36886874 Training Report on Gsm

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A

REPORT

ONINDUSTRIAL TRAINING

(12th May 2010 18th June 2010)

AT

BHARTI HEXACOM LIMITED(AIRTEL),JAIPURSubmitted for Partial Fulfillment Of

B.Tech Degree

IN

Electronics and Communication Engineering

Of

Rajasthan Technical University, Kota

Submitted by:

Sumit Kumar Kaushik

B.Tech 7th

Sem

GLOBAL INSTITUTE OF TECHNOLOGY

ITS-1, IT Park,Sitapura Jaipur-302022

Submitted to:

Mr. Rishabh Sharma

E.C.E Department


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Table of Contents

ACKNOWLEDGEMENT..................................................................1

COMPANY PROFILE.......................................................................2

INTRODUCTION..............................................................................5

EVOLUTION OF GSM......................................................................8

DESCRIPTION.................................................................................10

CONCLUSION.................................................................................34

BIBLIOGRAPHY.............................................................................36

ANNEXURE38

2 Ganpati Institute of Technology & Management, (2012-2013)


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ACKNOWLEDGEMENT

I take this opportunity with much pleasure to express my sincere thanks and gratitude toMr.Vishal Tiwari (Manager, VAS), Airtel, Jaipur. It gives me immense pleasure to extend

my gratitude towards Mr. Keshav Sharma (Quality Engineer), Airtel, Jaipur and the entire

Network and Quality team ofAIRTEL, Jaipur for providing their cooperation, constructive

criticism, valuable guidance and constant encouragement.

In addition, I wish to thank Airtel, Jaipur office to provide me the opportunity to acquire the

experience of knowing the corporate world and also providing the required facilities, well

working systems, besides complete collection of all latest technology softwares.

I am especially grateful to the professors and lecturers of our institute Global Institute of

Technology, who has been training us, since the first day, with the knowledge and support

in the most lucid manner.

It was really a good experience working in a professionally managed firm and learning from

such good and knowledgeable people. I hope it will really help me in future.

(Sumit Kumar Kaushik)



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CHAPTER 1 COMPANY PROFILE

From the first ever call on GSM, to the first call on LTE, we

operate at the forefront of each generation of mobile technology.

Our global experts invent the new capabilities you need in your

networks. We provide the worlds most efficient mobile networks,

the intelligence to maximize the value of those networks, and the

services to make it all work together seamlessly.

With an unswerving focus on quality, efficiency and reliability we

help you meet your mobile customers demands for universal

content and connectivity more efficiently and effectively.

Together, we deliver the innovations in mobile technology that

enable people and businesses everywhere to do more than ever

before.

As a mobile operator, you face challenges from many sides that

put your mobile network and your business model under extreme

pressure.



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By transforming your mobile network and your business, youll

turn your challenges into opportunities.

Working closely with you, we deliver the products and services

that will help drive your success - today and tomorrow.



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I Own Quality means that every Nokia Siemens Networks employee takes

personal responsibility on a daily basis for their actions and decision making to

achieve high quality for our customers.

Join the Nokia Siemens Networks quality journey

An important part of the Nokia Siemens Networks quality journey is

developing a partnering relationship with our customers, jointly working with

them to achieve and exceed their expectations to delight them.

Nokia Siemens Networks is undergoing a transformation

Were focusing our strategy on mobile broadband and services. Thats an

addressable market valued at almost 70bn in 2011, and where we hold a

strong second position.

This means building on our existing success in mobile broadband and

customer experience management - all supported by a strong services

organization with highly efficient global delivery.

Were maintaining high levels of R&D investment in key segments; in fact,

our investment in innovation around mobile broadband is expected to increase.

In addition, quality remains a priority and is another area where we will be

spending more.

By placing mobile broadband and services at the heart of what we do, our goal

is to provide the worlds most efficient mobile networks with the intelligence

to maximize the value of those networks and the services capability that makes

it all work seamlessly.

Our aim is to improve our long term competitiveness and profitability.



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On this page you can find links to the overall announcement we made on 23rd

of November 2011.

GLOBAL PRESENCE

Around the world, Nokia Siemens Networks expects a 100-fold

growth in network traffic at ever lower cost over the coming

years, and the majority of this growth is expected to come from

emerging markets like India. For Nokia Siemens Networks, India

is not just a high-growth market but also an innovation hub. The

manufacturing operations, global delivery centers and research

and development setups in India reflect Nokia Siemens Networks

unwavering focus on the country and enhanced proximity to its



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customers. Nokia Siemens Networks is making strategic

investments in India to further strengthen its local market position

and tap the tremendous local growth opportunities in mobile, fixed

and broadband segments.

Nokia Siemens Networks India has fully indigenized operations and workforce

with 13,000 people (direct & indirect) at 50 principle offices and present in

177 locations. Nokia Siemens Networks operations in India include marketing

and sales to HQ offices in Delhi NCR and Mumbai; two of out five Global

Network Solutions Centers (GNSC) in Noida (Delhi NCR) and Chennai; two

manufacturing facilities (2G/3G) in Chennai and Kolkata (for fixed line); and a

research and development center in Bangalore. Our global services

headquarters, GSM-Edge product management and a Centralized Solution

Support Center (CSSC) are also based in India strengthening our local

presence further.

Good housekeeping

We respect all relevant laws, regulations and international

standards. More than that, we aim to create an organization where

ethical business practice is a source of pride and employees have a

safe, motivating working environment.

Our Code of Conduct is central to operating responsibly. It is

reinforced with mandatory annual training for every employee and



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supported by detailed policies and guidelines. We also have strong

management systems in place covering anti-corruption, human

rights, labor conditions, occupational health and safety, and

environmental protection standards.

Our own operations have a relatively small environmental impact

but we have ambitious goals to improve the environmental

efficiency of our facilities, IT services, travel and service fleets.

Sustainable value for our customers

We extend the high demands we put on ourselves to our suppliers.

We also work closely with customers to improve the safety of all

workers involved in higher risk tower building and installation

works.

But we can do more. We put a lot of effort into helping customers

reduce their environmental footprint. As well as the industry-

leading energy efficiency of our base stations, we provide

solutions to optimize energy consumption in the entire network.

A good neighbor



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We want to contribute broadly to the communities where we

operate and employ people. We do this by minimizing any adverse

environmental effects of our operations and by connecting with

local communities.

Positive impacts on the planet

The greatest contribution we can make to sustainability is to use

our technology to benefit communities and the environment.

Telecommunications is in a unique position to drive social and

economic progress while helping to reduce the environmental

impacts of many industries. For example, we are working with

partners to deliver machine-to-machine (M2M) solutions as well

as to save energy in telecoms networks.

Additionally, we recognize our responsibility to carry out due

diligence so that our communications products are used to support

and not infringe human rights.



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.

GSM stands for Global Services for Mobile communication' and is an open,

digital cellular technology used for transmitting mobile voice and data

services. GSM supports voice calls and data transfer speeds of up to 9.6 kbit/s,

together with the transmission of SMS (Short Message Service).

This technology is globally accepted and most popular among all countries. It

is started in Europe to integrate all countries with wireless communication.

Earlier each country in Europe has its own standard for wireless

communication ,so due to this a person cannot use the same mobile in two

different country and cannot even communicate with the same mobile in

different countries, so due to this fragmentation problem occurred. So to

overcome this problem European Union (EU) came with GSM technology that

is accepted by whole continent and standardized by ITU-T. It is a 2 G

technology and worlds first cellular technology and it is most popular 2G

technology. Today GSM operator has largest customer base. In India totalcellular operator have more than 550 million customers and GSM has more

than 400 million customer bases alone. It is a second generation cellular

standard developed to cater voice services and data delivery using digital

modulation.

Objectives of GSM



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To eliminate the fragmentation problem in European Union.

To allow interaction with ISDN and PSTN.

The Goals of GSM

Improved spectrum efficiency

International roaming

Low-cost mobile sets and base stations

High-quality speech

Compatibility with ISDN and other telephone

Company services.

Support for new services

Specifications and Characteristics for GSM:

Frequency band the frequency range specified for GSM is 1,850 to

1,990 MHz (mobile station to base station).

Duplex distance the duplex distance is 80 MHz. Duplex distance is the

distance between the uplink and downlink frequencies. A channel has

two frequencies, 80 MHz apart.

Channel separation the separation between adjacent carrier

frequencies. In GSM, this is 200 kHz.



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Modulation Modulation is the process of sending a signal by changing

the characteristics of a carrier frequency. This is done in GSM via

Gaussian minimum shift keying (GMSK).

Transmission rate GSM is a digital system with an over-the-air bit rate

of 270 kbps.

Access method GSM utilizes the time division multiple access

(TDMA) concept. TDMA is a technique in which several different calls

may share the same carrier. Each call is assigned a particular time slot.

Speech coder GSM uses linear predictive coding (LPC). The purpose

of LPC is to reduce the bit rate. The LPC provides parameters for a filter

that mimics the vocal tract.



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DESCRIPTION

The basic architecture of the GSM is described in the figure below:

The abbreviations used in the figure above are described herein under:

HLR- Home Location Register:

HLR is database, which holds very important information of subscribers. It is

mostly known for storing and managing information of subscribers. It contains

subscriber service profile, status of activities, information about locations and

permanent data of all sorts. When new connections are purchased, these

subscribers are registered in HLR of mobile phone companies.



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MS-Mobile station:

It consists of mobile equipment and SIM. At the time of manufacturing, an

international mobile equipment number (IMEI) is programmed in ME.A SIMis required to activate the GSM services. A international mobile subscriber

identification (IMEI) number is programmed along with security parameter

and algorithm. The called number is not linked to ME but to SIM.A SIM has

following data stored in it. MSISDN (mobile subscriber isdn) IMSI

(international mobile subscriber identity) - 15 digit number. TMSI (temporary

mobile subscriber identity) 4 octets, allocated by VLR, continuously

changed.IMEI (international mobile equipment identity) unique, permanently

assigned to MS.



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VLR- Visitor Location Register:

VLR performs very dynamic tasks; it is database which stores temporary data

regarding subscribers which is needed by Mobile Services Switching Center-MSC VLR is directly connected to MSC, when subscribe moves to different

MSC location, Visitor location register VLR integrates to MSC of current

location and requests the data about subscriber or Mobile station (MS) from

the Home Location Register HLR. When subscriber makes a call the Visitor

location register-VLR will have required information for making call already

and it will not required to connect to Home Register Location - HRL again.

BSS-The Base Station System:

The base station system have very important role in mobile communication.

BSS are basically outdoor units which consist of iron rods and are usually of

high length. BSS are responsible for connecting subscribers (MS) to mobile

networks. All the communication is made in Radio transmission. The Base

station System is further divided in two systems. These two systems, they are

BSC, and BTS.



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BTS The Base Transceiver Station:

Subscriber, MS (Mobile Station) or mobile phone connects to mobile network

through BTS; it handles communication using radio transmission with mobilestation. As name suggests, Base transceiver Station is the radio equipment

which receive and transmit voice data at the same time. BSC control group of

BTSs.

BASE TRANSIEVER STATION (BTS)



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BSC The Base Station Controller:

The Base Station normally controls many cells; it registers subscribers,

responsible for MS handovers etc. It creates physical link between subscriber

(MS) and BTS, then manage and controls functions of it. It performs the

function of high quality switch by handover over the MS to next BSC when

MS goes out of the current range of BTS, it helps in connecting to next in

range BTS to keep the connection alive within the network. It also performs

functions like cell configuration data, control radio frequency in BTS.



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SIM-Subscriber Identity Module:

One of the key features of GSM is theSubscriber Identity Module, commonly

known as a SIM card. The SIM is a detachablesmart card containing the user's

subscription information and phone book. This allows the user to retain his or

her information after switching handsets. Alternatively, the user can also

change operators while retaining the handset simply by changing the SIM.

http://en.wikipedia.org/wiki/Subscriber_Identity_Modulehttp://en.wikipedia.org/wiki/Subscriber_Identity_Modulehttp://en.wikipedia.org/wiki/Smart_cardhttp://en.wikipedia.org/wiki/Smart_cardhttp://en.wikipedia.org/wiki/Subscriber_Identity_Modulehttp://en.wikipedia.org/wiki/Smart_card


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OSS -The Operation and Support System:

OMC- Operations and maintenance center is designed to connect to equipment

of MSC- Mobile Switching Center and BSC-Base Station Controller. The

implementation of OMC is called OSS-The Operations and Support

System.OSS helps in mobile networks to monitor and control the complex

systems. The basic reason for developing operation and support system is to

provide customers a cost effective support and solutions. It helps in managing,

centralizing, local and regional operational activities required for GMS

networks.

Authentication & Encryption:

Authentication: - Whenever a MS requests access to a network, the network

must authenticate the MS. Authentication verifies the identity and validity of

the SIM card to the network and ensures that the subscriber is authorized

access to the network.



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Kc:- The Kc is the 64-bit ciphering key that is used in the A5 encryption

algorithm to encipher and decipher the data that is being transmitted on the

Um interface.

A5:- The A5 encryption algorithm is used to encipher and decipher the data

that is being transmitted on the Um interface. The Kc and the plaintext data are

inputted into the A5 algorithm and the output is enciphered data. The A5

algorithm is a function of the Mobile Equipment (ME) and not a function of

the SIM card. The BTS also makes use of the A5 algorithm.

There are three versions of the A5 algorithm:

A5/1:- The current standard for U.S. and European networks. A5/1 is a stream

cipher.

A5/2:- The deliberately weakened version of A5/1 that is intended for export

to non-western countries. A5/2 is a stream cipher.

A5/3:- A newly developed algorithm not yet in full use. A5/3 is a block

cipher.

Triplets: - The RAND, SRES, and Kc together are known as the Triplets. The

AuC will send these three crypto variables to the requesting MSC/VLR so it

can authenticate and encipher.



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These channels are bi directional & have the same format & function on

both forward & reverse link.

They may exist in any time slot & on any ARFCN except TS 0.

a) Stand Alone Dedicated Control Channel [SDCCH].

b) Slow Associated Control Channel [SACCH].

c) Fast Associated Control Channel [FACCH].

a) Stand Alone Dedicated Control Channel [SDCCH]:

It is used to send authentication and alert messages as the mobile

synchronizes itself with the frame structure and waits for TCH.

It is used for location updating.

b)Slow associated Control Channel [SACCH]:

It is always associated with a TCH or a SDCCH & maps onto the same

physical channel.

On the forward link it is used to send changing control information to

the mobile, such as transmit power level instructions.

The reverse SACCH carries information about the received signal

strengths, quality of TCH & BCH measurement results from neighboring

cells.

c) Fast Associated Control Channel [FACCH]:

It is assigned whenever a SDCCH has not been dedicated for a

particular user and there is a urgent message to be conveyed.

It is assigned only to a traffic channel & relies on frame stealing to gain

access to the traffic channel.



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Value added services

Call waiting:

With Call Waiting on a Hutch phone, you can receive and hold an incoming

call when you are already talking to another person. When this service is

activated, the network notifies you of a new incoming call while you have a

call in progress, which means that if another person tries calling you midway

through a conversation, he/she will hear a message informing him/her that

your line is busy, while you will hear beeps at intervals.

Call Divert:

In case you are busy in a meeting, or if your cell phone is switched off, you

can forward incoming calls to a landline or another mobile phone - where

someone can receive messages on your behalf. You can also forward an

incoming call while speaking to someone.

Voice response services:

By using these services one can access information, download ringtones and

logos, and more. For this one has to just dial and speak on a no. for the desired

service. With Hutch World, one can enjoy a host of GPRS-based services

exclusively on Hutch GPRS phone. From astrology to photo messaging,

gaming, chat, news and even internet access.

Mail:

One can now send an SMS - without even using a mobile phone, from

wherever they are. All they need to do is type in their message and send it as e-

mail.



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Roaming:

Roaming is defined as the ability for a cellular customer to automatically make

& receive voice calls, send & receive data, or access other services when

traveling outside the geographical coverage area of the home network, by

means of using a visited network.

If the visited network is in the same country as the home network, this is

known as National Roaming. If the visited network is outside the home

country, this is known as International Roaming (the term Global Roaming has

also been used).

If the visited network operates on a different technical standard than the home

network, this is known as Inter-standard roaming.

GSM Roaming, which involves roaming between GSM networks, offers the

convenience of a single number, a single bill and a single phone with

worldwide access to over 205 countries. The convenience of GSM Roaming

has been a key driver behind the global success of the GSM Platform.

Mobile subscriber identities in GSM

International Mobile Subscriber Identity (IMSI):

An IMSI is assigned to each authorized GSM user. It consists of a mobilecountry code (MCC), mobile network code (MNC) (to identify the PLMN),

and a PLMN unique mobile subscriber identification number (MSIN). The

IMSI is the only absolute identity that a subscriber has within the GSM

system. The IMSI consists of the MCC followed by the MNC and MSIN and

shall not exceed 15 digits.



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Temporary Mobile Subscriber Identity (TMSI)

A TMSI is a MSC-VLR specific alias that is designed to maintain user

confidentiality. It is assigned only after successful subscriber authentication.

The correlation of a TMSI to an IMSI only occurs during a mobile subscribers

initial transaction with an MSC (for example, location updating). Under certain

condition (such as traffic system disruption and malfunctioning of the system),

the MSC can direct individual TMSIs to provide the MSC with their IMSI.

Mobile Station ISDN Number:

The MS international number must be dialed after the international prefix in

order to obtain a mobile subscriber in another country. The MSISDN numbers

is composed of the country code (CC) followed by the National Destination

Code (NDC), Subscriber Number (SN), which shall not exceed 15 digits. Here

too the first two digits of the SN identify the HLR where the mobile subscriber

is administrated.

The Mobile Station Roaming Number (MSRN):

The MSRN is allocated on temporary basis when the MS roams into another

numbering area. The MSRN number is used by the HLR for rerouting calls to

the MS. It is assigned upon demand by the HLR on a per-call basis. The

MSRN for PSTN/ISDN routing shall have the same structure as international

ISDN numbers in the area in which the MSRN is allocated. The HLR knows in

what MSC/VLR service area the subscriber is located. At the reception of the

MSRN, HLR sends it to the GMSC, which can now route the call to the

MSC/VLR exchange where the called subscriber is currently registered.



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International Mobile Equipment Identity:

The IMEI is the unique identity of the equipment used by a subscriber by each

PLMN and is used to determine authorized (white), unauthorized (black), and

malfunctioning (gray) GSM hardware. In conjunction with the IMSI, it is used

to ensure that only authorized users are granted access to the system.

Subscriber Authentication Key (Ki):

It is used to authenticate the SIM card.

Pin Unblocking Key (PUK)

In case of PIN, the PUK is needed for unlocking the SIM again. PUK is

numeric only, with eight digits. If a correct PUK is entered, an indication is

given to the user. After 10 consecutive incorrect entries the SIM is blocked.

Either the IMSI or the MSISDN Number may access the subscriber data. Some

of the parameters like IAI will be continuously updated to reflect the current

location of the subscriber. The SIM is capable of storing additional

information such as accumulated call charges. This information will be

accessible to the customer via handset key entry.

Personal Identity Number (PIN)

It is used to unlock the MS. If one enters the wrong PIN three times it will lock

the SIM. The SIM can be protected by use of PIN password.



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GSM Frequency Bands

There are a total of fourteen different recognized GSM

frequency bands. These are defined in 3GPP TS 45.005.



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BandUplink

(MHz)

Downlink

(MHz)Comments

380 380.2 - 389.8 390.2 - 399.8

410 410.2 - 419.8 420.2 - 429.8

450 450.4 - 457.6 460.4 - 467.6

480 478.8 - 486.0 488.8 - 496.0

710 698.0 - 716.0 728.0 - 746.0

750 747.0 - 762.0 777.0 - 792.0

810 806.0 - 821.0 851.0 - 866.0

850 824.0 - 849.0 869.0 - 894.0

900 890.0 - 915.0 935.0 - 960.0

P-GSM , i.e. Primary

or standard GSM

allocation

900 880.0 - 915.0 925.0 - 960.0

E- GSM , i.e.

Extended GSM

allocation

900 876.0 - 915 921.0 - 960.0

R- GSM , i.e. Railway

GSM allocation

900 870.4 - 876.0 915.4 - 921.0 T- GSM

18001710.0 -

1785.0

1805.0 -

1880.0



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BandUplink

(MHz)

Downlink

(MHz)Comments

19001850.0 -

1910.0

1930.0 -

1990.0

There are three different frequency bands on which mobile phones are usually

operates and these are Dual Band, Tri-Band and Quad Band.

Dual Band : Dual frequency band operates on 900MHz and 1800 MHz,

that means mobile phone that supports dual band can be operated

anywhere in the world where 900 MHz and 1800 MHz frequencies are

used. Dual Band GSM networks usually found in all continents Europe,

Asia, Africa, Australia and South America.

Tri-Band: three frequencies are supported in Tri Band, these

frequencies are 900 MHz, 1800MHz and 1900 MHz Tri band is also

supported all around the world these days.

Quad-Band: Quad Band supports four frequencies which are 850 MHz,

900 MHz, 1800 MHz , 1900 MHz Quad band also enables GSM phones

to road almost anywhere in the world. All countries support GSM

networks hence make communication possible.



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Handover:

Handover, or handoff as it is called in North America, is the switching of an

ongoing call to a different channel or cell. There are four different types of

handover in the GSM system, which involve transferring a call between

Channels (time slots) in the same cell,

Cells (Base Transceiver Stations) under the control of the same Base

Station Controller (BSC),

Cells under the control of different BSCs, but belonging to the same

Mobile services Switching Center (MSC), and

Cells under the control of different MSCs.

The first two types of handover, called internal handovers, involve only one

Base Station Controller (BSC). To save signaling bandwidth, they are

managed by the BSC without involving the Mobile service Switching Center

(MSC), except to notify it at the completion of the handover. The last two

types of handover, called external handovers, are handled by the MSCs

involved. Note that call control, such as provision of supplementary services

and requests for further handoffs, is handled by the original MSC.

Handovers can be initiated by either the mobile or the MSC (as a means of

traffic load balancing). During its idle time slots, the mobile scans the

Broadcast Control Channel of up to 16 neighboring cells, and forms a list of

the six best candidates for possible handover, based on the received signal

strength. This information is passed to the BSC and MSC, and is used by the

handover algorithm.



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The algorithm for when a handover decision should be taken is not specified in

the GSM recommendations. There are two basic algorithms used, both closely

tied in with power control. This is because the BSC usually does not know

whether the poor signal quality is due to multipath fading or to the mobile

having moved to another cell. This is especially true in small urban cells.

The 'minimum acceptable performance' algorithm [Bal91] gives precedence to

power control over handover, so that when the signal degrades beyond a

certain point, the power level of the mobile is increased. If further power

increases do not improve the signal, then a handover is considered. This is the

simpler and more common method, but it creates 'smeared' cell boundaries

when a mobile transmitting at peak power goes some distance beyond its

original cell boundaries into another cell.

http://www.cs.tu-berlin.de/~jutta/gsm/js-bib.html#bals1http://www.cs.tu-berlin.de/~jutta/gsm/js-bib.html#bals1


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Key Features

SIM (Subscriber Identity Module)

It is a memory device which is used to store the information of user such as

user privacy number, 4 digit PIN number, subscriber identification number and

user information. Called number is not associated with mobile station but to

SIM.

Increased Capacity

It provides better channel capacity than analog system. It provides 25KHZ per

user, that means eight conversation per 200KHZ channel pair(a channel pair

consists of a forward channel and a reverse channel). Channel coding and

modulation provided to enhance the channel capacity and from this 12 DB is

achieved as a channel to interference ratio(C/I ration), as compare to 18db of

analog system.

Frequency Hopping

It is a feature of GSM system in which frequency in a single channel

continuously hops and resultant provides a better coverage to a specific area.

Mobile Assisted Handover (MAHO)

GSM uses Mobile assisted handover technique. The mobile itself carries out

the signal strength and quality measurement of its server and signal strength

measurement of its neighbors. This data is passed on the Network which then

uses sophisticated algorithms to determine the need of handover.



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Discontinuous Transmission

In this GSM has a advantage of preventing system from interference and noise

by offsetting the silent time between the conversation and by blocking the

undesired signals.

Support of Short Service Message (SMS)

GSM has a advantage of short service messages assisted by paging channel of

system.

Frequency Reuse

GSM has a advantage of frequency reuse pattern from which same frequency

can be used in different cells. Normally 124 carriers are provided by the GSM

system and if we multiply it with the 7 time slots used for traffic than we get

868 numbers of calls can be made and that is very less in number. so to

overcome this problem same RF carrier is used for several conversation in

different cells and for this there is regular pattern is defined. The pattern to be

used depends on the traffic requirement and spectrum availability. Some

typical patter are 4/12 , 7/21 etc.



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other parts of the world. Different frequency bands are used by different

mobile phone operators.

Moreover, there are over 700 GSM networks available in the world operating

in their respective countries and providing international roaming services

courtesy GSM technology. There are over 2 billion GSM subscribers in the

world. Countries which are using GSM networks on larger scales are Russia,

china Pakistan, United States, India.

Giver the above facts and very good voice quality, support useful services and

standards, delivered by GSM, it is expected that GSM shall remain the

prominent technology for offering the mobile telephony.



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BIBLIOGRAPHY

1. www.gsmworld.com

2. www.gsacom.com

3. www. whytelecom.com

4. www .wikipedia .com

5. www.google.com

6. www.ask.com

7. www.search.com

http://www.gsmworld.com/http://www.gsacom.com/http://www.google.com/http://www.ask.com/http://www.search.com/http://www.gsmworld.com/http://www.gsacom.com/http://www.google.com/http://www.ask.com/http://www.search.com/


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Annexure

GSM: Global System for Mobile Communication

CEPT: Conference of European Posts and Telecommunications

ISDN: Integrated Services Digital Network

SIM: Subscriber Identity Module

VAS: Value Aided Services

BSS: The Base Station Subsystem

NSS: The Network and Switching Subsystem

OSS: The Operation and Support Subsystem

FDMA: Frequency Division Multiple Access

TDMA: Time Division Multiple Access

HLR: Home Location Register

MS: Mobile station

VLR: Visitor Location Register

AUC: Authentication Center

MSC: Mobile Services Switching Center



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