Nokia Siemens Networks Training Report

A

SUMMER TRAINING PROJECT REPORT

ON

“GSM ARCHITECTURE”

AT

“NOKIA SIEMENS NETWORK”

Submitted in partial fulfillment of the requirement for the award of degree

Of

BACHELOR OF TECHNOLOGY

SESSION (2012-2013)

SUBMITTED BY:-

DEEPAK AGRAWAL

3rd YEAR (ECE)

POORNIMA COLLEGE OF

ENGINEERING (PCE)

1

ACKNOWLEDGEMENT

It is my pleasure to be indebted to various people, who directly or indirectly contributed in the development of this work and who influenced my thinking, behavior, and acts during the course of study.

I express my sincere gratitude to Mrs. Gunjan Bhatt , worthy Principal for providing me an opportunity to undergo summer training at Nokia Siemens Network.

I am thankful to Mr. Akshay Kumar for his support, cooperation, and motivation provided to me during the training for constant inspiration, presence and blessings.

I also extend my sincere appreciation to Mr. Karunakar Rout who provided his valuable suggestions and precious time in accomplishing my project report.

Lastly, I would like to thank the almighty and my parents for their moral support and my friends with whom I shared my day-to-day experience and received lots of suggestions that improved my quality of work.

Deepak Agrawal

2

DECLARATION

I, Deepak Agrawal, student of B.Tech. III Year, studying at Poornima College Of Engineering, Jaipur. Hereby declare that the summer training report on “GSM ARCHITECTURE” submitted to “NOKIA SIEMENS NETWORK”, JAIPUR in partial fulfillment of Degree of “BACHELOR OF TECHNOLOGY” is the original work conducted by me.

The information and data given in the report is authentic to the best of my knowledge.

This summer training report is not being submitted to any other University for award of any other Degree, Diploma and Fellowship.

DEEPAK AGRAWAL

3

TABLE OF CONTENTS

1. COMPANY PROFILE

(Introduction, History, Founder, vision, mission, competitors, Organization structure, Products, achievements, address)

2. OBJECTIVES OF STUDY

3. SCOPE AND RATIONALE OF THE STUDY

4. INTRODUCTION OF THE MOBILE COMMUNICATION

5. STUDY OF GSM ARCHITECTURE

6. IT SECURITY

7. CONCLUSIONS

4

1. COMPANY PROFILE-

Nokia Siemens Networks is a multinational data networking and telecommunications equipment company headquartered in Espoo, Finland and a joint venture between Nokia of Finland and Siemens of Germany. It is the world's fourth-largest telecoms equipment manufacturer measured by 2011 revenues (after Ericsson, Huawei and Alcatel-Lucent). Nokia Siemens Networks has operations in around 150 countries.

1.1 HISTORY-

The company was created as the result of a joint venture between Siemens Communications division (minus its Enterprise business unit) and Nokia's Network Business Group.

The formation of the company was publicly announced on 19 June 2006. Nokia Siemens Networks was officially launched at the 3GSM World Congress in Barcelona in February 2007.

Nokia Siemens Networks then began full operations on 1 April 2007 and has its headquarters in Espoo, Greater Helsinki, Finland. In January 2008 Nokia Siemens Networks acquired Israeli company Atrica, a company that builds carrier-class Ethernet transport systems for metro networks.

The official release did not disclose terms; however they are thought to be in the region of $100 million. In February 2008 Nokia Siemens Networks acquired Apertio, Bristol UK-based, a mobile network customer management tools provider for €140 million.

With this acquisition Nokia Siemens Networks gained customers in the subscriber management area including Orange, T-Mobile, O2, Vodafone  and Hutchison 3G. On July 19, 2010, Nokia Siemens Networks announced it would acquire the wireless-network equipment division of Motorola.

The acquisition was completed on April 29, 2011 for US $975 million in cash. As part of the transaction approximately 6,900 employees transferred to Nokia Siemens Networks.

On November 23, 2011, Nokia Siemens announced that it planned to eliminate 17,000 jobs by the end of 2013 to enable Nokia Siemens to refocus on mobile broadband equipment, the fastest-growing segment of the market.

The reductions will slash the company’s work force by 23 percent from its current level of 74,000. The cuts follow Nokia Siemens’s $1.2 billion purchase of Motorola’s mobile network equipment business in July 2010, which added staff; and would help the company trim annual operating expenses by $1.35 billion by the end of 2013.

5

1.2 ADDRESS-

Nokia Siemens Networks Pvt. Ltd.,UDB Builders, Near Gopalpura Bye Pass, Jaipur- 302015

2. OBJECTIVE OF STUDY-

To provide an exposure to the students on real life organisational problems and to provide an opportunity to work on them intensively.

To enable the students to understand the organisation structure and processes in the practical setting.

To provide an opportunity to the students to analyse real life problems and apply the concepts and theory learnt in the class room.

The summer training also acts as a mechanism to help students to crystallize their career choices as they explore themselves in their project work.

3. SCOPE AND RATIONALE OF THE STUDY-

Every year since 2005 Nokia Siemens Networks has conducted its Global Acquisition & Retention Study, an extensive survey to identify the key drivers for customer experience.

Our aim is to help CSPs build more valuable customer relationships.

The study looks at the main reasons for churn and attempts to uncover steps that CSPs can take to build customer loyalty.

This is one of the industry’s most extensive research projects looking at the drivers of customer retention and acquisition in both fixed and mobile markets around the world.

The study was conducted during the first half of 2010 and covered more than 20,000 interviews across mature markets that have already experienced heavy shifts in the market shares of CSPs, as well as highly competitive emerging markets.

It Provide network to Vodafone and hence it has very large scope in telecom sector and market.

6

4. MOBILE COMMUNICATION-

One of the finest things that happened in 20th century is the use of radio channels for personal mobile communication systems. Considered to be a revolution of sorts in telecommunications, mobile communication is the fastest growing market segment and the field of intense research.

Mobile communication today is, perhaps, the most powerful catalyst for change in lifestyle of the people all over the world.Mobile communication slowly, but surely is evolving as the backbone for business transactions, efficiency and success silently taking over the role of the elder cousin PSTN.

The first mobile telephone service started in 1946 in St. Louis, Missouri, USA as a manually operated system. Between 1950 and 1960, it evolved as an automatic system with reduced cost and increased, but small subscriber base. Mobile telephony service in its useful form appeared in 1960s.

The first generation mobile communication systems appeared in 1970s and remained till 1980s. They used analog transmission techniques for the radio link and confined its users to their respective system areas for which the mobile phone was designed. Capacity of the system was very limited and roaming between the coverage areas of the different systems was impossible.Apart from being very expensive, these systems provided poor QoS and supported only voice communication. The second generation mobile communication systems grew out of the limitations of the 1st generation systems. They supported large subscriber base, carried both voice and data and have capability to design and deliver new value added services.

The radio link became digital enabling use of versatile signaling capabilities and cross-network roaming. However, multiple standards made seamless roaming across all the networks impossible. GSM and CDMA emerged as the trend setting technologies. The domination of the 2G systems in the mobile communication market became apparent in second half of 1990s.

The design objectives of the third generation mobile systems are to provide high functionality with seamless global roaming. Apart from providing very high data rates, 3G systems seek to integrate the wire lines systems with mobile systems. 3G would provide users consistent voice, data, graphical, multi-media and video-based information service regardless of their location in the network (Cordless, Cellular, Satellite, Fixed/Wire line and so on….). 3G systems would also integrate the Intelligent Network (IN) capabilities into mobile systems.

Basic to the design of a mobile communication system is the ability of the user to liberate himself from the confines of a wired line and therefore his freedom to move anywhere he wants. Mobile communication systems therefore are required to provide

7

seamless service while the customers are on move transcending geographical and network borders. Provision of service under such environment throws a number of challenging issues and the way these issues are addressed and resolved makes each system different from all others.

A comparison of a typical PSTN and mobile call scenarios is shown in figure:-

5. GSM ARCHITECTURE-

8

One of the important objectives of GSM group is to evolve a unified standard to provide seamless roaming across world. Another landmark decision taken by the group is to standardize a digital radio interface for the communication between the mobile handset and the radio transmitter/receiver. The design objectives of the GSM system can be briefly states as below:-

Excellent speech quality High security and privacy Low module terminal cost Low service and facilities cost Design of sleek and handled mobile terminals International roaming Wide range of services and facilities Ability to adopt to new and innovative features Narrowband ISDN compatibility Digital Radio High Spectral efficiency

The digital radio uses the 900/1800 MHz band. The mobile terminal vary in power class 20 watts to as low as 0.8 watts. A GSM cell can cover a maximum distance of up to 30 Kms. The system can provide service to mobile customers traveling up to a maximum speed of 250 Km/hr.

5.1 BASIC GSM NETWORK ELEMENTS:

AUC- Authentication Center

9

BSC- Base Station Controller BSS- Base Station Subsystem B&CCS - Billing and Customer Care System BTS- Base Transceiver System (Antenna System + Radio Base Station) EIR- Equipment Identification Register (for IMEI verification) ESS- Enhanced Services Subsystem IMEI- International Mobile Equipment Identity FNR- Flexible Numbering Register (for number portability) GMSC- Gateway MSC HLR- Home Location Register ISDN- Integrated Services Digital Network IWF- Interworking Function ILR- Interworking Location Register (for roaming b/w AMPS & GSM) IWMSC- Interworking MSC MS- Mobile Station MSC- Mobile Switching Center NSS- Network Switching Subsystem OMS- Operation and Maintenance Subsystem OSS- Operation and Support System PDN- Public Data Network PSTN- Public Switched Telephone Network SMS- Short Message Service VLR- Visitor Location Register

MOBILE STATION (MS) :

Mobile Station, in fact, consists of two distinct entities. They are:-

Mobile Terminal or Equipment (MT) Subscriber Identity Module (SIM) Card

The mobile terminal is the actual hardware and is almost anonymous. Moibile equipment is being manufactured by a number of vendors and a number of make and models are available in the market. Each MT is identified by a number embedded in it by the manufacturer called International Mobile Equipment Identity (IMEI).

IMEI is useful to locate those mobile phones that are reported stolen and also those manufactured without proper approval. IMEI is also useful to route calls from MTs without SIM to emergency services. Mobile terminals are distinguished mainly by their power class and application.

10

The SIM card is given by the service provider (PLMN Operator) when a customer enrolls himself as a subscriber of that PLMN. SIM makes the MT operational and provides the subscriber access to all his subscribed services. The subscriber information and provides personal mobility.

Each SIM is identified by a unique identifier called International Mobile Subscriber Identity (IMSI). The SIM holds such vital information such as Authentication Key, various algorithms, Cipher Key etc to ensure security of the subscription and privacy of the conversation.

Sicne SIM is such an important element of the personal subscription and can be used inconjunction with any MT, it can be protected with a password of 4 to 8 digits long to prevent misuase. Wrong entry of the password consecutively for 3 times would block the SIM cards are classified on the basis of their operating voltage and the capacity of the Random Access Memory (RAM).

BASE STATION SUBSYSTEM (BSS):

Base Station subsystem connects the MS to the rest of the network elements in the PLMN. It provides all the digital radio interface functions. BSS comprises of three parts:

Base transceiver Station (BTS) Base Station Controller (BSC) Transcoding and Rate Adoption Unit (XCDR/TRAU)

11

Base transceiver Station (BTS): BTS houses the radio transceivers that define a cell. It transmits to and receives signals from the MS. It handles the radio-link protocols with the Mobile Station for call and mobility related activities on one side and with the BSC on the other side. Each BTS can support a number of transceivers depending on the capacity of subscribers in the cell. The BTS needs to be rugged, reliable, and portable to ensure reliable service and coverage.

The Base Station Controller (BSC) manages the radio resources of one or a group of BTSs. BSC handles radio channel setup, performance improvement techniques such as control of the RF power levels, etc and handovers. It establishes connection between the mobile station and the MSC.

The Transcoder/Rate Adaptation Unit (TRAU) is the data rate conversion unit. The PSTN/ISDN switch is a switch for 64 kbps voice. Current technology permits to decrease the bit-rate (in GSM radio interface it is 13 kbps for full rate and 6.5 kbps for half rate). Since MSC is basically a PSTN/ISDN switch its bit-rate is still 64 kbps. That is why a rate conversion is required in between the BSC and MSC (see the figure below)

12

Network Switching Subsystem (NSS):

Fundamentally, the network and switching subsystems (NSS) is responsible for call connection, supervision and release operations between calling and called stations, where one or both of them are mobile stations (MS). Other functions include:

Handling short messages and packet data (email, fax and a variety of notifications)

Providing ‘bearer’ channel for data communications Maintaining database of its own users as well as visitors Variety of authentication and encryption Gateway to PSTN, other mobile networks and data networks including the

Internet

The central component in the NSS is the Mobile Switching Centre (MSC) that performs all the switching functions of the network. Those MSCs that interface with other networks are called Gateway MSC (GMSC). MSC realizes the above functions in conjunction with four intelligent databases called:

Home Location Register (HLR) Visitor Location Register (VLR) Authentication Centre (AuC) and Equipment Identity Register (EIR)

HLR contains the administrative information of each of the subscriber registered in the network and is the permanent copy of the subscriber data. Logically there will be one HLR per PLMN, implemented as a centralized or distributed database.

HLR maps each IMSI with a unique mobile phone number called Mobile Subscriber ISDN (MSISDN). This is the number dialed by others to access the mobile customer. HLR also holds most of the information held by the SIM and also more importantly contains the pointer to the current location of the mobile customer in order to gain access to him on an incoming call.

The home location register (HLR) is a database used for storing and managing subscriptions. Generally a PLMN (Public Land Mobile Network) consists of several HLRs. The first two digits of the mobile directory number (e.g. 0171 2620757) arethe number of the HLR where the mobile subscriber is stored. The data includes permanent data on subscribers (such as subscriber's service profile) as well as dynamic data (such as current location and activity status). When an individual buys a subscription from one of the GSM operators, he or she is registered in the HLR of that operator.

Data Elements (Subscriber) Examples:

• Mobile Station’s Identities:

13

o IMSI (International Mobile Subscriber Identity) (the primary Key),o Current TMSI (Temporary IMSI)o IMEI (International Mobile Equipment Identity)

• Mobile Station’s Telephone number

o MSISDN (Mobile Stations ISDN number)o Current MSRN (Mobile Station Roaming Number), if assigned

• Name and address of the subscriber

• Current service subscription profile

• Current location (MSC/VRL address)

• Authentication and encryption keys

o Individual Subscriber Authentication Key (KI)

• Mobile Country Code (MCC) and MNC (Mobile Network Code)

• List of MSC/VLR that belongs to this HLR

Each MSC has a VLR to holds the data relevant for handling calls from and to the MSs that are currently located in its area.

The relevant data is downloaded from the home HLR when the mobile subscriber switches on the mobile handset in the area of the visited MSC thereby initiating the process of registration. VLR holds the exact location of the MS and keeps on updating the location as the mobile move across its jurisdiction.

Authentication Centre is a protected database used for security purposes. It is considered as part of HLR and provides all the parameters needed for authentication of the subscriber and encryption of voice/data over radio channel.

The authentication center (AUC) provides authentication and encryption parameters that verify the user's identity and ensure the confidentiality of each call. The AUC protects network operators from different types of fraud found in today's cellular world. The GSM has standard encryption and authentication algorithm which are used to dynamically compute challenge keys and encryptions keys for a call.

Equipment Identity Register is a database that contains a list of all valid mobile equipment in the network. It generates Valid, Suspect & Fraudulent lists (also called white list, grey list and black list) of Mobile Hndsets through the use of International

14

Mobile Equipment Identity (IMEI). It forbid calls from unauthorized mobile terminals (non-standard and stolen terminals).

The equipment identity register (EIR) is a database that contains information about the identity of mobile equipment that prevents calls from stolen, unauthorized, or defective mobile stations. The AUC and EIR can be implemented as stand-alone nodes or as a combined AUC/EIR node.

The Gateway MSC (GMSC) is an MSC that connects the PLMN (Public Land Mobile Network) to a PSTN/ISDN.

The GSM Interworking (IW) function or Unit (GIWF/U) is for data communication (such as the Internet access) support. Though the basic function of MSC is voice traffic switching the MSC has additional capability to forward data between the mobile station and GIWF/U

The NMS (network Management subsystem) includes a message center. This includes Short Message Service (SMS), Multimedia Message Service (MMS), Fax, Voice Mail, Email and a variety of notifications. The MSC requires special capability to forward those messages between the message center and the mobile station.

The local number portability (LNP) service is an advance intelligent network (AIN) service of telecommunications network. This service allows a person to move his residence to a new city/province and still retain his/her old telephone number. The local telephone service provider/switch will recognize the old telephone number, and no new number will be assigned. A cell-phone with LNP service can do the same and Flexible Numbering Register (RNR) takes care of that.

OPERATION AND MAINTENANCE SUBSYSTEM (OMS):

OMS is used to configure, control and monitor the GSM network. It comprises of two parts:

Operation and Maintenance Centre - Switch Operation and Maintenance Centre – Radio

While OMC-S is used in conjunction with the NSS, OMCs-R is used in conunction with the BSS. The OMC-R controls the traffic load on the various cells and performs automatic reconfiguration of the transceivers to cope with the fluctuation of traffic, load caused due to the mobility of the customers.

The OMCs also provide traffic data measurements, reporting and analysis. OMCs also store all the data and software for the network elements and perform as the central maintenance control point for all the network elements.

15

ENHANCED SERVICES SUBSYSTEM (ESS):

The ESS includes such elements as Unified Messaging System (UMS), Wireless Application Protocol (WAP) System, Interlligent Network (IN) system, Content and Location Based Services (C&LBS) system etc.

The Unified Messaging System provides a variety of voice and data services such as:

Voice Mail Fax Mail E-Mail Visual Mail Short Message Service (SMS)

All the above services can be subscribed by the customer and can be provided from a single platform. The WAP system allows wireless access to Internet sites that are enabled for customized access from mobile handsets. Thus a customer, on move, can surf the web from his WAP enabled handset through the WAP gateway. The WAP system also manages telephony events such as incoming call etc when a subscriber connected to the Internet.Intelligent Network system provides a host of value added features and services such as:

Pre-paid service (PPS) Free Phone Service (FPH) Premium Rate Services (PRM) Mobile Virtual Private Network (MVPN) Universal Access Number (UAN) etc

The pre-paid service provided through IN system in conjunction with Voucher Management System (VMS) and Over-the-Air Charging (OTAC) system can provide national and international roaming and recharging through a variety of payment instruments such as Credit/Debit card, ECS etc.

It can also support a number of tariff and promotional plans that can be chosen by the customer himself/herself.

Content and Location Based Services can offer a variety of PUSH and PULL services ranging from advising the customer of the discounts being offered in the shops near his current ‘location’ to verification of flight details etc.

16

BILLING AND CUSTOMER CARE SYSTEM (B&CCS):

Billing and Customer Care System is responsible for obtaining the call details of each of the customers from the HPLMN as well as from all the VPLMNs for raising the invoice.

B&CCS incorporates a powerful and flexible rating engine that would enable the service provider to offer innovative and competitive tariff packages.

The Customer Care module includes an automatic Service Provisioning Module that will activate / deactivate a customer account from a Customer Care terminal without the need for any manual intervention.

The CC module also would handle the Trouble Tickets generated on faults reported by the customer and routes such tickets automatically to appropriate terminal for action.

The B&CCS also incorporates a sophisticated Printing Subsystem for distributed printing of the customer invoices.

6. IT SECURITY:-

Information technology plays very important part in our life, so its security is a big issue. It’s a jungle out there:

Computer viruses Network worms Trojan horses Logic bombs Unwanted warnings Unwanted messages Address book theft Hijacked home pages DNS poisoning Denial of service attacks Zombies, IP spoofing Buffer overruns Password grabbers Password crackers Hoaxes Ploys Pop-ups Scams Spam

17

SALIENT DIFFERENCE:-

1) COMPUTER VIRUS Needs a host file Copies itself Executable

2) NETWORK WORM Do not needs a host file (Self contained) Copies itself Executable

3) TROJAN HORSE Do not needs a host file (Self contained) Does not copy itself Imposter program

TYPICAL SYMPTOMS:-

File deletion File corruption Visual effects Pop-Ups Erratic ( and unwanted) behavior Computer crashes

REASONS:-

Software companies rush products to the consumer market (“No program should go online before its time…

Recycling old code reduces development time, but perpetuates old flaws. Market share is more important than security Interface design is more important than security New feature designs are more important than security Ease of use is more important than security

7. CONCLUSION:-

GSM is a 2nd generation mobile communication systems. The data transmission speed of GSM was only 9.6 Kbps and this speed is considered to be too inadequate for many applications. The data speed of GSM can be increased to 171.2 Kbps using GPRS and to 384 Kbps using EDGE.Now 4G is being used in Japan and will come in India (Except Kolkata) soon.

18