Six Months Industrial Training Report

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Six Months Industrial Training Report At TATA TELESERVICES LTD.Submitted in partial fulfilment of the requirements for the award of degree of

BACHELOR OF TECHNOLOGY IN ELECTRONICS & COMMUNICATION ENGINEERING

SUBMITTED TO: Er. Vijay Banga HOD ECE

SUBMITTED BY: Name: Yogesh Sharma Roll No. : 80602108132

ACKNOWLEDGMENTI am highly grateful to the Er.Vijay Banga , HOD ( ECE), Amritsar College of Engineering & Technology, (Amritsar), for providing this opportunity to carry out the six month industrial training at Tata Teleservices Ltd. I would like to expresses my gratitude to other faculty members of Electronics & Communication department of ACET, Amritsar for providing academic inputs, guidance & encouragement throughout the training period. The author would like to express a deep sense of gratitude and thankful to the higher authorities of Company, without whose permission, wise counsel and able guidance, it would have not been possible to pursue my training in this manner. The help rendered by Mr Gurminder Singh Bhullar, Supervisor (Technology) for Experimentation is greatly acknowledged. Finally, I express my indebtedness to all who have directly or indirectly contributed to the successful completion of my industrial training.

Yogesh Sharma

TABLE OF CONTENT

S.No. 1 2 3 4 5 6

Content Page No. Company Profile Overview Of multiple acess technology CDMA Advantage BTS(Base Transceiver Station) Huawei 3900 BTS Practical Work

1 1 2 4 5 7

COMPANY PROFILETata Teleservices Limited spearheads the Tata Groups presence in the telecom sector. The Tata Group had revenues of around US $62.5 bn in Financial Year 2007-08, and includes over 90 companies, around 350,000 employees worldwide and more than 3.2 million shareholders. Incorporated in 1996, Tata Teleservices is the pioneer of the CDMA 1x technology platform in India. It has embarked on a growth path since the acquisition of Hughes Tele.com (India) Ltd [renamed Tata Teleservices (Maharashtra) Limited] by the Tata Group in 2002. It launched mobile operations in January 2005 and today enjoys a pan-India presence through existing operations in all of Indias 22 telecom Circles. The company is also the market leader in the fixed wireless telephony market. The companys network has been rated as the Least Congested in India for last four consecutive quarters by the Telecom Regulatory Authority of India through independent surveys.

Today, Tata Teleservices Ltd, along with Tata Teleservices (Maharashtra) Ltd, serves over 36 million customers in more than 320,000 towns and villages across the country, with a bouquet of telephony services encompassing Mobile Services, Wireless Desktop Phones, Public Booth Telephony and Wireline Services. Other services include value-added services like Voice Portal, Roaming, Post-paid Internet Services, Three-way Conferencing, Group Calling, Wi-Fi Internet, USB Modem, Data Cards, Calling Card Services and Enterprise Services. Some of the other products launched by the company include Pre-paid Wireless Desktop Phones, Public Phone Booths, Mobile Handsets and Voice & Data Services such as BREW Games, Voice Portal, Picture Messaging, Polyphonic Ring Tones, and Interactive Applications like news, cricket, astrology, etc. In December 2008, Tata Teleservices announced a unique reverse equity swap strategic agreement between its fully-owned telecom tower subsidiary, Wireless TT Info-Services Limited, and Quippo Telecom Infrastructure Limitedwith the combined entity kicking off operations with 18,000 towers, thereby becoming the largest independent entity in this space. Tata Teleservices bouquet of telephony services includes mobile services, wireless desktop phones, public booth telephony and wireline services.

Board of DirectorsMr. Ratan N. Tata Designation : Chairman Company : Tata Teleservices Ltd.

Mr. K. A. Chaukar Designation : Managing Director Company : Tata Industries Ltd.

Mr. Anil Kumar Sardana Designation : Managing Director Company : Tata Teleservices Limited

.

Mr. N. S. Ramachandran Designation : Director, Company : Tata Teleservices Ltd.

Mr. N. Srinath Designation : CEO & MD Company : Tata Docomo.

Dr. Mukund Govind Rajan Designation : MD

Company : Tata Teleservices Maharashtra Ltd.

Mr. Anuj Maheshwari Designation : Director Company : Temasek Holdings Advisors India Pvt Ltd., ("THAIPL")

Mr Toshinari Kunieda Designation : Senior Vice President Managing Director Global Business Division Company : NTT Docomo, INC.

Mr. Kiyoshi Tokuhiro Designation : Senior Vice President

Managing Director of Network Department Company : NTT Docomo, INC.

CODE DIVISION MULTIPLE ACCESS

Code division multiple access (CDMA) is a channel access method used by various radio communication technologies. It should not be confused with the mobile phone standards called cdmaOne, CDMA2000 (the 3G evolution of cdmaOne) and WCDMA (the 3G standard used by GSM carriers), which are often referred to as simply CDMA, and use CDMA as an underlying channel access method. One of the basic concepts in data communication is the idea of allowing several transmitters to send information simultaneously over a single communication channel. This allows several users to share a band of frequencies . This concept is called multiple access. CDMA employs spread-spectrum technology and a special coding scheme (where each transmitter is assigned a code) to allow multiple users to be multiplexed over the same physical channel. By contrast, time division multiple access (TDMA) divides access by time, while frequency-division multiple access (FDMA) divides it by frequency. CDMA is a form of spreadspectrum signalling, since the modulated coded signal has a much higher data bandwidth than the data being communicated. An analogy to the problem of multiple access is a room (channel) in which people wish to talk to each other simultaneously. To avoid confusion, people could take turns speaking (time division), speak at different pitches (frequency division), or speak in different languages (code division). CDMA is analogous to the last example where people speaking the same language can understand each other, but other languages are perceived as noise and rejected. Similarly, in radio CDMA, each group of users is given a shared code. Many codes occupy the same channel, but only users associated with a particular code can communicate. The technology of code division multiple access channels have long been known. In the USSR, the first work devoted to this subject was published in 1935 by Professor D.V. Aggeev in the "CDMA". It was shown that

through the use of linear methods, there are three types of signal separation: frequency, time and compensatory. The technology of CDMA was used in 1957, when the young military radio engineer Leonid Kupriyanovich in Moscow, made an experimental model of a wearable automatic mobile phone, called LK-1 by him, with a base station. LK-1 has a weight of 3 kg, 20-30 km operating distance, and 20-30 hours of battery life. The base station, as described by the author, could serve several customers. In 1958, Kupriyanovich made the new experimental "pocket" model of mobile phone. This phone weighed 0.5 kg. To serve more customers, Kupriyanovich proposed the device, named by him as correllator. In 1958, the USSR also started the development of the "Altay" national civil mobile phone service for cars, based on the Soviet MRT-1327 standard. The main developers of the Altay system were VNIIS (Voronezh Science Research Institute of Communications) and GSPI (State Specialized Project Institute). In 1963 this service started in Moscow and in 1970 Altay service was used in 30 USSR cities.

STEPS IN CDMA MODULATIONCDMA is a spread spectrum multiple access technique. A spread spectrum technique spreads the bandwidth of the data uniformly for the same transmitted power. A spreading code is a pseudo-random code that has a narrow Ambiguity function, unlike other narrow pulse codes. In CDMA a locally generated code runs at a much higher rate than the data to be transmitted. Data for transmission is combined via bitwise XOR (exclusive OR) with the faster code. The figure shows how a spread spectrum signal is generated. The data signal with pulse duration of Tb is XORed with the code signal with pulse duration of Tc. Therefore, the bandwidth of the data signal is 1 / Tb and the bandwidth of the spread spectrum signal is1 / Tc. Since Tc is much smaller than Tb, the bandwidth of the spread spectrum signal is much larger than the bandwidth of the original signal. The ratioTb / Tc is called the spreading factor or processing gain and determines to a certain extent the upper limit of the total number of users supported simultaneously by a base station.

Each user in a CDMA system uses a different code to modulate their signal. Choosing the codes used to modulate the signal is very important in the performance of CDMA systems. The best performance will occur when there is good separation between the signal of a desired user and the signals of other users. The separation of the signals is made by correlating the received signal with the locally generated code of the desired user. If the signal matches the desired user's code then the correlation function will be high and the system can extract that signal. If the desired user's code has nothing in common with the signal the correlation should be as close to zero as possible (thus eliminating the signal); this is referred to as cross correlation. If the code is correlated with the signal at any time offset other than zero, the correlation should be as close to zero as possible. This is referred to as auto-correlation and is used to reject multi-path interference. In general, CDMA belongs to two basic categori