage the existing infrastructure
• DSL makes economic sense
– Reuse of existing telephone Outside Plants and reduces
the deployment costs and risks
– Deployed incrementally without large capital investment.
27

28. x Digital Subscriber Lines (x DSL) What ?
• DSL has many flavors
– xDSL is a generic abbreviation for the many flavours of
DSL or DSL Technology.
• DSL enables more bandwidth
– DSL refers to the technology used between a customer’s
premises and the telephone company, enabling more
bandwidth over the already installed copper cabling than
user have traditionally had.
– One may be able to receive data at rates up to 6.1 Mbps
(millions of bits) per second (of a theoretical 8.448
megabits per second),
28

29. x Digital Subscriber Lines (x DSL) What ?
• Provides a variety of services
– Internet Access
– Telecommuting (The practice of using telecommunication
technologies to work a site away from office )
– Distant learning
– On-line gaming
– Remote LAN Access
– Videoconferencing etc
– Continuous transmission of motion video, audio
29

30. x Digital Subscriber Lines (x DSL) What ?
• DSL enables new applications
– Services requiring real-time, interactive
multimedia and broadcast-quality video.
– Such applications include
• Video conferencing
• Video-on-demand
• IP TV
• Many Many More………
30

31. x Digital Subscriber Lines (x DSL) What ?
• Transmission speeds are not affected by
other users going on-line
– DSL is one customers dedicated line,
– Generally transmission speeds are not affected
• DSL is "always on"
– DSL is always connected - just like a standard telephone.
There is no time wasted in dialing up the service.
31

32. 32

33. x Digital Subscriber Lines (x DSL) What ?
Public Telephone
Network
DSL Access
Multiplexer
 Central Office
Telephone Line
6Mbps Internet
Customer
Premises DSL
33

34. x Digital Subscriber Lines (x DSL) What ?
34

35. x Digital Subscriber Lines (x DSL) Why ?
• DSL makes use of Huge Investment which has
already been done on Copper
• Eliminates the need for upgrades
– Unlike competing technologies, DSL eliminates the need
for extensive and expensive infrastructure upgrades
• DSL bridges gap between latest technologies and
copper
– DSL is the best Choice to bridge the gap between the
latest bandwidth hungry applications and the already
cheaply available copper cable ,
35

36. x Digital Subscriber Lines (x DSL) When ?
• Saving of time is essential .
• High Data rates are required.
• Revenue Saving is desired .
• Unmet broadband demand is to be met.
• Growing Traffic needs are to be satisfied.
• Alternate to insufficient optical fiber deployment is
required.
36

37. How does DSL technology achieve
information rates in the millions of
bits per second over those same
copper loops?
37

38. The answer is simple
As most speech energy lay in the frequency
range below 3500 Hz. Thus, for faithful
reproduction of speech, only a narrow range of
frequencies (0-3500 Hz), needs to be
transmitted. The telephone networks are
designed to pass frequencies in the range 300 –
3400 Hz.DSL uses a much broader range of
frequencies than the voice channel . Thus
,eliminating the 3,400-Hz boundary and using all
bandwidth of underutilized copper .
38

39. x Digital Subscriber Lines (x DSL)
• xDSL modems take advantage of the spectrum
above the telephone audio channel.
– DSL increases data rates by greatly increasing the
frequency range of the communication signal (from about
10KHz to over 1.0MHz).
– To do this they require the installation of special
equipment at the central office and customer premise
39

40. Frequency Range of Copper Line
Frequency Range
300 Hz to 3.3 kHz - Analog Voice 4 kHz to 1.1 MHz - ADSL Data
40

41. xDSL-Flavors
41

42. xDSL-Flavors
Symmetric DSL
Asymmetric DSL
42

43. Asymmetric DSL
• Why it is called Asymmetric DSL ?
– faster downstream rate vs. upstream rate.
• Applications
– Web-browsing, IP TV , Video on demand (VoD)
Asymmetric DSL and Derived Types
1 ADSL
2 Universal ADSL (UDSL), G.Lite or DSL Lite
3 Rate-Adaptive DSL (RADSL)
43
4 Very High Bit-rate DSL (VDSL)

44. Symmetric DSL
• Why it is called Symmetric DSL?
– Downstream & upstream rates are equal
• Applications
– Office type applications like Video conferencing
• Types
– High bit-rate DSL (HDSL)
– Single-pair HDSL (SHDSL)
– ISDN DSL (ISDL)
44

45. Differences in different flavors /variants of DSL
Few key differences
1 Speed
How much data can be sent or received in a certain amount of
time ?(bit rate)
2 Line Coding
How the information is encoded and sent on the line ?
3 Number of Lines
What are the requirements in terms of twisted pairs ?
4 Reach
How many feet/meters the signal can reliably travel ?
45

46. Asymmetric DSL and Derived Types
46

47. Asymmetric DSL and Derived Types
• ADSL
• Universal ADSL (UDSL), G.Lite or DSL Lite
• Rate-Adaptive DSL (RADSL)
• Very High Bit-rate DSL (VDSL)
47

48. ADSL
• Why it is called ADSL ?
– ADSL is called "asymmetric" because most of its two-way
bandwidth is devoted to the downstream direction i.e sending data
to the user.
• Data Rate and Reach
– Only a small portion of bandwidth is available for upstream or
user-interaction messages. Using ADSL, up to 6.1 Mbps of data can
be sent downstream and up to 640 Kbps upstream
– The data rate of ADSL is highly dependent upon the distance from
Central Office (CO) to the Consumer Premises
– ADSL is designed to co exist with a regular phone line (phone
operates at frequencies up to 4 KHz). ADSL will extend out to
18,000 ft, but its ideal rates only operate out to 9,000 ft.
– Speeds and distances based on good pair
48

49. ADSL
• Advantages
– Well suited to residential application.
– Peacefully co-exists with current phone service.
• It has large downstream data capacity
– ADSL (like most flavors of xDSL) is always connected
• Disadvantages
– For Large business upstream data rates are often just
as important as downstream ,which would make ADSL a
poor choice
– Data rates also suffer dramatically as line length
increases.
49

50. ADSL
50

51. ADSL (Operation)
• To create multiple channels ,ADSL Modem
divide the available bandwidth of a
telephone line by using Frequency Division
Multiplexing (FDM).
• By FDM , ADSL splits off a 4 kHz region
for basic telephone service at the lower end
of the band. One band is used for upstream
and one band for downstream is assigned.
51

52. ADSL Spectrum - FDM
52

53. Type of Asymmetric DSL- G.Lite
• DSL Lite, Splitter less ADSL or UADSL (Universal ADSL)
• A derivative of ADSL technology
• ITU-T Standard
• UADSL is Output of Universal ADSL Working Group (UAWG)
• Slower version
• provides a data rate of 1.544 Mbps downstream and from 128 Kbps
to 384 Kbps upstream.
• Simpler Hardware design
• Because of the lower bit rate, hardware design for G.Lite is easier
53

54. Types of Asymmetric DSL- G.Lite
• No Splitter Required
• Where wiring in the home is old or done poorly,the voice
and data signals can interfere with each other .In those
cases ,small Micro Filters are placed on each phone line
in the house.
• Higher noise levels can be tolerated, eliminating the
need for a POTS splitter.
• Cost effective solution as no splitter required
54

55. Types of Asymmetric DSL- G.Lite
• The 0 to 4 kilohertz (KHz) range is used for POTS
• The 20 KHz to 130 KHz range is used to transmit
data upstream
• The 140 KHz to 550 KHz range is used to transmit
data downstream
The (3) Divided Segments of G.Lite 55

56. G.Lite DMT Spectrum
56

57. 57

58. Types of Asymmetric DSL- RADSL
• RADSL (Rate Adaptive DSL )
• By dynamically decreasing or increasing the bit-
rate ,rate adaptive technology uses the optimal
speed for the Line.
• Modem periodically assesses line quality and adjust
transmission rate
• Generally used to extend reach of systems to areas
that are far from the central office.
58

59. Types of Asymmetric DSL- RADSL
• Operates over single twisted-pair copper loop
• Downstream: 1 to 12 Mbps
• Upstream: 0.128 to 1 Mbps.
• In summary RADSL gives flexibility to adapt to
the changing conditions and adjust the speeds in
each direction to potentially maximize the
throughput on each line.
59

60. Types of Asymmetric DSL- VDSL
• VDSL (Very high bit rate DSL)
• Data rates: Up to 52 Mbps (13, 26, or up to 52 ) in
one direction and 2 Mbps in the other
• Meets businesses and residences with broadband
access requirements over a Fiber-To-The-Curb
(FTTC) network.
• Ultra High Speed data access such as Streaming
video possible. 60

61. Type of Asymmetric DSL- VDSL
61
VDSL Network

62. Symmetric DSL and Derived Types
62

63. Symmetric DSL
• Why it is called Symmetric DSL?
– Downstream & upstream rates are equal
• Applications
– office type applications like Video conferencing
• Types
– High bit-rate DSL (HDSL)
– Single-pair HDSL (SHDSL)
– ISDN DSL (ISDL)
63

64. Type of Symmetric xDSL-HDSL
• HDSL (High bit rate Digital Subscriber Line)
– 1.544/2.048 Mbits bi-directional service
• Matured and cheaper type of DSL .
• Developed in late 1980’s as an alternative to T1/E1 standards .
• Initially T1/E1 lines were developed and deployed for high speed data
transmission.
– They are dedicated lines where there is always a connection between the
end user and the service provider.
– A leased T1 /E1 line has customarily been quite expensive. 64

65. Types of Symmetric xDSL-HDSL
65

66. Types of Symmetric xDSL-HDSL
• HDSL was designed to automatically compensate for line
conditions.
• HDSL uses Duplex transmission sending data bi-directionally
against T1/E1 which uses Simplex Transmission
• HDSL transceivers can transmit a 2.048 Mbps data signal
over two, 0.5mm, twisted wire pair loops at a distance of up
to 4.2 km without the need for repeaters
66

67. Types of Symmetric xDSL-HDSL
67

68. Types of Symmetric xDSL-HDSL
• HDSL is designed to run at the same bit rate as a
T1/E1 line (1.544/2.048 Mbps) and it uses the same
number of lines, but it can achieve this same bit
rate on less expensive lines over a greater distance.
• To do this, it sends a half rate signal (784/1040
kbps) on each line.
68

69. Types of Symmetric xDSL-HDSL
• Advantages
– Matured and proven technology.
– Very easy and economical to install.
– Having decent transfer rate in both directions at
1.544/2.048 Mbps (784/1040 kbps x 2).
• Dis-advantages
– Requires two twisted pairs of wires to operate
– High deployment cost for service providers.
– Slightly slower in speed than other forms of DSL,
69

70. 70

71. Types of Symmetric DSL- SHDSL
• SHDSL (Single-pair HDSL)
• Single twisted pair of wires is used.
• This helps to drive the cost of a system down.
• Having transfer rate in both directions at
1.544/2.048 Mbps .
• SHDSL supports repeaters ,which further
increases the reach capability 71

72. Types of Symmetric DSL- SHDSL
• It can be used to provide variety of rates between
192 Kbps and 2.312Mbps and can extend 5.5 km @
256 Kbps.
• Ideally suited to SOHO market
72

73. Types of Symmetric DSL- IDSL
• IDSL (ISDN Digital Subscriber Line).
• IDSL provides DSL technology over existing ISDN lines.
•
• Even though the transfer rates for IDSL are about the
same as ISDN (144kbps v. 128kbps), and IDSL circuits can
only carry data (not voice), the major benefits of switching
to IDSL from ISDN are
– Always-on connections, as opposed to dial-up, thus eliminating call
setup delays;
– Transmission of data over the data network, rather than the PSTN.
73

74. DSL Reaches and Rates
74

75. 75

76. Comparing Access Technologies
76

77. DSL Architecture
77

78. DSL Central Office Components
• DSLAM (Digital Subscriber Line Access Multiplexer)
– Aggregates traffic from multiple DSL Modems
and combine it into higher speeds before sending
it to the Internet or data network.
– It is a mechanism at a phone Company’s central
location that links many DSL customers
(Connections) to a single high speed Data Line
– DSLAMs are generally flexible and able to
support multiple types of DSL in a central office
78

79. DSL Central Office Components
– DSL customer Terminates individual subscriber line and
integrates it into the telephone and data networks.
– Multiple DSLAMs are further connected to B-RAS
(Broad band Remote Access server) and hence to
Internet Cloud.
– Splitters and filters are also located at the telephone
company equipment.
– Modern DSLAMs support
• Multiple DSL transmission types
• ADSL, SDSL, etc
• Different protocol
79
• Different modulation techniques

80. DSL Central Office Components
80
DSLAM

81. DSL Customer Premises Equipment (CPE)
• Splitter / Filters
– Separates the low frequency voice signals from the high
frequency data signals.
– If we will not install the DSL splitter on our telephone
line, the phone line signals can interfere with DSL
modem. And we can face noise, low speed data or service
break down.
81

82. DSL Customer Premises Equipment (CPE)
– DSL Modem
– Couples DSL to PC or Ethernet Equipment
82

83. PSTN Internet
IP /ATM
DSLAM
Subscriber Premises
Local Loop
Splitter Less than 18,000 ft. --
Low
Frequencies Central Office
High
Frequencies
PC with DSL Modem
83
Network Topology DSL Connection With Splitter

84. Network Diagram of DSL
84

85. DSL Coding Techniques
85

86. Coding Techniques for xDSL
• Many approaches have developed as a means
of encoding data on to xDSL Circuits
• The Commonly used modulations are
– Discrete MultiTone Modulation (DMT)
– Carrierless Amplitude Phase Modulation (CAP)
– Quadrature with Phase Modulation (QAM)
86

87. Line Coding Techniques for ADSL
• Discrete MultiTone Modulation (DMT)
– Used in Industries
– DMT uses multiple narrowband Carriers ,
– DMT systems divide the frequency band into 256 sub
carriers with the standard 4.3125 kHz bandwidth.
– 32 of these channels are reserved for upstream data.
– All Carriers transmitting simultaneously in a parallel
transmission mode
– Each of these carriers carries a portion of the
information being transmitted
87

88. Line Coding Techniques for ADSL
• These carriers can be independently modulated
DMT Spectrum 88

89. Current Version of DSL
VDSL: Broadband To The Home
Reach over copper: 300m - 2Km
Data rates: Up to 52 Mbps
VDSL
Symmetric and Asymmetric
Copper
operation
VDSL
FTTB
Street Cabinet VDSL
Copper
VDSL
FTTC
Central Office Copper
.
VDSL
.
.
VDSL

90. PTCL Announcing Bandwidth (DSL) Data Rate Up to
50 Mbps
• PTCL Announcing Bandwidth (DSL) Data Rate Up to 50 Mbps
Using VDSL2 Bonding Technology
• PTCL has become the 1st operator in the world to use
VDSL2 Bonding technology to provide to its bandwidth
hungry DSL customers with Bandwidth up to 50 Mbps on its
existing Copper network.
• VDSL2 Bonding takes two copper based lines per subscriber
and aggregates them to almost double the bandwidth speed
available to the existing customers and also expands high
speed broadband access to areas that are underserved
today. Using VDSL2 Bonding technology, service providers
can extend the life of their existing copper infrastructure
supporting the delivery of bandwidth intensive services90
such as Triple play service, data and IPTV.

91. THANKS 91

92. Picture Abhi baqi ha
mery Dost……. 92

93. What is Next Generation Networks (NGN ) ?
− NGN is based on standard protocols and packet switching network
− In broad sense
− NGN refers to integrated network that adopts new technologies
extensively, focuses on IP, and provides voice, data, and multimedia
service at the same time.
− In narrow sense
− NGN refers to the Open , Integrated and Distributed network that
employs soft switch at the control layer

94. What is Next Generation Networks (NGN ) ?
Voice+ Data
+Video
Video

95. Conventional Network

96. Limitations of Conventional Network
− Switches are aged .Legacy Switch is designed for Speech .
Data Traffic is increasing day by day. Networks are going to
be complex and need to be consolidated
And…
− I want to protect existing SDH transmission investment
− I want to keep current access layer architecture
What shall I do?
96

97. NGN is Ready Now
• NGN will fully replace the TDM network
owing :
– technical advances
– cost savings
– long term revenue generation
• The market and technology is mature for
the large scale deployment of NGN
97

98. NGN is Ready Now

99. NGN is Ready Now
Competitive NGN Standardization of More and more commercial
and more commercial
equipment price NGN protocols NGN applications
NGN applications
worldwide
worldwide
Maturity and Openness Settlement of More successful
of NGN services QoS/Security problems interoperability test
99

100. Comparison of Circuit switching in TDM Switch Model
and Packet switching in NGN Model
Intelligent Network (SCP)
SoftSwitch Expanded Services
CPU
Switching Array Signaling
IP Core Module
Signaling
Gateway
Trunk Module User
Access Module
Trunk Media Access Media
Gateways Gateway

101. Hybrid Networks
Gateways allow PCs
Public Switched Telephone
Network to also reach phones
Initially, PC to PC voice calls over
the Internet
PSTN
Gateway for Media &
Signaling
TMG
Multimedia PC
IP Network
Gateway for Media &
Signaling TMG
Multimedia PC
PSTN
…or phones to reach phones

102. Next Generation Networks NGN
(Architecture of NGN)
• Four Layers Model of NGN
1. Edge Access Layer
2.Core Switching Layer
3.Network Control Layer
4.Service Management Layer

103. Four Layers Model of NGN
103

104. Other Network
MRS
MGCP
APP Server
SCP
MML/SNMP/CORBA FTP
Network management
INAP
BC (Billing cent
PARLAY
SIP
H.323
Heart Beat
Soft switch
SoftSwitch
SIGTRAN
MGCP/SIP/H.323
SG H.248
MGCP
EPhone
MGCP / H.248
TMG
AMG IAD
Soft Switch Interfaces and Protocols
Service Layer
Control layer
104
Access Layer

105. Any comments or
questions?
Thank you !
105