CHAPTER 1

COMPANY PROFILE

1

Introduction of Industry

The ITI Ltd Mankapur was established in the year 1982. The construction work started on 31st

May 1983 and by April 1985 the production had also started. The first complete Exchange was

provided to INDIA by ITI Mankapur Unit and hence Mankapur was given the unique

distinction of “Digital City of India” at that time. The land area covered by ITI Ltd is 352 acres.

The factory area is 77,500 sq meters while the air conditioned space within the factory is 44,300

sq meters. The township under ITI Mankapur consists of 3,000 residences, three intermediate

schools, two clubs, and one recreation center (auditorium) post office, banks, shopping complex,

pollution free area and swimming pool.

Main divisions of ITI Limited, Mankapur

1. Component Division - Where different circuit components are manufactured or stored if

purchased from other sources.

2. Circuit Division - It is the division where circuits are developed on the base material. It

consists of Printed Circuit Board Plant and Hybrid Circuit Section.

3. SEA (Switching Exchange Assembly) Division - It is the division where different circuit

components are assembled on the PCB.

4. New Products Division - It is the division where new products are manufactured, mainly

the Surface Mount Technology.

5. Central Services Division - It is the division which provides A.C facilities, water

supplies, electricity supplies etc used in the factories.

Products of ITI Ltd, MANKAPUR

E10B Exchanges

CSN-MM Exchanges

CSN-MM Exchanges

C-DOT Exchanges

B.T.S

GSM

2

Products and Specification of ITI Ltd:

E10B Exchanges - It is the Electronic Digital (10 digit) basic exchange which works at a

temperature of 18-22 degree Celsius.

CSN-MM Exchanges - It is numeric satellite control media exchange along which works

at a temperature of 18-22 degree Celsius.

CSN-MM Exchanges - IT is a multimedia exchange to meet the demand of Internet and

ISDN facilities.

C-DOT Exchanges - Control department of TELEMATICS Exchange was designed by

Mr. Shyam Petroda of Gujrat (The scientific advisory in the ministry of Mrs. Indira

Gandhi) to suit the Indian climatic condition. The exchange works satisfactorily up to 35

degree Celsius.

B.T.S - Base Transceiver Station is manufactured in ITI Ltd MANKAPUR.

G.S.M - It stands for Global System for Mobile Communication.

The above products are telecom products. Besides these, ITI also produces non-telecom products

like NCM (Note Counting Machine), Fire Alarm etc.

Project Title and Objective

Mission

The mission of industry is to be the leader of the domestic market and be an important

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

solution to the customers.

The other is to build core competences to enter in new business areas.

HRD (Human Resource Development)

The human resource and development center is headed by Mr. S.S.Bisht (Manager HRED)

Different types of training programs are provided by it

Summer training

3

Winter training

Parts of HRD

H.R.D. Office

Library

Computer lab

Programming Room

Auditorium

Objectives of H.R.D

The HRD has following objectives

Create business and strategic thinking.

Build managerial and technical competencies.

Promote a culture of achievement and excellence.

Improve quality of work life in organization.

Encourage empowerment of team and individual.

Improve organizational learning.

Optimize resource utilization and create atmosphere of cost consciousness.

Create financial edge to finance in purchase of the customers

4

CHAPTER 2

INFORMATION SYSTEM

5

ERP (Enterprise Resources Planning)

E.R.P system are software package soothing several module such as human resource, finance and

production, marketing, advertising etc, providing cross organization integration of data through

embedded business process. 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. E.R.P could gain very much attention in a

very short span of time and 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 businessman manage important part of this business.

Evolution of E.R.P

1950s – Inventory Control Module (ICM)

1960s –Material Requirement Planning (MRP1)

1970 –Material Requirement Planning (MRP2)

1990 – Enterprise Resource Planning (ERP)

1994 – Supply Chain Management (SCM)

Later – Customers Relation Management (CRM)

E-Commerce

E-Governance

Business to Business

Business to Customer

6

Industrial 5Ms

M1-Material

M2-Man

M3-Machine

M4-Money

M5-Marketing

How 5Ms are covered in ERP

ICM-Only inventory inside the factory were controlled.

MRP1-Inventory in store, WIP, Finished goods inventory to be received from supplier against

P.O i.e. M1 (Total Material)

MRP2-All manufacturing resource of industries i.e. M1, M2, M3 (Material, Man and Machine)

were controlled.

ERP-M4 and M5 (Money and Marketing) was not covered up to MRP2 was covered here.

ERPs and Some Facts

After studying the business process of 500 fortune companies’ software for standard

process is made to plan all the resources of enterprise known as ERP.

ERP-It is companywide computer software system used to manage and co-ordinate all the

resources information and function of a business shared single or distributed data.

An ERP system has service oriented architecture with modular hardware and software

units “services” that communicate on a local area network. The modular design allows a

business to add or configure models while preserving data integrity in one shared data

base that may be centralized or distributed.

ERP is supposed to be the biggest and costliest software in single package.

EAS-Enterprise application suite is a name for formally developed system which include

all segments of business as ordinary internet browser as a thin client.

7

ERP and Some Fact Modules

Some examples of module in ERP which formally would have been standalone application

Supply chain management

Warehouse management

Customer relationship management

Sales order management

Product lifecycle management

Online sales

Financials

Human resources

Decision support system

To be considered ERP system software must provide the function of at least two systems. For

example a software package that provides both payroll and counting function technically be

considered ERP software.

ERP and Some Facts – Manufacturing

Manufacturing modules cover all the resources involving production of all the products by

company which includes

Engineering

Bills of material

Scheduling

Capacity

Workflow management

Quality control

Cost manufacturing

Manufacturing process

Manufacturing project

Manufacturing flow

8

ERP and Some Facts-SCM

SCM stands for supply chain management and it includes

Order to cash

Inventory

Order entry

Purchasing

Product configuration

Supply chain planning

Supplier scheduling

Inspection of goods

Claim processing

Common calculation

purchase order

tender sales invoice

Ssssssssssssss quotation product

material sales order

purchase invoice payment

Finance

General ledger

Cash management

Accounts payable

Accounts receivable

Fixed asset

Project Management

9

SUPPLIER FACTORY CUSTOMER

Costing

Billing

Time & expense

Performance units

Activity management

Human Resources

Human resources

Payroll

Training

Time & expense

Roistering

Customer Relationship Management

Sales and marketing

Commission

Services

Customer contact and call center support

ERP are incorrectly called back office system indicating that customer and the general public is

not directly involved. This is contrasted with the front office system like CRM system that deal

directly with customer or e-business system such as e-governance or e-telecom and e-finance.

Supplier Resource Management System

To implement ERP system, companies often seek the help of ERP vendor or of third party

consulting three areas of professional services: consulting, customization, and support. Client

companies may also employ independent program management, business analysis, and change

management UAT (user acceptance testing) specialist to insure their business.

ERP is the future core for all industry related software are concerned.

10

CRM, B2B, SCM are the peripheral of ERP.

B2B, B2C

11

CRM

SCMERP

CHAPTER 3

OVERVIEW OF GSM

12

Introduction

GSM stands for global system for mobile communication. It was first developed in EUROPE but

is now used everywhere in the world. Analog cellular system is known as 1 st generation digital

system. Digital system are 2nd generation system. The digital transmission over air interface has a

number of analog transmissions.

Some of them are

Better speech quality

Speech privacy and security

High spectral efficiency

Data services and ISDN capability

Better resistance to interface

Limitation of Fixed Line Telephone

Main limitations of fixed line telephony are

No mobility

Prone to failure

Delay in new connection

Security hazard

Very less value added services

Different Versions of GSM

GSM-900(standard): This is a standard for digital voice transmission in the 900MHZ

band. This is so called primary band two sub-bands of 25MHz.

GSM-1800: Because of growing number of subscriber a further set of frequency 75MHZ

in the 1800 band were allocated for digital mobile services in Europe. This was three

times the bandwidth allocated for GSM-900. GSM-900 component can be used in GSM-

1800. Only the mobile station and the radio base transceiver themselves need a different

specification.

13

GSM-900: It is the standard for the 1900MHZ band. The bandwidth of this is 60MHZ. It

uses the same component as GSM900 or GSM1800.

EGSM: EGSM stands for enhanced data rate for GSM evolution. It has all the provision

of above GSM services but it has additional features of increased data rate for GPRS

(general packet radio services) and many others.

Objectives of GSM

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

Services Provided by GSM

Tele-Services:- Telephony

Data services:-

Circuit switched data up to 9600bps (9.6kbps)

G3 Facsimile of third generation

SMS (short message services)

Supplementary services

Call forwarding, when subscriber unavailable

Call barring for O/G or I/C calls

Caller identification

Supplementary services:-

Call waiting

Multiparty conversation

14

Range of One Channel

In case of GSM band frequency

890 to 915MHZ - uplink frequency

935 to 960MHZ - downlink frequency

Each uplink band and downlink band is of 25MHZ duration. Now 25MHZ is divided in 125

parts.

Each part is called channel.

1 channel = 1ARFCN = 25MHZ/125 = 200KHZ

So 1channel = 200KHZ

Hence each channel became 200KHZ. Each person is allocated for 1channel. Hence in one band

of frequency 125 persons can talk at a time.

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 of fixed time period. Hence more users can use the same channel

of FDMA by time division multiplexing. This method is called TDMA.

Capacity can be extended by introducing TDMA in following way:

After FDMA each channel is of 200KHZ. Now 200KHZ 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

over to provide gap to next frame. This one channel is used as a guard to avoid overlapping

15

between frames. Hence from 125 channels including TDMA number of time slot used for traffic

=124*8=992.

Hence 992 persons can talk from one frame. In this way it increases the capacity of the traffic.

CDMA (code division multiple access)

This is used in WLL also in GSM. FDMA and TDMA both are used at a time. In this method

complete frequency band is divided in 64-code channels. Each code channel can be used by

different users. The entire users will communicate at the same time and transmit and receive

related to its code. A spread technology is used in which radio signals associated with a call is

spread across a single board frequency spectrum (1.25). The CDMA frequency access method

allows the services provider to reuse the same frequency in adjacent cells. This is because a code

is assigned to each frequency in the spectrum to decipher the signal, therefore signals in the same

frequency but with different code appear as noise to the other end.

Reuse of same frequency allows CDMA to have more capacity compared to have more capacity

compared to TDMA and FDMA. CDMA system has the ability to communicate with more than

one cell at a time during call. This is known as hand–off and provides uninterrupted call while

mobile station move between cells.

GSM Network

The meaning of various components of GSM is:

16

MS BTS BSC MSC

HLR

VLR

EIR

AuC

SMS

OMC

MS- mobile station

BSS- base station subsystem

BTS- base transmission system

HLR- home location registers

VLR- visitor location registers

BSC- base station controller

AuC- authentication centre

SMS- short message service

MSC- mobile service switching centre

EIR- equipment identity registers

GSM Element: Mobile Station

It consists of Mobile Equipment and SIM card

Mobile Equipment

Uniquely identified by IMEI (international mobile equipment identity)

SIM (subscriber identity module)

Uniquely identified by IMSI (international mobile subscriber identity)

Also contains a secret key for authentication

Can be protected against unauthorized use by a PIN (personal identity number)

Can also store SMS for later retrieval

IMSI and IMEI are independent (personal mobility)

BSS (base station subsystem)

BSS (base station subsystem)

BTS (base transceiver station)

Radio transceiver

Handles radio link protocol with the MS

17

BSC (base station controller)

Manages the radio resources for one or more BTS

Handles radio channel set-up, frequency hopping, handovers

HLR (home location register)

It 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 mobile station.

Important data fields

MSISDN (mobile subscriber ISDN number)

Present VLR

IMSI (international mobile subscriber identity)

VLR (visitor location register)

It contains selected administrative information from the HLR necessary for call control and

provision of the subscriber services, for each mobile currently located in the geographical area

controlled by VLR.

EIR (equipment identity register)

Database of all valid mobile equipment in the network (IMIE)

Three lists corresponding to the status of the equipment

White list –allowed to number

Grey list-observation

Black list-banned number

AuC (authentication centre)

It is a protected database that stores a copy of a secret key number. Number is used for

authentication and encryption.

18

GSM: Location Update

@ @

# #

# @

$

& *

*=location update message

$= subscription data return

&=Location cancellation message

@= Location update request

#=Acknowledgement of location update

Each MSC has a HLR which stores the details of the subscriber and each HLR has a VLR while

stores the changing position of mobile. If a mobile is in different MSC area then VLR of

previous MSC sends some details of the subscriber of the HLR of new MSC.

abis

19

MS BSS

NEW

MSC

NEW

VLR

PREVIOUS

VLR

PREVIOU

S MSC

HLR

BSC2

BTS2

VLR2

E1

VLR3

abis abi

VLR

GSM Network: Call Routing

Call Routing Procedure

1. Fixed subscriber initiates a call to a mobile subscriber and he dials the MSISDN.

2. Incoming call intimated to the gateway MSC.

20

MSC

MSC2222

22

MSC1

BSC1

BTS2

MSC2

BSC2

BTS2

HLR2

HLR1

HLR3

PSTN

GATEWAY

MSC

TERMINATIN

G

MSC

MSC

FS MS

HLR VLR

3. Based on the dialed digits (MSISDN), the gateway MSC recognizes that it cannot

route the call further, but must interrogate the mobile user’s home location register.

4. The HLR interrogates the VLR that is presently serving the subscriber referred to by

the MSISDN.

5. The VLR returns the routing information to the HLR. This is MSRN (mobile

subscriber routing number), defined by the E.164 numbering plan. The MSRN is not

assigned to the subscriber. It is taken from a pool.

6. The MSRN is passed on by the HLR to the gateway MSC.

7. Based on the MSRN it receives, the gateway MSC routes the call to the terminating

MSC, using standard network routing capability.

8. The terminating MSC asks the VLR for information that it will enable it to correlate

the incoming call referenced by the MSRN, with the IMSI (international mobile

subscriber identity).

9. The identity of the terminating mobile subscriber (relation between the MSRN and

IMSI) is ascertained and passed to the terminating MSC.

10. The identity of the MS being determined, a paging request is sent to the BSS.

11. The mobile station is paged.

12. The paging response is sent from the MS to the BSS

13. The paging response is sent back to the terminating MSC.

14. The call from the fixed subscriber to the mobile subscriber is through.

Other Element

BC- to collect bill data for public land mobile network (PLMN)

SC- to provide special service to mobile subscriber in the public land mobile network

Normal Burst Period

tb DATA BITS S TRNG

SEQUENCE

S Data bits tb gb

GSM Standards: Basic Unit is a Burst Period

21

Tail Bits at 2 positions, 3 bits each 06bits

Data Bits at 2 positions, 57 bits each 114bits

Stealing Bits at positions, 1 bit each 02bits

Training Sequence of 26 bits 26bits

Guard bits of 8.25 bits 8.25bits

156.25bits

Frame Structure

BPO BP1 BP2 BP3 BP4 BP5 BP6 BP7

Once TDMA frame consists of 8 burst period

One burst period = 15/26ms = 0.577ms

One frame = 8*(15/26)ms = 4.615ms

Multi Frame Structure

One Multi Frame consists of 26 frames

F0-F11, F13-F24 : TCH(Traffic Channel)

F12: SACCH (slow associated control channel)

F25: Presently Unused

TCH for uplink and downlink separated by 3TCH

Control Channel defined as 51 frame MF

Burst Types

Normal Burst- used to carry data

F Burst- used in FCCH (frequency correction channel)

22

S Burst- used in SCH (synchronization channel)

Access Burst- used in RACH (random access channel)

Dummy Burst- used when mobile is in active state

GSM 900/GSM 1800

GSM-900 GSM-1800

Uplink band 890-915MHZ 1710-1785MHZ

Downlink band 935-960MHZ 1805-1880MHZ

Channel spacing 200KHZ 200KHZ

Total channel 124 374

Duplex spacing 45MHZ 95MHZ

Time slot 8 8

Radio Link Aspects

ITU Allocation for GSM900

Band 890-960MHZ for uplink (MS to BSS)

Band 935-960MHZ for downlink (BSS to MS)

To maximize the capacity utilization

Access technique is FDMA/TDMA/FDD

25MHZ bandwidth is divided into

124 carrier (ARFCN)

Spaced 200KHZ apart

TDMA superposed on the carrier frequencies

Each base station assigned multiple frequencies

23

Frequency Hopping

Objective

Multi-path fading is dependent on carrier frequency. Changing the carrier frequency

slowly helps alleviate the problem.

Co-channel interference is in effect randomized

Realization

The ARFCN for the channels is changed in each successive frame, based on hopping

sequence. The hopping sequence changes for each TDMA frame.

Discontinuous Transmission

Average person speaks for 40% of the time.

Transmitter turned off during silence period

Benefit: minimized co-channel interference

Added benefit conserves power

VAD (voice activity detection)

Voice misinterpreted as noise, clipping occurs.

Noise misinterpreted as voice, efficiency decreases.

Comfort noise creation at the receiver during off period.

Discontinuous Reception

Paging channel is used for alerting mobiles.

Paging channel is structured into sub-channels.

MS to listen only to its own sub-channel

For power conservation at the MS

24

Voice Processing

@

@

@=speech

GSM Radio Link Characteristics

GSM-900 and GSM-1800 radio link

Access methods TDMA

Modulation methods GMSK

RF channel spacing 200KHZ

Voice circuits per carrier 8

Gross bit rate 271kbits/s

Spectral efficiency 1.35 bits/HZ

Speech coder rate 13kbps (full rate)

Error protected coded speech 22.8kbps

Overhead 11.1kbps

25

SPEECH

CODING

CHANNEL

CODING

TNTER

LEAVING

CIPHERING MODULATI-

ON

SPEECH

DECODING

CHANNEL

DECODING

DEINTER

LEAVING

DECIPHERIN-

G

DE

MODULATI-

ON

26

CHAPTER 4

ELECTRONIC ASSEMBLY

Electronic Assembly on PCB

1. Mixed technology (combination of both SMT and THT)

2. THT (through hole technology)

27

3. SMT (surface mount technology)

THT assembly was replaced by SMT as component of THT assembly had lead which is

hazardous for health. So SMT technology was introduced in which component were lead free.

SMT Technology

All the cards used in mobile product that is BTS rack are prepared here through SMT

technology.

Assembly Procedure of Different Cards

1. Input Loader – The multilayered PCB is loaded on input loader in stacks and then it is

verified there if it is the same PCB whose program has been loaded.

2. Soldering Machine – In this machine there is a screen similar to that of PCB inserted has

same circuitry made on it. The solder paste is squeezed over it once in forward direction

and then it return back removing the extra paste.

3. Manual checking of card is done here through magnifying glass if solder paste is placed

properly or not.

4. XP142E (chip shooter) – This machine has been manufactured by JAPANESE company

called FUZI. It is used for placing finer components on the board. When the first card

enters into it then it is verified at each point. It verifies the board from the reference point

on the PCB board which is called FUDICIAL. The X and Y dimension of PCB board are

compared from that point. After the verification of 1st card at each and every point on the

board, component placement is done. There are two cameras inside the machine. The

camera scans the location of the point where component is to be placed and place it on

the right position through nozzle. Nozzle create vacuum and sucks the component of

same type from the component tape and place it on the exact location as the programming

is done. Speed of nozzle is very high.

5. XP242E (fine pitch placer) – Large component are placed through it. Its nozzle can pick

single component at a time. Its speed is 6500comp/sec.

6. Manual verification of component placed is done through magnifying glass to check

whether the components are properly placed or splited.

28

7. Heating – After this, it goes to oven to properly paste the component on the solder. It is

heated in four zones.

Preheating zone (heated slowly 45 c to 110 c)⁰ ⁰

Soak zone

Reflow zone

Cooling zone

The heating process takes 6 minutes. The oven used is air force conviction oven.

Second Insertion

In second insertion, connectors are inserted on the PCB board as these can melt down in oven

during heating process, so it is inserted in the second insertion.

1. Insertion – The second insertion is done on MIPFE (manual insertion press feet machine).

In this machine different shapes of nozzle for different types of connectors are inserted

manually in the machine. Then support is provided to avoid breaking of the PCB. Even

the support is different for different types of connectors.

2. Soldering – Soldering of these components are done manually. Solder paste contain

62%Sn, 36%Pb and 2%Ag. It is stored at -5 c to 5 c. Once it is taken out then after 24hrs⁰ ⁰

it cannot be used again.

29

CHAPTER 5

BTS (BASE TRANRSCEIVER STATION)

Introduction

BTS is the main part of the mobile communication. It consists of family of cards. Whole system

of BTS consists of

1. FAN unit (it have 9 fans)

30

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 types

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. TREPA card (transceiver equipment power amplifier)

4. TREPS card (transceiver equipment power supply)

5. RT card (transceiver)

6. ANC card (antenna network chamber)

TREPA, TREPS and TEPA are types of RT cards. One BTS sector name: alpha, beta, gamma

sectors. One sector can contain one ANC card and maximum four RT cards. In one BTS 12 RT

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

then to BSC.

BTS Racks

TOP FAN

CONNECTION AREA

T T T T

31

R

X

R

X

R

X

R

X

FAN STAGE

AIR INLET

A

N

C

A

N

C

DUMMY PANEL

T

R

X

T

R

X

T

R

X

T

R

X

FAN STAGE

AIR INLET

S

U

M

A

A

N

C

DUMMY PANEL

T

R

X

T

R

X

T

R

X

T

R

X

FAN STAGE

AIR INLET

STAND

XIBM – External Alarm Input Multistandard

MSCA – Multi Standard Connection Area

One TRE = 1TEPA + 1TREDA + 1TREA

32

Racks Assembly

As shown in above 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 and other for

ANC. The last shelf has also four parts for RT. Upon every RT one fan unit is available for

cooling. It consist of a MSD unit for maintenance.

SUMA Cards (brain of the BTS)

Functions

1. Timing and clock generation

2. Management of internal digital interface

3. Operation and maintenance function

4. Remote inventory

5. Digital transmission

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

ANC Function

This card is not manufactured here

1. Setting the LNA game for the assigned TREA receiver

2. LNA alarm supervision

3. Measuring of 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

Transceiver (TRX) Level

33

The transceiver (TRX) level coves GSM850, GSM900, GSM1800 and GSM1900 functionalities

including full rate, half rate, enhanced full rate, antenna diversity, radio frequency hopping and

different ciphering algorithms.

For each band these functions are integrated into one single module. Inside each TRX module a

RF loop is implemented. The TRX module also handles the RSL (radio signaling link) protocol.

Base Station Control Function (BCF) Level

Function

1. Generating the clock for all other BTS modules

2. Ensuring central BTS operation and maintenance application

3. Handling of a A-bis transmission links

4. Controlling the battery

5. Setting the optimum voltage and current for battery charging

6. Controlling the AC/DC function

Twin Wide Band Combiner Module

The twin wide band combiner stage (Any) combines up to four transmitters into two outputs and

distributes the two received signal up to four receivers. The module includes twice the same

structure.

Each structure containing

One wide band combiner concentrating two transmitter output into one

Two splitter each one distributing the received signal to two separate output s providing

diversity and non-diversity paths

Any is only necessary for sectors with five or more TRXs

Antenna Coupling Level

The antenna coupling level is the stage between the antennas and the TRX level; it handles the

combining function as well as the interface with the antenna. A single module called antenna

34

network combiner performs these functions for up to 4TRXs. For configuration of higher

capacity, a combiner stage can be added. Thanks to the ANc flexibility and the modular building,

the antenna coupling level can be adapted.

35

CHAPTER 6

PREPARATION OF PCB

Base material

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

dimension of which PCB are generally made of:

240*400sqmm

280*400sqmm

36

300*400sqmm

300*500sqmm

300*600sqmm

The raw material used for manufacturing of the PCB is “Copper Clad Epoxy Laminate”.

The dimensions are

920*1220sqmm

1220*1220sqmm

Their thickness generally comes in the multiple of 0.8mm. Copper Clad of thickness 17.5 or 35.0

or70 microns is laminated on the both sides of glass epoxy.

Cutting

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

Baking

After cutting the base material to required size, in order to make the surface coating of Cu even

to remove the volatile impurities, vapors and moistures and moreover make the sheet plane, the

raw sheet of glass epoxy with Cu clad laminate is baked in oven at 3 different temperatures

depending upon the thickness of raw material. The process requirement time and temperature are

given below

Curing of PCB base material at 140 c for 12hrs⁰

Straightening of wrapped material at 140 c for 12hrs ⁰

Drilling

After backing the next step is drilling. The stacks of 3 raw material sheets are made along with

entry sheet and back up sheet. The stack is centered and pinned here. The lot of three stacks is

thus held together by pinning.

37

Debarring

After drilling holes, burns left over the sheet and on the edges are removed by debarring.

Debarring removes unwanted material and makes hole perfect. Also the board surface gets

smoothened.

Electroless Plating

It is purely a channel process which is done to make the epoxy area between the two Cu clad

plates conducting. A 2micron Cu layer is formed over the holes as a result of electro less plating.

In this process the surface of Cu also gets evened. As no electrode is used for plating, so it is

called as “electro less plating”.

Pumicing

Gem stones are crushed to powered form which is dissolved in a container and sprayed over Cu

sheet to make it little rough for better lamination and 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 on to a roller and after the blank board is

inserted from below, the film gets laminated on to the blank Cu sheet.

Exposure

The sheet prepared so far is now placed under the circuit layer (diazo, photo tool) and microwave

rays pass becomes hard and the rest remains soft.

Development

In this process the unexposed sensitive photo resist is removed and 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. The inspection is carried out under 10X magnifying

glass.

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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. On open tracks, Cu plating of about 25micron is done.

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. It is done using ammoniac 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 and

ink is poured from top and with the help top of leveler, it is leveled properly. Then it is cured at a

temperature of 80 c for 30 minutes to make ink adhere properly to the board. After curing, a⁰

photo tool is placed over the sheet and UV rays are passed through it. The points where holes are

to be formed remains soft as light cannot pass through it. After exposure, passing through

Na2CO3 solution due to which we get an impression of holes on the board. Then again it is

baked at temperature 120 for 4hrs.⁰

HAL (hot air leveling)

The board or the sheet till now produced consists of complete ink and 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.

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Screen Masking/Printing

A polyster cloth of size 100*100sqmm is used. The ink is coated on this screen to be called as

skin mesh. The screen printing is done by special type of chemical fersol-29. The screen

developing and 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 and only desired circuit is left behind.

Testing

This is done to detect any anomaly. Error detected is shown by printer and 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 is done for very sophisticated result.

Quality Control

In the end inspection of the PCB is done. Plate is visually inspected to meet the desired

specification.

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CHAPTER 6

SIX SIGMA

Introduction

Six Sigma is a business management strategy originally developed by Motorola. As of 2009, it

enjoys widespread application in many sectors of industry, although its application is not without

controversy.

Six Sigma seeks to improve the quality of process outputs by identifying and removing the

causes of defects (errors) and variability in manufacturing and business processes. It uses a set of

quality management methods, including statistical methods, and creates a special infrastructure

of people within the organization ("Black Belts”, “Green Belts", etc.) who are experts in these

methods.[2] Each Six Sigma project carried out within an organization follows a defined sequence

of steps and has quantified financial targets (cost reduction or profit increase).

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Methods

Six Sigma projects follow two project methodologies inspired by Deming's Plan-Do-Check-Act

Cycle. These methodologies, comprising five phases each, bear the acronyms DMAIC and

DMADV.

DMAIC is used for projects aimed at improving an existing business process.

DMADV is used for projects aimed at creating new product or process designs.

DMAIC

The DMAIC project methodology has five phases:

Define high-level project goals and the current process.

Measure key aspects of the current process and collect relevant data.

Analyze the data to verify cause-and-effect relationships. Determine what the

relationships are, and attempt to ensure that all factors have been considered.

Improve or optimize the process based upon data analysis using techniques like Design of

experiments.

Control to ensure that any deviations from target are corrected before they result in

defects. Set up pilot runs to establish process capability, move on to production, set up

control mechanisms and continuously monitor the process.

DMADV

The DMADV project methodology, also known as DFSS ("Design For Six Sigma"), features

five phases:

Define design goals that are consistent with customer demands and the enterprise

strategy.

Measure and identify CTQs (characteristics that are Critical To Quality), product

capabilities, production process capability, and risks.

Analyze to develop and design alternatives, create a high-level design and evaluate

design capability to select the best design.

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Design details, optimize the design, and plan for design verification. This phase may

require simulations.

Verify the design, set up pilot runs, implement the production process and hand it over to

the process owners.

n the closest to the work.

Origin and meaning of the term "six sigma processes"

Graph of the normal distribution, which underlies the statistical assumptions of the Six Sigma

model. The Greek letter σ (sigma) marks the distance on the horizontal axis between the mean,

µ, and the curve's inflection point. The greater this distance, the greater is the spread of values

encountered. For the curve shown above, µ = 0 and σ = 1. The upper and lower specification

limits (USL, LSL) are at a distance of 6σ from the mean. Due to the properties of the normal

distribution, values lying that far away from the mean are extremely unlikely. Even if the mean

were to move right or left by 1.5σ at some point in the future (1.5 sigma shift), there is still a

good safety cushion. This is why Six Sigma aims to have processes where the mean is at least 6σ

away from the nearest specification limit.

The term "six sigma process" comes from the notion that if one has six standard deviations

between the process mean and the nearest specification limit, as shown in the graph, practically

no items will fail to meet specifications. This is based on the calculation method employed in

process capability studies.

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Capability studies measure the number of standard deviations between the process mean and the

nearest specification limit in sigma units. As process standard deviation goes up, or the mean of

the process moves away from the center of the tolerance, fewer standard deviations will fit

between the mean and the nearest specification limit, decreasing the sigma number and

increasing the likelihood of items outside specification.

Sigma levels

The table below gives long-term DPMO values corresponding to various short-term sigma levels.

Note that these figures assume that the process mean will shift by 1.5 sigma towards the side

with the critical specification limit. In other words, they assume that after the initial study

determining the short-term sigma level, the long-term Cpk value will turn out to be 0.5 less than

the short-term Cpk value. So, for example, the DPMO figure given for 1 sigma assumes that the

long-term process mean will be 0.5 sigma beyond the specification limit (Cpk = –0.17), rather

than 1 sigma within it, as it was in the short-term study (Cpk = 0.33). Note that the defect

percentages only indicate defects exceeding the specification limit that the process mean is

nearest to. Defects beyond the far specification limit are not included in the percentages.

Sigma level DPMO Percent defective Percentage yield Short-term Cpk Long-term Cpk

1 691,462 69% 31% 0.33 –0.17

2 308,538 31% 69% 0.67 0.17

3 66,807 6.7% 93.3% 1.00 0.5

4 6,210 0.62% 99.38% 1.33 0.83

5 233 0.023% 99.977% 1.67 1.17

6 3.4 0.00034% 99.99966% 2.00 1.5

7 0.019 0.0000019% 99.9999981% 2.33 1.83

Reception

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Six Sigma has made a large impact on industry and is widely employed as a business strategy for

achieving and sustaining operational and service excellence. However, various criticisms of Six

Sigma have arisen.

Lack of originality

Noted quality expert Joseph M. Juran has described Six Sigma as "a basic version of quality

improvement", stating that "[t]here is nothing new there. It includes what we used to call

facilitators. They've adopted more flamboyant terms, like belts with different colors. I think that

concept has merit to set apart, to create specialists who can be very helpful. Again, that's not a

new idea. The American Society for Quality long ago established certificates, such as for

reliability engineers.

Role of consultants

The use of "Black Belts" as itinerant change agents has (controversially) fostered a cottage

industry of training and certification. Critics argue there is overselling of Six Sigma by too great

a number of consulting firms, many of which claim expertise in Six Sigma when they only have

a rudimentary understanding of the tools and techniques involved.

Some commentators view the expansion of the various "Belts" to include "Green Belts," "Master

Black Belts" and "Gold Belts" as a parallel to the various "belt factories" that exist in martial arts

Potential negative effects

A Fortune article stated that "of 58 large companies that have announced Six Sigma programs,

91 percent have trailed the S&P 500 since". The statement is attributed to "an analysis by Charles

Holland of consulting firm Qualpro (which espouses a competing quality-improvement

process)." The gist of the article is that Six Sigma is effective at what it is intended to do, but that

it is "narrowly designed to fix an existing process" and does not help in "coming up with new

products or disruptive technologies." Many of these claims have been argued as being in error or

ill-informed.

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A Business Week article says that James McNerney's introduction of Six Sigma at 3M may have

had the effect of stifling creativity. It cites two Wharton School professors who say that Six

Sigma leads to incremental innovation at the expense of blue-sky work. This phenomenon is

further explored in the book, Going Lean, which provides data to show that Ford's "6 Sigma"

program did little to change its fortunes.

Based on arbitrary standards

While 3.4 defects per million opportunities might work well for certain products/processes, it

might not operate optimally or cost-effectively for others. A pacemaker process might need

higher standards, for example, whereas a direct mail advertising campaign might need lower

ones. The basis and justification for choosing 6 (as opposed to 5 or 7, for example) as the number

of standard deviations is not clearly explained. In addition, the Six Sigma model assumes that the

process data always conform to the normal distribution. The calculation of defect rates for

situations where the normal distribution model does not apply is not properly addressed in the

current Six Sigma literature.

.

CHATER 7

SUGGESTIONS AND FUTURE TRENDS

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Suggestions

The first complete exchange was provided to INDIA by ITI LTD, Mankapur Unit and hence

Mankapur was given the distinction of “Digital City of India” following are the few suggestion

regarding the development and production.

Research and Development Unit of the ITI LTD, Mankapur should be provided with

more financial support so that they can develop new technologies.

ITI should train more number of employees with the new technologies and should send

more number of employees to France in “ALCATEL” which has collaboration with ITI.

Machines which are not in use should be replaced by new ones.

ITI should call ‘Motivating Gurus’ to its organization to motivate employees to give their

fullest.

ITI should employ new engineers which has the passion for passion for work.

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Conclusions

We are living in an information age which is related as “A Magical technology which combines

the skillful hands with the reasoning minds”. Because of its very high positive impacts on

employments, wages, labor, skill, productivity and research, IT is treated as a strategic industry.

Information is the basic source in today`s society.

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. IT based process enhanced countries access to global

knowledge, market and capital.

Thus “Tools for RF Planning and Design for GSM” is software which performs all the above

mentioned activities in a training scenario in an effective manner. It fulfills all the needs

perceived by the user.

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Bibliography

Company Manual

Wireless Communication And Networks, by William Stallings

Websites:

www.google.com

www.wikipedia.com

www.whatis.com

www.yahooanswers.com

www.ebooks.com

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