CELLULAR MOBILE RADIO T ALT CENTRE PART I

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

T ALT C 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 OVER THE WORLD. ALT CENTRE

MOBILE COMMUNICATION WHAT • 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) T ALT CENTRE

MOBILE COMMUNICATION 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 T ALT CENTRE

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

T ALT CENTRE MOBILE COMMUNICATION • 1946 - 1960 s • Appeared 1980 s 1990 s 2000 s 1 G 2 G 3 G • Analog • Multi Standard Terrestrial Digital Multi Standard Unified Standard Terrestrial Terr. & Sat

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 T 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 T 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 T ALT CENTRE

MOBILE COMMUNICATION T ALT CENTRE 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 & 2 MB/S FAST WIRELESS ACCESS TO INTERNET • FULL MOTION VIDEOPHONE • TERRESTRIAL & SATELLITE COMPONETS

T ALT CENTRE CELLULAR MOBILE CONCEPTS

CELLULAR MOBILE CONCEPTS T ALT CENTRE • 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

CELLULAR MOBILE CONCEPTS FERQUENCY SCARCITY PROBLEM T ALT CENTRE • Tel Ex. WIRED NETWORK 100, 000 50 Khz = 5 Ghz (NOT POSSIBLE) Hence Individual RF Loop is not extended But a Common group of channels is shared

CELLULAR MOBILE CONCEPTS T ALT CENTRE ASSUMPTIONS Traffic /User = 30 m. E , GOS = 1%

CELLULAR MOBILE CONCEPTS T 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

CELLULAR MOBILE CONCEPTS T ALT CENTRE 1 OMNI DIRECTIONAL CELLS 2

CELLULAR MOBILE CONCEPTS WHAT IS A CELL ? T ALT CENTRE • 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)

CELLULAR MOBILE CONCEPTS 2 1 4 6 ALT CENTRE GIVEN FREQ. RESOURCE 3 7 T ALT C 5 A CLUSTER OF CELLS 1 2 3 4 5 6 7

CELLULAR MOBILE CONCEPTS T ALT CENTRE 2 7 2 3 7 1 6 R 4 5 D 3 Given Freq Resource 1 6 4 12 3 456 7 5 Frequency Reuse Pattern “N”=7 CELLULAR PRINCIPLE N=7

MOBILE COMMUNICATION Cellular Principle T ALT CENTRE • 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

CELLULAR MOBILE CONCEPTS FREQUENCY REUSE PATTERN T ALT CENTRE f 3 3 * 1 2 f 1 f 2 Three Sectored Cell 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

CELLULAR MOBILE CONCEPTS • T ALT CENTRE 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 TRUNKING EFFICIENCY 10 50 subs 20 132 Subs • It is better to have a single cell than to split into two with half the number of access channels

CELLULAR MOBILE CONCEPTS An Example Assume Number of Voice Channels = 395, Average Call Duration = 2 Minutes , Go. S = 2% Using Traffic Tables we get : T ALT CENTRE

T ALT C Cellular Environment ALT CENTRE • 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 • Signal fluctuations due to mobility of the user Distortions

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

MOBILE COMMUNICATION BASIC RADIO INFORMATION BASE BAND b/s Hz MODULATOR TRANS/RECE BASE BAND MODULATOR TRANS/RECE Speech Coder Spectrum &C/No Cellular Principle 32 Kb/s, 13 Kb/s or LESS QPSK or Its Variants N=1, 3, 4, 7 T ALT CENTRE

MOBILE COMMUNICATION T ALT CENTRE . . MOBILE SWITCH BASE STATION CONTROLLER TYPICAL ARCHITECTURE MOBILE SUBSCRIBER

GSM CAPACITY CONSIDERATIONS T ALT CENTRE 1 1 2 8 8 Access Channels 1 --Signaling 7 - Voice With 2 % Go. S 2. 94 E 2. 94 E/25 m. E=120 Subs/Sector 3 = 360 Subscribers

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

MOBILE COMMUNICATION PROJETED MARKET SIZE WORLD CELLULAR PCS MARKET 1 N 2004 • • ASIA -PACIFIC WESTERN EUROPE NORTH AMERICA LATIN AMERICA EASTERN EUROPE AFRICA MIDDLE EAST 35% 30 % 17 % 8% 5% 3% 2% 225 M 192. 85 M 109. 25 M 51. 5 M 32. 25 M 19. 25 M 12. 5 M T ALT CENTRE

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

T ALT C Public Land Mobile Network • • ALT CENTRE INDIA has adopted GSM standard for PLMN. Digital Cellular System. Operates at 900 MHz. International Roaming facility. Power class 0. 8 to 20 W. Cell Radius upto 35 Kms. Maximum mobility speed 250 Km/hr.