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MMMAAAHHHAAANNNAAAGGGAAARRR TTTEEELLLEEEPPPHHHOOONNNEEE NNNIIIGGGAAAMMM LLLtttddd...(((MMMTTTNNNLLL)))MTNL(Mahanagar Telephone Nigam Ltd.) was constituted in the year April,1986.

Previously it was a government organisation under the department of Telecommunication.

The basic of MTNL is to provide best and fault free telephone services to the subscribers so

that they are satisfied with what they get.

MTNL is fast emerging as a global giant in the telecom sector in its endeavour to provideworld class telecom services, MTNL is equipping itself with the state-of-art machines and

acquiring the latest gadgets to achieve the target of office automation.

MTNL is pioneering the introduction of information technology in the telecom-sectorthrough human resource development, capacity building, computerization of consumer services

like telephone directory, integrated computer networks, computer based scanning and signaturerecognition of subscribers, internet and customer service management etc.

The perceived threat of the Y2Kproblem was addressed effectively on a war footing. Inaddition, the Information Technology Division of MTNL is constantly keeping at bay hackers andattacks from viruses such as the recent I LOVE YOU bug.

For an organisation like MTNL, the customer support services like billing, Directory Enquiry,

IVRS, FRS, commercial etc. are very important. It plays an important role in the implementation of thesesupport services. Directory enquiry service is an essential customer care service being provided by

telecommunication service provider, It helps the customers to find out the whereabouts of their associates. Itcomes to their rescue in times of emergencies. MTNL New Delhi is regularly updating telephone directory

on CDROM. For national directory services also, MTNL was the first to integrate and start the service.

Presently directory enquiry services system is being accused by nearly 250 cities of India.

HHHIIISSSTTTOOORRRIIICCCAAALLL DDDEEEVVVEEELLLOOOPPPMMMEEENNNTTT OOOFFF DDDEEELLLHHHIII TTTEEELLLEEEPPPHHHOOONNNEEESSS

1911 : Establishment of Delhi Telephones system with manual exchange 1926 : Opening of first automatic exchange (Lothian Exchange) 1972 : X-Bar (31) Janpath-1 exchange commissioned. Delhi telephone crosses 1 lac

lines

1973 : Opening ofX-Bar (67) Chanakya Puri exchange. 1975 :X-Bar Janpath-IV (34) exchange commissioned. X- Bar Shahdara East (20) exchangecommissioned. 1976 : Shakti Nagar (74) exchange commissioned. Idgah-II (52) X-Bar exchange

inaugurated by Fakhuruddin Ali Ahmed, President of India, on 28.8.76 and presided over byMr. S.D. Sharma (Minister of communications). Opening of Shahdara East (20) Extension-I,

X-Bar exchange on 31.8.76. It was inaugurated by Mr. H.K.L. Bhagat (Minister of State forWorks and Housing) and Mr. S.D. Sharma (Minister of communications). Opening of Hauz

Khas (65) X-Bar exchange on 18.10.76


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1991-92:Commissioning of gross switching capacity of 1,18,000 lines. Interactive graphicssystem (IGS) for computerization of outdoor network plant installed. I-NET services installed.

1992-93: 83,558 new telephone connections provided. Morning wake up call facilityintroduced free to all electronic exchange customers. Voice Mail Services introduced.

1993-94: Commissioning of gross switching capacity of 1,69,250 lines out of which 100500lines of new technology. Waiting list under OYT & Special category made current in most

areas.

1994-95: Record commission of gross switching capacity of 226000 lines. 1995-96 : Record commission of gross switching capacity 323200 lines. Automatic Changed

Number Announcement Service 1951/1952 using Interactive Voice Response System (IVRS)introduced. Fault Repair Service of all major exchanges computerized. Multimedia center with

video conferencing facility opened.

1996-97 : Commissioning of gross switching capacity of 241028 lines and provision of 203100lines in one year which is an all-time high. The waiting list almost completed except few

pockets. ISDN services introduced commercially.

1997 : Wireless in local loop (WILL) phone system introduced.SSSEEERRRVVVIIICCCEEESSS BBBYYY MMMTTTNNNLLL

CUSTOMER SERVICE CENTER (CSC)The various servicecenters provided are as follows :

Area Customer Service Centers{Located at the headquarters of the Area General Manager} Sub-Area Customer Service Centers

{Located at the office of Dy.General Manager of the respective

division}

Divisional Customer Service Centers{Located at the office of the Divisional Engineer(Outdoor)of the respective division}

Mobile Customer Service Centers


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CUSTOMER SERVICE MANAGEMENT SYSTEM (CSMS)A fully computerized single window facility for all telephone related work, covering fromregistration of new phones to billing services and fault repair services.

I. Computerized booking of complaint 198/2198II. Helpline serviceIII.Voice Mail Fault Repair Service(VMFRS)

DIRECTORY INFORMATION SERVICESI.Computerized Directory EnquiryII. On-line Directory Information ServiceIII.

Directory Dial up Service

IV. Directory service for I-NET SubscribersV. Know your billing cycle/bill date

VOLUNTARY DEPOSIT SCHEME(VDS)Under this scheme, the customer may make an advance deposit to MTNL based on hisaverage billing and this deposit will be adjusted in the future telephone bills.

INTELLIGENT NETWORKIntelligent Network Service( IN-Service ) e.g. free phone, premium rate service, tele

voting, virtual private network, universal access network and Virtual Calling Card orAccount Calling Card.

Virtual Calling CardThis service allows customers to make a call from any tone telephone in the networks ofDelhi and Mumbai to any destination-local, national or international even if the telephone

from where the call is made is without STD facility.

Account Calling CardThis service also provides the same facility as VCC. As in the case of VCC, here also

there is no need of a telephone connection.


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HOTLINEFor instant connection to your most often called number this facility is quite useful. With

this facility one can connect the phone to any one pre-determined number.

CALL FORWARDING/ CALL TRANSFERWith this facility, incoming calls can be forwarded to any other telephone number withinthe same local area by availing this facility.

TELEPHONE SERVICES Voice

Plain old telephone services through distinguished Public Switched Telephone Network

with variety of phones plus services and direct-in-dialing facility ofPABXs connected tothe PSTN.

Dolphin Cellular services provided by MTNL.

GarudaWireless in Local loop (WLL) : Service offered are both in fixed mode as well asportable mode (mobile).

ISP (INTERNET SERVICE PROVIDER)Various features of internet service provided are as follows :

I.Single access numberII. Faster accessIII. Uninterrupted serviceIV. E-commerceV. Online telephone directory( www.mtnl.net.in|)VI. Hourly News updateVII. Login package CDs available for 199/250/500 hoursVIII.No registration charges

ATM SERVICESCUSTOMER CARE SERVICES


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I.New telephone registration, bill payment and complaint registration through internetII.Smart Card for payphoneIII. Meditation Billing Customer Care in GSM MobileIV. Data Ware HousingV.Call Center

VOICE MAIL SERVICESI-NET

Data Service through X.25based Packet Switched Public Data Network is called I-NET.

ISDNIntegrated Service Digital Network (ISDN) to meet the requirements of customer fordata, voice and video on one line, both in Basic Rate Access(64 kbps) and Primary Rate

Access(2Mbps).

OTHER SERVICES OFFERED BY MTNL TO THE SUBSCRIBERS

I.Telax-operational on local and international levelII. Leased LineIII. Telephone directory of MTNL is available on CD-ROM as well as on the internetIV. Single window computerized customer service centers introduced to provide

solution to all telephone related matters

V. Introduction of electronic bill clearence scheme : Bill presentment and onlineelectronic bill payment of telephone bills by MTNL subscribers implemented for Delhi

subscribers.

VI. Call Waiting : 118 (Activation)VII. Abbreviation Dialing : 110+directory no.+xxVIII.

Call Diversion : 114+Telephone no.(Activation)115+ Telephone no. (Deactivation)

IX. Morning Alarm : 116 (Activation), 117 (Cancellation)X. Dynamic Lock : 123-abcd-abcd (Registration)

124-abcd-1 (Lock)124-abcd-3 (Open)

XI. Absent Subscriber (Abs)XII. Caller Line Identification, Hotline.


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TTTEEELLLEEEPPPHHHOOONNNIIICCC CCCOOOMMMMMMUUUNNNIIICCCAAATTTIIIOOONNN

Telephony is the branch of line communication which deals with the transmission of

spoken message. Telephony is the most widely used and common for telecommunication.Speech from one subscriber is converted into electrical signals in the telephone instrument

which are transmitted over wires to the telephone exchange for being conveyed to another

subscribers instrument where the electrical signals are converted back into sound energy.The telephone exchange serves the essential purpose of interconnecting different

subscribers.

TELEPHONEA Telephone is a device which transmits and receives speech at a distance. The

conversion between two speakers across a distance is due to the sound waves carried bythe intervening medium that is air these sound waves are generated by the human voice.

When these waves exert pressure on the diaphragm of the human ear, he receives thespeech, although the audio frequencies range from 16 to 20,000Hz , a human voice or a

musical instrument does not always produce all these frequencies. On the other hand theygenerate much narrower band of frequencies.

TELEPHONE TRANSMITTERIt is a transducer converting sound energy into electrical energy. The type of transmitter

most widely used in telephone hand-sets of today is the carbon granule transmitter. Itconsists of a carbon granule chamber within which there are two carbon electrodes F and

M. One of them that is F is fixed and the other that is M is movable along the conical

diaphragm D.

When the diaphragm moves to and fro due to the impinging sound waves, the pressure on

the carbon granule varies. The electrical resistance offered by the carbon granule variesaccording to the pressure and the current in an external circuit having these carbon

granules as variable will vary.

TELEPHONE RECEIVERThis does the reverse function of a transmitter. It is a transducer which converts electricalenergy into sound energy. The coming voice frequency current passes through a coil

producing magnetic flux in the magnetic path consisting the iron path of the permanentmagnet, the pole pieces and the diaphragm.


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SYSTEM FUNCTIONINGThe function of the whole system (connection between subscriber and the exchange) isquite simple. Two or more telephone exchange can also communicate with each other by

sing optical fibre cables(OFC), this method adopts in such a case when the subscriberscommunicate indirectly to the another exchange. Suppose an exchange have the capacity of

five thousands subscriber but there is more than five thousand subscribers under thatexchange so in that condition this exchange communicates with other one. Other many

conditions are also used for communication links of exchanges which is not described here.

Another essential component required for transmission and reception of speech of a systemis the dial. The dial is used to send specific impulses over the subscriber line, when the

subscriber lifts his hand-set, the dc loop between subscriber and the exchange is closed andsteady current flows through the loop. The impulsing spring of the dial which is connected

in series with the line breaks the loops as many times as the number is dialed.

The two contacts doc1 and doc2 are called dial of normal contacts and close as soon as the

finger plate of the dial is displaced from its normal position. When impulses are being sentby successive closing and opening of the impulsing spring s-1 contacts doc1 and doc2 arein closed position and the loop current flows through these contacts, the bell, the

transmitter and the receiver all remaining shunted.

NETWORKSNetworks play an important role to run, connect and communicate between exchanges orsubscribers. In the telephone departments, there are these networks as given below:

I.Cable NetworkII. Transmission NetworkIII. Switching Network


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SUBSCRIBER LINE CONFIGURATION

SUBSCRIBER LINE CONFIGURATION is divided into two parts :

Indoor PartIt further consists of :

I.TelephoneII. Distribution Point (D.P.) - 10/20 pairIII. Cabinet Outdoor Part

It further consists of :

I.Main Distribution Frame (MDF)II. Switch Room


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FIBER OPTICS

Transmitting communications signals over hair thin strands of glass or plastic Not a "new" technology Concept a century old Used commercially for last 25 years

FIBER HAS MORE CAPACITY

This single fiber can carry more communications than the giant copper cable!


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FIBER OPTIC APPLICATIONS

Fiber is already used in:-- 90% of all long distance telephony

50% of all local telephony Most LAN (computer network) backbones Many video surveillance links

Fiber is the least expensive, most reliable method for high speed and/or long distancecommunications

While we already transmit signals at Gigabits per second speeds, we have only started toutilize the potential bandwidth of fiber

OPTICAL FIBERCABLE

A thin glass strand designed for light transmission. A single hair-thin fiber is capable of

transmitting trillions of bits per second. In addition to their huge transmission capacity, opticalfibers offer many advantages over electricity and copper wire. Light pulses are not affected by

random radiation in the environment, and their error rate is significantly lower. Fibers allowlonger distances to be spanned before the signal has to be regenerated by expensive "repeaters."

Fibers are more secure, because taps in the line can be detected, and lastly, fiber installation isstreamlined due to their dramatically lower weight and smaller size compared to copper cables.


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SPLICING OF OFCCABLE

There are two splicing technique:

1. FUSION SPLICING2. MECHANICAL SPLICING


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Fusion Splicing

1. Understand that fusion splicing is basically two or more optical fibers being permanentlyjoined together by welding using an an electronic arc. If a poor spice is made, the fiber

ends may not melt together properly and problems can arise.

2. Prepare the fiber by stripping the coatings, jackets and tubes, making sure that only barefiber is left showing. You will want to clean all the fibers of any filling gel. A cleanenvironment is REQUIRED for a good connection.

3. Cleave the fiber. A good cleaver is mandatory to obtain a successful splice. When fusingthe fibers together, you can either align the fibers manually or automatic, depending onwhat type of machinery you have. Once you've obtained a proper alignment, an electrical

arc is used to melt the fibers together creating a permanent weld of the two fiber ends.

4. Protect the fiber with heat shrink tubing, silicone get. This will keep the optical fiber safefrom any outside elements it may encounter or future breakage.

FUSSION SPLICER


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Mechanical Splicing

1. Understand that the basic difference between mechanical splicing and fusion splicing isyou don't require a fusion splicer. It's also considered a quicker method and there is no

heat involved.

2. Prepare the fiber by stripping all the protective coatings away. You will then want tocleave the fiber as in fusion, but precision is not as critical to the splice. The ends are thenmechanically joined together by positioning them inside the mechanical splice unit. In thisstep a connector or an adhesive cover is used to join the splice together.

3. Protect the fiber with heat shrink tubing. As in fusion splicing, this will keep the opticalfiber cable safe from the outside elements or breakage.

TIPS AND WARNING:

# Mechanical splicing costs more per splice, the initial investment will be much lower thanfusion.

# In fusion optical splicing, the initial investment in machine costs will be much higher, but thecost per splice is much lower than mechanical.

# Mechanical is quicker and easier, but the alignments of the fibers are not as accurate as fusion.

Whichever method you decide to use, make sure the person doing the splicing is trained in the

operation they will be performing.


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SSSWWWIIITTTCCCHHHIIINNNGGG SSSYYYSSSTTTEEEMMMSSS

There are many switching systems used such as :

MEC X BAR FETAX SPC ETB C-DOT OCB 283 CDMA EWSD 5ESS

FETAX, SPC, ETB, OCB 283 are based on FRANCE technology.C-DOT is based on INDIAN technology.

CDMA used in mobiles is based onCHINESE technology.EWSD is a SIEMENS make.

5ESS is an AT&T (Bell Lab. USA)make.

555EEESSSSSS SSSWWWIIITTTCCCHHH

5ESS stands for :

5 : 5th

generation product as assigned by LUCENT TECHNOLOGY

E : Electronic

S :Switching

S : System

The 5ESS switch is a digital exchange that can serve as a local(lines), toll(trunks),tandem(lines and trunks) or international gateway exchange depending upon the type of

switch. It can serve a small community with fewer than 100 subscribers or large

metropolitan area more than 100,000 subscribers.

The 5ESS switch is the most flexible digital exchange for use in the global switching

network. It switches ISDN voice and data, local voice and long distance calls, internetaccess, wireless PCS, advanced intelligent network services, interactive video and

multimedia services--- moving any kind of traffic(voice, data, video) on the publicswitched telephone network(PSTN). For service providers who need packet technology,

the 7R/E Packet Driver converts your 5ESS Switch into a packet switch. The 5ESSSwitch can transform your network into a multi-functional network, meeting your needs as

well as those of your residential and business subscribers.


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The 5ESS is a digital switching system with distributed processing. Distributed processingmeans that multiple processors handle all call processing functions

5ESS ACCESS TANDEM SWITCHA high-capacity, high speed trunk switch that provides communication links betweenmultiple regions and networks. It stores sufficient routing data to access a particular

switch in another service providers network and vice-versa. Eliminating the need for eachend office to store routing information provides faster call transfer, results in

administrative cost savings and gains access charge revenues.

The Tandem Switch is a high capacity, high speed switch that connects geographicallydispersed networks. Local end office switches are linked to each other via access tandem

switches. Each access tandem switch aggregates voice anddata calls from several localswitches, then connects to a tandem switch in another areas network to move calls from

one region to another. Typically, the tandem switch receives toll traffic and uses its trunksto process and route the traffic to and from another service providers end office switch.

Tandem switches have only trunks, not lines, which allow faster call transfer nationwide.

This multi-use, flexible switch eliminates the need for each end office switch to storemultitudes of routing information, provides faster call transfer and results in cost savings

as well as gaining regulatory access charge revenues.

5ESS SWITCH HARDWAREThe 5ESS Switch hardware is subdivided into three major types of equipment moduleswith each of them involved in varying degrees in setting up and tearing down of every call

:

Switching Module (SM)It connects the customer.

Communication Module (CM)It provides a path for control and data messages.

Administrative Module (AM)It collects the call completion data for engineering and billing.

Each module performs the assigned functions that contribute to the total operation of the4ESS switch. The SM connects all the lines and trunks to the 5ESS switch. It performs the

call processing functions. There can be many SMs per 5ESS switch. The CM providescommunication between SM and AM. There is one CM per 5ESS switch.


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MODULAR DISTRIBUTED DESIGN

AM

SM

SM

FEATURES OF 5ESS SWITCH

High ReliabilityThe 5ESS switch has the latest amount of downtime of any switch in its class, accordingto analysis of the latest U.S. FCC quality reports. The reports reveal that among four

major switch vendors, the 5ESS switch is in four standard performance categories and setnew in two key areas.

Multiple ApplicationsThe 5ESS switch is the only switch in the market today that can deliver any media of the

same switch. The 5ESS can deploy all types and combinations of services from a single platform including wireline, wireless, voice and data. Together with the 7R/E Packet

Driver, the 5ESS switch integrates IP/ATM networks and circuit switching. Therefore,

service providers can offer the latest data services by building on their current switchinvestment.

Modular DesignThis feature distinguishes the 5ESS switch from all others because its intelligence is

distributed into modules. This unique architecture allows growth in increments simply byadding modules, which can be dedicated to specific services, such as long distance and

data services. Therefore, adding new services when and where the service provider needsthem becomes quick and easy. Also, remote switch modules can be located upto 600 miles

CM

NCT

links

DSCH

NCT

links


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from the host switch, making it easy to enter new categories. Basically, the switch supports

any network strategy without locking the service provider into a specific future and withoutinterrupting current services.

Market LeadershipWith an embedded base of more than 108 million lines and 48 million trunks served by4000 host switches in more than 52 countries. The 5ESS switch product family includes arange of switches in varying sizes to meet diverse communication needs. The 5ESS switch

is a market leader. A full-sized as the most reliable 5ESS switch serves upto 250,000subscriber lines and over 100,000 trunk lines, with the flexibility to meet the most

diverse business needs.

5ESS Supports WirelessThe 5ESS switch continues Lucent Technologys leadership role in the wireless areaproviding advanced wireless services such as FDMA/TDMA/CDMA on the 5ESS Switch

Very Compact Digital Exchange (VCDX). This low cost service application eliminates

the pops and clicks of call hand-offs between cells over a large geographic areas. Itimproves billing for cellular customers to increase revenue and improve customersatisfaction and offers multiple grades of service to provide pricing flexibility for targeting

different customers in the wireless market.

5ESS Switch ConfigurationsSeveral switch configurations are available to serve differing networking functions andneeds. The 5ESS switch innovative modular design assures network operators ofcomplete

flexibility in planning switch deployment and network growth.

BENEFITS OF 5ESS SWITCHI.The only media switch in the market today providing wireless, wireline, voice and data

on a single platform.

II. A high density switch, reducing floor space requirements and power consumption.III. A high capacity switch allowing fewer layers in the network providing network

efficiency and reduced operational costs

IV. #1 in reliability according to U.S. FCC Automatic Reporting Management andInformation (ARMIS) Report

V. Capable of evolving to the 7R/E Packet Solutions.


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5ESS SWITCH APPLICATIONSCurrent applications supported by the system are as follows :

I.Local ExchangeII. Toll ExchangeIII. GatewayExchangeIV. OSPS (Operator Service Position System)V. ISDN (Integrated Services Digital Network)VI. STP (Signaling Transfer Point)VII. SSP (Services Switching Point or Action Control Point)VIII.MSC (Mobile Switching Center or Wireless)

Local ExchangeLocal subscribers gain access to the local exchange through lines. The exchange switches acall from an internal subscriber to another subscriber directly or through a trunk circuit to a

subscriber in another exchange. A trunk circuit (or trunk) connects a local exchange to alocal exchange or a toll exchange. A local exchange has high percentage oflines and a

smallpercentage oftrunks.

Toll ExchangeA Toll Exchange or Trunk tandem Exchange connects a local exchange to another local

exchange or to a gateway exchange. A Toll exchange has highpercentage oftrunks but lowpercentage oflines, if any.


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Gateway ExchangeThere is one international network consisting of interconnected gateway exchanges. Each country

(A and B) in this network has its own gateway exchange, an international toll exchange.International calls enter or leave the country from this exchange.

Operator Service Position SystemThe 5ESS-2000 offers automatic operator services via the OSPS. OSPS applications aredirectory enquiry to supply directory numbers to calling subscriber. Traffic Assistance

allows operators to complete calls and respond to enquiries for subscriber. The OSPS usesa special SM called PSM (Position Switching Module).

Integrated Service Digital NetworkAnother type of 5ESS-2000 switch application is the ISDN. It offers new voice and dataservices and allows features such as OSPS. It also allows voice, data and signaling

information to travel over the same digital subscriber line. It lets all three components usethe same transmission path simultaneously.

C

2

1

C


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Two people with ISDN can make phone calls and use their computer terminals to accessone or more computers at the same time. ISDN service is fully compatible with POTS

service. ISDN service requires specific ISDN hardware and software in the SM.

Signaling Transfer PointThe STP is an exchange application that sends signaling message on the way to the proper

destination over a different path than voice circuit. TPs are associated with theCSS7(common channel signaling 7) network. This application allows for more efficient use oftrunk circuits.

Service Switch PointThe SSP, also called ACP (action control panel)is a 5ESS-2000 switch application that

is a part of IN (intelligent network) configuration. IN technology allows the introductionof advanced services, primarily through software updates, with minimal network

rearrangements and minimal service disruption. The SSP is able to recognize the incomingIN calls, process them or request call handling instructions by use of a remote database

that is accessed by many switches in the IN.

Mobile Switching CenterThe MSC (Mobile Switching Center) perform the switching function for wireless systems.

This 5ESS-2000 switch application monitors subscriber mobility manages resources,communicates with other networks, performs call routing and control functions. The

MSC configuration includes the AM, CM, SMs, WGSM (wireless global switchingmodule), at least one WSM (wireless switching module) and possibly a WRSM (wireless

remote switching module) or multimodule.


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GROWTH AND DEGROWTHModular architecture makes it easy to increase or decrease the capacity of the exchange.

Increase in the capacity of the switch is called growth. Decrease in the capacity of theswitch is called degrowth. The SM is the primary module for growth and degrowth is

accomplished by changing the number of SM in a switch or the number of units within the

SM.

SWITCHING MODULE

The primary job of the switching module is to connect subscriber lines and inter-office trunks the 5ESS switch. A switching module is a multi-unit component and is located in a variable

number of cabinets. The switching modules are available in two models :

SM configurationEach SM contains a duplicated MCTSI, duplicated DLIs and two LDSU DSUs. All otherhardware components are configured according to office requirements.

SM-2000 configurationEach SM-2000 contains a duplicated MCTSI, duplicated NLIs and LDSF DSCs. All

other hardware components are configured according to office requirements which canhandle more calls with less equipment.

Switching Module(SM) is the most essential and vital part of a switching system.

Originally SMs were called IMs (Interface Modules). With in a switch it performs the90% of all the call processing functions as well as the circuit maintenance functions. The

main function which constitute the process of call processing are :

I.Line scanning for tone originationsII. Dial tone generationIII. Digit collection and analysisIV. Call supervisionAn SM terminates analog lines, analog trunks and digital trunks and lines. Within the

switch architecture, SMs perform the time division switching functions. SMcommunicates with the AM for maintenance purpose or for obtaining routing information.

TYPES OF SMLSM (Local Switching Module)

This type of SM serves local lines & ISDN users. The LSM is usually referred as SM.


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HSM (Host Switching Module)This type of SM provides normal LSM subscriberinterfaces and also one or more RSMs

(Remote Switching Module).

RSM (Remote Switching Module)This type of SM is designed to meet the needs of those communities that are too small to

be served by their own 5ESS switch in a remote area. This can be done by having theRSM connected to a HSM. This HSM can be far away as 242km. From host upto 4

RSMs, called a MMRSM (Multi mode RSM), can be interconnected to serve.

PSM (Position Switching Module)This type of SM supports OSPS features.

SM COMPONENTS

HERE : SMP It is used for processing the calls.

TSI Time Slot Interchanger.

LDSU Local Digital Service Unit.GDSU Global Digital Service Unit.PSU Packet Switch Unit.

SM can be broadly classified into two categories :

SMC

LTP

The three main functional areas that exist in an SM are :

CONTROL UNITS

MCTSI

SMP TSI

AIU

PS

U

SERVICE UNITS

DIU

TSI

TSI

LDSU GDSU

DSU 2

TSI TSI


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I.Interface UnitII. Control UnitIII. Service Unit

SM INTERFACE UNITSThe interface units interface the telephone lines with the system. There are various types ofinterfaces needed to convert the telephone signaling systems into the format of the internal

digit format needed by the exchange. Interface units exist for all the types of analog anddigital lines and trunks, as well as for transmission systems between central offices.

Every setup of a speech connection is started with detection in one of the interface units.

Each interface unit has circuits that are developed for a particular type of signaling. Afterconverting these signal into internal format of the exchange it transmits them to control unit

which acts on them and make a connection from the interface unit to the service unit. In theservice unit, tone detectors and tone generators are present. Detected tones are decoded

and then the decoded value is transmitted to the control unit. Upon command from thecontrol unit, call processing and signaling tones can be generated (by the LDSU) and

transmitted to the interface units. In this way, the control unit receives the information fordigit analysis and is able to respond according to the signaling type.

There are various types of SM interface units which are as follows :

Line UnitIt is the interface to the analog subscribers of various signaling types. The concentrationratio can vary from 4:1 to 10:1 depending on how the line units are equipped. The speech

output per line is 64 time slots which enables a line unit to interface a maximum of640subscribers (10:1). A line unit is divided into two service groups, each processing 32 of

the 64 time slots output by the line unit. It ensures that if an error has occurred in oneservice group then only maximum 32 calls within a line unit will be affected.

Integrated Service Line Unit-version 2 (ISLU2)This interface unit is designed to meet the ITU-T requirements for an ISDN. It can interface with bothanalog as well as digital subscriber lines. The digital interface includes the U-DSL (digital subscriber

lines). An ISLU2 can upto a maximum of1024 analog and digital lines.

A version of ISLU2 is RISLU2 (Remote ISLU) which may be located on the subscribers premiseswhen a large number of lines are to be interfaced from the same location. Since it is capable of

performing line concentration, it can be used as pair gain system. Its an economical way for remoteunits.


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Analog Trunk UnitIt is an interface unit to the analog trunks. In this unit after conversion to the internal formatof the exchange, the trunk traffic is transmitted to the control unit without any

concentration factor. Since the trunk unit has 64 time slots available, every trunk unit caninterfere with 64 analog trunks. These are grouped in pair of 32-32 trunks each. An error

would affect a service group of trunks maximum.

Digital Line Trunk Unit (DLU)It is the interface unit to the digital trunks. A DLU is equipped with DFI (digital facility

interface) circuits. With a 30 channel digital inter-exchange transmission facilities, eachDFI can interface with a digital link carrying 30 datachannels plus 2 signaling channels.

In case of common channel signaling (CCS) DFI can interface with a digital transmissionfacility carrying 31 data channel and 1 signaling channel.

Any combinations of interface unit may be installed as long as the capacity of standard

control unit of SM200 is not exceeded. The signaling requirements of the interface units

are handled under the control of the switching module control unit.All these interfaces support the signaling specifications from ITU-T.

SM CONTROL UNITSThe control units control the operation of the SM and perform the time switching of aspeech sample. A speech sample can be switched either between two subscribers connected

to the same switching module or between two subscribers on different SM2000s via theCM. The control units are fully duplicated in an active/standby configuration. Both of them

receive the output signals of interface units, but the response of only active mode is

acknowledged.


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SM Control Unit & SMCCabinet

A control unit is based on the following components:

Module Controller Time Slot Interchanger (MCTSI)This is made up of sub-components like Switching Module Processor Unit (SMPU), Time

Slot Interchanger Unit (TSIU) etc.

The primary jobs of the SMPU are :

I.Controls call processing activities for the peripheral units in the switching module.II. Handles maintenance activities for the switching module.III. Monitors and reports all switching module activities to the AM to generate

hardware status reports

IV. Handles subscriber data and control messages from the switching moduleperipherals and CM.

V. Performs a bootstrapper function which enables the 5ESS switch to rapidlyreload memory in the SMP.


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Network Link Interface (NLI)The Network Link Interface (NLI) is a one paddle board component. The NLI is located in

the backplane of the TSIU shelfin an SMC cabinet of an SM-2000. The main functions ofNLI are :

I.Connect MCTSI to the Time Multiplexed Switch (TMS) part of CM.II. Convert subscriber data and control messages.

Dual Link InterfaceThe Dual Link Interface (DLI) is a one circuit pack component.

The DLI is located in the MCTU shelfof the SMC cabinet of a SM. The primary job ofthe DLI is to connect the MCTSI to theTMS.

Apart from the above main components of Control Unit, RSMs contain:

Facility Interface UnitIt is located in shelf of RSM and contains components, the remote link interface. The

primary jab of the RLI is to transmit subscriber data and control messages between a SMat a host site and a SM at a remote site. It also generates clock pulses for the RSM when

the RSM is operating in a stand alone mode.

Remote Clock Unit (RCLKU)It has the following sub-parts :

I.RCLK Oscillator :During a normal operation state, the RCLK oscillator provides a synchronizer witha source to remove jitter from the clock pulses that are received from the SM at the

host site. During isolation from the host office the RCLK oscillator generates clockpulses for the RSM.

II. RCLK Synchronizer :During a normal operation state the RCLK synchronizer removes jitter from the

clock pulses.

SM SERVICE UNITSService Unit performs all tone detection and generation functions.Service Unit also provides test functions and call processing

function such as three-party or six-party conferencing. It is

composed of following sub-units :


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Packet Switch UnitThe Packet Switch Unit Model 2 (PSU2) is a one to five shelf unit. The PSU2 is located inan LTP cabinet of a SM. The primary job of the PSU2 is to route packets of control

messages & subscriber data to ISDN lines & C7 signaling trunks. The C7 signals are usedto provide a path to set up and tear down trunk calls.

Service Announcement SystemIt provides general recorder announcements like The following number has been changedor This number does not exists and others.

Global Digital Service FunctionThe Global Digital Service Function is a one circuit pack component. The GDSF is

located in SMPU orDSU shelf of a SM-2000 cabinet, orCSU shelf of a SM cabinet. Itreceives and control message from MCTSI through PICB and tone generation and analysis

through PIDB.

The primary job of the GDSF are :

I.Perform three and six port conference callingII. Perform transmission testIII. Perform integrated system testIV. Generate an measure various tones to test POTS and ISDN subscriber lines and

trunks

Global Digital Service UnitThe Global Digital Service Unit is a multi-circuit pack component. The GDSU is located

in a cabinet of SM.The primary jobs of the GDSU are to :

I.Perform three to six user conferencingII. Perform transmission tests on subscriber loops and trunks

Local Digital Service Unit (LDSU)It is one of the important parts of service unit which is connected through PICB to ControlInterface (CI ) ofMCTSI and through LDSUB to Data Interface (DI). Through PICB

transmission of control messages occur to the SMP and through LDSUB tones are sendand receive the TSI.

The functions of LDSU are :

I.Generates call processing tones for digit and call progress alerts in an SM.II. Decodes call processing tones for routing calls in an SM.


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CCCAAALLLLLL PPPRRROOOCCCEEESSSSSSIIINNNGGG

------------------------------------

Calling Subscriber Called Subscriber

Call handling is the processing of calls from callingsubscribers to the calledsubscribers. In all exchanges the basic function is to process a call i.e. to assign a

suitable path between the calling and called subscriber and thus ensure a faithfulcommunication between the two. In 5ESS switch the 90% of call processing is done in

SM Unit.

A call processing may occur between following types of communications systems :

I.Public Switched Telephone Network (PSTN) : A tele-communication network set up byan administration to perform telephonic services for public subscribers. The maincharacteristic of PSTN is that most PSTN subscribers have analog access to the network.

II. Integrated Services Digital Network (ISDN) : A network which provides end-to-enddigital connectivity to support a wide variety of services. Users of ISDN have access to

a limited set of standard, multipurpose customer interfaces.

III. Global System for Mobile Communication (GSM) : A cellular network based ondigital technology with international coverage for mobile telephony.

IV. Intelligent Network (IN) : A network that is organized in such a way that telephonecalls, received by the IN are interrupted in query a database. The database has thecapability to handle the call based on a number of predefined conditions.

V. Personal Handy phone System (PHS) : A cellular network which offers low costtelephone service with low speed mobility.

STAGES OF CALL PROCESSING FOR PSTNDigit Dialing Screening Index Digit Analysis

Routing Charging Termination

Origination/Incoming


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A call enters the exchange over a line (origination) or a trunk

(incoming).

Digit CollectionThe collection of digits from the incoming line or trunk.

Digit collection is responsible for :

I.Collecting dialed digits from incoming trunks or lines.II. Supporting the signaling protocol of the incoming trunk or line.III. Performing dial timing requirements.

Digit AnalysisThe digits collected by digit collection are analysed to determine routing.

Digit analysis is responsible for :

I.Identification of the call type (normal call, dialed service, emergency number).II. Interdigit timing requirements (for example determine the minimum number of

digits that are required to route the call).

III. Generation of routing request data (for example destination index).Carrier Selection

Enables network subscribers to select the carrier used for a call. The carriers other than theaccess provider are called Other Licensed Operators (OLOs).

Input and OutputThe input for digit collection and digit analysis are the incoming digits. The output from

the digit collection and digit analysis is for instance :

I.The Screening IndexII. The Destination IndexIII. Charging Information

ROUTINGRouting is defined as the process of selecting the correct circuit path for a message. It

translates the destination data received from digit analysis into the physical port thatleads to the dialed destination (an outgoing trunk or line).

RouteA possible trunk group (or multiple hunt group) leaving the exchange and leading to (but

not necessarily connected to) the specified destination. The actual trunk (or line) must befound by hunting the group for an idle member.


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Data associated with a route includes :

I.The trunk group (or multiple hunt group) member.II. The type of route (hunted, reorder, congestion, maintenance, etc.).III. Digit deleting and prefixing database.IV. The alternate (or next) route if the specified trunk group (or multiple hunt group) isbusy.Any route can be associated with one and only one trunk group. However the same trunkgroup can be busy by more than one route.

TERMINAL ALLOCATIONTerminal allocation is connecting the correct circuit path for a message to the incomingtrunk or line.

Route IndexAn arbitrary number assigned by the telephone administration to uniquely identify one

route out of the exchange. Route indices can also be assigned to specific announcementsor tones.

Alternate Route IndexIt defines the next or alternate. An Alternate Route Index (ARI) can be used if the current

route's trunk group (or multiple hunt group) is busy.

Screening IndexAn arbitrary number assigned by the telephone administration to uniquely identify the

source of the originating line or incoming trunk call for routing and charging purposes. Ascreening index allows the same call type dialed to the same destination to be routed or

charged differently, based on who originated the call. Screen Indices are obtained fromline or trunk port data.

Destination IndexAn arbitrary number assigned by the telephone administration to uniquely identify each

destination that can be reached for routing and charging purposes. Destination indices are

obtained as an output of digit analysis.

Types of terminations are :

I.Line Termination (for the route types line and DSL)II. Multi-Line Hunt TerminationIII. Trunk Termination


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CCCHHHAAARRRGGGIIINNNGGG

Charging is the function that assesses the cost of the usage of switching capacity and that passes

on that assessment to the billing center.

Currently two charging methods can be distinguished:

I. Automatic Message Accounting (AMA)II. Multimetering (MM), also known as Periodic Pulse Metering (PPM).

In an exchange either method can be used or in combination.

AMAAutomatic Message Accounting (AMA) is a method of charging whereby for each call, records

are generated for billing purposes. The records contain the information needed to generate adetailed subscriber bill, for example call start time, call end time, call duration, calling partynumber, called party number, and so on.

Advantages :

I. Allows detailed billing per call type or even per individual callII. Does not require tariff intelligence to be present in the exchange

Disadvantages :

I. Requires large amounts of charging data to be collected and processed.II. Requires alternative methods to drive home meters and payphones.

MMMultimetering (MM) is a method of charging whereby a call is charged in terms of charge units.The number of units to be charged is based on the distance (or route) of the call, the date and the

time of day. All this information yields a charge rate which determines how many charge unitsare applied over a set time interval. Each time this interval expires during the call the calling

party is charged the pre-determined number of units.

Advantages :

I. Only requires the number of imposed charge units to perform billing.II. Uses the charge units to generate meter pulses (to drive home meters and payphones or

to transmit charging information to other exchanges).

Disadvantages :


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I. On accumulates charge units.II. No history is kept, so no detailed billing is possible.

What is charged?

I. Basic analog Public Switched Telephone Network (PSTN) calls.II. Basic digital Integrated Services Digital network (ISDN) Calls.

III. Basic wireless calls (mobile originations and terminations), location updates and HomeLocation Register (HLR) interrogations.

IV. ISDN data packet calls.V. Subscriber programming actions for PSTN, ISDN and wireless supplementary services,

for example activation, deactivation and interrogation.

VI. Exchange executable services like Alarm Call Service (ACS). The subscriber is chargedwhen the service is executed by the system.

VII. All answered and unanswered calls that complete a Service Control Point (SCP) query,using the Intelligent Network (IN)

VIII. PBX trunk originations.Who is charged?

I. Individual subscribers (PSTN and ISDN), mobile subscribers, individual PBX lines andPBXs

II. Other administrations (to share revenues)III. Intelligent Network (IN) service providers.

Types of outputNormally the charging data is sent to a billing center. A billing center is a system, external to theexchange that performs the billing.

The charging data is sent to the billing center using:

I. Magnetic tapeII. Direct data link to remote billing center.


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MMMAAAIIINNNTTTEEENNNAAANNNCCCEEE TTTOOOOOOLLLSSS

A maintenance staff responsible for maintaining a 5ESS switch uses the followingmaintenance tools :

I.Master Control Center (MCC)II. Trunk and Line Workstation (TLWS)III. Recent Change and Verify (RC/V)IV. Diagnostic ProgramsV. Documentation

MCCThe MCC is the most important maintenance tool. Almost all the maintenance tasks can

be performed from MCC. It uses a full-colour video display terminal as a window to thesystem. By entering poke commands selected from menus on the terminal screen or manmachine language commands selected from the 5ESS-2000. Switch commands and report

manual, maintenance personnel can diagnose equipment, remove equipment from service,restore equipment to service, test lines and trunks, modify the database and service

features for customers. The ROP (Receive- only Printer) provides a printed copy ofreports from the MCC.

The primary functions of the MCC are to provide the following :

I.Visual Display of the system status and alarm information.II. The means to control, test and reconfigure the system.III. The means to manually recover the system.IV. Access to exchange data.

TLWSIt is a software function and is not related to a specific piece of equipment. As the nameimplies, the TLWS function is used to test trunks and lines (subscribers). Its functions

can be performed from the MCC terminals known as supplementary TLWS positions.

RC/VIt is also a software function. It is used to make addition, deletion , insertion, updationorchanges to the database of the system. For instance, adding subscriber lines, changing

the digit analysis, deleting trunks and so on are performed using the RC/V function. Forexample : update the subscriber class from Local to STD.

Updb-sbldn : directory no. , SBclass=STD ;


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Diagnostics ProgramsWhen a piece of equipment is faulty, the maintenance technician can run a specific

diagnostic on that piece of equipment. The switch has the ability to tell the maintenancestaff which circuit pack is most likely the faulty one and must be changed. The accuracy

of the diagnostic process is quite impressive, more than 95% of system faults can bepinpointed, correctly. For example : for diagnostic of Line Ckt. Dgn AIU : LC= xxx-

xxx-xx-xx ;

DocumentationIt plays a very important role in troubleshooting. Since a procedure may change over tim

always refer to the documentation at the switch. Updating documentation must be performwhenever changes in new equipments are made.

FFFAAAUUULLLTTTDDDEEETTTEEECCCTTTIIINNNGGGTTTOOOOOOLLL///TTTEEESSSTTTIIINNNGGGTTTOOOOOOLLL

OTDR Testing

OTDR (Optical Time Domain Reflectometer) technology is designed

to provide a single ended test of any cable. Utilizing sophisticated

algorithms, the equipment is able to calculate exact length and

approximate loss of events along the cable span.


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FEATURES:

1. Generates a baseline trace:A visual of the link.

2. Can identify and evaluate

specific events in the link.

3. Cable acceptance tool.

4. Fault location tool.

5. Excellent documentationcapabilities.

6. Limited use in short length

networks.

Documents

Final Report Auto Saved)