GSM: GLOBAL SYSTEM FOR MOBILE COMMUNICATION B. TECH SEMINAR REPORT Submitted in partial fulfillment for the award of the Degree of Bachelor of Technology in Electronics & Telecommunication Engineering By SADASIBA ROUT ROLL NO. : 07ET072 REGN. NO. : 0701223138 Under the guidance of PROF. DR. B.K.PATNAIK Department of Electronics & Telecommunication Engineering Krupajal Engineering College PRASANTI VIHAR, PUBASASAN, KAUSALYA GANGA, BHUBANESWAR-751 002 CERTIFICATE This is to certify that the seminar on ´GSM COMMUNICATIONµ is a bonafide record of the seminar delivered by ´SADASIBA ROUTµ(Roll No.:07ET072)under my supervision and guidance, in partial fulfillment of the requirements for the award of Degree of Bachelor of Technology in Electronics & Telecommunication Engineering from Krupajal Engineering College ,Bhubaneswar for the year 2010-11. PROF.DR.B.K. PATNAIK (Guide) Place: Bhubaneswar Date: 08-09-2010 ACKNOWLEDGMENT I thank my seminar guide Prof.Dr. B.K. Patnaik, Department of EN&TC, KEC, for his proper guidance, and valuable suggestions. I am indebted to Prof. S. K. Dash, the HOD, Electronics & Telecommunication division & other faculty members for giving me an opportunity to learn and present the seminar. If not for the above mentioned people, my seminar would never have been completed successfully. I once again extend my sincere thanks to all of them. SADASIBA ROUT ABSTRACT Global System for Mobile (GSM) is a second generation Cellular standard developed to cater voice services and data delivery using digital modulation .TheGSMservices are tele-services, bearer or dataservices,supplimentary services. The characteristics of GSM standards are fully digital system using 900, 1800 MHz frequency band. Compatibility with ISDN, Full international roaming capacity, Support of short message services.GSM has more advantages over analog system.GSM enables tele-services like services that enables voice communication through mobile phones. TABLE OF CONTENTS CHAPTER NO. 1. 2. TITLE PAGE NO. 1 2 INTRODUCTION HISTORY 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. GSM SERVICES SYSTEM ARCHITECTURE GSM FRAMESTRUCTURE TECHNICAL SPECIFICATION CALL ROUTING BUILDING BLOCKS SECURITY CHARACTERISTICS ON GSM STANDARD ADVANTAGES OVER ANALOG SYSTEM APPLICATION FUTURE( WHAT¶S NEXT) CONCLUSION BIBLIOGRAPHY APPENDIX 3-4 7-10 11 12 12-14 17 23 23 24 25 26 27 28 29 LIST OF FIGURES FIG N0. FIGURE NAME PAGE 01. GSM ARCHITECTURE 5 02. 03. 04. 05. 06. 07. 08. 09. 10. 11. GSM OPERATION FRAME STRUCTURE OUTGOING CALL INCOMING CALL HAND OFF GSM NETWORK AREA AUTHENTICATION IN GSM KEY GENERATION&ENCRYPTION NETWORK LOCATION UPDATE GSM: FDMA 6 11 13 14 15 16 18 19 20 21 GSM: INTRODUCTION Global System for Mobile (GSM) is a second generation cellular standard developed to cater voice services and data delivery using digital modulation .The GSM services are tele-services, bearer or data services,supplimentary services.The characteristics of GSM standards are fully digital system using 900,1800 MHz frequency band. Compatibility with ISDN, Full international roaming capacity, Support of short message services.GSM enables teleservices like services that enable voice communication through mobile phones. 1 HISTORY Developed by Group Spéciale Mobile (founded 1982) which was an initiative of CEPT ( Conference of European Post and Telecommunication ).Aim : to replace the incompatible analog system. Presently the responsibility of GSM standardizationresides with special mobile group under ETSI ( European telecommunication Standards Institute ).Full set of specifications phase-I became available in1990.Under ETSI, GSM is named as ³ Global System for Mobile communication ³.Today many providers all over the world use GSM (more than 135 countries in Asia, Africa, Europe, Australia, America)More than 1300 million subscribers in world and 45 million subscriber in India. 2 GSM SERVICES Tele-services Bearer or Data Services Supplementary services TELE SERVICES Telecommunication services that enable voice communication via mobile phones and offered services like Mobile telephony, Emergency calling . BEARER SERVICES Include various data services for information transfer between GSM and other networks like PSTN, ISDN etc at rates from 300 to 9600 bps.It provides Short Message Service (SMS) up to 160 character alphanumeric data transmission to/from the mobile terminal, Unified Messaging Services(UMS) like Group 3 fax, Voice mailbox, Electronic mail . 3 SUPPLEMENTARY SERVICES Call related services are Call Waiting- Notification of an incoming call while on the handset, Call Hold- Put a caller on hold to take another call, Call Barring- All calls, outgoing calls, or incoming calls, Call Forwarding- Calls can be sent to various numbers defined by the user,Multi Party Call Conferencing - Link multiple calls together, CLIP Caller line identification presentation,CLIR Caller line identification restriction,CUG Closed user group. 4 GSM SYSTEM ARCHITECTURE GSM communication system is divided into many parts. These are given below Mobile Station (MS) Mobile Equipment (ME) Subscriber Identity Module (SIM) Base Station Subsystem (BSS) Base Transceiver Station (BTS) Base Station Controller (BSC) Network Switching Subsystem (NSS) Mobile Switching Center (MSC) Home Location Register (HLR) Visitor Location Register (VLR) Authentication Center (AUC) Equipment Identity Register (EIR) 7 SYSTEM ARCHITECTURE: MOBILE STATION (MS) The Mobile Station is made up of two entities: 1. 2. Mobile Equipment (ME). Subscriber Identity Module (SIM). MOBILE EQUIPMENT: Portable, vehicle mounted, hand held device uniquely identified by an IMEI (International Mobile Equipment Identity).It is used for Voice and data transmission, Monitoring power and signal quality of surrounding cells for optimum handover. Its Power level is 0.8W ± 20 W and supports160 character long SMS. SUBSCRIBER IDENTITY MODULE (SIM): It provides smart card contains the International Mobile Subscriber Identity (IMSI) and allows user to send and receive calls and receive other subscribed services and encoded network identification details- Key Kick and A3, A5 and A8 algorithms and protected by a password or PIN. It Can be moved from phone to phone ± contains key information to activate the phone. 8 BASE STATION SUBSYSTEM (BSS): Base Station Controller (BSC): It manages Radio resources for BTS and assigns Frequency and time slots for all MS¶s in its area and handles call set up. It provides transcending and rate adaptation functionality, Handover for each MS, Radio Power control and It communicates with MSC and BTS. Network Switching Subsystem (NSS): Mobile Switching Center (MSC) It manages communication between GSM and other networks and Call setup function and basic switching and Call routing and Billing information and collection and Mobility management such as - Registration. - Location Updating. - Inter BSS and inter MSC call handoff. MSC does gateway function while its customer roams to other network by using HLR/VLR. 9 Home Location Registers (HLR): It is a permanent database about mobile subscribers in a large service area (generally one per GSM network operator).Its a database contain IMSI MSISDN, prepaid /postpaid. It controls roaming restrictions, supplementary services. Visitor Location Registers (VLR): It is a temporary database which updates whenever new MS enters its area, by HLR database and controls those mobiles roaming in its area, reduces number of queries to HLR. Its database contains IMSI, TMSI, MSISDN, MSRN, Location Area, authentication key. Authentication Center (AUC): It protects against intruders in air interface and maintains authentication keys and algorithms and provides security triplets (RAND, SRES, and Kc).It is generally associated with HLR. Equipment Identity Register (EIR): It is a database that is used to track handsets using the IMEI (International Mobile Equipment Identity) and made up of three sub-classes: The White List, the Black List and the Gray List. It has only one EIR per PLMN. 10 GSM SPECIFICATION Carrier Separation : 200 Khz . Duplex Distance : 45 Mhz. No. of RF carriers : 124. Access Method : TDMA/FDMA. Modulation Method: GMSK. Modulation data rate : 270.833 Kbps. CALL ROUTING It provides two types of services. These are described below. Call Originating from MS. Call termination to MS. 12 BUILDING BLOCKS The building blocks of GSM are of various types which are described briefly. AMPS ± Advanced Mobile Phone System. TACS ± Total Access Communication System. NMT ± Nordic Mobile Telephone System. AMPS ² Advanced Mobile Phone System It is a analog technology which is used in North and South America and approximately 35 other countries and it operates in the 800 MHz band using FDMA technology. TACS ² Total Access Communication System It is variant of AMPS. It deployed in a number of countries and primarily in the UK. NMT ± Nordic Mobile Telephone System It is a analog technology. It deployed in the Benelux countries and Russia and operates in the 450 and 900 MHz band. It is the first technology to offer international roaming only within the Nordic countries. 17 SECURITY IN GSM On air interface, GSM uses encryption and TMSI instead of IMSI.SIM is provided 4-8 digit PIN to validate the ownership of SIM.3 algorithms are specified : - A3 algorithm for authentication. - A5 algorithm for encryption. - A8 algorithm for key generation. CHARACTERISTICS OF GSM STANDARD It is fully digital system using 900, 1800 MHz frequency band. TDMA over radio carriers (200 KHz carrier spacing). The 8 full rate or 16 half rate TDMA channels per carrier. It provides User/terminal authentication for fraud control. Encryption of speech and data transmission over the radio path. It has all international roaming capability. It is of low speed data services (up to 9.6 Kb/s) and can Compatibility with ISDN.Also support of Short Message Service (SMS). 23 ADVANTAGES OF GSM OVER ANALOG SYSTEM Its Capacity increases and reduced RF transmission power and longer battery life.Fascilities of International roaming capability.It has better security against fraud (through terminal validation and user authentication).Also provides Encryption capability for information security and privacy and Compatibility with ISDN,leading to wider range of services. 24 GSM Applications It has various application which are listed below: Mobile telephony. GSM-R. Telemetry System. - Fleet management. - Automatic meter reading. - Toll Collection. - Remote control and fault reporting of DG sets. Value Added Services. 25 FUTURE OF GSM 2nd Generation GSM -9.6 Kbps (data rate) 2.5 Generation ( Future of GSM) HSCSD (High Speed ckt Switched data) Data rate : 76.8 Kbps (9.6 x 8 kbps) GPRS (General Packet Radio service) Data rate: 14.4 - 115.2 Kbps EDGE (Enhanced data rate for GSM Evolution) Data rate: 547.2 Kbps (max) 3 Generation WCDMA(Wide band CDMA) Data rate : 0.348 ± 2.0 Mbps. 26 CONCLUSION The aim of the training report is to give an overview of the GSM system and not to provide a complete and exhaustive guide. As it is shown above, GSM is a very complex standard. It can be considered as the serious attempt to fulfill the requirements for a universal personal communication system.GSM is used as a basis for the development of the universal mobile telecommunication system (UTMS) 27 BIBLIOGRAPHY The following is the list of resources referred to during the creation of this seminar Report. Mobile Communication by Johen Schiller,Low priccce Edition. www.scribd.om\gsmreport www.projects&seminar.com\gsmrepot www.uscwc.com\gsmreport www.en.wikipedia.org/wiki/gsmseminar_report 28 APPENDIX 1. GSM:Global system for mobile 2. MS:Mobile Station 3. ME: Mobile Equipment 4. SIM: Subscriber Identity Module 5. BSS:Base Station Subsystem 6. BTS:Base Transceiver System 7. BSC: Base Station Controller 8. NSS:Network Switching System 9. MSC: Mobile S witching Centre 10. HLR:Home Location Resister 11. VLR:Visitor Location Resister 12. AUC:Authentication Centre 13. EIR:Equipment Identity Resister 14. EMEI:International Mobile Equipment Identity 15. CDMA:Code Division Multiple Access 16. TDMA:Time Division Multiple Access 17. FDMA:Frequency Division Multiple Access 18. GMSC: GATEWAY MOBILE SWITCHING CONTROL 29