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ALT CENTRE

T. T. L. A. C. ALT CENTRE. CELLULAR MOBILE RADIO. PART I A Brief History. PART II Cellular Concepts. PART III GSM- Radio Interface. T. T. L. A. C. ALT CENTRE. MOBILE COMMUNICATION. REVOLUTION IN TELECOM.

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ALT CENTRE

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  1. T T L A C ALT CENTRE CELLULAR MOBILE RADIO PART I A Brief History PART II Cellular Concepts PART III GSM- Radio Interface

  2. T T L A C ALT CENTRE MOBILE COMMUNICATION • REVOLUTION IN TELECOM. • MOBILE COMMUNICATION IS A VERY RAPIDLY GROWING AND A POPULAR SERVICE. • MORE THAN 40 FOLD INCREASE IN LAST 10 YEARS • IT HAS BECOME A BACKBONE FOR BUSINESS • SUCCESS AND EFFICIENCY • CHANGED THE LIFE STYLE ALL OVERTHE • WORLD.

  3. T T L A C ALT CENTRE MOBILE COMMUNICATIONWHAT • PHONES ON THE MOVE • IT ALLOWS TO COMMUNICATE TO PEOPLE • WITH ANYBODY WHILE ON MOVE • (PHONES FOR THE PEOPLE , NOT FOR THE PLACES) • PROVIDES VOICE , FAX, SLOW SPEED DATA (today) • WIRELESS APPLICATION PROTOCOL (WAP) • ENABLES HIGHER BANDWIDTH ACCESS (WIRELESS ACCESS TO INTERNET)

  4. MOBILE COMMUNICATION T T L A C ALT CENTRE OBJECTIVES • Any time Anywhere • Mobility & Roaming • High capacity & subs. density • Efficient use of radio spectrum • Seamless Network Architecture • Low cost • Flexibility • Innovative Services • Standard Interfaces

  5. T T L A C ALT CENTRE MOBILE COMMUNICATION HISTORY • 1946 Appeared in St .Louis USA • 1970 BELL LAB introduced Cellular Principle • 1979 AMPS System in US • 1980s TACS & NMT systems • 1990s Digital Systems

  6. T T L A C ALT CENTRE MOBILE COMMUNICATION • 1946- 1960s 1980s 1990s 2000s • Appeared 1G 2G 3G • Analog Digital Digital • Multi Multi Unified Standard StandardStandard Terrestrial TerrestrialTerr. & Sat

  7. T T L A C ALT CENTRE MOBILE COMMUNICATION FREQUENCY BANDS • GSM 890-915 MHz (Uplink) 935-960 MHz (Downlink) • DCS 1710-1785: 1805-1880 MHz • DAMPS 824-849 : 869 - 894 MHz • CDMA 824-849 : 869 - 894 MHz • PDC 940-956 : 810 - 826 MHz

  8. T T L A C ALT CENTRE MOBILE COMMUNICATION WIRELESS GENERATIONS • 1 G -analog (cellular revolution) - only mobile voice services • 2 G - digital (breaking digital barrier) - mostly for voice services & data delivery possible • 3 G - Voice & data ( breaking data barrier) - Mainly for data services where voice services will also be possible

  9. T T L A C ALT CENTRE MOBILE COMMUNICATION THIRD GENERATION (3 G ) STANDARD INTERNATIONAL MOBILE TELECOM 2000. ( IMT-2000) IMT  A FUTURE STANDARD IN WHICH A SINGLE INEXPENSIVE MOBILE TERMINAL CAN TRUELY PROVIDE COMMUNICATIONS ANY TIME AND ANY WHERE

  10. T T L A C ALT CENTRE MOBILE COMMUNICATION THIRD GENERATION (3 G ) S DTANDARD INTERNATIONAL MOBILE TELECOM 2000. ( IMT-2000) • ITU’s VISION FOR THIRD GENERATION MOBILE SYSTEM • SINGLE UNIFIED STANDARD (Data & Multimedia Services) • ANYWHERE, ANYTIME COMMUNICATION ACROSS NETWORKS, ACROSS TECHNOLOGIES, SEAMLESS OPERATION USING A SMALL POCKET TERMINAL WORLDWIDE. • HIGH SPEED ACCESS 384 KB/S & 2MB/S FAST WIRELESS ACCESS TO INTERNET • FULL MOTION VIDEOPHONE • TERRESTRIAL & SATELLITE COMPONETS

  11. T T L A C ALT CENTRE CELLULAR MOBILE CONCEPTS

  12. T T L A C ALT CENTRE CELLULARMOBILECONCEPTS • RADIO IN LOCAL LOOP • LIMITED AVAILABILITY OF RF SPECTRUM • CELLULAR PRINCIPLE • INTERFERENCE PROBLEM • INTERFERENCE AND SYSTEM CAPACITY • FREQUENCY REUSE PATTERN • TRUNKING EFFICIENCY • CELLULAR ENVIRONMENT • CAPACITY CONSIDERATIONS • FUTURE TRENDS

  13. T T L A C ALT CENTRE CELLULARMOBILECONCEPTS FERQUENCY SCARCITY PROBLEM  Tel Ex.   WIRED NETWORK 100,000 50 = 5 Ghz  Khz (NOT POSSIBLE) Hence Individual RF Loop is not extended But a Common group of channels is shared

  14. CELLULARMOBILECONCEPTS T T L A C ALT CENTRE ASSUMPTIONS Traffic /User = 30 mE , GOS = 1%

  15. CELLULARMOBILECONCEPTS T T L A C ALT CENTRE • 360 * 25 * 2 * 1000 = 18 Mhz • FOR A CELL OF 10 KM RADIUS ONLY • WHICH IS IMPOSSIBLE TO BE ALLOCATED • HENCE FREQUENCY REUSE IS A MUST TO • COVER THE TOTAL SERVICE AREA WITH • A LIMITED AVAILABLE RF RESOURCES • HENCE THE NEED FOR A CELLULAR PRINCIPLE

  16. T T L A C ALT CENTRE CELLULARMOBILECONCEPTS 2 1 OMNI DIRECTIONAL CELLS

  17. CELLULARMOBILECONCEPTS T T L A C ALT CENTRE WHAT IS A CELL ? • A base station (transmitter) having a number of RF channels • is called a cell • Each cell covers a a limited number of mobile subscribers • within the cell boundaries ( Coverage area) • Typical Cell Radius Aprrox = 30 Km (Start up), 1 KM (Mature)

  18. T T L A C ALT CENTRE GIVEN FREQ. RESOURCE 1 2 3 4 5 6 7 CELLULARMOBILECONCEPTS 2 3 7 1 4 6 5 A CLUSTER OF CELLS

  19. T T L A C ALT CENTRE 2 2 7 3 7 1 Given Freq Resource 3 6 4 5 6 4 1 2 3 4 5 6 7 5 Frequency Reuse Pattern “N”=7 CELLULARMOBILECONCEPTS D R 1 CELLULAR PRINCIPLE N=7

  20. T T L A C ALT CENTRE MOBILE COMMUNICATION Cellular Principle • SIMULTANEOUS RE USE OF SAME FREQUENCIES AT DIFFERENT GEOGRAPHICAL LOCATIONS • SERVES MORE COVERAGE AREA • REQUIRES LESS RF BW TO COVER A GIVEN AREA • FREQ. REUSE INTRODUCES INTERFERENCE • INTERFERENCE LIMITED SYSTEMS • COMPROMISE BETWEEN SPEECH QUALITY & SYSTEM CAPACITY

  21. CELLULARMOBILECONCEPTS T T L A C ALT CENTRE f3 1 * 3 f1 2 f2 Three Sectored Cell FREQUENCY REUSE PATTERN GSM = 4/12 ; 4 Cell Pattern & each cell with 3 sectors DAMPS = 7/21 ; 7 Cell Pattern & each cell with 3 sectors CDMA = 1/3 ; 1 Cell Pattern & each cell with 3 sectors

  22. CELLULARMOBILECONCEPTS T T L A C ALT CENTRE TRUNKING EFFICIENCY 20 10 10 50 subs 50 subs 132 Subs TRUNKING EFFICIENCY • The Number Of Users Served In A Cell Are Directly • Proportional To The Access Channels Allocated In A Cell • More The Number Of Access Channels In A Cell • Further Increase In The System Handling Capacity • It is better to have a single cell than to split into two • with half the number of access channels

  23. CELLULARMOBILECONCEPTS T T L A C ALT CENTRE An Example Assume Number of Voice Channels = 395, Average Call Duration = 2 Minutes , GoS = 2% Using Traffic Tables we get :

  24. T T L A C ALT CENTRE Cellular Environment • Cellular Environment is quite different from fixed radio systems -Cellular approach -MOBILITY of the user -Dynamically changing surrounding terrain conditions •  RF Signal attenuates, RF d-  =4 (generally) • Multipath Fading  Distortions • Signal fluctuations due to mobility of the user

  25. T T L A C ALT CENTRE CELLULAR ENVIRONMENT -COUNTER MEASURES • Techniques • Power Control • Channel Coding • Interleaving • Equalization • Slow Frequency Hopping • Antenna Diversity

  26. T T L A C ALT CENTRE b/s Hz INFORMATION BASE BAND MODULATOR TRANS/RECE MOBILE COMMUNICATION BASIC RADIO TRANS/RECE Cellular Principle N=1,3,4,7 BASEBAND Speech Coder 32Kb/s,13Kb/s or LESS MODULATOR Spectrum &C/No Q P S K or Its Variants

  27. T T L A C ALT CENTRE .. MOBILE COMMUNICATION BASE STATION MOBILE SUBSCRIBER BASE CONTROLLER MOBILE SWITCH TYPICAL ARCHITECTURE

  28. T T L A C ALT CENTRE 1 2 8 1 1 1 GSM CAPACITY CONSIDERATIONS With 2 % GoS  2.94 E  2.94E/25mE=120 Subs 8 Access Channels 1--Signaling 7- Voice 120 Subs/Sector  3 = 360 Subscribers

  29. T T L A C ALT CENTRE 1 12 1 12 12 1 GSM CAPACITY CONSIDERATIONS 4 4 4 8 Access Channels 1--Signaling 7- Voice 32 Access Chls 3--Signaling 29- Voice 96Access Chls 9--Signaling 87- Voice 3200 3 = 9600Subs 120 3 = 360 Subs 840 3 = 2520 Subs

  30. T T L A C ALT CENTRE MOBILE COMMUNICATION PROJETED MARKET SIZE WORLD CELLULAR PCS MARKET 1N 2004 • ASIA -PACIFIC 35% 225 M • WESTERN EUROPE 30 % 192.85 M • NORTH AMERICA 17 % 109.25 M • LATIN AMERICA 8 % 51.5 M • EASTERN EUROPE 5 % 32.25 M • AFRICA 3 % 19.25 M • MIDDLE EAST 2 % 12.5 M

  31. T T L A C ALT CENTRE MOBILE COMMUNICATION PROJETED MARKET SIZE CELLULAR MARKET WORLD INDIA • 2000 426 M 3 M • 2005 850 M 25 M • 2010 1700 M More than fixed lines • 2015 3000 M ---- It won’t be long before we ask “Phones used to have wires -- why”?

  32. T T L A C ALT CENTRE Public Land Mobile Network • INDIA has adopted GSM standard for PLMN. • Digital Cellular System. • Operates at 900 MHz. • International Roaming facility. • Power class 0.8 to 20W. • Cell Radius upto 35 Kms. • Maximum mobility speed 250 Km/hr.

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