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 of B.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 Kumar B.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.
EA (switching exchange assembly) Divisions: - Where different circuit
3.
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 (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
Mobile Network
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, mobilestation & 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
[email protected] 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 BTS2. AC power supply BTSAccording 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
company’s business.
into
every aspect of
a
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 assessmentprinciples 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)
G at e
G at e
DEFINE- Formally define the process improvement goals that are consistent with customer demands and enterprise strategy. G at e
G at e G at e
MEASURE-To define baseline measurements on current process for future comparison, map and measure process in question and collect required process data. 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.
GAT E
GAT E
GAT design, and plan for design DESIGNDevelop detail designs, optimize GAT E
E
verification. This phase may require simulations. GAT E
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 1.0 2.0 3.0 4.0 5.0 6
YIELD 690000 308537 66800 6210 233 3.4
30.90% 69.2% 93.31% 99.38% 99.977% 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.
COMPETITOR S SUPPLIER S
ENTERPRIS E FUNCTIONAL AREAS
CUSTOMER S
Evolution of ERP •
1950s – Inventory control module.
•
1960s – material requirement planning (MRP1)
•
1970s - manufacturing resource planning (MRP2)
•
1990s - enterprise resource planning (ERP)
•
1994-
•
Later - customer relation management (CRM)
Supply chain management
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.
SUPPLIER S
MANUFACTU RER
AVAILABLE ERP IN THE WORLD •
BAAN.
•
J. D. Edward.
•
SAP.
•
Ramco.
•
QaD.
•
Oracle.
•
People soft.
•
BOI.
CUSTOMER
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 • Very strong for discrete manufacturing industries. • Long relationship with CMC for hardware maintenance. •
License fee is comparatively cheap.
SAP • 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 SCREE N PRINTIN G
FINAL TEST
ENCAPSULA TION
FIRING
LASER TRIMMIN G
ASSEM BLY
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 5500C 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:
15
16
17
14 18
1 13
12
1
10
11
3
8 9
7
2
6
1
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
4
5
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
2) Punching
2) Coil &
Assembly Transformer 3) CNC
3) MDF
4) Metal part
4) Relay
Assembly 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
14
15
1
13
2 3
2
4 11
5
9 17 19
18
8
6
12
1
20 17
10
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)
1
1. GATES
2
16
KEYS:
7
16
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: 1H 440
2H 250
3H 270
4H 280
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. 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,
components)
value
and
marking
of
the
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.