A Presentation on Training Report at

Tata Teleservices LtdPresented by: Ketul patel

Manish ShahInternal Guide: Mr. Mehul Patel

External Guide: Mr. Paresh Panchal Mr. Nayan Patel

Company Profile

• Tata Teleservices Spearheads the Group’s presence in the Telecom sector. Incorporeted in 1996,TTSL was the first to launch CDMA mobile services in India with the Andhra Pradesh circle.

• The Company offers services under the brand name ‘Tata Indicom’ .

• Having pioneered the CDMA 3G1X technology platform in India, Tata Teleservices has established a robust and reliable telecom infrastructure that ensures quality in its services. It has partnered with Motorola, Ericsson,Lucent and ECI Telecom for the deployment of a reliable, technologically advanced network.

Services Offered

• TATA Indicom CDMA Mobile (Voice &Data)• Fixed Wireless Terminal ( For Limited Mobility )• Data Card & USB Modem for Laptop & PCs for High-

speed Internet connectivity• Pay Telephone Booth • Fixed Wire line Phone Connection with Broadband• ISDN Connections to Customer & Corporates

A Brief History• Mobile telephony started with the need for communication, to a

person on the move.

• The initial versions of Mobile phones worked on analog technology (1G).

• They worked on wide area broadcast principle similar to a Radio or TV system.

• Each Transmitter site covered large areas.

Multiple Access Technologies• FDMA – (example : Analog ) Frequency Division Multiple Access each user has a private frequency

• TDMA – ( example: GSM )Time Division Multiple Access

each user has private time and private frequency

• CDMA – ( example : IS 95 , 1x) Code Division Multiple Access

users co-mingle in time and frequency but each user has a private code

What is CDMA?

• Code division multiple access (CDMA) is a wireless cellular technology

• CDMA was adopted by the Telecommunications Industry Association (TIA) in 1993

• Uses the principle of spread spectrum communication

CDMA Network Architecture

1X Air-IF

MobileStation

PSTN

IS-41CBSC

IN

HLR/AuC

PLMN

SMSC

VMS OtherMSC

MSC

BTS

BTS

BTS

PSTN

PLMN

PDSNPDSN

Internet

CDMA Network Architecture

• The CDMA system primarily consists of following basic networks –

Core Switching Network

Radio Access Network

Packet Core Network

Adjuncts

Transmission Network

Core Switching Network (CSN)

• Mobile Switching Center (MSC) Provides all of switching and signaling functions Establishes call from and to MS within a services area as well as different services

area

• Visitor Location Register (VLR) The VLR contains the information (Users’ profile, users location information etc) of

subscribers who are attached to the system which helps to make correct routing of (terminating) calls.

• Home Location Register (HLR/AuC) Database that stores and manages subscribers’ profiles. Contain Electronic Serial Number (ESN), Mobile Identification Number (MIN) etc

and the restrictions for call making eligibility. AuC handles subscriber authentication and encryption functions for security

purposes and inter works with MSC through HLR.

Radio Access Network (RAN)

• BSC ( Base Station Controller)

All radio resources are primarily managed by the BSC.

Handle connections to Mobile Stations.

It is connected with MSC for providing services to MS (Mobile Station) through BTS.

Also connected to the PDSN to provide packet data services to the MS.

Performs vocoding of the voice signal

Routes calls to the MSC.

Handles call control processes.

Traffic Handler, Power Control, Frame selection/distribution.

Radio Access Network (RAN)

• BTS ( Base Transceiver Station) Provides transmission and reception of radio communication for interfacing with

the MS Provide the radio connection between mobile users and the switch Connected with Base Station Controller for providing services to the MS. Performs the CDMA processing of all signals including power. BTS allocates radio resources. Consists of 3 Sectors.

• MS ( Mobile Station) MS is the wireless terminal used by subscribers to access the CDMA network over

a radio interface. The MS includes portable units, packet data access units, and units installed in

vehicles, and fixed Terminals.

Packet Core Network (PCN)

• PDSN (Packet Data Service node) PDSN provides mobile communication subscribers with

packet data service through interface with Internet network.

• AAA (Authentication, Authorization and Accounting) It contains subscriber packet –data – provisioning information

and is used to authenticate and determine the parameters of a subscriber’s packet data session.

AAA also generates “Billing Records (UDRs - - - Usage Data Records)” for packet data usage.

Adjuncts• Adjunct systems provide value-added services to the subscribers

of the network.

• Short Message Service Center (SMSC) SMSC is responsible for the relaying, storing and forwarding of short messages

between the mobile station and other networks.

• Voice Mailing System (VMS) The VMS provides facilities to callers for recording voice messages for retrieval

later by the CDMA subscribers.

Adjuncts• Operation and Maintenance Center (OMC) OMC performs operation and maintenance functions for all elements in the

network.

• Customer Care and Billing System (CCBS) CCBS collects and processes the charging data and manages call information.

• WIN( Wireless Intelligent Network) Supports various features/services like prepaid, VPN, Free phone etc.

• OTAF ( Over The Air Function) The OTAF is an entity that interfaces to the Customer Care to support service-

provisioning activities.

Transmission Network• Transmission Network provides physical connectivity between different Network Elements.

It provides the physical media through which the data flows between two elements in a Network.

• Types of Transmission Systems

• Copper Wire Copper pair is used to connect two communication elements through Modems (BTS- Tx

system )

• Optical Fibre Communication System Optical Fibre is used as a media between two network elements to carry high bandwidth data

upto 10 Gbps. PDH optical Transmission System SDH optical Transmission System

• Microwave Communication System Microwaves between 1 GHz to 30 GHz is used to connect two Elements. PDH Microwave Radios & SDH Microwave Radios

TTSL Network in Gujarat

AhmedabadAhmedabad

BarodaBaroda

SuratSurat

RajkotRajkot

Network OperationsMainly consists of -

• Field Team – Ensures Network Availability Fault Rectification Preventive Maintenance Project Roll Out RF optimization

• Operation & Maintenance Centre (OMC )- 24*7 Regional OMC of Gujarat in Ahmedabad Network Alarm Monitoring Fault Escalation & resolution Database Configuration changes Performance Monitoring and Analysis Capacity Up gradation Customer Complaints Resolution

BTS Site• BTS Shelter

– BTS Equipment– Transmission Equipment ( Radios / Muxes )– Rectifiers– Battery Bank– ACs

• DG• TOWER

– RF cables– Microwave Antennas– BTS Sector Antennas– Aviation Lamp– Lightening Arrestor

STRUCTURE OF OMC

BASIC FUNCTIONS OF OMC1. SITE MONITERING 2. FAULT MANAGEMENT3. ALARM MONITORING

4. MOBILE SUBSCRIBER DATA ADMINSTRATION 5. PERFORMANCE ANALYSIS6. CONFIGURATION CHANGES7. BACKUPS8. ANALYSIS REPORT ON NETWORK OUTAGES9. CASCADING BTS SITES

BASIC FUNCTIONS OF OMC• Site Monitoring In a particular node i.e. BSC or remote

BSC, there are a number of sites defined depending upon the coverage area and its density .A particular site is divided into 3 sectors having same frequencies in different direction, all these sectors and sites have a neighbouring relationship for the purpose of handovers.

BASIC FUNCTIONS OF OMC• Alarm Monitoring This is the prime function, which continuously

monitors the alarm reported by all BTSs, BSCs, MSC and other elements. It gives an audible alarm for pre-set alarm conditions. Alarms for field sites (BTS’s and BSCs) also include environmental alarms, which are must for field located sites as these are in cabins

BASIC FUNCTIONS OF OMC

Alarm Monitoring and rooms which have supporting accessories

like power, air cons, and fire hazards, security problems,since it is not possible to man hundreds of fields locates sites for these types of issues, so these alarms are also reported to at the OMCR form where again these are reported back to the site engineers and technicians for suitable action to be taken to remove them.

BASIC FUNCTIONS OF OMC• Fault Management Fault Management relates to the software as well

as hardware faults in the MSC, BSC, HLR, BTS, and DLC.

Various faults occurring are – - Group Switch Alarm

- Software Error Alarm

BASIC FUNCTIONS OF OMC

Fault Management Mobile Subscriber Data Administration OMC along with managing & maintaining

sites and their corresponding alarms also manages the mobile subscriber data and have the authority of granting services to them and also barring the same if need arises. As in other functions in this also we have a few commands that prints out the services provided to the subscriber.

BASIC FUNCTIONS OF OMC

• Network Analysis The OMC also gives the data for network

performance which is an indication of quality of service provided to your customer. OMC gives statically analysis of traffic like total calls made, no of outgoing and incoming calls , incoming calls, MS to MS, MS to PSTN calls etc, no calls dropped , traffic loading on the loading etc.

BASIC FUNCTIONS OF OMC Network Analysis With this data the network quality is observed, with

which further network expansion and other functions could be planned effectively.

• Configuration Changes All the GSM network elements are highly digital

systems, with enormous software control, so there is almost continuous requirement of software changes in the existing systems,

BASIC FUNCTIONS OF OMC Configuration Changes and also with expansion all the changes are to

be done form OMC. Ericsson has defined a set of various command for the purpose of expansion which may include adding TRUs in a particular BTS, a new E1 etc, this in turn depends upon the performance analysis which gives the traffic load in a particular channel, congestion occurring in a particular site

BASIC FUNCTIONS OF OMC Configuration Changes In case of any need of expansion in the BTS , in

addition to an already existing BTS cabinet that can hold up to 6 TRUs, another cabinet is installed at the BTS , and the software for the same is loaded from the OMC. In case of traffic exceeding the limits, and impossibility of adding TRUs, as an E1 can support TRUs only up to a fixed value, a new E1 is added. In case of extra traffic load, cascaded sites are made independent having a separate E1.

BASIC FUNCTIONS OF OMC• Backups Backups are basically taken for the purpose of

redundancy. As the software is loaded for all the hardware installed which is very much prone to errors and bugs, also the network changes are being made continuously ,so it becomes very essential to have a back up, a duplicate copy of all the changes made and that even very up to date. There are two types of Backups:

BASIC FUNCTIONS OF OMCBackups• Manual ( on OD- Optical disk)• Automatic( on Hard disk) Backups taken can otherwise be categorized as:

• CP (Central Processor)• SP (Support Processor)

BASIC FUNCTIONS OF OMCBackups• CP Backup contains software loaded in CP, this

is taken weakly. It also includes information about new E1s added.

• SP Backup are very important & critical backups, it’s the backup of the software of the exchange and data stored in it.

• In case of any crash or errors in the software loaded, it is reloaded by giving a reset to the software in the exchange which then picks up the last backup from the OD.

BASIC FUNCTIONS OF OMC• Report On Outages A report on the total outages of the day is

made on regular basis, on which the analysis is done. Outages cover the total number of sites down through out the day, the time period for which it was down and the main reason for the failure of site. This analysis is basically done for future improvement and development. With this, in case of any hardware problem or even software is taken care of.

BASIC FUNCTIONS OF OMC• Cascading & Expanding Bts Sites Cascading is the term used when the same E1

shares two or more sites. This is done in sites where the traffic load is low and a single E1 is enough to carry the traffic for all the cascaded sites.

BASIC FUNCTIONS OF OMC

Cascading & Expanding Bts Sites A single E1 has got 32 channels, each channel

having 8 time slots, so in case of places where there is less need of channels (low traffic), and a single E1 can handle it well. With doing so it saves the cost of putting a new E1 for all the different sites, thus proving to be economical for the company

PRACTICAL WORK

1) Everyday at 9.30 am I have to go company & start my training by visiting different site in ahmedabad city.

2) At that site I do some work like : • Alarms checking• Cable routing• E1 patching / removing

PRACTICAL WORK

• Checking connectivity between IDU & ODU• Radio installation• To insert login cable & check link to other site• Antenna alignment• Make site in working condition

3) Types of Alarms: Alarms – 1) Minor :- No incoming signal 2) Major :- No outgoing signal 3) OMU block 4) To give the INTERCOM facility at CAMBAY I

have check LOS by using GPS device. 5) POWER PLANT & BATTERY BANK installation

at SHAPATH due to loss of voltage.

6) I have done a VSWR measurement at VRUDAVAN SHOPPING CENTRE at manekchawk.

7) With help of OTDR(Optical Time Domain Reflectometer) we can locate the OPTICAL fault within particular FIBRE link by radiating LASER from the source.

8) At some site I have (Juhapura,Nawab complex)done antenna TILTING (Electrical & Mechanical alignment) to solve the coverage problem.

9) By observing FMS from MSC we can see where & Which kind of problem occurred and how to solve it quickly as possible as.

10)Went to the site, viramgam, to route traffic. Connect the higher capacity multiplexer [XDM-500] & Disconnect the cable from [XDM-100].

11)Connect the higher capacity multiplexer in SR-HOUSE.

12)Survey of line of sight of nearer BTS at santej,shymal using GPS system

13)We went to NEWYORK TOWER,SG Highway there TTSL provides wireless services. It has intercom in fordshowroom.

By using PRI meter we detected the signal from BTS the line was clear. The problem was in EPBX(swiching).

14)In BTS, the replace the faulty LPA, In place install new LPA, and unlock LPA by the MSC.

15)AT NANO project, science city install COW BTS, first install CDMA antenna,

and MW link antenna,also alignment nearer MW antenna (BTS ).

16)Visited at paldi given DC power supply (-48 v), purpose standby Ethernet line (FOC line) in

DLC.17) I have done NMS(Network Management System)

from which we can check REMOTELY other site ODU & IDU confugration ,frequency plan etc.

NETWORK CONNECTIVITY• Land line to Landl line call • Land line to Mobile call • Mobile to landline call • Mobile to Mobile call We have so far discussed the each unit

individually in the network. Now all this unit work together to make a complete communication. Considering each and every form of communication in detail one by one.

LAND LINE TO LAND LINE CALL• SAME OPERATOR WITHIN THE NETWORK

CALLING PARTY CALLED PARTY

LAND LINE TO LAND LINE CALL• A landline party called the number of another

landline phone of the same operator and within that network. The call is taken by the RLU of that area of the called party. RLU sends it to the Wire Line switch. If the called party is near by the switch it transfers the call directly to the called party over copper cable. In case called party is far from the switch, then the call is first routed to the RLU of that location. From RLU the call is transferred to the called party.

LAND LINE TO LAND LINE CALL• This is the same case as of the previous one.

The only difference is that the calling party is near at the wire line switch. So it directly connects to the switch, no need of the RLU.

LAND LINE TO LAND LINE CALL• DIFFERENT OPERATOR WITHIN THENETWORK

POI: Point Of Interconnection, this unit connects the different operators switch. So that call connectivity can be possible in case of different operators too.

• When a calling party called a number belongs to the other operator in that network, call first goes to the RLU, which route it to the wire line switch. After knowing that it belongs to the other operator, the call is transferred to the POI for the interconnectivity with the other operator. From that it is transferred to that operators switch and then RLU, From RLU to the called party.

LAND LINE TO LAND LINE CALL• DIFFERENT NETWORK

LAND LINE TO LAND LINE CALLDIFFERENT NETWORK• When a calling party dials a number to the

subscriber that belongs to the other network, then call is transferred from RLU to the Wire Line Switch. There it judges that it belongs to the other network, so it route it to the switch of that network. From there it transfers to the RLU and then to the called party.

LAND LINE TO MOBILE CALL• SAME OPERATOR

LAND LINE TO MOBILE CALLPSTN: Public Switch Telephone Network. It represents

the wire line network. When a landline subscriber called to a mobile party,

the call is routed from landline phone to the MSC with the help of PSTN. PSTN can consist of the many RLU and many wire line switch depending upon the requirement. At MSC first of all authentication takes place, after valid authentication it routes the connection to the BTS of that area, where mobile is moving. From BTS the connection is routed to the mobile phone.

LAND LINE TO MOBILE CALL

LAND LINE TO MOBILE CALL1. A call for the mobile station arrives from the

PSTN to the MSC.2. The MSC queries the HLR about the mobile

station’s location and status. The status indicates whether mobile is powered up or down. The location indicates in which cell or zone the mobile is currently is located.

3. The MSC sends a paging message to the mobile station through the BTS. The BTS transmits a paging message over the air.

LAND LINE TO MOBILE CALL4. The MSC authenticates and set up the

security to the mobile station.5. The BSC allocates radio resources. 6. To alert the subscriber, the BSC instructs the

mobile to start generating a ringing tone by sending an alert message.

7. When the subscriber answers, message is sent to the MSC. Now the two parties are connected.

LAND LINE TO MOBILE CALL• DIFFERENT OPERATOR

LAND LINE TO MOBILE CALL• DIFFERENT OPERATOR In case of the different operators, first call is

routed from calling party to the POI with the help of the PSTN network. POI connects different operators. Now the call is routed to the other operators MSC. From there it transfers to the corresponding BTS. BTS sends signal to the mobile handset of the called party.

MOBILE TO LANDLINE • SAME OPERATOR

When a mobile subscriber called to a landline phone of the same operator, then the call is transferred to the MSC with the help of the BTS. MSC route it to the PSTN network. Which routed it to the landline phone

MOBILE TO LANDLINE• Call setup(Base station controller)

MOBILE TO LANDLINE• The call set up procedure is explained below:1. The mobile station sends an origination

message to the MSC through the BTS.2. The MSC authenticates and sets up security to

the mobile station. 3. BSC allocates radio resources for traffic

channel.4. Now MSC initiates the call with the help of

the PSTN network.5. Call set up successfully, then the MSC

connects the two parties.

MOBILE TO MOBILE CALL• SAME OPERATOR

When a mobile call is made to other mobile within the same operator, then call is first routed to the MSC with the help of the BTS. MSC routes it to the corresponding BTS, which transfers it to the mobile handset.

MOBILE TO MOBILE CALL• OTHER OPERATOR

When mobile to mobile call between different operators, first the call is routed to the MSC through BTS. Then it transfers call to POI. POI provides interconnectivity between different operators. POI transfers call to the other MSC. After MSC the call is transferred to the called mobile phone with the help of the BTS.

Home Automation Control System Using DTMF Telephone Line

• Simply plugs into your telephone line* and provides 4 independently controllable relay outputs. You can then call your number using a DTMF (tone dialling) telephone from anywhere in the world and remotely turn on/off any of the relays as desired.

• This device connects to the telephone line and can be used to remotely control up to 4 relay outputs using a DTMF (tone dialing) telephone. A number of user settings are available to improve the usability and security of the device..

• The unit is controlled by an Atmel 89C2051 microcontroller.

• It is possible to connect a wide variety of devices to the relays for example security lights, heating and pump controllers, computers, etc.

• The user can set a 4-digit security Password, Tamper facility, number of Rings to Answer, Auto Hang-up time and Lockout facility. Compatible with all European, North American and Asian phone networks.

• Supplied with a high quality custom made case.

Basic Network Element

A few of the benefits of CDMA are

Superior voice quality (with EVRC) Better reception with less background noise,

Fewer dropped calls, Enhanced security and greater reliability.

Also, CDMA allows for more users to be on the system at once –

Greater network capacity, Resulting in fewer blocked calls for the users of a

CDMA network.

WHY IS CDMA BETTER---------?

INTRODUCATION TO SDH & PDHWhat is E1?• E1 is a digital communication link that enables the

transmission of voice, data, and video signals at the rate of 2.048 Mbps.

• It was introduced in the 1960’s.• E1: Speech signal Fm= 4 kHz• So from sampling theorem the freq = 2*Fm = 8 kHz• Now 1 byte is = 8 bit • Each channel have a rate of 8 kHz * 8 bit = 64 kbps• There are 32 channels.• So the total rate is 32*64 kbps = 2.048 MBPS.

What is T1 frame ? At 8000 frames per second.Bit per frames (24 * 8)+1 =193Bit rate 8000*193=1.544 MBPSFrame duration :125 microsecondsBit time : 647.7 nanosecondsChannel rate : (8000*8)=64 Kbps

What is PDH?

What is PDH?

• PDH stands for plesiochronous Digital Hierarchy. Plesiochronous means almost synchronous (same bit rate but not synchronized to common master clock). As you can see in the graphic, the multiplexer inputs have signals (tributaries) with different clock sources. Then it uses internal timing to generate a higher rate signal which contains the different tributaries.

Primary Rate on A PDH System• Depends on the country Primary rate refers to the basic rate on which

the multiplexing system is based on. For ITU transmission networks, the primary rate is 64 Kbps. This rate will be multiplexed to the first level of the PDH hierarchy and transmitted at a higher rate. Then, it is a multiplexed to the fourth level of the hierarchy.

Primary Rate on A PDH System

Hierarchy Levels of PDH System• The multiplexing structure for the ITU-PDH

system is shown in the fig.

SDH (SYNCHRONOUS DIGITAL HIERACHY)

• SDH is A Standard For Speed-High Capacity Optical Telecommuncation Network Based On Synchronous Multiplexing.

• IT ALSO SUPPORT ELECTRICAL & MICROWAVE COMMUNCATION ACCORDING TO USER’S REQURIEMNET.

• SDH Multiplex Law Bit Rate Digital Signals To Higher Bit Rate and Transmit Large Information Efficiently.

SDH (SYNCHRONOUS DIGITAL HIERACHY)

• It works on a single clock source.• This standard is common to all countries so no

need for extra effort for matching.• SDH is a synchronous digital transport system

with a built in management channel for remote management of complex topologies.

Why use SDH?• With the introduction of PCM technology in

the 1960s, communications networks were gradually converted to digital technology over the next few years.

• To cope with the demand for ever higher bit rates, a multiplex hierarchy called the plesiochronous digital hierarchy (PDH) evolved.

Why use SDH?• The bit rates start with the basic multiplex rate of 2

Mbit/s with further stages of 8, 34 and 140 Mbit/s. • In North America and Japan, the primary rate is 1.5

Mbit/s. Hierarchy stages of 6 and 44 Mbit/s developed from this.

• Because of these very different developments, gateways between one network and another were very difficult and expensive to realize. The 1980s saw a start in the development of the synchronous digital hierarchy(SDH), with the intention of eliminating the disadvantages inherent in PDH.

Why SDH NEDDED?• Plesynchronous digital hierarchy(PDH) is an older

version when mainly point to point transmission was the main network application.

• But as subscriber go on increasing and system become wireless, it is very complex & costly network and it is not possible to handle manually.

Why SDH:• To cope up the demand of higher bit rate SDH

technology is introduced.

• The fig. itself shows that in PDH point to point wired connection is there while with SDH there is one equipment only, having facility of connection

• In SDH it is possible to connect and all fault management can be done easily.

Multiplexing hierarchy

• As shown in fig. in PDH system we are using a set of multiplexer and equal no. of demultiplexer.

• So we have to demux all the channels though we require only one or two.

• So SDH is a faster, cost effective and simple system

Advantages of SDH Over PDH:Higher Transmission rate: Transmission rate up to 10 Gbps can be

achieved by the modern SDH system. SDH is therefore considered to be more suitable for backbone.

Simplified Add/Drop function: Compared with older PDH system, it is much

easier to insert and extract low bit rate channels from or into the high-speed bit streams in SDH.

Advantages of SDH Over PDH:

High availability and capacity matching: With SDH network providers can react quickly and

easily to the requirements of their customers.Reliability: Modern SDH networks include various back-up and

repair mechanisms to cope up with system faults.Interconnection: SDH makes it much easier to set up gateways between

different network providers and to SONET systems.