GLOBAL SYSTEM FOR MOBILE COMMUNICATION

GSM – GLOBAL SYSTEM FOR MOBILE COMMUNICATION : GSM – GLOBAL SYSTEM FOR MOBILE COMMUNICATION SARTHAK SAPTARSHI BANDOPADHYAY RIDDHI CHAKRABORTY ARKA GHOSH SHIMUL GHOSH SK.GULSHAN MASUD HOSSAIN TANAY SAHA DALAL Under the guidance of Asst.prof . SUDIP DOGRA Head of the Department

WHAT IS COMMUNICATION? : WHAT IS COMMUNICATION?

Slide 3 : COMMUNICATION is the process of establishing connection or link between two points for information exchange.

TYPES OF COMMUNICATION : TYPES OF COMMUNICATION LINE COMMUNICATION WIRELESS COMMUNICATION

LINE COMMUNICATION : LINE COMMUNICATION In Line Communication , the medium of transmission is a pair of conductors called transmission line. The transmitter and receiver are connected are connected through a wire or line. Examples:- Telephone Broadband Dial-up internet

Problems:- : Problems:- Installation and maintenance cost high. It is complex. Overcrowds open space. Not fit for long distance communication. Lack of mobility.

Slide 7 :

WIRELESS COMMUNICATION : WIRELESS COMMUNICATION WHY WIRELESS?

Slide 9 : To span a distance beyond the capabilities of typical cabling. To avoid obstacles such as physical structures, EMI, or RFI. To provide a backup communications link in case of normal network failure. To link portable or temporary workstations. To overcome situations where normal cabling is difficult or financially impractical. To remotely connect mobile users or networks.

Slide 10 : WHAT IS WIRELESS COMMUNICATION?

THE BEGINING : THE BEGINING Most important discovery made in wireless history was in 1888 by Rudolf Hertz. First commercial radio factory called “Wireless Telegraph and Signal Company“ was set up by G.Marconi in 1896. First commercially available radio telephone network was set up by Bell Laboratories in earl 1950’s.

Slide 12 : Wireless communication may be via: Radio frequency communication. Microwave communication, for example long-range line-of-sight via highly directional antennas, or short-range communication, or Infrared (IR) short-range communication, for example from remote controls or via IRDA RANGE:- Wireless communication spans the spectrum from 9 KHz to 300 GHz

Different modes of wireless communication:- : Different modes of wireless communication:- One to Many(BROADCASTING):-Broadcasting is the distribution of audio and/or video signals which transmit programs to an audience. This is one-way type of communication. There are two types of broadcasting. One can record and then broadcasts Live Broadcasting

ONE - ONE WIRELESS COMMUNICATION : ONE - ONE WIRELESS COMMUNICATION CORDLESS SYSTEM PAGING SYSTEM WALKIE-TALKIE CELLULAR SYSTEMS

CORDLESS SYSTEM:- : CORDLESS SYSTEM:- Cordless telephone systems are full duplex communication systems that use radio to connect a portable handset to a dedicated base station, which is then connected to a dedicated telephone line with a specific telephone number on the public switched telephone network (PSTN). The base station is on the subscriber premises.Its coverage is upto 100mts. DISADVANTAGE:- Limited Range and Mobility.

Paging systems:- : Paging systems:- Paging systems are communication systems that send brief messages to a subscriber. The message may be either a numeric message, an alphanumeric message, news headlines, faxes or a voice message. A message is sent to a paging subscriber via the paging system access number (usually a toll-free telephone number) with a telephone keypad or modem. The issued message is called a page. The paging system then transmits the page throughout the service area using base stations which broadcast the page on a radio carrier. DISADVANTAGE:- It is a simplex system where messages are received but not acknowledged.

Walkie-talkie:- : Walkie-talkie:- This is a half duplex type of radio systems which allows two-way communication, but use the same radio channel for both transmission and reception. It is portable in nature i.e. a radio terminal that can be hand held and used by someone at walking speed. DISAVANTAGE:- Limited mobility. Push to talk and Release to listen are its constraints.

CELLULAR SYSTEMS:- : CELLULAR SYSTEMS:- It is a full duplex system which allows simultaneous radio transmission & reception. It provides unlimited mobility. It accommodate a large number of users over a large geographic area within a limited frequency spectrum.

Problems of Early Mobile Radio Systems : Problems of Early Mobile Radio Systems Same frequencies could not be reused. Any attempts to achieve frequency reuse would result in interference. Low user capacity.

Slide 20 : Cellular Communication

WHY THE NAME”CELLULAR”? : The term cellular comes from the honeycomb shape of the of the areas into which a coverage region is divided, known as cells. A cell is the basic geographic unit of the cellular system. WHY THE NAME”CELLULAR”?

THE CELL CONCEPT : THE CELL CONCEPT It solves the problem of spectral congestion & user capacity. Here a single high power transmitter (large cell) is replaced with several low-power transmitters (small cells). The small cells provide coverage to a small portion of the service area. Each base station is allocated a portion of the total number of channels available to the entire system. Neighbouring base stations are assigned different groups of channels so that the interference between Base station is minimized.

COVERAGE PATTERNS : COVERAGE PATTERNS

COMPONENTS OF CELLULAR SYSTEMS : COMPONENTS OF CELLULAR SYSTEMS The cellular communications system consists of the following four major components:- 1. public switched telephone network (PSTN) 2. mobile telephone switching office (MTSO) 3. cell site with antenna system 4. mobile subscriber unit (MSU)

Slide 25 : PSTN The PSTN is made up of local networks, the exchange area networks, and the long-haul network that interconnect telephones and other communication devices on a worldwide basis. Mobile Telephone Switching Office (MTSO) The MTSO is the central office for mobile switching. It houses the mobile switching center (MSC), field monitoring and relay stations for switching calls from cell sites to PSTN. The MSC controls calls, tracks billing information, and locates cellular subscribers. The Cell Site The term cell site is used to refer to the physical location of radio equipment that provides coverage within a cell. A list of hardware located at a cell site includes power sources, interface equipment, radio frequency transmitters and receivers and antenna systems.

Slide 26 : Mobile Subscriber Units (MSUs) The mobile subscriber unit consists of a control unit and a transceiver that transmits and receives radio transmissions to and from a cell site. Three types of MSUs are available: 1. the mobile telephone (typical transmit power is 4.0 watts) 2. the portable (typical transmit power is 0.6 watts) 3. the transportable (typical transmit power is 1.6 watts

FREQUENCY REUSE:- : FREQUENCY REUSE:- Only a small number of radio channel frequencies were available for mobile systems, so frequency reuse of radio channels help to carry more than one conversation at a time. It is the design process of selecting and allocating channel groups for all the cellular base stations within the system. The same group of channels are may be used to cover different cells but are separated from one another by large distance to avoid interference. So we increase additional radio capacity without increasing radio spectrum. Here, number of available frequencies is 7, the frequency reuse factor is 1/7. Each cell is using 1/7 of available cellular channels.

CLUSTER : CLUSTER A cluster is a group of cells. No channels are reused within a cluster. In a cluster complete set of available frequencies are used. Example:- Let S duplex channels are present. Each cell has K channels(k

Channel capacity : Channel capacity It is the measure of total number of Duplex channels. Let a cluster (N cells) is repeated M times within the system the channel capacity C=MKN=MS If N(cluster size)is reduced keeping cell size constant then more clusters are required to cover the area which increases C. N is the measure of how much interference a mobile or base station can tolerate.

CHANNEL ASSIGNMENTS : CHANNEL ASSIGNMENTS Objectives:- Efficient utilization of radio spectrum. Increasing capacity. Minimizing interference. TYPES FIXED Channel assignment Dynamic Channel assignment

HANDOFF : HANDOFF The final obstacle in the development of the cellular network was, when a mobile subscriber traveled from one cell to another during a call. The adjacent areas do not use the same radio channels, a call must either be dropped or transferred from one radio channel to another when a user crosses the line between adjacent cells. To avoid this he process of handoff was created. Here MSC automatically transfers the call to a new channel of a new base station.

Handoff Types : Handoff Types Intra-cell handoff – narrow-band interference => change carrier frequency – controlled by BSC Inter-cell, intra-BSC handoff – typical handover scenario – BSC performs the handover, assigns new radio channel in the new cell, releases the old one Inter-BSC, intra-MSC handoff – handoff between cells controlled by different BSCs – controlled by the MSC Inter-MSC handoff – handoff between cells belonging to different MSCs – controlled by both MSCs

Handoff Types (cont’d) : Handoff Types (cont’d)

Handover Scenario at Cell Boundary : Handover Scenario at Cell Boundary

Handoff – 1G (Analog) systems : Handoff – 1G (Analog) systems Signal strength measurements made by the BSs and supervised by the MSC BS constantly monitors the signal strengths of all the voice channels Locator receiver measures signal strength of MSs in neighboring cells MSC decides if a handover is necessary

Slide 36 : Second generation systems & onwards:- Nowadays handoff decisions are mobile assisted. It is known as MAHO(Mobile Assisted Handoff). Every Mobile stations measures the received power from surrounding BS & reports the results to serving BS. A handoff is initiated when power received from BS of a neighboring cell is more by certain level for certain period of time from the serving BS. MAHO enable the handoff at faster rates. MAHO is suitable for microcellular environments. Intersystem handoff occurs when a mobile moves from one cellular system to another controlled by different MSC.

Problems faced : Problems faced In practical cellular systems, several problems arise when attempting to design for a wide range of mobile velocities:- High speed vehicles pass through the coverage region of a cell within a few seconds. Pedestrian users may never need a handoff during a call. Addition of microcells to provide capacity ,the MSC can quickly become burdened if high speed users are constantly being passed between very small cells. Practical limitation is the ability to obtain new cell sites. Another practical handoff problem in microcell systems is known as cell dragging.

The umbrella cell approach : The umbrella cell approach By using different antenna heights and different power levels, it is possible to provide “large” and “small” cells which are co-located at a single location. This technique is called the umbrella cell approach . It is used to provide large area coverage to high speed users while providing small area coverage to users traveling at low speeds. The umbrella cell approach ensures that the number of handoffs is minimized for high speed users and provides additional microcell channels for pedestrian users.

Cell Dragging : Cell Dragging WHAT IS IT? It is a practical handoff problem in microcell system. As the user travels away from the base station at a very slow speed, the average signal strength does not decay rapidly. The received signal at the base station may be above the handoff threshold, thus a handoff may not be made. This creates a potential interference and traffic management problem. HOW IT IS SOLVED? Handoff thresholds and radio coverage parameters must be adjusted carefully. For analog system =6 dB to 12 dB .Time to handoff=10secs. For digital system = 0 dB and 6 dB .Time to handoff=1to 2 secs.

Small-scale FADING : Small-scale FADING What IS IT? It is rapid fluctuations of the amplitudes , phases or multipath delays of a radio signal over a short period of time or distance. WHY IT OCCURS? It is caused by interference between two or more versions of transmitted signal which arrive at receiver at slightly different time. These waves are called multipath waves. f2 f1 Frequency Separation: |f1-f2| Multipath Channel Receiver

Small scale fading effects : Small scale fading effects Rapid changes in signal strength over a small travel distance or time interval. Random frequency modulation due to Doppler shifts on different multipath signals. Time dispersion (echoes) caused by multipath propagation delays.

Factors influencing small-scale fading : Factors influencing small-scale fading Multipath propagation often lengthens the time required for the baseband portion of the signal to reach the receiver. Relative motion between the base station and mobile results into frequency modulation due to Doppler shift. When surrounding objects move at a greater rate than mobile, then it dominates fading. The transmission bandwidth of the signal also influences small-scale fading.

Types of small scale fading : Types of small scale fading

Flat fading : Flat fading When channel bandwidth is greater than bandwidth of transmitted signal then flat fading occurs. Occurs when the amplitude of the received signal changes with time as channel gains changes over time. Occurs when symbol period of the transmitted signal is much larger than the Delay Spread of the channel. May cause deep fades.

Frequency selective fading : Frequency selective fading When channel bandwidth is smaller than bandwidth of transmitted signal then this type of fading occurs Occurs when channel multipath delay spread is greater than the symbol period. Symbols face time dispersion Channel induces Intersymbol Interference (ISI) Bandwidth of the signal s(t) is wider than the channel impulse response.

Fast fading : Fast fading Due to Doppler Spread Rate of change of the channel characteristics is larger than theRate of change of the transmitted signal The channel changes during a symbol period. The channel changes because of receiver motion. Coherence time of the channel is smaller than the symbol period of the transmitter signal Occurs when: BS < BD and TS > TC BS: Bandwidth of the signalBD: Doppler Spread TS: Symbol PeriodTC: Coherence Bandwidth

Slow fading : Slow fading Due to Doppler Spread Rate of change of the channel characteristics is much smaller than theRate of change of the transmitted signal Occurs when: BS >> BD and TS << TC BS: Bandwidth of the signalBD: Doppler Spread TS: Symbol PeriodTC: Coherence Bandwidth

Generations of Mobile Communication : Generations of Mobile Communication First Generation (1G) Systems Second Generation (2G) Systems Global System for Mobile Technology (GSM-2G) CdmaOne, IS-95 (2G) TDMA, IS-54, IS-136 (2G) Third Generation (3G) Systems Fourth Generation(4G) systems

First Generation (1G) Systems : First Generation (1G) Systems AMPS, the first generation cellular systems using analog voice transmission came into operation in 1983 and were referred to as an analog technology. This is because the RF carrier is modulated and transmitted using frequency modulation (FM), a simple analog modulation technique, with Frequency Division Multiple Access (FDMA) as the channel multiple access method. However, the control of the connection set up, the change of the base stations during a connection, (so-called hand-over or handoff) caused by the mobile station mobility, as well as other control procedures such as mobile station control, are implemented by transmission of digital signals.

Drawbacks of 1G : Drawbacks of 1G The first generation systems suffer from: Poor voice quality Poor battery life Large phone size No security, frequent call drops Limited capacity and poor handoff reliability between cells Much more modern systems technologically better than AMPS,are now available

2G SYSTEMS : 2G SYSTEMS The development of the digital technology, on one hand, and frequent cases when analog systems reached their full capacity, especially in big cities, on the other hand, led to the development of the second-generation (2G) systems. The main aim in the design of the 2G systems was the maximization of the system capacity measured as the number of users per spectrum per unit area. 2G networks are digital, both systems use digital signaling to connect the radio towers (which listen to the handsets) to the rest of the telephone system. Three primary benefits of 2G networks over their predecessors were that phone conversations were digitally encrypted, more efficient on the spectrum allowing for far greater mobile phone penetration levels; and data services for mobile, starting with SMS.

CAPACITY OF 2G SYSTEMS : CAPACITY OF 2G SYSTEMS Using digital signals system capacity in two key ways: Digital voice data can be compressed and multiplexed much more effectively than analog voice encodings through the use of various codecs, allowing more calls to be packed into the same amount of radio bandwidth. The digital systems were designed to emit less radio power from the handsets. The cells are smaller, so more cells could be placed in the same amount of space.

DRAWBACKS OF 2G : DRAWBACKS OF 2G There are drawbacks to the current GSM: The GSM is a circuit switched, connection oriented technology, where the end systems are dedicated for the entire call session. This causes inefficiency in usage of bandwidth and resources. The GSM-enabled systems do not support high data rates. They are unable to handle complex data such as video. These devices have small hardware configurations with less powerful CPUs, memory and display units, and support simple functionality. Only basic messaging services such as SMS can be supported. The GSM networks are not compatible with the current TCP/IP and other common networks because of differences in network hardware, software and protocols

Evolution of Wireless Sys. (2.5G) : Evolution of Wireless Sys. (2.5G) 2G telephony is highly successful Enhancement to 2G on data service GSM: HSCSD and GPRS IS-95: IS-95b IS-136: D-AMPS+ and CDPD The improved data rate is still too low to support multimedia traffic ITU initiated 3G standardization effort in 1992, and the outcome is IMT-2000.

Goals of 3G Systems : More services Web browsing VoD Video phone call Mobile computation Improved quality Higher rates: 2.048 Mbps for low speed users, 384 Kbps for modest speed users and 144 Kbps for high speed users More reliable and larger capacity Compatible with 2G systems More flexible Support both circuit-switching and packet-switching Work in hierarchical mode with pico-/micro-/macro-cells Support asymmetric services … Goals of 3G Systems

Evolution of Wireless Sys. (4G) : Evolution of Wireless Sys. (4G) Problems of 3G systems Immature 3G license auction increases the financial burden What are the killer applications of 3G? No unified standard (political factors dominate) 4G systems Research initiated, but still not well-defined Data-oriented, seamless integrated with wireline Indoor data rate up to 100 Mbps, outdoor data rate up to 20Mbps.

Slide 57 : Paradigm From 1G to Beyond 3G

GSM – GLOBAL SYSTEM FOR MOBILE COMMUNICATION : GSM – GLOBAL SYSTEM FOR MOBILE COMMUNICATION

DISCUSSION TOPICS : DISCUSSION TOPICS History Building Blocks System Architecture Features (Basic and Advanced) Advantages of GSM Future – what’s next

HISTORY : HISTORY Overview of GSM Milestones 1982 GSM Group, set up by CEPT, started Investigation to reserve a Spectrum in 900 MHz band for Pan-European Cellular Digital Telephony 1986 Two 25 MHz frequency Blocks [890-915 MHz, 935-960 MHz] reserved by EC, July 01, 1991 set as Introduction date. Choice of Digital and Narrow band [Approx. 200 KHz] TDMA made. 1987 13 Operators from 12 European Countries signed MOU to Support GSM 1989 ETSI established which took over GSM from CEPT 1992 Introduction of first Commercial GSM Network 1994 51 Commercial Networks Established 1996 More Than 20 Million Subscribers in 191 Networks, More than double of all Subscribers of other Digital Systems [D-AMPS, PDC, IS-95 CDMA] 2006 More than 2 billion subscribers (30% of world population and 82% of cellular market)

HISTORYcontd. : HISTORYcontd. GSM criteria – Good subjective speech quality Low terminal and service cost Support for international roaming – one system for all of Europe Ability to support handheld terminals Support for range of new services and facilities Enhanced Features ISDN compatibility Enhance privacy Security against fraud

Building Blocks : Building Blocks AMPS – Advanced Mobile Phone System TACS – Total Access Communication System NMT – Nordic Mobile Telephone System

Building Blockscontd. : Building Blockscontd. AMPS – Advanced Mobile Phone System analog technology used in North and South America and approximately 35 other countries operates in the 800 MHz band using FDMA technology

Building Blockscontd. : Building Blockscontd. TACS – Total Access Communication System variant of AMPS deployed in a number of countries primarily in the UK

Building Blockscontd. : Building Blockscontd. NMT – Nordic Mobile Telephone System analog technology deployed in the Benelux countries and Russia operates in the 450 and 900 MHz band first technology to offer international roaming – only within the Nordic countries

GSM System Hierarchy : GSM System Hierarchy Location Area MSC R. . . . . . GSM Network MSC Region Location Area BSC BSC Location Area . . . . . . . MSC R.

System Architecture : System Architecture Mobile Station (MS) Mobile Equipment (ME) Subscriber Identity Module (SIM) Base Station Subsystem (BBS) Base Transceiver Station (BTS) Base Station Controller (BSC) Network Subsystem Mobile Switching Center (MSC) Home Location Register (HLR) Visitor Location Register (VLR) Authentication Center (AUC) Equipment Identity Register (EIR)

System ArchitectureMobile Station (MS) : System ArchitectureMobile Station (MS) The Mobile Station is made up of two entities: Mobile Equipment (ME) 2. Subscriber Identity Module (SIM)

System ArchitectureMobile Station (MS) contd. : System ArchitectureMobile Station (MS) contd. Mobile Equipment Produced by many different manufacturers Must obtain approval from the standardization body Uniquely identified by an IMEI (International Mobile Equipment Identity)

System ArchitectureMobile Station (MS) contd. : System ArchitectureMobile Station (MS) contd. Subscriber Identity Module (SIM) Smart card containing the International Mobile Subscriber Identity (IMSI) Allows user to send and receive calls and receive other subscribed services Encoded network identification details Protected by a password or PIN Can be moved from phone to phone – contains key information to activate the phone

System ArchitectureBase Station Subsystem (BSS) : System ArchitectureBase Station Subsystem (BSS) Base Station Subsystem is composed of two parts that communicate across the standardized Abis interface allowing operation between components made by different suppliers Base Transceiver Station (BTS) Base Station Controller (BSC)

System ArchitectureBase Station Subsystem (BSS) contd. : System ArchitectureBase Station Subsystem (BSS) contd. Base Transceiver Station (BTS) Houses the radio transceivers that define a cell Handles radio-link protocols with the Mobile Station Speech and data transmissions from the MS are recoded Requirements for BTS: ruggedness reliability portability minimum costs

System ArchitectureBase Station Subsystem (BSS) contd. : System ArchitectureBase Station Subsystem (BSS) contd. Base Station Controller (BSC) Manages Resources for BTS Handles call set up Location update Handover for each MS

System ArchitectureNetwork Subsystem : System ArchitectureNetwork Subsystem Mobile Switching Center (MSC) Switch speech and data connections between: Base Station Controllers Mobile Switching Centers GSM-networks Other external networks Heart of the network Three main jobs: 1) connects calls from sender to receiver 2) collects details of the calls made and received 3) supervises operation of the rest of the network components

System ArchitectureNetwork Subsystem contd. : System ArchitectureNetwork Subsystem contd. Home Location Registers (HLR) - contains administrative information of each subscriber - current location of the mobile Visitor Location Registers (VLR) - contains selected administrative information from the HLR authenticates the user tracks which customers have the phone on and ready to receive a call periodically updates the database on which phones are turned on and ready to receive calls

System ArchitectureNetwork Subsystem contd. : System ArchitectureNetwork Subsystem contd. Authentication Center (AUC) mainly used for security data storage location and functional part of the network Ki is the primary element Equipment Identity Register (EIR) - Database that is used to track handsets using the IMEI (International Mobile Equipment Identity) Made up of three sub-classes: The White List, The Black List and the Gray List Optional database

System Architecture : System Architecture

GSM Interfaces: : GSM Interfaces: Radio Interface: Describes Data Interchange between MS and BSS Abis Interface: Describes Data Communications between BTS and BSC, allows Various Manufacturers Equipment A Interface: Describes Data Interchange between BSS and NSS

GSM EVOLUTION : GSM EVOLUTION

2G EVOLUTION TO 3G : 2G EVOLUTION TO 3G

CALL PROCESSING & MOBILE TERMINATING CALLS : CALL PROCESSING & MOBILE TERMINATING CALLS

SPEECH PROCESSING : SPEECH PROCESSING

STEPS: : STEPS: SPEECH CODING SPEECH ENCODER

CHANNEL ENCODING : CHANNEL ENCODING

INTERLEAVING : INTERLEAVING

Basic Features Provided by GSM : Basic Features Provided by GSM 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

Advanced Features Provided by GSM : Advanced Features Provided by GSM Calling Line ID - incoming telephone number displayed Alternate Line Service - one for personal calls - one for business calls Closed User Group - call by dialing last for numbers Advice of Charge - tally of actual costs of phone calls Fax & Data - Virtual Office / Professional Office Roaming - services and features can follow customer from market to market

Advantages of GSM : Advantages of GSM Crisper, cleaner quieter calls Security against fraud and eavesdropping International roaming capability in over 100 countries Improved battery life Efficient network design for less expensive system expansion Efficient use of spectrum Advanced features such as short messaging and caller ID A wide variety of handsets and accessories High stability mobile fax and data at up to 9600 baud Ease of use with over the air activation, and all account information is held in a smart card which can be moved from handset to handset

Slide 89 : Numbering Arrangement International Mobile Subscriber Identification number (IMSI) It identifies a unique international universal number of a mobile subscriber, which consists of MCC+MNC+MSIN. 1) MCC: country code, 460 2) MNC: network code, 00 or 01 3) MSIN: subscriber identification, H1H2H3H4 9XXXXXX, H1H2H3H4: subscriber registering place H1H2: assigned by the P&T Administrative Bureau (operator )to different provinces, to each province H3H4: assigned by each province/city the IMSI of user will be written into the SIM card by specific device and software and be stored into the HLR with other user information.

Slide 90 : It is the subscriber number commonly used. China uses the TDMA independent numbering plan: CC+NDC+ H1H2H3H4 +ABC CC: country code, 86 NDC: network code, 135—139, 130 H1H2H3H4: HLR identification code ABCD: mobile subscriber number inside each HLR Mobile Subscriber ISDN Number(MSISDN) Numbering Arrangement

Slide 91 : International Mobile Equipment Identification code (IMEI) It will uniquely identify a mobile station. It is a decimal number of 15 digits. Its structure is: TAC+FAC+SNR+SP TAC=model ratification code, 6 digits FAC=factory assembling code, 2 digits SNR=sequence code, 6 digits SP=reserved, 1 digit Numbering Arrangement

Mobile Subscribers : Mobile Subscribers

Mobile Subscribers by Region : Mobile Subscribers by Region

GSM facing Challenges : GSM facing Challenges Higher Costs incurred on Network Capacity Increase Business Market Saturation More Money on Advertisement and Subsidies/Customer Discounts Interconnection Costs [to PSTN/ISDN] are very high Leased Line Costs to Interconnect own Infra-structural elements are very high High License Costs With Implementation of De-regulation policies this will CHANGE.

Future -- UMTS (Universal Mobile Telephone System) : Future -- UMTS (Universal Mobile Telephone System) Reasons for innovations new service requirements availability of new radio bands User demands seamless Internet-Intranet access wide range of available services compact, lightweight and affordable terminals simple terminal operation open, understandable pricing structures for the whole spectrum of available services

Slide 96 :

What’s Your Wireless Dream? : What’s Your Wireless Dream? Whoever, Whenever, Wherever, Whomever, Whatever personal communication? Shrinking the world into earth village? Outdoor classroom on lawn under trees? Call for help in icy storm? Browsing web on cozy seashore?