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Submitted for fulfillment of Project work in

Electronics and Communication Engineering”


AMIE (Institution of Engineers- India)

(Year 2014 Term MAY/JUNE)

Submitted By- Project Guide-

Suresh Chandra Pandiya Dr. Ashok Kumar Jetawat

ST510455-1 MIE


It gives me immense pleasure in certifying that the Project entitled “Study the ADSL & Other Problems in Broadband Technology with Solutions” and submitted by Suresh Chandra Pandiya (ST510455-1) is based on the work research carried out under my guidance. He has completed all the requirements as per Project Work regulations of “The Institution of Engineers (INDIA)”. No work has been done on this project till dated.

Dr. Ashok Kumar Jetawat, MIE




I express my deep gratitude to all persons who helped me for successful completion of the project. First of all myself is highly grateful to the Institution of Engineer, INDIA for including in syllabus. This provides us the opportunity to work on a wonderful emerging topic.

I would like to thanks Dr. Ashok Kumar Jetawat (Project Guide) for taking interest in my topics. He has been source of inspiration for us throughout the project cycle & extricating me whenever I found myself in & impasse. This project would not have been completed without his valuable suggestion & help.

I would like to extend sincere thanks to my workplace company, Bharat Sanchar Nigam Limited, O/o Dhariyawad, Udaipur (Raj.) for providing me such a helpful environment during the project.

I would also like to thank Mr. Sanjay Samariya (JTO (Incharge), Dhariyawad, BSNL) and Mr. Sunil Ji (SDE, Broadband, Udaipur, BSNL) for his valuable guidance, without which it would not have been possible for me to complete the project work.

In making of this project I gain a lot of knowledge about various Broadband Technologies with analyzing the problems & finding the solutions.

(Suresh Chandra Pandiya)



    • Title of the Project.

    • Introduction

    • Objectives of the study.

    • Methodology of the study.

    • Statement of the Problem.

    • Input Data/Structure/Questionnaire.

    • Analysis/Solution/Description.

    • Final Result.

    • Conclusion.

    • Scope of Future Study.

    • References

Title of Project

Study the ADSL & Other Problems in Broadband Technology with Solutions


Advances in telecommunications and data technology are creating new opportunities for countries, businesses and individuals—just as the Industrial Revolution changed fortunes around the world. The new economy is defining how people do business, communication, shop, have fun, learn, and live on a global basis—connecting everyone to everything. This evolution of Internet has come into existence & Internet service is expanding rapidly. However, technological advances promise big increases in access speeds, enabling public networks to play a major role in delivering new and improved telecommunications services and applications to consumers. The Internet and the network congestion that followed, has led people to focus both on the first and last mile as well as on creating a different network infrastructure to avoid the network congestion and access problems

A historic opportunity awaits the communication industry in the years ahead – a chance to connect most of the world using wireless and wire line technologies. Broadband connections will be available just about anywhere in the world, across developed and growth markets. But it will take more extensive use of wireless access and new wire line installations with improved performance to offer true broadband connectivity. The ADSL technology is most used broadband technology in India which gives a best internet speed to the consumer’s home.

Objective of the Study

The study of this project describes the introduction about the xDSL Broadband technologies, their types, problems faced and their solutions. The Internet is very necessary and important part of our life. The Broadband is a very high speed internet technology. The Internet or Broadband connects us to the world; by it we can connect & communicate to anywhere in the world as like as we are sitting in front of them.

The objective of study is to cover the following points as stated below -

    • Study of various DSL Broadband Technologies.

    • Study and analyze various ADSL& other problems in Broadband technology.

    • Give solutions and suggestions to remove the Broadband problems.

All the points mentioned above will describe the whole scenario of the projects in all the aspects based on the conditions of utilities. In this we will know broadband problems and their possible solutions.

Methodology of Study

The methodology of this study describes about the process or the methods which we will follow to complete the study.

Study of DSL Broadband Technology

The first step of this project is to study about various DSL Broadband Technologies. This will describe the basic idea of the technologies which are used in providing the internet to the consumers.

Study of ADSL & other problems in Broadband Technology

The second step of method is to search and investigate about all the problems in broadband technologies. This will include the main ADSL broadband problems and also include the other problems in broadband technologies. If we understand the problems and also understand the technical aspects of them, then we can find much better and easy solutions of problems.

Analysis of working environment

In this step we will see the actual environment where this technology used and analyze and understand the working structure which was installed to serve this technology to the consumers. Also we understand the broadband structure in India and know how internet works from customer to internet server.

Analysis of problems with the help of data collection

Here we will analysis Broadband services; analyze the problems with the help of some logics, knowledge and practical working.

  • Simulation method of broadband provision

  • Working principals of software & BB modems

  • Discuss with technical team

Problem solving activities

After identification of the problem the problem solving session will start. In this session we will discuss the problems with technical engineer and experts or we will do the brainstorming session with all technical staff. If some web based help is required, we do so with help of various search engines. The list of activities involve in problem solving are

  • Discuss with technical engineer or expert.

  • Web search engines - Google and Wikipedia and blogs.

  • Brain storming section.

By these we can understand the problems in better way and get better solutions.

Re-verification of the problem

After getting the solutions, these will be implemented in working method of installation or provision of broadband. Now the solutions were re-verified by applying them in practical aspects. The main activities involves are discussion, Feedback & implementation.

What is Broadband?

A definition to broadband is a must as different service providers defines in their own terms & context. TRAI (Telecommunication Regulatory Authority of India) defines broadband as follows:-

An ‘always-on’ data connection that is able to support interactive services including Internet access and has the capability of the minimum download speed of 256 kilobits per second (kbps) to an individual subscriber from the Point of Presence (POP) of the service provider intending to provide Broadband service. [02]

Where multiple or such individual Broadband connections are aggregated and the subscriber is able to access these interactive services including the Internet through this POP. Broadband is always on. It does not block phone lines and there is no need to reconnect to network after logging off. The interactive services will exclude any services for which a separate license is specifically required, for example, real-time voice transmission, except to the extent that it is presently permitted under ISP license with Internet Telephony.


The Broadband is very necessary in present days, not only in business purposes but also in many other activities as communication, research, entertainment, medical etc. The efficiency of work and the speed of work is much increase by the use of Broadband.

PROFESSIONAL ACTIVITIES: - The use of Broadband is much greater in the professional activities. The professionals use Broadband in communication, home business, audio and video conferencing to save the time and money. The following are main professional activities-

  1. Telecommuting

  2. Video Conferencing

  3. Home Based Business

  4. Home Office

ENTERTAINMENT ACTIVITIES: - The level of entertainment is gone to beyond by the use of Broadband. It is used in online gaming, chatting, surfing etc. The Broadband reduces the use of mobile SMS, calling etc. The following are the main entertainment activities-

  1. Web surfing

  2. Video on Demand

  3. Video Games

CONSUMER ACTIVITIES: - The main advantage of Broadband is use in consumer activities which resolves many problems of consumer in study, communication, medical etc. The main consumer activities are as follows-

  1. Telemedicine

  2. Distance learning

  3. Information gathering

  4. Photography

  5. Video conferencing among family and friends

I describe here only very short use of Broadband. The activities describe above are mostly used activities among people. A fast internet or Broadband connection is increasingly viewed as a vital utility and need at work and home – its kind of the electricity of the 21st century. The internet offers an almost infinite range of opportunities for social interaction.

Broadband Access (Classification)

Broadband access technology is broadly classified into two categories. They are Wired Line & Wireless and further classified as detailed in the following diagram [1].

Broadband Access Technologies

Wire line

DSL (Digital Sub’s Line)

Cable Modem

Optical Fiber Technologies

PLC (Power Line) Communication)


FSO (Free Space Optics)

3G Mobile

Wi-Fi (Wireless Fidelity)




Figure: - (1) Broadband Classification, Source-

The above figure shows about all the broadband technologies used in this world. These are mainly classified in wireless and wire line and further classified in many technologies. Some of them are used in India. In India mostly the DSL, 3G, OFC and WiMAX are used.


The Wired line Broadband technology is that in which Broadband or internet is provided through any guided physical line. The physical line may be specified as copper twisted wire, optical fiber cable, power line cable etc. All are used as path for internet data which are transmitted or received by consumer. Many technologies incorporate with wired line broadband technology as shown in diagram (1). I am describing the DSL wired line technology in this project which is as follows-

  1. DSL (Digital Subscriber Line)

DSL uses the existing twisted-pair telephone lines to access media for internet. Over a period of time, a number of technologies (xDSL) have been introduced to provide faster data speeds over this medium. The various xDSL technologies are given as ADSL, VDSL, RADSL, HDSL, and SDSL. All have their special characteristics in the range of speed in downloading and uploading.

Roughly, xDSL standards can be divided into the following three groups: -

  1. Symmetric DSL – The symmetric DSL provides the same data rate for upstream and downstream transmissions. It used where data uploading is greater and similar use for data downloading. This DSL technology has three types which are define according to the bit rate provided. The highest bit rate is 4.6 Mbps which provide in SHDSL technology. The following table (1) gives the information about maximum upstream and downstream rate with the maximum local length of wire possible for that.

DSL Variant

Max Up/Downstream Rate

Max local loop wire length

HDSL – High data rate Digital Subscriber Line

1.5 Mbps / 1.5 Mbps

3.7 km

SDSL – Symmetric Digital Subscriber Line

2.3 Mbps / 2.3 Mbps

3.0 km

SHDSL – Symmetric High bit rate Digital Subscriber Line

4.6 Mbps / 4.6 Mbps

5.0 km

Table: - (1) Symmetric DSL Variant with Up/Down stream rate and local wire length


  1. Asymmetric DSL – The Asymmetric DSL technology provides higher downstream data rate then upstream data transmission rates. This technology used mainly in higher data downloading and very short use of data uploading. Most home consumers are using this technology for downloading data, movies, songs etc. This technology have following types which shown in table (2): -

DSL Variant

Max Up/Downstream Rate

Max local loop wire length

ADSL – Asymmetric Digital Subscriber Line

1.0 Mbps / 10 Mbps

5.5 km

ADSL Lite – Asymmetric Digital Subscriber Line

384 Kbps / 1.5 Mbps

5.5 km

ADSL (2) – Asymmetric Digital Subscriber Line

1.0 Mbps / 12 Mbps

5.5 km

ADSL (2+) – Asymmetric Digital Subscriber Line 2+

1.0 Mbps / 20 Mbps

5.5 km

ADSL (2++) or ADSL 4 – Asymmetric Digital Subscriber Line 2++

52 Mbps over short distances

Developing technology

Table: - (2) Asymmetric DSL Variant with Up/Down stream rate and local wire length Source-

  1. Symmetric and Asymmetric DSL – The Symmetric and Asymmetric DSL technology can transmit data both symmetrically and asymmetrically and includes the following type shown in table (3):

DSL Variant

Max Up/Downstream Rate

Max local loop wire length

VDSL – Very High bit rate Digital Subscriber Line

10 Mbps / 10 Mbps symmetric 1.5 Mbps / 52 Mbps asymmetric

0.3 km – 1.3 km

VDSL 2 – Very High bit rate Digital Subscriber Line

100 Mbps / 100 Mbps symmetric

0.5 km

Table: - (3) Symmetric and Asymmetric DSL Variant with Up/Down stream rate and local wire length, Source-

The DSL technology has various variant which are classified according to their upload and download characteristics. The Symmetric DSL gives symmetry in download and upload data rate and the Asymmetric DSL technology gives asymmetry in upload and download data stream rate which can also be defined as required by consumer for his specific use.

ADSL (Asymmetric Digital Subscriber Line)

Asymmetric Digital Subscriber Line (ADSL) is a form of DSL, a data communications technology that enables faster data transmission over copper telephone lines than a conventional modem can provide to consumers. ADSL has the distinguishing characteristic that the data can flow faster in one direction (used for download streaming) than the other (used for upload streaming) i.e., asymmetrically.


ADSL is in place used due to both technical and marketing reasons in India. On the technical side, there is likely to be more crosstalk from other circuits at the DSLAM (Digital Subscriber Line Access Multiplex) end (where the wires from many local loops are close together) than at the customer premises. Thus the upload signal is weakest, while the download signal is strongest at the noisiest part of the local loop. The DSLAM aggregates all the lines of customer and splits data and voice signals. Then it connect customer to the BBRAS and internet servers.

The various forms of digital subscriber line (DSL) services are broadband in the sense that digital information is sent on multiple channels. Each channel has higher frequency than the baseband voice channel, so it can support plain old telephone service on a single pair of copper wires at the same time. We can use both voice service and data service at the same time.


To obtain the asymmetrical data transfer to suit requirement of Internet and LAN access, the ADSL signal firstly splitting the available bandwidth on the twisted copper wire (telephone wires) into three different channels: 

A high speed downstream channel (ranges from 1.5 to 8 Mbps).

A medium speed upstream channel (ranges from 16 kbps to 1 Mbps).

POTS (Plain Old Telephone Service) channel.

ADSL used two separate frequency bands. The band from 25.875 kHz to 138 kHz is used for upstream communication, while 138 kHz - 1104 kHz is used for downstream communication this shows in following diagram (5)

Frequency plan for ADSL

frequency plan for adsl

Figure: - (2) Source-

Firstly the POTS channel is splits off from the digital modem by filter unit. After the POTS channels are splits from the digital data transfer bandwidth, the 26 kHz to 1.1 MHz is data bandwidth.

Common Elements in ADSL: - The common elements of ADSL are CPE, DSL modem, POTS splitter, DSLAM, Aggregator, PSTN, and MDF etc. The connectivity diagram of all is shown in figure (3) which shows all the basic elements used in ADSL technology.

CPE (Customer Premises Equipment) containing a Splitter (which splits the voice and data), a PC & ADSL Modem (which connects consumer to DSLAM).

Central Office Premises is containing equipments DSLAM (Digital Subscriber Line Access Multiplex), MDF & PSTN. MDF is a frame where both voice and data line coming and combined signal is gone to local copper line towards the customer.

Aggregator and ATM core consists of Tier II, Tier I switches, BRAS (Broad Band Remote access Service), Servers and Core routers.

Figure: - (3) Elements in ADSL, Source -

Factors Determining ADSL Connectivity: -

The distance from the DSLAM (Digital Subscriber Line Access Multiplex) to the customer end effects on data rate. More the distance, data rate will reduce. Signal attenuation and SNR (Signal to Noise Ratio) are defining characteristics, and can vary completely independently of distance (e.g., non-copper cabling, cable diameter) as shown in table (4).

Data Rate - Wire Size – Distance

Data Rate

Wire Size


1.5-2.0 Mbps

0.5 mm

18000 Feet

5.5 Kms

1.5-2.0 Mbps

0.4 mm

15000 Feet

4.6 Kms

6.1 Mbps

0.5 mm

12000 Feet

3.7 Kms

6.1 Mbps

0.4 mm

9000 Feet

2.7 Kms

Table: - (4) Data Rate, Wire Size and Distance

Source -

Figure: - (4) ADSL Broadband Router


The ADSL technology is the basic technology in India to use Broadband or high speed internet and provided by the BSNL. BSNL also provide Broadband service to the rural area and take part in social improvement of rural people. The ADSL Broadband router as shown in figure (4) has various LED indication on the front side. The main LED’s are known as POWER, ADSL or LINK, INET or Internet, LAN 1/2/3/4, WLAN etc. All have their specific characteristic. The ADSL or LINK LED gives indication about connectivity between DSLAM and Router and the INET shows connectivity to internet server or DNS server. The LAN 1/2/3/4 is used to show connection to PC from modem or router and WLAN shows that the Wi-Fi or wireless is working.

Broadband Technology Network Architecture

The broadband network of BSNL (Deploy under the project “National Internet Backbone-II”) comprises the managed MPLS backbone and the broadband access. This backbone network carries broadband and narrowband Internet traffic, content based service traffic, Virtual Private Network (VPN) traffic, IP TAX traffic, etc. The MPLS backbone has two layers the CORE & the EDGE networks. The CORE network that comprises the routers connected with the high speed STM - 16 transmission links whereas the EDGE network comprises the EDGE routers connected to the CORE routers through the Gigabit Ethernet or STM-16 links. This layer aggregates customer traffic, enforces QOS (Quality of Service) and extends managed access to the customer. This layer provides the customer access through three mechanisms: (a) Dialup, (b) Dedicated access, and (c) Broadband access. NIB-II is a mission to build world-class infrastructure that will help accelerate the Internet revolution in India.

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