Training Report of iti mankapur
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Transcript of Training Report of iti mankapur
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.
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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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