Training Report on

Title, Title, Title,

In

Name of Company/Organization

Submitted for partial fulfillment of award of BACHELOR OF TECHNOLOGY

degree

in Electronics & Communication Engg.

By

STUDENT

(Name/Roll No.)

DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGG.

MORADABAD INSTITUTE OF TECHNOLOGY

Ram Ganga Vihar, Phase –II, Moradabad-244001 (U.P)

Session: 2009-10 GONDA-271308 AAIDU-ALLAHABAD

CERTIFICATE

This is to certify that Mr. AMIT KUMAR , VSTR No.26, student ofB.Tech. Electronics and Communication Engineering from Allahabad Agricultural Institute-Deemed University, Allahabad has successfully completed his summer training at ITI Ltd. Mankapur, Gonda from 15-05-09 to 14-06-09.

It is further certified that during the summer training period the candidate attended the factory and office regularly and punctually.

S.S.BISHT

MANAGER (HRED) ITI Ltd. Mankapur, Gonda

ACKNOWLEDGEMENTS

This project is the outcome of the efforts of several people, apart from the team members, and it is important that their help be acknowledgement here.

First of all I want to present my sincere gratitude and deep appreciations to Mr. S.S.BISHT, MANAGER (HRED) to allow me to undertake the industrial training in ITI Ltd. Mankapur, one of the leading public sector amongst the Electronics industries in India.

Without motivation, a person is literally unable to make his best effort. I am highly grateful to him for his guidance as he played an important role in preparing me for industrial culture and making me aware of actual scenario and work culture in organization.

I would like to devote my special thanks to Mr. KULDEEP SHARMA for teaching GSM in a very easy and interesting manner.

I would like to thanks Mr.B.K.VERMA, (AO-HR-ED) and rest all faculty member of HRED centre ITI Ltd. Mankapur and all the employee of ITI Ltd. Mankapur, who devoted their valuable time to render me information about the complexities of industries and technical know-how.

The factory has a beautiful and well organized work environment which made a great pleasure and an easy task to learn and understand the principles and theories.

Amit KumarB.Tech E.C.E(IIIrd year)AAI-DU, Allahabad

PREFACE

In-Plant training has been misinterpreted by most of us as a platform for project performation. Industrial training, in a true sense, has been included in the curriculum to make the students well versed with the technical procedure of various industries and the basic criteria for management of resources in a company or industry. The educational institutions sole aim by industrial training is to improve the technical know-how and to have a hand on experience to make them realistic in thinking to understanding the procedure for manufacturing keeping in mind the minute detail which will benefit the customer. Like no learning is proper without implementation, similarly the terms and procedures we learn are of no use until and unless we bring them in practical applications. To summaries, industrial training teaches us industrial ethics, advance technical know-how and helps us to get acquainted with industrial working style. The document summaries the current state of I.T.I. Ltd. Mankapur in year 2008. The document provides information about raw material, working procedure and final products of different divisions. Overall it provides a common wide understanding of all divisions.

CHAPTER 1

ITI LIMITED

1.1. INTRODUCTION:-

I.T.I. Ltd. was the first public sector undertaking of the free INDIA. It was

established in year 1948. The first manufacturing unit was established at the Bangalore

complex in Karnataka under the name of Indian Telephone Industry Limited (I.T.I.). As time

progressed the full name of I.T.I. become a misnomer as the industry began to manufacture

several other electronic hardware than those required in the field of telephony. Now this

public sector enterprise is only known as I.T.I. Ltd.

1.2The Units of I.T.I. Ltd. Are:-

●Bangalore:- The major products are “ESSCON PROJECT” for Defence purpose, MSC

Products, CDMA (Handsets).

●Palghat:- Scratching cards, GSM, MSE.

●Naini (U.P.):- Latest Transmission equipments (ADSL).

●Raibareily (U.P.):- B.T.S. and Power plant.

●Mankapur (U.P.):- GSM, BTS, C-Dot and Landline communication.

●Srinagar (Jammu & Kashmir):- Presently shut down.

1.3.ABOUT MANKAPUR UNIT

The I.T.I. Ltd. Mankapur was established in the year 1982.The construction work

started on 31 May 1983 and by April 1985.the production has also started. The first complete

electronic exchange was provided to INDIA by I.T.I. Mankapur Unit and hence Mankapur

was given the unique distinction of “Digital City of INDIA” at that time. The land area

covered by I.T.I. Ltd. is 352 acres. The factory covered area is 77,500 sq.meters, while the

air- conditioned space within the factory is 44,300 sq.metres. The township under I.T.I.

Mankapur consist of 3,000 residences, three Intermediate schools, two clubs, and one

recreation centre(auditorium), post-office, banks, shopping complex, pollution free areas and

a swimming pool.

1.4.Main divisions at I.T.I. Ltd. Mankapur:-

1. Component divisions: - Where different circuit components are manufactured or

stored if purchased from other sources.

2. Circuit Divisions: - Where circuits are developed on the base material. It consists

of Printed Circuit Board Plant & Hybrid Circuits section.

3. EA (switching exchange assembly) Divisions: - Where different circuit

components are assembled on the P.C.B.

4. New Products Divisions: - Where new products are manufactured, mainly

uses the surface mounting technology.

5. Central Services Divisions: - Which provides AC facilities, water supplies,

electricity supplies etc. used in factory.

1.5. PRODUCTS OF I.T.I. LTD.:-

● E10B Exchanges: - Electronic Digital (10-digit) basic exchange which work at a

temperature of 18-22 degree Celsius.

● CSN-MA Exchange: - Numeric Satellite control media analog exchange which work

at a temperature of 18-22 degree Celsius.

● CSN-MM Exchange: - Multimedia exchange to meet the demand of Internet and

ISDN facilities

● C-DOT Exchange: - Control department of Telematics exchange was designed by Mr.

Shyam Petroda of Gujarat (The scientific advisor in the ministry of Mrs. Indira Gandhi) to

suit the Indian climatic conditions. The exchange works satisfactorily up to 35 degree

Celsius.

● B.T.S.:- Base transceivers station, is manufactured in I.T.I. Ltd. Mankapur.

● G.S.M.:- Global System for Mobile communication.

Other product

The above products are telecom products. Besides these I.T.I. also produces non telecom

products like NCM (note counting machine), FNDM (Fake Note Detection Machine),

Fire-alarms, Inverters etc.

1.6..MISSION:-

● The mission of the Industry is to be the leader in the domestic market and be an important

player in the global market for voice data and Image communication by providing total

solutions to customers.

● To build core competencies to enter in new business areas.

1.7.H.R.D.(Human Resources & Development)

The Human Resource & Development Centre is headed by Mr. S.S.Bisht (Manager

HRED). H.R.D. stands for Human Resources & Development centre. H.R.D. has major task

to control the manpower. Different type of training programs are also provided by the

H.R.D. as like:-

1. Summer Training.

2. Winter Training.

1.7.1. Parts of H.R.D.:-

1. H.R.D. Office.

2. Library.

3. Computer Lab.

4. Programme Rooms.

5. Auditorium.

1.7.2. Objectives of H.R.D.:-

The H.R.D. has following objectives:-

● To facilitate realization of lean and effective organization.

● Create businesses and strategic thinking.

● Build managerial and technical competencies.

● Promote a culture of achievement and excellence.

● Improve quality of work life in organizations.

● Encourage empowerment of team and individuals.

● Improve organizational learning.

● Optimize resources utilization and create atmosphere of cost consciousness.

● Create financial edge to finance in purchase of the customers.

Chapter 2

ELECTRONIC SWITCHING

2.1. WHAT IS A TELEPHONE SWITCH?

Basically it is a device or a system that connects one telephone line to another so that 2 or

more people can have a conversation over their respective telephones or so that your

computer’s modem can connect to a remote modem such as a remote modem owned by an

ISP (internet service provider ) which in turn connects you to the internet.

2.2. THE INVENTION OF AUTOMATIC SWITCHING

Almon B. Strowger was an undertaker in Kansas city, USA, the story goes that there was a

competing undertaker locally whose wife was an operator at the local telephone exchange.

Whenever a caller asked to be put through to Strowger, calls were deliberately put through to

his competitor. This obviously frustrated Strowger greatly & he set about devicing a system

for doing away with the human part of the equation!

Strowger developed a system of automatic switching using an electromechanical switch

based around electromagnets & pawls. With the help of his nephew (W.S. Strowger) he

produced a working model in 1888.in this selector, a moving wiper (with contacts on the end)

moved up to & around a bank of many other contacts, making connection with any one of

them.

2.3. CROSS BAR SWITCH

A crossbar switch is one of the principle architechtureused to construct switchesof

many types.crossbarswitches are some times referred to as “crosspointswitches”. The other

principleswitch architectures are that of memoryswitches or crossover switch(banyan switch).

A CB exchange was divided into an originating side and a terminating side when a user

picked up their handset, the resulting line loop operating the users’ line relay caused the

exchange to connect the users’ telephone to an originating sender, which return the user a dial

tone.the sender then recorded the dialled digits and passed them to the originating marker,

which selected an outgoing trunk & operated the various crossbar switches stages to connect

the calling user to it .

2.4. E 10 B

The E 10 B sys has been developed in terms of an integrated tele.netwk ,rather than in

terms of individual tele exchnges. It is French techno. which is not manufactured now in ITI ,

Mankapur.

It shapes 2 fundamental principles with the original Planton Exchnge:

Ude of digital PCM techniques.

Separation of the sw.ng exchng function (at exchng level )from the management

functions(at netwk levels).

2.4.1.Scope – This engineering instruction deals with the additional facilities incorporated in R.23

version of OCB 283 exchnges.2.4.2.General –

The following evolutions & changes introduced in R.23 version of OCB 283 sys: Hardware changes

Analogue subscriber facilities

ISDN supplementary services

Operation& maintainance

New parameters

New call handling architecture

V5.2 interface

Extended translation resources

Intelligent netwk

Other implementation

Chapter 3

3.1. C - DOT

SEA (switching exchng assembly)division of ITI Mankapur produces exchng for fixed

line .C-DOT is one such exchng .its technology is Indian .

CDOT DSS MAX IS A UNIVERSAL DIGITAL SW .this can be confifured for diff

appl. As local transit or integrated local & transist sw .

High traffic / load handling capacity upto 8 LACKS BHCAwith termination capacity

of 40,000 lines . as local exchng or 15000 trunks as Trunk Automatic Exchhg.

3.2 Flexible architecture

It is possible to upgrade a working CDOT SBM or MBM exchng to provide ISDN

service by adding min additional hardware while retaining the existing hardware .

It supports ISDN subscribers thru remote sw unit(RSU). The processor architecture is

characterised by distributed control & message based comm. In order to achieve a

loosely coupled for flexible system architecture.

Software is written in HLL-“C.”

3.3. Basic building modules of C-DOT DSS MAX

Base module(BM)

Central module(CM)

Administrative module(AM)

i/o Module (IOM)

3.3.1. Base Module

It interfaces the external world to the sw thru subscri.lines like analoge & digital trunks,

CCM(coin collect metering ) & PBX lines. Each BM can interface upto 2024 terminations. It

carries out majority of call processing functions along with maintenance& operation funct

with the help of IOM.

In Single Base Module(SBM) exchng configuration , the BM acts as independent sw sys &

provide connections to 1500 lines &128 trunks .

In such configuration ,BM directly interfaces with IOM for bulk data storage,operations &

maintenance functions .

Clock& synchro is provided is provided by the source within BM .

3.3.2. Central module

Consists of message sw space to provide inter module comm.& performvoicev & data

switching btw BMs. It also provides clock & synchro on a centralized basis.

3.3.3. Administrative module

Performs system level resource allocation & processing function on a centralized

basis. It performs all the memory & time intensive call processing support functions & also

administration & maintainance functions. It communicates with the BM via the CM. It

supports the IOM for providing man machine interface. It also supports the Alarm Display

Panel (ADP) for the audio visual indication of faults in the system.

3.3.4. Input / Output module

It is a powerful duplex computer systemthat interfaces various secondary storagedevices like

disk drives, cartridge, tape drive & floppy drive.it supports printers & upto 8 serial ports for

video display units, which are used for man machine communication interface.All the bulk

data processing & storage is done in this module.

3.5. Remote Switch Unit (RSU)

RSU is an integral part of DSS architecture.

In order to realise a RSU ,the normal BM can be modified for remating with the host

exchng via 2Mbps digital links .

No. Of 2 Mbps links btw main exchng & RSU is primerly determined by the traffic .

A max 16 PCMs can be provided btw RSU & main exchng . analoge & digital trunk

interfaces are also implemented in RSU to support direct parenting of small exchng

from RSU itself instead of parenting it to the main exchng .

As far as call processing is concerned ,RSU is an autonomous exchng capable of

local call completion .in the event of failure of PCM links RSU goes to standalone

mode of operation .in case ,it is not possible to process a call request due to

unavailability of links to the host ,the subscriber is connected to appro.tone or

announcement.

3.6. Common Channel Signalling # 7 (CCS#7)

It is implemented in CDOT DSS to provide value added services in netwk

eg.intelligent netwk services,ISDN services .ISDN serv.are the most widely used carriors to

transport the bulk volume of data . with the increasing use of internet access , the use of

ISDN interface is likely to go up as it has to provide reliable access to the user @

64/128kbps.It integrates computer on telephone on single access.

3.7. Redundancy

To meet the stringent availability CDOT DSS employs “hot standby techniques” for

all processor complxes so that event of the failure of any one security block not more than 8

subscrib . will be effected .

Hardware crosslink btw have been planned in such a way that even failure 2

dissimilar processors donot effect the sys performance . In the event of failure of 1

unit ,other units will share its load preventing the disruption of services.

3.8. C –DOT Card Assembly

The basic work of this shop is to design & assemble various sorts of cadrs which are used

for connection & control of subscriber lines & inserted in the rack of C – DOT telephone

exchange in their respective places.In C – DOT exchange ,mainly 3 kinds of cards are used :

CLR (Control Line Rack) Cards group

CNR (Connection Network Rack) Cards group

SPL (Special Line Cards) Cards group

Chapter 4

G.S.M OVERVIEW 4.1. INTRODUCTION:-

G.S.M was though first developed in Europe but is now

used everywhere in the worldG.S.M. is the short form for Global Services for Mobile

communication. Analog cellular system is known as 1st generation digital system. Digital

system are second generation system. The digital transmission over air interface has a number

of advantages over analog transmission. In G.S.M. System, TDMA in a combination with

FDMA is used. The usage of each radio channel is portioned into multiple (8) time slots and

each user is assigned a specific frequency\time slot combination.

4.2. Some Version of G.S.M:-

1. G.S.M.-900(STANDARD)

2. G.S.M.-1800

3. G.S.M.-1900

Figure1.1. frequency limitation in GSM 900/1800

4.3. Limitation Of Fixed Line Telephone:-

Main limitations of fixed telephone system are:-

1. No mobility.

2. Delay in new connection.

3. Security Hazard.

4. Prone to failure.

5. Very less value added services.

To overcome these difficulties world wide communication organization has establish

committee to study about wireless telephony. Those groups of members were named as

CEPT (Conference of European Post &

4.4. EVOLUTION OF G.S.M. STANDARDS:-

●1980’s:-

During this period, Advance Mobile phone services (AMPS) was there in America.

●EARLY 1980’s:-

European nations were developing cellular solutions but no common standard was

available.

●1982:-

CEPT (Conference of European Posts and Telegraph) formed a study group called the

Group for Special Mobile (G.S.M.) To honor the group the technology is named as

G.S.M.

●1989:-

1. G.S.M. responsibility was transferred to ETSI (European telecom standards

institute.)

2. Global system for Mobile communication.

●1990:-

Phase-1 of G.S.M. specification was published during this period.

● MID-1991:-

* Commercial Service Started;

* G.S.M. facility was launched in four countries:-

1. France

2. Italy

3. U.K.

4. Germany

● 2009:-

Commercial Services available in maximum all countries.

4.5. OBJECTIVES OF G.S.M.

● Good speech quality.

● Low terminal and service cost.

● Support for international roaming.

● Ability to support handheld terminals.

● Support for range of new services and facilities.

● Spectral Efficiency.

● ISDN compatibility.

4.6. SERVICES PROVIDED BY G.S.M:-

● Tele-Service: - Telephony.

● Data Service: -

-Circuit Switched Data up to 9600 bps (9.6kbps).

- G3 Facsimile-Of third generation.

- S.M.S.

● Supplementary Services:-

- Call forwarding, when subscriber is unavailable.

- Call barring for outgoing or incoming calls.

- Call identification.

- Call waiting.

- Multiparty Conversion.

4.7. RANGE OF ONE CHANNEL:-

Let’s take the case of G.S.M. Band frequency.

890 to 915 MHZ - Uplink Frequency

935 to 960 MHZ - Downlink Frequency

Each Uplink band & Download band is of 25 MHZ duration. Now 25 MHZ is divided

in 125 Parts. Each part is called Channels.

1 Channel=1 ARFCN=25 MHZ 125=200KHZ

So, 1Channel=200 KHZ.

Hence each channel becomes 200 KHZ .Each person is allocated for 1 Channel.

Hence in one band of frequency 125 Persons can talk at a time.

4.8. TDMA (Time Division Multiple Access):-

After FDMA it was later found that division of frequency itself was not sufficient to

meet the capacity of requirement. So frequency channels are again divided into time domain

called time slots.This means that multiple users will use the same channel frequency but not

at the same instance.Each user will be given a time slot of fixed time period. Hence more

users can use the same channel of FDMA by time division multiplexing. This method of

increasing the capacity is called Time Division Multiple Access (TDMA).

4.8.1. How & how much Capacity Can Be Extended By Introducing

TDMA:-

After FDMA each channel is of 200 KHZ. Now 200 KHZ is again divided into same

slots. 125 Channels=125*8=1000 time slots. But out of 125,124 channels are used for speech

transmission. One channel in each frame is left for providing gap to next frame. This one

channel is used as a guard to avoid overlapping between two frames. Hence from 125

channels including TDMA no. of time slots used for traffic=124*8=992 .Hence 992 persons

can talk from one frame. In this way it increases the capacity of traffic.

4.9. CDMA (Code Division Multiple Access)

This is used in WLL where as in G.S.M. FDMA and TDMA both are used at a time. In this

method complete frequency band is divided in 64 codes-channels. Each code channel can be

used by different users. The entire user will communicate at the same time and transmit &

receive related to its code.

A spread spectrum technology is used in which the radio signals associated with a call is

spread across a single board frequency spectrum(1.25 MHZ).

Figure 4.1 FDMA/TDMA

Chapter 5

INTRODUCTION TO CELLULAR COMMUNICATION:-

In a wireless communication to access the subscriber two R.F. channels are needed per

active cell. But in a city if there is large no. of subscriber it needs large no. of channels to

accommodate them. But there is limitation of availability of spectrum. To overcome this

limitation total area of city will be divided into zones, called CELLS. Each CELL has base

station Transceivers (BTS).

The location of site will be on following factor:-

1. Coverage of prime locations.

2. Cost factor.

3. Availability of power, security and open space.

4. Nearby installation of other B.T.S.

5. Terrain condition.

Figure 5.1. Cellular telephony

5.1. CELL STRUCTURE:-

Each cell is hexagonal in shape. Each cell may be of different shape and size. In highly

dense area, the size of cell will be small and in lesser dense area cell size will be larger. Size

of cell on highways and on main roads, cell size is optimized to cover larger length along the

road. This can be made possible by using highly directive antenna.

Figure 5.2. Frequency reuse cellular telephony

Chapter 6

G.S.M.NETWORK ELEMENTS:-

Figure 6.1. G.S.M. Network

The meanings of various components of G.S.M. as used in public land Mobile Network

(PLMN) are:-

MS - Mobile Station

BSS - Base Station Subsystem

NSS - Network Station Subsystem

B.T.S. - Base Transceivers Station

B.S.C. - Base Station Controller

B.C. - Billing Centre

M.S.C.-Mobile Switching Centre

H.L.R. - Home Location Register

V.L.R. - Visiting Location Register

A.U.C. - Authentication Centre

EIR- Equipment Identity Register

OMC- Operation and Maintenance Centre

SMSC- Short Message Service Centre

VMSC- Voice Mail Services Centre

STF- Speech Transcoder Frame

6.1. MOBILE STATION

The Mobile Station(MS) represent the terminal equipment as use by subscriber supported by

G.S.M. wireless system .It consists of two parts:-

● SIM (Subscriber Identity Module)

● Mobile Equipment.

It do following operation;-

● Radio Transmission Termination.

● Radio Channel Management

● Speech Encoding / Decoding.

● Radio Link Error Protection.

● Flow Control of Data.

● Mobility Management and Rate adaptation Of User Data to Radio link.

● Performance Measurement of Radio Link

6.2. BSS:-

The B.T.S., BCF and STF together from the BSS via Air link connection is mode between the

BSS & the mobile station.

6.3. B.T.S.:-

The BTS by means of an antenna receives the signals as sent by the Mobile station. Several

types of an antenna configuration are there depending on need. In the BTS an MRIF (Mini

Rack Interface) is present. The MRIF then passes on the signal to the BCF through Abis

link .In an Abis link speech and signal travel at a rate of 16Kbps.

● BTS has a set of transceivers to communicate with mobile in its area.

● One BTS cover one or more than one Cell.

● Capacity of Cell depends upon the no. of transceivers in a cell.

● BTS is connected to BSC through Abis link of 2Mbps.

● BTS transmits and receives voice at 13Kbps on Um i.e. Air interface.

● BTS commands Mobile set to set Transmission Power, Timing advance and

Handover.

6.4. BCF:-

The BCF takes part in signaling part of data. It has two types of services COWS & CEWS are

meant for common channel signaling to other parts like STF etc. CEWS do signaling related

to the BCF. The signals coming at 16Kbps where speech is not touched in the BCF.

6.5. STF:-

The BCF is then connected to the STF by an M link. In this, signal travel at a rate of

64Kbps. This receives speech at 16Kbps & signals at 64 Kbps. It takes care of the speech

part. It contains certain STU cards which connected to the MSC by A link.

6.6. MSC:-

MSC means Mobile Switching Centre. It provides switching of Cell like PSTN exchange and

is the heart of GSM network. Switching means connecting, maintaining & release of mobile

to mobile, mobile to PSTN &PSTN to mobile Cells. It has data base of all subscribers and

stored in HLR, VLR etc.Database includes identity of subscriber MSC is weighted by no. of

subscribers. For example, MSC of 1 lakh subscriber means that MSC can provide connection

to 1 lakh and beyond which it need another MSC. The MSC perform the switching function

for all mobile station located in its geography area covered by its BSS.

6.6.1. Function of MSC

● Call handling that copy with mobile nature of subscriber.

● Management of required logical radio link channel during calls.

● Management of MSC-BSS signaling protocol.

● Handling location Register, ensures inter working between mobile, mobile-

station & VLR.

● Control of inter BSS and inter MSC handovers.

● Standard functions of local exchanges.

● Exchange of signaling information with other systems.

● Acts as gateway to interrogate HLR.

6.7. AUC:-

● Contain subscriber authentication data called subscriber keys.

● Generates security related parameter needed to authorize services.

● Generates unique data pattern called chipper key to encrypt user data and

speech.

6.8. HLR:-

● MSC store all the data base of subscriber in HLR.

● MSC communicates with HLR to get database of subscriber on call.

● Contains administrative information of each subscriber registered in the

corresponding GSM network.

● Location of the mobile is typically in the form of the signaling address of the

VLR associated with the MS.

● Important data fields are:-

* MSISDN

* Present VLR

* IMSI (International Mobile Subscriber Identity)

6.9.VLR:-

Contains temporary database of subscriber. Temporary database means mobile status

(like ON/OFF), Location of mobile, that is in which cell is the mobile so that incoming call

can be directed to that cell. Again in Roaming case i.e. if any subscriber is coming from

some other MSC area, then it is known to as visitor for that MSC. When that visitor

subscriber switches on its mobile then first make request for call, then MSC confirms to HLR

& HLR confirms it from original HLR and stores the database to visitor VLR.

6.10. EIR:-

It is accessed during the equipment validation procedure when a mobile station access. It

contains identity of mobile station equipment called IMEI.

The three lists corresponding to the status of the equipment are:-

● White list (valid)

● Grey list (suspected)

● Black list (banned)

6.11. OTHER ELEMENTS:-

● BC:. - To collect billing data for Public land Mobile Network (PLMN).

● SC: - To provide special service to mobile subscriber in the Public Land

Mobile Network (PLMN)

Figure 6.2. GSM location updation

Figure 6.3. GSM network call routing

Chapter 7

Burst

Figure 7.1. Normal burst period structure

Figure 7.2. frame structure

BURST TYPES:-

● Normal Burst - Carry Data

● F Burst -Used in FCCH (Frequency Correction Channel)

● S Burst - Used in SCH (Synchronization Channel)

● Access Burst - Used in RACH (Random Access Channel)

● Dummy Burst-

Figure 7.3. burst types

Chapter 8

Logical channel

Figuer8.1. logical channel types

8.1. TRAFFIC CHANNEL:-

● TCH / F-Traffic Channel Full Rate. -@13 Kbps

● TCH / H-Traffic Channel Half Rate.-@6.5 Kbps

● EFR-Enhanced Full Rate.-@13 Kbps.

8.2. BROADCAST CHANNEL DOWNLINK:-

● BCCH-(Broadcast Control Channel.) -Broadcasting Network /cell

specific information.

● FCCH-(Frequency Correction Control Channel)

● SCH -(Synchronization Channel.)-Synchronization of mobiles

(TDMA, FN & BSIC).

● CBCH (Cell Broadcast Control Channel.)

8.3. COMMON CONTROL CHANNEL:-

● DOWNLINK –

PCH

* Paging Channel.

* For Alerting Channel.

AGCH

*Access Grant Channel.

* For Granting Access to Mobile.

● UPLINK

RACH

* Random Access Channel.

* Mobiles seeking attention of the BTS.

8.4.DEDICATED CONTROL CHANNEL:

Slow

SACCH

* Slow Associated Control Channel (Duplex).

* Transmission of Signaling Data(Radio link supervision,

Measurement, Transmit Power Control, Timing

Advance).

● Fast

SDCCH

* Stand Alone Dedicated Control Channel (Duplex).

* Signaling Channel used for service request.

FACCH

* Fast Associated Control Channel.

* Stealing Flag & Preparation.

* Used during cell setup, Handover.

8.5. RADIO LINK ASPECTS:-

● ITU Allocation for GSM 900

-Band 890-915 MHZ for Uplink (MS to BSS).

-Band 935-960 MHZ for Downlink (BSS to MS).

● To maximize the capacity utilization.

-Access technique is FDMA /TDMA/FDD.

● 25MHZ bandwidth is divided into:-

-124 Carriers (ARFCN).

-Spaced 200 KHZ apart.

* TDMA superimposed on carrier frequency.

* Each Base Station is assigned multiple frequencies.

8.6. FREQUENCY HOPPING:-

8.6.1.OBJECTIVE: - Multiple-Path fading is dependent on carrier

frequency. Changing the carrier frequency slowly helps alleviate the

problem.Co-Channel interference is in effect randomized.

8.6.2 REALIZATION: - The ARFCN for the channel is change in each

successive frame, based on HOPPING Sequence. The HOPPING Sequence

changes for each TDMA Frame.

Figure8.2. frequency hopping

Chapter 9

BTS (Base Transceiver Station)

BTS is the main part of the mobile communication.bts consists of mainly three cards.

Whole system of BTS consists:

1. Fan unit (It have 9 fans)

2. Racks

3. FACB (Fan control Board)

BTS can be classified as:

According to power supply

1. DC power supply BTS-

2. AC power supply BTS-

According to sites it is of two type

1. INDOOR BTS

2. OUTDOOR BTS

BTS consists of mainly these cards

1.SUMA CARD(Station unit module advance)

2.TEPA card(Transmitter Equipment Power amplifier)

3.TERPA CARD(Transceiver Equipment Power Amplifier )

4.TREPS(Transceiver Equipment Power supply )\

5.RT CARD(Transceivers)

6.ANC CARD(Antenna Network Chamber)

TREPA, TREPS & TEPA are the types of RT card .one bts three

sectors named: ALFA, BETA GAMA sectors. One sector

can contain one ANC card and maximum four RT cards. In one BTS 12RTcards are

connected. RT cards are connected to the ANC cards and ANC connected to BSC and then

MSC

BTS RACKS

RACKS ASSEMBLY-As shown in figure a rack has six shelves. In first shelf

there are parts (XIBM, MSCA, POWER SUPPLY (-48V)).Second shelf can be

divided into four parts (4RT)

And third is of two parts for ANC, again four parts for RT and then again two

parts one for SUMA & other for ANC. The last shelf also has four parts for RT.

Upon every RT one fan unit is available for cooling. It also consists of a MSD

unit for maintenance.

SUMA CARDS (BRAIN OF THE BTS)

FUNCTIONS

1. Digital transmission

2. Timing and clock generation

3. Management of internal digital interface

4. Operation and maintenance function

5. Remote inventory

6. Control DC-DC converter & check in of battery

ANC Function- (This Card is not Manufactured Here): The ANCON is

responsible for maintaining the operation of the ANC,

Its principles are:-

1. Setting the LNA Game for the assigned for TREA receiver

2. LNA Alarm Supervision

3. Measuring Alarm VSWR

4. Selection of Antenna Sector

5. Reporting VSWR Alarm

6. RF cabling status Detection

7. Remote Power ON/OFF via the BCB Interface

8. Status Display via front panel LED’S

9. RI via the BCB Interface

Quality of Alcatel BTS

- Very high radio performances, in particular

* Reception sensitivity, -111 dBm,

* Improved Output Power, (Standard 45 W),

- Radio (synthesizer) Frequency Hopping,

- Antenna Diversity (as standards option),

- Minimum Service Interruption

- Very High BTS availability

Due to Module Reliability

Due to System Architecture,

- Optimized software release migration. (Simultaneously stores two

software-versions).

Flexibility of Alcatel BTS

- Wide possibilities of extensions and sectorization, within the same

cabinet, e.g., the MBO2 cabinet can accommodate up to six sectors with a

twelve-TRX total capacity,

- Outdoor BTS modularity provides flexibility for other equipments

(Transmission Equipment, Batteries, Microwave, DDF etc.),

- System Architecture and Cabinet for GSM 850, GSM 900, GSM 1800

and GSM 1900 remains the same,

- High modularity,

- Reduced set of modules and a common interface

Future Proof BTS.

- GPRS Ready

- EDGE Ready by “add TRE” operation

- UMTS Ready: the MBI5 and MBO2 outdoor cabinet allow mixed

configurations GSM + UMTS.

Transceiver (TRX) level

The transceiver (TRX) level covers GSM 850, GSM 900, GSM 1800 and GSM

1900 functionalities, including full rate, half rate, enhanced full rate, antenna

diversity, radio frequency hopping (synthesized hopping) and different

ciphering algorithms. For each band, these functions are integrated into one

single module. Inside each TRX module, an RF loop is implemented. The loop

test is performed after downloading the frequencies to the BTS as a supplement

to the autotest. The TRX module also handles the Radio Signaling Link (RSL)

protocol.

Base station Control Function (BCF) level

This level is ensured by the Station Unit Module (SUM), which is the central

unit of the BTS. There is only one such module per BTS, whatever the number

of sectors and TRXs is; this common control function of the SUM is also called

Station Unit Sharing. The main base station control functions performed are as

follows:

- Generating the clocks for all other BTS modules; the clocks can be

either synchronized to an external clock reference - e.g. A-bis link, GPS

or another BTS - or generated in a pure free-run mode by an internal

frequency generator.

- Ensuring central BTS Operation & Maintenance (O&M) application,

- Handling the A-bis transmission links (up to two A-bis interfaces),

- Handling Operation and Maintenance Link (OML) and Qmux

(transmission equipment supervision) protocols,

- Controlling the AC/DC function when integrated inside theBTS

(Outdoor or Indoor AC configurations),

- Controlling the battery (capacity, voltage, temperature),

- Setting the optimal voltage and current for battery charging

Antenna Coupling Level

The antenna coupling level is the stage between the antennas and the TRX

level; it handles the combining functions as well as the interface with the

antennas. A single module called Antenna Network Combiner (ANc) performs

these functions for up to 4 TRXs. For configurations of higher capacity, a

Combiner stage can be added. Thanks to the ANc flexibility and this modular

building, the antenna coupling level can be adapted to a wide range of

requirements (reduction of attenuation losses, minimization of the number of

antennas…).

 The general functions performed at this level are:

- Duplexing transmit and receive paths onto common antennas;

- Feeding the received signals from the antenna to the receiver front end, where

the signals are amplified and distributed to the different receivers (Low Noise

Amplifier (LNA) and power splitter functions);

- Providing filtering for the transmit and the receive paths;

- Combining, if necessary, output signals of different transmitters and

connecting them to the antenna(s);

- Supervising antennas VSWR (Voltage Standing Wave Ratio).

The Antenna Network Combiner (ANc) module

The Antenna Network combiner module (ANc) connects up to four transmit

signals to two antennas, and distributes the received signals from each antenna

to up to four receivers (for the normal and the diversity reception). This module

includes twice the same structure, each structure containing:

 - One duplexer allowing a single antenna to be used for the transmission and

reception of both downlink and uplink channels- hence minimizing the number

of antenna

- A frequency selective VSWR meter to monitor antenna feeder and antenna

- One LNA amplifying the receive RF signal, and giving good VSWR values,

noise compression and good reliability

- Two splitter levels distributing the received signal to two or four separate

outputs so that each output receive the signal from its dedicated antenna and

from the second one (diversity)

- One Wide Band Combiner (WBC), concentrating two transmitter outputs into

one, only for configurations with more than two TRX.

 Each sector is equipped with at least one such stage, which features very high

sensitivity reception, low attenuation, and minimum inter-modulation products.

The ANc can be manually configured (on site) in two modes depending on the

number of TRX in the sector:

- The No-combining mode for configuration up to 2 TRX, for which the Wide

Band Combiner is not needed therefore bypassed.

 - The Combining mode for configuration from 3 up to 4 TRX, for which the

Wide Band combiner is not bypassed.

ISO

ISO (International Organization for Standardization) is the world's largest

developer and publisher of International Standards.

ISO is a network of the national standards institutes of 157 countries, one

member per country, with a Central Secretariat in Geneva, Switzerland, that

coordinates the system.

ISO STRUCTURE

What “International Standardization” means?

When the large majority of products or services in a particular business or

industry sector conform to international standards, a state of industry-wide

standardization can be said to exist. This is achieved through consensus

agreement between national delegations representing all the economic

stakeholders concerned –suppliers, users, government regulators and other

interest groups, such as consumers. They agree on specifications and criteria to

be applied consistently in the classification of materials, in the manufactures

and supply of products, in testing and analysis, in terminology and in the

provision of services. In this way International standards provide a reference

framework, or a common technological language, between suppliers and

their customers-which facilitates trade and the transfer of technology.

Standards help to:

Adopt best practices, Discipline

Systematic approach to work

Reduces cost of rework and improves productivity

Improves Employee involvement, Morale and work culture

International recognition for quality and export worthiness benefits of

software certification benefits to your software application.

Establishes a level of quality for your software product.

Instills credibility in your company and software product.

Provides a third party, unbiased evaluation of your product

New and repeat business

Added exposure. Customers will be able to find your product from our

site .Benefits to your customers.

Confidence that your software is reliable, secure and safe

Confidence that your software will not install viruses or anti spyware.

Confidence that you will stand behind your product

Confidence that your company is credible

ISO’s 9000

ISO 9000 is a family of standards for quality management systems.

ISO 9000 is maintained by ISO, the International Organization for

Standardization and is administered by accreditation and certification bodies.

Some of the requirements in ISO 9001 (which is one of the standards in the ISO

9000 family) include

-A set of procedures that cover all key processes in the business

monitoring processes to ensure they are effective;

- Keeping adequate records;

-Checking output for defects, with appropriate and corrective action where

necessary;

- Regularly reviewing individual processes and the quality system itself for

effectiveness; and

-Facilitating continual improvement

Overview of standards and certification

Why standards & certification

Academic degrees are recognized because they come from a recognized

institution that is usually accredited .They attest that the individual holding a

diploma has knowledge of the subject matter. They don’t necessarily speak to

competency of third party assessment.

Certificates- certificates are the smallest building block. A certificate of

accomplishment means that one has successfully completed a specific course or

program. A certificate may be awarded based on seat time (the person sat

through so many hours of training) or assessment.

Certification-ISO does not itself certify organizations. Many countries have

formed accreditation bodies to authorize certification bodies, which audit

organizations applying for ISO 9001 compliance certification. Although

commonly referred to as ISO 9000:2000 certifications, the actual standard to

which an organization's quality management can be certified is ISO 9001:2000.

Both the accreditation bodies and the certification bodies charge fees for their

services.

The various accreditation bodies have mutual agreements with each other to

ensure that certificates issued by one of the Accredited Certification Bodies

(CB) are accepted world-wide.

An ISO certificate is not a once-and-for-all award, but must be renewed at

regular intervals recommended by the certification body, usually around three

years. In contrast to the Capability Maturity Model there are no grades of

competence within ISO 9001.

Popular organizational standards/Models/certificates for IT Industry

ISO 9000:2000

SEI CMM

SEI-CMMI

SIX SIGMA

ITIL

What is quality?

Quality is an “Ability of a set of inherent characteristics of a product, system, or

process to fulfill requirements of customers and other interested parties.”

A Quality Management System (QMS)- is a System to establish a quality

policy and quality objectives and to direct and control the organization to

achieve those objectives

What is ISO 14000?

I.S.O. 14000 provides an internationally recognized set of standards for

incorporating environmental management into every aspect of a

company’s business.

ISO 14001:1996-Environmental Management System-Specification with

guidance for use

ISO 14001-2004-Environmental Management System-Requirements with

guidance for use

ISO 14004:2004-Environmental Management System-General guidelines on

principles, system and support techniques

ISO 14015:2001-Environmental Management –Environmental assessment of

sites and organization (EASO)

ISO 14031:1999-Environmental Management –Environmental performance

evaluation-guidelines

ISO/TR 14032:1999-Environmental Management-Examples of

environmental performance evaluation (EPE)

ISO 14040:1997-Environmental Management –Life Cycle assessment-

principles and framework

ISO 14041:1998-Environmental Management - Life Cycle assessment-Goal

and scope definition and inventory analysis

ISO 14042:2000-Environmental Management- Life Cycle assessment-Life

cycle impact assessment

ISO 14043:2000-Environmental Management- Life Cycle assessment-Life

cycle interpretation

Advantages:

According to the Providence Business News , implementing ISO often gives

the following advantages:

A) Create a more efficient, effective operation

B) Increase customer satisfaction and retention

C) Reduce audits

D) Enhance marketing

E) Improve employee motivation, awareness, and morale

F) Promote international trade

G) Increases profit

I) Reduce waste and increases productivity

SIX SIGMA

The concept of SIX SIGMA was put forward by “MICKEL HARRY” who was

an engineer with Motorola in 1985. He introduced six sigma to his company

which was facing the downfall and after following six sigma principles, the

company got the regular boost in their bottom line.

According to john Maxwell,

“Leadership determines the direction of company, organization determines

the potential of company, and personnel determine the success of

company”.

IMPLANTATION METHODOLOGIES

Six Sigma has two key methodologies-

(1)DMAIC

(2)DMAD

DMAIC (Define Measure analysis Improve Control)

DEFINE- Formally define the process improvement goals that are consistent

with customer demands and enterprise strategy.

MEASURE-To define baseline measurements on current process for future

comparison, map and measure process in question and collect required

process data.

Gate

Gate

Gate

Gate

Gate

ANALYZE- To verify relationship and causality of factors. What is the

relationship? Are there other factors that have not been considered?

IMROVE- Optimize the process based upon the analysis using techniques

like design of Experiments.

CONTOL- Setup pilot runs to establish process capability, transition to

production and thereafter continuously measure the process and institute

control mechanisms to ensure that variances are corrected before they result

in defects.

DMADV (Define Measure Analysis Design Verify)

It is used to create new product designs or process designs in such a way that

it results in a more predictable, mature and defect free performance.

GATE

GATE

GATE

GATE

GATE

DESIGN- Develop detail designs, optimize design, and plan for design

verification. This phase may require simulations.

VERIFY- Design, setup pilot runs, implement production process and

handover to process owners.

FEATURES OF SIX SIGMA:

It can measure how good our product, services & processes really are.

It helps in establishing a gauge pace in race for total customer

satisfaction.

It describes quantitatively how a process is performing.

By SIX–SIGMA, a process must not produce 3.4 defects per million

opportunities.

It can measure any defect which helps in eliminating them.

It denotes statistically how a given process deviates from perfection.

It helps an organization in increased market share, customer satisfaction,

cost reduction and dramatic boost to bottom line.

SIX-SIGMA CHAIN

Six-Sigma identifies 5 key roles for its successful implementation:

1. Executive leadership: includes CEO & other key top management team

members. They are responsible for setting up a vision of SIX SIGMA

implementation. They also empower the role holders with the freedom &

resources to explore new ideas for breakthrough improvements.

2. CHAMPIONS (for process management & project championing): these

are responsible for the SIX SIGMA implementation across the

organization in an integrated manner. The executive leadership draws

them from the upper management. Champions also act as mentor to Black

Belts .This level of certification is now called “Quality Leader”.

3. MASTER BLACK BELTER (trainer, coach, quality controller to

provide facilities to improve project, statistical analysis of data):

identified by champions, act as in-house expert for the organization on

SIX SIGMA.

4. BLACK BELTER (to lead the project team fully responsible for

technicalities involved in project, general process control &

improvement): operate under Master Black Belts to apply SIX SIGMA

methodology to specific projects. They devote 100% of their time to SIX

SIGMA.

5. GREEN BELTERS (project work, general process control for particular

assigned, head of project control team): these are the employees who take

up SIX SIGMA implementation along with their other job

responsibilities.

COMPARISION OF VARIOUS VALUED SIGMAS

SIGMA PPM YIELD

1.0 690000 30.90%

2.0 308537 69.2%

3.0 66800 93.31%

4.0 6210 99.38%

5.0 233 99.977%

6 3.4 99.9997%

Below Four Sigma loss is around (10-15) % and it is useless to do a process

below Four Sigma.

COMPANIES FOLLOWING SIX SIGMA

Motorola, GE, Honeywell, Sony, Nokia, Polaroid, Capara Maruti, Tata SSL,

Whirlpool of India, Hughes, Escorts hospital, Caterpillar, Bharti telecom.

SIX SIGMA PROJECTS

1. Project should be identifiable process, input & output.

2. A good SIX SIGMA project should never have a predetermined

solution.

3. If solution/answer is already known, just go & fix it instead of adopting

SIX SIGMA processes.

4. All projects need to be approached from prospective of understanding

the variation in process input, controlling them & eliminating them.

5. For the projects that have the operators or operator training as an input,

focus should be given to reduce the operator variation, thereby making

the process more robust to different or untrained operators.

STEPS TO ATTAIN SIX-SIGMA

1. ENLIGHTMENT.

2. ACCEPTANCE.

3. TOOLS.

4. DEPLOYMENT.

5. RESULTS.

6. RENEWAL.

Initially companies took six years to implement six-sigma but now

companies can implement it within a short period of time.

 

ERP (ENTERPRISE RESOURCE PLANNING)

ERP system are software package soothing several module, such as human

resources ,sales , finance& production, marketing, advertising etc. providing

cross organization integration of data through embedded business processes.

These software packages can be customized to accommodate the specific need

of an organization.

It takes care of all activities in organization, including planning, manufacturing,

sales and marketing and many more. ERP could gain much attention in a very

short span of time &many software applications sprang up to business managers

to implement ERP. Typically, an ERP, the expansive set of activities supported

by multi module application software helps the business man manage important

part of his business.

COMPETITORS

ENTERPRISE

FUNCTIONAL AREAS

SUPPLIERS CUSTOMERS

Evolution of ERP

1950s – Inventory control module.

1960s – material requirement planning (MRP1)

1970s - manufacturing resource planning (MRP2)

1990s - enterprise resource planning (ERP)

1994- Supply chain management

Later - customer relation management (CRM)

FEATURES OF ERP

ERP performs core business behavior& increases customer services &

there by augmenting the corporate image.

ERP fills the sequence break across the organization.

ERP provide for compressive integration of system not only

transversely.

ERP is a single elucidation for better project management.

ERP not only addresses the current requirement of the company but also

provide the opportunity of persistently improving &cleansing business

processes.

ERP provides business intelligence tool like decision support system

(DSS), executive information system (EIS), reporting, data mining

&early warning system (ROBOT) for enabling people to make better

decision & accordingly improve their business processes.

SUPPLY CHAIN MANAGEMENT

SCM can be defined as the process of planning, implementing and controlling

& efficient & cost effective flow of raw materials, in process inventory,

finished good & related information from point of origin to point of

consumption for the purpose of conforming to customer requirements. The 5

basic components of SCM are as follows –

Plan

Source

Make

Deliver

Return

.

SIMPLE MODEL

The simple manufacturing enterprise buys item from external supplier&

internally produces items for direct sale & shipment to customers. The ERP sys

must handle buy & make items at a single site operations.

SUPPLIERS MANUFACTURER CUSTOMER

AVAILABLE ERP IN THE WORLD

BAAN.

J. D. Edward.

SAP.

Ramco.

QaD.

Oracle.

People soft.

BOI.

BaaN

Founded by Jan Baan in 1978 in the Netherlands.

BaaN manufacturing control sys (BMCS) was the 1st package developed

by BaaN for MRP1, CRP& MRP2.

The company BaaN has become one of the world’s biggest software

group &expects to remain on a fast track for the foreseeable future.

BaaN solutions are used to achieve streamline the planning process by

integrating diverse information, insuring smooth planning. With the help

of BaaN we get better decision support.

SAP

SAP is the world’s leading providers of collaboration e-business

solutions. SAP ranks the world ‘s 3rd independent software provider

It has been in the business of e-business for 35 years. Founded in 1972 by

5 former IBM engineers.

Through this people in business around the globe are improving

relationships with the customer& partners, streamlining operations&

achieving significant efficiencies through there supply chain.

Unique core processes like from aerospace to utilities, are supported

effectively by SAP’s 23 industries solution.

Visibility through the business processes.

Workflow management and event triggered processes.

Empowered users.

Informed management decisions.

WHY ITI HAS GONE FOR BaaN:

BaaN SAP

Very strong for discrete

manufacturing industries.

Long relationship with CMC for

hardware maintenance.

License fee is comparatively

cheap.

Very strong for process

industries &finance company.

CMC was implementation

partner of SAP.

License key is comparatively

large.

CIRCUIT DIVISION

PCB PLANT

HYBRID PLANT

PCB PLANT

BASE MATERIAL

CUTTING

DRILLING

ELECTROLESS PLATING

PUMICING

LAMINATION

EXPOSURE

DEVELOPMENT

ELECTROPLATING

STRIPPING

ETCHING

Sn - Pb STRIPPING (SOLDER STRIPPING)

PISM (PHOTO IMAGE SOLDER MASK)

HAL (HOT AIR LEVELLING)

SCREEN MASKING/PRINTING

ROUTING

TESTING

QUALITY CONTROL

Flowchart for preparation of final PCB

BASE MATERIALS:

PCB unit is meant for producing printed circuit boards of various dimensions.

The most common dimension of which PCBs are generally made of:

240×400 Sq. mm.

280×400 Sq. mm.

300×400 Sq. mm.

300×500 Sq. mm.

300×600 Sq. mm.

The raw material used for the manufacturing of the PCB is “COPPER CLAD

EPOXY LAMINATE”.

The dimensions are:

920×1220 Sq. mm.

1220×1220 Sq. mm.

Their thickness generally comes in the multiple of 0.8mm.Copper clad of the

thickness 17.5 or 35.0 or 70 microns is laminated on the both sides of the glass

epoxy.

CUTTING:

It is carried out by saw cutting machine. Cutting is done by two types of blades.

One is used for cutting copper clad glass epoxy. This blade has diamond in its

circumference shape, which serves as the cutting edge & the blade is circular in

shape. Other blade used is for the entry sheet & the back up sheet. The blade

used for this purpose is carbide blade.

BAKING:

After cutting the base material to required sizes, in order to make the surface

coating of Cu even, to remove the volatile impurities, vapours & moistures &

moreover to make the sheet plane, the raw sheet of glass epoxy with Cu clad

laminate is baked in oven at 3 different temperatures depending upon thickness

of raw material. The process requirement time and temperatures are given

below:

Type Of Process Temperature Cycle Time

Curing of PCB base material 140 12 hr

Straightening of warped material 140 12 hr

Straightening of warped circuit 140 12 hr

For the purpose of straightening of warped material load is also used along with

temperature application. The heating is done in oven named as “Kerry Oven”.

DRILLING:

After baking, the next step is drilling. The stacks of 3 raw material sheets are

made along with entry sheet & back up sheet. The stack is centered & pinned

here. The lot of three stacks is thus held together by pinning. Pinning & stacking

is done by a manual machine. The cards (raw material) from this goes to the

drilling section. In the drilling section, drilling on the boards are done in which

further SMD (Surface Mounting Device) is used for insertion of components.

There are two machines being used for drilling purpose. One machine requires

program to be located by magnetic tape on paper tape. Another drilling machine

has computer control & is called CNC. The computer is there to initialize the

process. There are various sizes of drill bits in CNC itself. The operating

temperature of machine is 200C to 250C.

DEBURRING:

After drilling holes, burrs left over the sheet & on the edges are removed by

deburring. Deburrring removes unwanted materials & makes holes perfect.

Also, the board surface gets smoothened.

ELECTROLESS PLATING:

It is purely a chemical process which is done to make the epoxy area between

the two Cu clad plates conducting. A 2 micron Cu layer is formed over the holes

as a result of electroless plating. In this process, the surface of Cu also gets

evened. This is also called alkaline plating & is done with the help of chemicals.

As no electrode is used for plating purpose, so called as “electroless plating”.

PUMICING:

Gem stones are crushed to powdered form which is dissolved in a container &

sprayed over the Cu sheet to make it little rough for better lamination & for

removing any hand marks, grease or dust which may have accumulated during

the process.

LAMINATION:

The polymer film to be laminated is first mounted onto a roller and after the

blank board is inserted from below, the film gets laminated on to the blank Cu

sheet. The polymer film used is a special kind of consisting of 3 layers. The

lowest one is called myler. One of the sheets inside has glue attached to it,

which holds the film to the Cu sheet

EXPOSURE:

The sheet prepared so far is now placed under circuit layer (Diazo; Photo Tool)

& UV rays are passed through it. The part through which the UV rays pass

becomes hard & the rest remains soft (tracks).

DEVELOPMENT:

In this process, the unexposed sensitive photo resist is removed & so we finally

get the tracks printed on the Cu sheet. In this process, the sheet is passed

through 1% Na2CO3 solution which removes the soft, unpolymerized layer.

Then inspection is carried out under 10× magnifying glass.

ELECTROPLATING:

After development, card is fed to electroplating apparatus. Sn-Pb plating is

done on the Cu plate. Here current is passed on the plate, so is called as

electroplating. The thickness of Sn-Pb to be applied is 12.5 micron. On open

tracks, Cu plating of about 25 micron is done. Current is passed through a

mixture of Sn-fluberate, Pb-fluberate & fluberic acid. DYNATRON F is the

machine used for electroplating. In PTH (Plated Through Holes) lane,

deposition of Cu is done inside the hole to establish the continuity between two

surfaces. Electroplating involves following processes:

Cleaning chemical.

Acid cleaning.

Cleaning through water.

Electro etch cleaning.

STRIPPING:

In this process, the electroplated sheet is passed through the solution of NaOH

which removes the hard layer or the polymerized layer.

ETCHING:

After stripping the polymerized layer, the Cu becomes visible. This Cu layer is

then removed by etching. Etching is done using Ammonical Cu solution.

SOLDER STRIPPING:

In this process, solder Sn-Pb layer is stripped off leaving circuit pattern that is,

Cu over epoxy layer. HNO3 is used for this purpose.

PISM (Photo Image Solder Masking):

In this process, ink is put over the developed board like dying. Board is inserted

from bottom & ink is poured from top & with the help of leveler, it is leveled

properly. Then it is cured at a temperature of 800C for 30 minutes to make ink

adhere properly to the board. After curing, a photo tool is placed over the sheet

& UV Rays are passed through it. The points where holes are to be formed

remains soft as light can’t pass through it. After exposure, passing through

Na2CO3 solution due to which we get an impression of the holes on the board.

Then, again it is baked at temperature 1200C for 4 hrs.

HAL (Hot Air Leveling):

The board or the sheet till now produced consists of complete ink & copper are

to be soldered which is done using a solder. Therefore a layer of solder is

developed over these holes by dipping the PCB in a bath of molten solder.

SRCEEN MASKING/PRINTING:

A polyester cloth of size 100×100 sq. cm is used. The ink is coated on this

screen to be called as skin mesh. Then screen printing is done by special type of

chemical fersol-29. The screen developing & cleaning is done using water,

which is made to fall on the screen to remove excess ink.

ROUTING:

Here, unwanted portion of the plate is removed & only desired circuit is left

behind.

TESTING:

This is done to detect any anomaly. Error detected is shown by printer & it can

be rectified if within limits, otherwise discarded. Visual inspection is done to

check any discrepancy crack or any connection fault. Bare board testing (BBT)

is done for very sophisticated result.

QUALITY CONTROL:

In the end, quality inspection of the PCB plate is done. Plate is visually

inspected to meet the desired specifications like conduction area must be totally

covered by solder resist, overlapping of solder resist must be admissible, solder

must pass adhesive test etc.

HYBRID PLANT

As indicated by the name, the division is responsible for development of hybrid

networks which are to be mounted on the PCB or which can be used directly.

Hybrid networks are comprised of both active & passive elements. Active

networks consist of components like transistors, diodes, capacitors. Passive

networks consist of purely resistive elements. Hybrids are based on two

technologies:

Thin film technology

Thick film technology

Here, thick film technology is being used.

The various sections of hybrid department are :

Screen printing

Firing

LASER trimming

Assembly

Encapsulation

Final testing

PROCESS OF HYBRIDIZATION

SCREEN PRINTING

FIRING

LASER TRIMMING

ASSEMBL- Y

ENCAPSULATION

FINAL TEST

SCREEN PRINTING:

In this section, 1st steel mesh is prepared by cutting plates into required sizes.

Then, they are held in clamps from all sides & appropriate tensile strength is

maintained. The frame is oriented at 450. This is done to prevent viscous paste

from flowing. The different materials used for conduction & resistors are:

A silver coloured paste of Silver Palladium for conduction.

Paste of Ruthenium Oxide for resistors.

A green coloured paste is used for protective cover.

FIRING:

Substrate after printing of every component is sent to the firing section. In this

section, the substrate is put into the firing machine where it is subjected to high

temperature, as per requirement. Conductors and resistors are subjected to a

temperature of 8500C for 90 minutes. When the protective cover is printed on

the substrate, it is sent to this section & is subjected to a temperature of 550 0C

for 45minutes.

LASER TRIMMING:

The resistive networks are always made of value lower than the required value.

This is done because the manufactured value of resistive networks can be

increased to required value by LASER trimming based on following formula:

R = S×L/A; where R = Resistance, S= Resistivity, L= Length, A= Area.

ASSEMBLY:

In this section, lead pins of conductive materials are inserted in the chip for

making contacts. The pins are soldered using a material that consists of lead, tin,

silver.

ENCAPSULATION:

The resistive network covered with Epoxy Powered network is inserted into the

bar of powder coating machine. Air is rotated for uniform cooling. The network

is sent to the masking section where various specifications like file, batch

number, rating are masked on the network.

FINAL TESTING:

The resistive network before being used is subjected to different climatic

conditions artificially created. The conditions are:

Temperature : (21±7)0C

Dust level : zero

Relative humidity : 55±5%

COMPONENT DIVISION

LAYOUT OF COMPONENT DIVISION:

14

15 16 17

18

1

1

13

9 7 6 1 5

4

2

12

1110

8 3

KEYS:

1. GATES

2. CANTEEN

3. OFFICES

4. NCM & RELAY

5. CM OFFICE(P.I.)

6. MANUFACTURING OF NCM PARTS

7. OFFICES

8. STORE

9. C & T

10.SHOE RACK

11.TOILET & WATER

12.U.P.S. SYSTEM

13.TOOL ROOM

14.PAINTING

15.PLATTING

16.WELDING

17.PUNCHING MACHINES

18.DIFFERENT TYPES OF PUNCHING MACHINES

Component division is concerned with the mechanical work being carried out in

the industry. Here many piece parts and shelves are made for exchange. The

work assign to this division is t manufacture and assemble different components

that are utilized in production of exchange.

COMPONENT DIVISION

MANUFACTURING ASSEMBLY

1) Moulding 1) Connector

Assembly

2) Punching 2) Coil &

Transformer

3) CNC 3) MDF

Assembly

4) Metal part 4) Relay

Assembly

5) NCM

Assembly of different components is done in Production Unit 1 and

manufacturing is done in Production Unit 2.

PRODUCTION UNIT 1

In this section following type of components are assembled:

Connector Assembly

Coil Winding and Transformer

MDF (Main Distributed Frame)

Relay Assembly

CONNECTOR ASSEMBLY:

Here 4 T types of connectors are manufactured handing different sizes,

dimensions, number of pins etc. Assembly of connector requires

Plastic raw material(insulator)

Metallic piece(conductive)

Plastic raw material is manufactured in moulding shop and metallic pieces are

manufactured in punching shop. Different type of tools and machine used in this

shop are:

Hand press tool

Combination separation tool

Assembly machine

Locking machine

COIL AND TRANSFORMER ASSEMBLY:

In this shop coil and different type of transformer used in exchange are

manufactured. Different types of transformer prepared here are:

Tube transformer

Pulse transformer

Power transformer

Converter transformer

Switching transformer

Various machines are used in this shop are:

Coil and winding machine

Auto shop machine

Pneumatic assembly machine

Tape ringing machine

Automatic marking machine

After assembly the transformer is subjected to testing in order to avoid any

discrepancy. The following parameters on which a transformer is tested are:

Number of turns

Resistance

Inductance

Transformer ratio

Insulation strength

Dielectric test

Thermal test

Short circuit in winding

NOTE COUNTING MACHINE (NCM):

NCM (Note Counting Machine) is used for note counting. It has many function

of note counting. It works on 230V AC supply. It works on suction bare. It has

some important parts:

SPINDLE MOTOR: Rotates spindle unit. It has speed 1450 rpm power

rating 20W and current 0.5A.

HOPPER MOTOR: Moves the hopper. It has gears. It has speed of 1450

rpm but gears convert it into 56 to 60 rpm. Its power rating is 20W and

current 0.5A.

SPINDLE ASSEMBLY: Spindle is a moving part of NCM. It has five

fingers which suck the note with the help of vacuum.

VACUUM PUMP MOTOR: It has two parts. One part sucks the air and

the other part blows the air on the spindle finger. Its speed 2850 rpm

power rating 0.25 HP and current 1.8A.

TRANSFORMER: It takes 230V AC and given 9V and 22V AC output.

DAMPER UNIT: Its main work is to move the hopper plate smoothly.

POWER SUPPLY: It takes supply from transformer 9V and 22V AC

from transformer and gives 5V and 24V DC to mother board.

MOTHER BOARD: It has some IC relays connectors LEDs. It has 5V

DC supply for display unit keyboard IC, switches, and relays. It has 24 V

supply for batch solenoid and stamp solenoid and 230V supply for

spindle hopper and vacuum pump motor.

FILTER: It has three air filter and an EMI filter paper filter (transparent)

for suction. Oil filter for diaphragm assembly.EMI filter is an electronic

device which protects from the disturbance in 230V AC supply.

DIAPHRAGM ASSEMBLY: It works on suction system. It has a

diaphragm and sensor which moves up and down. Sensor senses the

counting and displays it with the help of mother board.

PRODUCTION UNIT 2

This section includes:

Moulding

Punching

CNC

Metal part

MOULDING:

In this shop various components of plastics are manufactured that are used in

manufacturing of racks of exchanges. Component of NCM, antennal clamps and

other miscellaneous components are also made. Components used in NCM are

cam, damper cover, damper unit, gears, and several other big parts that are not

manufactured here. Other important parts are charger case and carbon rings etc.

for relay unit socket, pilling support and other insulating parts are

manufactured. For this purpose a machine called AIMM (Automatic Injection

Moulding Machine) is used. The moulding has three main parts:

Injection unit

Mould unit

Control unit

PUNCHING:

In punching shop, conductors are made. Raw materials are copper, bronze,

brass, stainless steel etc. There are several steps to manufacture a product. these

are as follows:

Planning and control department decides the total quantity of products

and fixes quality at which it should be manufactured.

After this we decide that which raw material would be used and then

choose an appropriate tool for a particular product.

Then appropriate machine is selected.

After manufacturing the product it is sent to quality control for quality

check.

Some machines used for punching:

High speed automatic punching

Sawing machine

Buffering machine

CNC (COMPUTERIZED NUMERIC CONTROL):

In this shop punching and bending of heavy components is done by CNC

punching and CNC bending machine.

1) CNC PUNCHING MACHINE : This machine equipped with 45

different types of punching tools. A program is fed to the control

panes of machine used to monitor punching machine.

FEATURES:

Capacity - 30 tones

Table travel - 1270 mm (Y-axis) on change

Carriage travel - 1830 mm(X-axis) adjusted X2

Stroke/min - 350

Maximum rate - 200

Maximum sheet size - 1270 × 3660

Relative humidity - 75%

2) CNC BENDING MACHINE : This machine is used for bending the

surfaces. It works on the principle of hieratic pressure i.e. pressure

applied by machine is due to the pressure of oil in tank. The

dimension angle of bending is feed through the control panel. This

machine can bend a no of surfaces at different angles in a single cycle

using different tool machine.

FEATURES:

Capacity - 400 tones

Table length - 4000mm

Ramp travel - 300 mm

Max sheet thickness - 10 mm

operating temperature - 00C to 350C

Relative humidity - 75%

SEA PLANT

(SWITCHING EXCHANGE ASSEMBLY)

WAY TO COMPONENT

DIVISION

KEYS:

1. GATES

2. TOILET AND WATER

3. STORE ROOM

4. COMPONENT INSERTION-I & TESTING

5. SOLDERING (CSN)

6. INSERTION - II & QC

7. TESTING (FINAL)

8. RACK ASSEMBLY

9. SYSTEM INTEGRATION TESTING

10.QC & QA

11.CANTEEN

12.CWM OF ICE (SIT)

13.CWM OF ICE (RACK)

14.CWM OF ICE (CARD)

2

14 15 13

16 1 16

4

3

2

1

5

6

7

2

12

11

17

1819

9 8

20

101

17

15.CM OFFICE

16.SHOE RACK

17.OFFICE CWM(CSN or NP) & MODEL EXCHANGE

18.NP & CSN OR TABA HALL

19.WAY TO COMPUTER DIVISION

20.BTS MANUFACTURING

In SEA plant where the entire integration takes place and final product is

assembled. This plant takes input from the PCB, hybrid, component divisions and

these inputs are processed according to need and final product is given as output.

Currently this section goes both telecom and non-telecom products are being

assembled.

TELECOM PRODUCTS:

As it has already being specified that the major telecom products of ITI

Mankapur are exchanges. These exchanges may be of E10B, CSN and C-DOT

technology. Currently C-DOT and CSN exchanges are being made and repair.

As the E10B technology is outdated only repairing of these exchanges are being

carried out according to request of Customer. The main processes of SEA plant

are as follows:

1. COMPONENT PREPERATION:

Components are cut to desired size by instruments like:

RCD CUTTER : Which is a machine for manual cutting two terminal

medium and large size components like capacitor, resistor. This machine

can cut a maximum 556 components per hour.

MK6 CUTTER : This is used for cutting small size two terminal

components. It has a C058 Cutter: It is used for cutting connectors.

Connectors are inserted and cut when pedal is pressed.

REDIAL SUPER : It is also a component cutting machine with a maximum

capacity of 3600 components per hour. It is a radial cutter.

2. PCB PREPERATION:

Preparation of PCB involves:

Marking of PCB with suitable codes

Heat sinks and connectors are connected

Masking is done on the holes, which are drilled for component to be

inserted during second insertion

Baking of PCB plates is done at temperature of 10ºC for a period of 10

3. FIRST STAGE INSERTION:

Components which need to be solved are manually inserted on the PCB

according to the desired circuit. Diagram is given by the method section. To

speed up the process, an optical film of the given circuit is used.

4. VISUAL INSPECTION:

Before soldering, the cards are manually checked for error.

5. SOLDERING:

The soldering of components of first stage is done after visual inspection. The

soldering is done with the help of WAVE SOLDERING MACHINE. This

machine has been imported from CIT Alcatel France. The parameters of the

machine are as follows:

Name of machine - Ultrapak with Wave Dynamic (machine parameter

with no-clean flux).

Flux density maintained at .810 to .815.

Conveyer speed - 9m/min; tolerance - 0.1.

First preheated temperature - 400 degree Celsius; variation - 20 degree

Celsius.

Solder bath temperature - 243 degree Celsius; variation - 05 degree

Celsius.

In this machine, the PCB with the lose component is passed through the heater

first. Then the flux is applied to the leads to be soldered. After this the PCB

passed through the solder bath & the components get soldered. This machine

uses two waves to provide reliable fixation. It has a moving wave along with a

stationary wave.

6. SECOND INSERTION:

The components which cannot withstand high temperature of the solder bar

are inserted manually in the hole of the PCB. If the cards contain some SMD

components it sends to CSN section for this purpose. The card is then tested

and sent to the store.

7. TESTING:

The cards are tested for their conductivity, continuity and other parameter.

Each tester has achieved an ideal card on its CPU. If the difference of

parameter is greater than the tolerance with respect to ideal card then card is

sent to the repair section.

8. QUALITY CHECK:

Before the cards are inserted in the racks. They are randomly checked for

their ideal performance. The pass cards are inserted in the racks and the other

are sent back.

9. RACKS ASSEMBLY:

In the racks assembly the output of components and SEA PLANT are

integrated. The racks which house the exchanges are manufactured in

component division. their connectors, MFD & other components are installed

and then they are sent to rack assembly. In rack assembly the quality checked

cards are inserted and after connection

C-DOT Exchanges are being tested in SEA PLANT.

10.QUALITY CONTROL:

In this section of SEA PLANT, manufactured cards or assembly of racks are

tested or Q.C. checked. If card performs right operation then it is OK & sent to

the quality assurance department. If card or rack is not performing right

operation then it is sent for repairing and after that, again tested.

11.QUALITY ASSURANCE:

When quality is tested then it is assured that the product has performed right

operation. For this some cards or racks are randomly picked and tested. Again

if it performs right operation then we mark Q.A. & whole lot is ready to go to

customer’s hand. If it does not perform right operation then we return the

cards or racks to Q.C.

NON-TELECOM PRODUCTS:

The Non-Telecom products of ITI Mankapur include:

1. NCM (Note Counting Machine)

2. NBM (Note Bundling Machine)

3. FNDM (Fake Note Detector Machine)

4. Inverter

5. Energy meter

6. UPS (Uninterrupted Power Supply)

NCM, NBM, FNDM are basically Banking Automation products. NCM is

being made in component division and has been discussed in detail in

component section. The remaining Non Telecom Products are being made in

SEA- Plant. Out of above mentioned products we had to study only FNDM. Its

detail is as follows.

FNDM:

As the name indicates, this machine is used for detecting whether the note is

true or fake. This machine is used to provide Banking Automation. This

machine consists of 2 tubes. One is normal DL tube & other is UV tube. On the

upper side of the metal body, the UV tube is put on the lower side the DL is

present. The working of machine is very simple. The note to be tested is placed

on the machine. First, DL tube is ON & the face which is not clearly visible

become visible after this the UV lamp is switched ON & the water marks on the

note become visible. Thus fake note can be detected if the is aware of the

correct identification marks of the note. The main disadvantage of this machine

is that it tests one note at the time. An advance of this machine is being

developed in which several bundles of the notes can be tested at the same time.

In the advance version 2 sets of UV lamps are present, one above & one below.

The bundles of notes to be tested are passed through these lamps, the fake note

can be clearly detected as its entire length shines in contrast to the true note,

shines at one point of its length.

SWITCHING EXCHANGE ASSEMBLY

SEA division of ITI, Mankapur produces exchange for fixed line. The main type

of exchange which is manufactured here is E10B and C-DOT. E10B is French

technology where as C-DOT is Indian. The use of E10B is absolute. So,

nowadays only mode of C-DOT is taken in. The assembly is done here.

C-DOT:

C-DOT DSS MAX is universal digital switch. This can be configured for

different application as local transit or integrated local and transit switch.

High traffic/load handling capacity up to 8,00,00 BHCA with termination

capacity of 4000 lines as local exchange or 15,000 trunks as trunk automatic

exchange the C-DOT DSS family is ideally placed to meet the different

requirement of any integrated digital network.

The design of C-DOT DSS MAX has envisaged a family concept. The

advantages of family concept are standardized components, commonly in

hardware documentation, training installation and field support for all

products and minimization of inventory of spaces. In fact this modular

design has been consciously achieved by employing appropriate hardware,

software equipment practices

FLEXIBLE ARCHITECTURE:

C-DOT DSS is a modular and flexible digital switching. System which provides

economical means of serving metropolitan under and rural environments. It

incorporates all important and mandatory services needed by user with option of

up gradation to add new features and services in future.

The architecture for C-DOT DSS is such that it is possible to upgrade a

working C-DOT SBM or MBM exchange to provide ISDN service by

adding a minimum additional hardware while retaining the existing

hardware.

Another factor of the architecture is its support to ISDN subscribers

through remote switching unit (RSU). The processor architecture is

characterized by distributed control and message-based communication in

order to achieve a loosely coupled network for flexible system

architecture.

Software is written in high level language ‘c’ and distributed over various

processors and is structural as hierarchy of virtual machine.

TECHNOLOGY:

The system employs a T-S-T switching configuration and is based on a 32

channel PCM structure. It uses a basic rate of 64 Kbps and 2 Mbps primary

multiplexing rate. It uses a basic rate control is distributed over the system

by using 32-bit, 16 bit, 8 bit microprocessors. All the critical central

circuitry has built-in-redundancy.

System hardware utilities advanced concepts in micro-electronics form a

compact and optimum design. Basic memory unit has been implementing as

16 MB dynamic Ram board.

Single chip digital processors are used for implementing DTMF and MF

receivers. High performances, high densities VLSI chip detect multiple

tares and simultaneously perform signal filtering or four channels. This

approach reduces costs, power dissipation and saves PCB space.

A to D carburetion is done by CODEC chips and ASICS/FPGA’s which

makes cards small & compact.

BASIC BUILDING MODULES OF C-DOT DSS MAX:

Base module(BM)

Central module(CM)

Administrative module(AM)

I/O Module (IOM)

BASE MODULE:

It interfaces the external world to the switch through subscriber lines like analog

& digital trunks, CCM (Coin Collection & Metering) & PBX lines. Each BM

can interface up to 2024 terminations. It carries out majority of call processing

functions along with maintenance & operation functions with the help of IOM.

In Single Base Module (SBM) exchange configuration, the BM acts as

independent switch system & provides connections to 1500 lines &128 trunks.

In such configuration, BM directly interfaces with IOM for bulk data storage,

operations & maintenance functions. Clock & synchronization is provided by

the source within BM.

CENTRAL MODULE:

Consists of message switch space to provide inter module communication &

performs voice & data switching between BMs. It also provides clock &

synchronization on a centralized basis.

ADMINISTRATIVE MODULE:

Performs system level resource allocation & processing function on a

centralized basis. It performs all the memory & time intensive call processing

support functions & also administration & maintenance functions. It

communicates with the BM via the CM. It supports the IOM for providing man

machine interface. It also supports the Alarm Display Panel (ADP) for the audio

visual indication of faults in the system.

INPUT / OUTPUT MODULE:

It is a powerful duplex computer system that interfaces various secondary

storage devices like disk drives, cartridge, tape drive & floppy drive. It supports

printers & up to 8 serial ports for video display units, which are used for man

machine communication interface. All the bulk data processing & storage is

done in this module.

REMOTE SWITCH UNIT (RSU):

RSU is an integral part of DSS architecture.

In order to realize a RSU, the normal BM can be modified for remoting

with the host exchange via 2Mbps digital links.

Number of 2 Mbps links between main exchange & RSU is primarily

determined by the traffic.

A maximum 16 PCMs can be provided between RSU & main exchange.

Analog & digital trunk interfaces are also implemented in RSU to

support direct parenting of small exchange from RSU itself instead of

parenting it to the main exchange.

As far as call processing is concerned, RSU is an autonomous exchange

capable of local call completion. In the event of failure of PCM links

RSU goes to standalone mode of operation. In case, it is not possible to

process a call request due to unavailability of links to the host, the

subscriber is connected to appropriate tone or announcement.

COMMON CHANNEL SIGNALLING NO.7 (CCS NO. 7):

It is implemented in CDOT DSS to provide value added services in network,

e.g. intelligent network services, ISDN services. ISDN services are the most

widely used carriers to transport the bulk volume of data. With the increasing

use of internet access, the use of ISDN interface is likely to go up as it has to

provide reliable access to the user @ 64/128 Kbps. It integrates computer on

telephone on single access.

REDUNDANCY:

To meet the stringent availability CDOT DSS employs “hot standby

techniques” for all processor complexes so that event of the failure of any one

security block not more than 8 subscribers will be affected.

Hardware crosslink btw have been planned in such a way that even failure 2

dissimilar processors do not affect the system performance. In the event of

failure of 1 unit, other units will share its load preventing the disruption of

services.

C –DOT CARD ASSEMBLY:

The basic work of this shop is to design & assemble various sorts of cards

which are used for connection & control of subscriber lines & inserted in the

rack of C-DOT telephone exchange in their respective places. In C-DOT

exchange, mainly 3 kinds of cards are used:

CLR (Control Line Rack) Cards group

CNR (Connection Network Rack) Cards group

SPL (Special Line Cards) Cards group

CSN (CENTRAL SATELLITE NUMERIC)

In the technology affect of electronics switching exchanges, CSN was leap of

C-DOT. It was the technology developed by CIT ALCATEL; France. In ITI

Mankapur, the connection work of OCB-283 is done. Control, operation and

maintenance is done at Palghat.

CSN MM (one rack) has a capacity of 2048 subscribers. The number of

different types of cards used in CSN MM is 33. The cards are made by surface

mount technology.

The PCB from PCB section is input for the manufacturing section of CSN MM

cards. The board with printed circuit is first made to apply on a solder paste on

it. This is done by the solder pasting machine. This machine has a frame exactly

same as the circuit printed on the PCB. Their centers are coincided and placed

on the machine. The material used as solder paste has following constituent - Sn

62%, Pb 36%, Ag 2%. Two cameras observe the fixation. Pneumatic air

pressure (6 bar) sucks the card and create vacuum. There is a squeeze brush

which moves back and froth for one complete cycle. If the distance of holes is

very small then it can be fixed to move for half cycle. The back and forth

motion spread the solder paste in the holes of PCB. If however one time pasting

on cards does not give fine results then before second time paste on card the

isopropyl alcohol is used to wash off.

PICK AND PLACE MACHINE:

It is a CNC machine which is microprocessor controlled. After pasting card is

sent to this machine where components are picked one at a time and placed at

the appropriate position on card automatically. The chip or IC are sent by the

help of rollers on PLC (Plastic Loaded Chip Carrier). It checks the SMD’s

before putting on any IC. It throws the faulty IC to the dustbin.

REFLOW (Thermo Tech Oven):

After placing and centering, the card is sent to oven so that components can be

tightly fixed. The thermo tech oven has six zones. First, the solder melts and

then it is cooled. In this way, the grip of solder becomes strong. The process is

called REFLOW. Then the inspection of card is done by bare eyes through

inspection machine to check whether the components are placed correctly or

not. We can also check misalignment or disconnection.

Now for bottom side assembly various machines are involved:

1) GLUING MACHINE: The glue is epoxy silicon which is applied to

the bottom part of the car. This gluing machine has two parts:

Gluing unit

Pick and place unit

GLUING UNIT: In this unit the adhesive is applied by two springs

on the bottom of the card via a nozzle. It makes adhesive dots between

slots so that components are tightly glued.

PICK AND PLACE UNIT: This picks and places the components at

appropriate place.

2) CURING: This card is then put to oven which is divided into six

zones. There are two plates at upper side and lower side and there is a

covering for these plates.

Parameters for curing:

Conveyer speed: 60 cm per minute

Temperature zone:

After this, the card goes to the manufacturing area where the component, which

can not be placed on the card, is placed manually. Then soldering is done with

the help of wave soldering machine.

WAVE SOLDERING:

After assembly manual inspection of components is done. Then after this, it is

put in the baking oven to remove moisture. After that, it comes to wave

soldering machine. This wave soldering machine is little different from the

machine used in C-DOT soldering. It has a real wave like solder flowing in it to

solder the component. After placing the cards on conveyer, at first flux is

sprayed on the card by nozzle. This smoothen the plate and device the leads of

components for soldering. Then it passes through 3 pre-heaters maintained at

gradually increasing temperature of 250 degree centigrade, 350 degree

centigrade, 400 degree centigrade. The flux is completely vaporized which is

necessary for better soldering.

Then it passes through the solder bath having two waves of solder flowing in

opposite direction. The tank of solder bath contains 400 Kg of solder. The

solder has following composition: Sn 63%, Pb 37% with melting point 170°C to

180°C.

1H 2H 3H 4H

440 250 270 280

The temperature of both is kept at 243°C so that the solder comes in molten

form. At the output, air cooling is done for a while and then the card is sent for

marking which specifies the card.

CARD TESTING IN CSN SHOP:

After marking the cards, come to the card testing section. Here the function and

manufacturing defects are traced using electronic machine.

Processes in card testing:

Input from manufacturing

MDA(Manufacturing defect analyzer)

FDA(Functional defect analyzer)

Final testing

Burn in for 48 to 72 hours

Quality control test

Sample test

Custome

QUALITY CONTROL PLANT

This shop controls and checks the quality of the products manufactured

by the plant.

Quality is fitness for use.

QC is of types:

IGI (Inwards Goods Inspection): Function of IGI to check the

supplied goods. Steps in IGI are:

To check the qualification of the supplier

Visual check(damage, value and marking of the

components)

Electrical test

It passed, given to PPC(production, planning and control)

IPQC:

In this process, quality of the finished and unfinished products is

checked by the sampling process.

The vital point is how much sample should be taken and how much

should be passed so that whole sample is considered to be passed.

For this we have sampling plan.

ITI (SEA) QC follows the standard MIL STD.105 D. This is

military standard.

Apart from sample size the other two criteria are there to pass the

sample lot:

AQL (Acceptable Quality Level): It is that quantity which

customer would always accept.

(QL: Quality level: percentage defective)

Level: Amount of inspection. This gives the sample size of

inspection.

Here, we usually do level two checkings.

There are 3 types of sampling plans :

1) Single sampling plan (used in SEA- QC)

2) Double sampling plan

3) Multiple sampling plan

WHAT IS QUALITY CONTROL?

It is that process through we measure actual quality performance,

compare it with standard & act on the difference.

INSPECTION:

It is the process by which we check the product whether it confirms or

don’t confirm the given specification.

Three main parts of QC are:

Plan : Test data

Measure : Carry out test & generate data

Control : Analyze data & generate corrective action

RELIABILITY:

It is measured in terms of quality & time.

QUALITY ASSURANCE

Quality assurance is responsible to plan, control & execute the inspection,

testing, verification & surveillance function which are required to attain &

sustain the product quality as specified. The officer of quality assurance shall be

responsible to assure that the products are accepted as per delivering plan. The

officer shall be responsible to organize intra structure mainframe & all other

inputs required for smooth operation of the department. He is authorized to

release the product to dispatch after obtaining the clearance from customer

(BHARAT SANCHAR NIGAM LTD.) quality assurance wherever applicable.

It is a department that is used for checking purpose of the final product before

the dispatch according to the customer demand.

WORKING PROCESS:

There are various working processes that are used:

1) Offering of equipment by production to purchase order

2) Visual inspection by quality assurance officer

3) Functional inspection by quality assurance

4) Offering of equipment by quality assurance to BSNL or MTNL

5) Release the inspection certificate

6) Dispatch the material to the site by sells & setting department

7) Realization of finance bill by sells department

QUALITY ASSURANCE TESTING:

The quality assurance shall carry out 100% administration check and card visual

check on sample as per sample plan level (iii) on the cards taken from two of

the racks of the lot as per sample plan level (iii).

For logic test, AQL is 0.65% and for analogic test, AQL is 1.0%.

RETESTING:

If the lot is successfully passes all the above tests then the lot is offered to DOT

(Department Of Telephone). Quality assurances along with the reports received

from SEA plant and the reports regenerated during the quality assurances

checks along with LEQ.

BSNL QUALITY ASSURANCES TESTING:

The BSNL quality assurance carries out the following checks before acceptance

& issuing clearance for dispatch.

100% administration checks of 2 racks picked up from the lot after

removing the wrapping remaining racks are checked without the scale

/wrapping.

One of the two racks is subjected to rack visual check.

Visual checks of cards are carried out as per the sample plan(III) on

samples taken from two racks with 4%AQL(acceptable quality level) for

major defects and 10% AQL for minor defects.

Cards in the lots are grouped as logic and analogic cards and samples are

taken for the functional test by cards in card test from the second rack of

the lot as per the sample plan.

30% of the rack is subjected to RI test.

MAINTENANCE/EXTENSION CARDS/SSC CARDS:

These cards are offered by SEA plant after completion of 100% administration

and visual check and 10% of cards are tested in RI test.

These cards are subjected to following checks:

1) Administration check - 100%

2) Visual check on sample basic

3) Functional test on sample basic

Sample plan level (IV):

AQL (Acceptance Quality Level) - 0.65% logic cards

AQL (Acceptance Quality Level) - 1.0% analogic cards

After successful completion of checks as above, the cards are offered to BSNL

Quality assurance department along with report and LEQ.

CONCLUSION

We are living in an information technology age which is rated as “A magical

technology which combines the skillful hands with the reasoning minds”.

Because of its very high positive impacts on employment, wages, labour skills,

productivity and research, IT is treated as a strategic industry. Information is the

basic resource in today’s society. Information technologies in modern computer

based information systems are once again being portrayed as measure force for

organizational and managerial changes. A centralized computer system would

process all the data for an organization, control all of its operation and carry out

all the tasks.

Naturally, highly automated system does not require as many people as manual

methods. Therefore, there has been significant reduction in the number of

people required for performing manual task in the organization.

Knowledge and ideas are the heart of the development process and are

increasingly over shadowing the natural resource base because knowledge

generation and information processing are at the roots of new productivity. IT

based processes enhanced countries access to global knowledge, market and

capital.

Thus, “TOOL FOR RF PLANNING AND DESIGN FOR GSM” is a

software which performs all the above mentioned activities in a training

scenario in an effective and efficient manner. It fulfils all the needs perceived by

the user.