BRIEF HISTORY OF MOBILE COMMUNICATIONS1973 - Dr. Martin Kooper Father of Mobile Phones Technology uses Simple Receiver & Transmitter1978- Bahrain Telephone Company -1G( Ist Generation)Commercial Cellular Telephone Systemonly 250 Subscribers
1980- NTT-Nippon Telegraph & TelephoneCompany ( Ist Generation(1G)) New Cellular Technology in Japan1981- Nordic Mobile Phone ( Ist Generation(1G)) Used in Northern European Countries Offers Speech onlyFirst Generation (1G) mobile systems were designed tooffer a single service, i.e., speech.
Second Generation (2G) 1982- GSM -Group Speciale Mobile (IInd Generation(2G)) Global System for Mobile Communication Fully Digital Technology Offers Speech & Data Service Most successful DIGITAL MOBILE COMUNICATION SYSTEM1983- AMPS-Advanced Mobile Phone System(IInd Generation(2G)) Developed in US1991-DECT-Digital Enhanced Cordless Telephone(IIndGeneration(2G)) Developed by ETSI(European Technical Standard Institute)
Second Generation (2G) mobile systems were alsodesigned primarily to offer speech with a limited capability tooffer data at low rates.(max 9.6kbits/s)GSM (Global System for Mobile comm)can only offer a datarate of 9.6 kbps2.5G-GPRS General packet Radio Service GPRS allows simultaneous voice and data communicationIncrease data transmission speeds from the current 9.6 Kbps to over 100Kbps2.75G- EDGE -Enhanced Data rates for GSM Evolution Supports High-speed data applications such as video services 384 kbps data transfer rate
THIRD GENERATION(3G) 1998-Satellite Mobile Communication System Using in Europe 2 Satellite systems are used 1. Iridium-66 satellites 2.Globalstar-less than 35 System is now called UMTS Universal Mobile Telephone System2001-3G Mobile Systems IMTS -International Mobile Telecomm. System
Third Generation (3G) mobile systems are expected tooffer high-quality multi-media services and operate in differentenvironments3G systems are referred to as Universal MobileTelecommunications System (UMTS) in Europe andInternational Mobile Telecommunications 2000(IMT2000) worldwide.Frequency band 1.8 -2.5 GHz2Mbps data transfer rate. 4G SYSTEMS Frequency band (2 – 8 GHz) Expecting- 20 Mbps-100Mbps Data Transfer Rate
Defining Mobility .. From the Latin word “Mobilis” = “to move” able to move freely or easily Properties Reachability (anywhere) Accessibility (any device) Service portability
2 Different Kinds of MobilityUser MobilityUser accessing the telecomm. services at different places.ie the User can be mobile and services will follow him…..Device Portability Communication Device Moves(with or without a user)eg. Mobile phone system
2 types of Voice & Data Communication1. Wired Communication2. Wireless Communication
Wireless Transmission Without wire communicating Downlink Freq. R1 R2 signals Base Station R4 R3
In Mobile communication Downlink Freq. R1 R2 signals R4 R3 Uplink Freq.
Uplink Freq - From Receiver to Base stationDownlink Freq- From Base station To ReceiverGSM Mobile Communication Frequency range inIndia 890-915 MHz- Uplink Freq 935-960 MHz - Downlink Freq.
Signal propagation ranges Transmission range – communication possible – low error rate Detection range – detection of the signal sender possible – no communication transmission possible distance Interference range detection – signal may not be interference detected – signal adds to the background noise
BTS -Base Transceiver StationThese transmitting stations or Base stations are called AntennasIn Mobile comm. They are called BTS -Base Transceiver Station
Each Base Station covers a certain area called a CELL For Each BTS only one cell Cell-A basic geographic unit of a cellular system
Maximum Cell Radii is 100 of metres in cities 35 kms in Open space Radio stations use powerful transmitters with huge cells
Mobile Base stations generate very small cells why?890-915 MHz- Uplink Freq935-960 MHz - Downlink Freq. f3 f5 f2 1. Frequency Reuse f4 f6 f5 f1 f4 f3 f7 f1 f2 2. Less Transmission power 3. Local Interference only
Components in Cellular System Architecture 1. Cell-A basic geographic unit of a cellular system 2. Cluster(Cell Site) -Group of Cells f5 f4 f6 f1 f3 f7 f2
Cells with the same no. have the same set of frequencies f3 7 cells in one cluster f5 f2f4 f6 f5 f1 f4 Coverage area of Cells are calledf3 f7 f1 FOOTPRINT f2 No Channels are reused within a cluster
3. Cell Splitting Cities contain large number of low power BTS Produce large no. of cells Handle heavy traffic & Less Interference
3. Cell Splitting Rural areas contain only one high power BTS Produce only one cell Covers more area, Interference will be very high
Some FiguresNo. of Cells in one cluster or cellsite = 3Subscribers supported per cell = 596Total No. of Subscribers /Cluster or cellsite =1788
POPULAR TECHNOLOGY USED IN MOBILE COMMUNICATION
GSM - Group speciale Mobile Global system for Mobile Communication 2nd Generation system Formed in 1982 Initially Implemented in Europe Using 10 billion People in 212 countries Technology that widely used in India-700 million customers 9.6 Kbits/sec DTR(Data Transf. Rate)
Major Companies dealing GSM Technology inIndia
Primary Objective of GSM GSM phone is compatible with Fixed Landline Networks
GSM Mile Stones Year Mile Stone 1982 GSM Formed 1986 Field Test 1987 Access Methods Chosen 1988 MOU Signed 1989 Validation of GSM System 1990 Preoperation System 1989 Validation of GSM System 1991 Commercial System Startup 1993 Coverage of Main Roads/Cities 1995 Coverage of Rural areas
GSM in 3 Frequencies GSM -900 MHz Used In 890-915 MHz- Uplink Freq India 935-960 MHz - Downlink Freq.GSM 1800 MHz 1710-1785 MHz -Uplink Freq. DCS-1800 1930-1990 MHz- Downlink Freq Digital Comm. ServiceGSM 1900 MHz 1850-1910MHz- Uplink Freq PCS-1900 1930-1990MHz- Downlink Freq Personal Comm. Service
Ingredients 3: Infrastructure 2 Not „visible“, but comprise the major part of the network (also from an investment point of view…) Management Data basesSwitching units Monitoring
GSM network is mainly divided in to 3 Major Systems 1. Switching System (SS) 2. Base Station System(BSS) 3. Operation & Support System(OSS)
PSTN AUC VLR Switching system HLRPLMN GMSC EIR Operation & MSC SupportOther GIWU System Base Station OSS BSC System BTS Mobile Station
1. Switching System(SS) Heart of GSM Performs Call Processing and Subscriber related functions Functional Units in SS 1. MSC- Mobile Service Switching Centre High Performance Digital Switch Fixed Backbone Complete Connection Setup & Release IWF - Connects to other Networks
2. HLR - Home Location Register Most Important Database Stores Permanent Data about the subscriber Location Information MSIN no. ,IMSI no. MSRN no.Eg:-IMSI(MCC+MNC+MSIN)3. VLR- Visitor Location Register Database Stores temporary data about subscriber 4. AUC- Authentication Centre Provides Security User Authentication & Data Encryption
5. EIR- Equipment Identity Register Database contains the information about the identity of mobile equipment- Unique identity number for mobile devices IMEI- International Mobile Equipment Identity NO.*#06# -Shows a 17 digit No.In Nokia Phones#92702689# ShowsSlnoMfg datePurchase date……..
2. BSS- Base station System All Radio related functions Consists of 2 Components 1. BSC- Base Station Controller High Capacity Switch Call Configuration Handover Freq. Distribution 2. BTS- Base Transciever Station Handles Connection to the MS Generate Cells
3. OSS- Operation & Support System Functions for network operations & Management Consists of one important functional unit OMC-Operation & Maintenance Center Monitor & Controls the System A/C & Billing Subscriber & Security Management
Additional Functional Elements 1. MXE -Message Center Provides SMS, Voicemail,Fax, E-mail etc 2. MSN -Mobile Service Node Provides Intelligent Network Services 3. GMSC- Gateway Mobile Service Switching Centre A gateway that interconnects two networks: the cellular network and the PSTN.
GSM Services1. SMS - Short Message Service -160 alphanumeric characters2.EMS- Extended Message Service -760 alphanumeric characters3.MMS-Multimedia Message Service4. Cell Broadcast5. Call forwarding6.Barring of Incoming Calls7. Barring of Outgoing Calls8.AOC- Advice of Charge9. Call hold10. Call waiting
11. CLIP- Call Line Identification Presentation12. CUG - Closed user Group
Evolution Path for GSM IMT-2000 Capable Systems 3GGSM GPRS EDGE Existing New spectrum spectrum 2G evolved 2G 3G14.4 kbps 64–115 kbps 115–384 kbps 0.384–2 mbps
Key Feature of GSM SIM- Subscriber Identity Module Detachable Smart Card User Subscribed Information Phone Book PIN- Personal Ident. No. Size-16KB,64 KB,512 KB
2 Types of Calling In GSM 1. Calling to Mobile (Mobile Terminated Call) 2. Mobile to Fixed Telephone Network (Mobile Originated Call)
Mobile Terminated Call 1: calling a GSM subscriber 2: forwarding call to GMSC GSM 3: signal call setup to HLR 4 HLR VLR 4, 5: request MSRN from 5 8 9 3 6 VLR 14 15 calling 7 6: forward responsible station 1 PSTN 2 GMSC MSC MSC to GMSC 10 10 13 10 16 7: forward call to BSS BSS BSS current MSC 11 11 11 8, 9: get current status of 11 12 17 MS MS 10, 11: paging of MS 12, 13: MS answers 14, 15: security checks 16, 17: set up connection
Mobile Originated Call 1, 2: connection request 3, 4: security check VLR 5-8: check resources 3 4 (free circuit) PSTN 6 GMSC 5 MSC 9-10: set up call 7 8 2 9 1 MS BSS 10
Advantages of GSMLess signal deterioration inside buildings.Ability to use repeatersThe availability of Subscriber Identity Module allows users to switchnetworks and handsets.GSM covers virtually all parts of the world so international roaming is nota problem.The much bigger number of subscribers globally creates a betternetwork effect for GSM handset makers, carriers and end users.