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MOBILE COMMUNICATION. Introduction . History of Mobile Communication. Mobile phones have their roots in radiophones.
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History of Mobile Communication • Mobile phones have their roots in radiophones. • Radiophones have a long and varied history going back to Reginald Fessenden’s invention and shore-to-ship demonstration of radio telephony, through the Second World War with military use of radio telephony links and civil services in the 1950s, while hand-held cellular radio devices have been available since 1973.
Due to their low establishment costs and rapid deployment, mobile phone networks have since spread rapidly throughout the world, outstripping the growth of fixed telephony. • The concepts of frequency reuse and handoff as well as a number of other concepts that formed the basis of modern Cell Phone or mobile phone.
Cellular technology • Cellular Technology - Telephony, a generic for all wireless phones, and cellular, a term derived from cellular base stations that control phone calls, are a combination of technologies that allow for mobile phone transmission and reception in a given area.
First Generation • First Generation Mobile Phones (Also known as 1G ) came into vogue first in the United States of America in 1973. • It used analog signals and hence needed more than one base stations which were closely located.
The first handheld mobile phone to become commercially available to the US market was the Motorola DynaTAC 8000X which received approval in 1983. • Mobile were too robust and heavy, they were static and designed for permanent installation in vehicles.
Features of First generation • Analog voice signaling was use. • Less Secure • Not much reliable networks. • No SMS and Roaming Facility. • Example: Advanced Mobile Phone System (AMPS) is the analog mobile phone system standard developed by Bell Labs.
Second Generation • Second Generation Mobile Phones (Also known as 2G ) adopt the system of digital signaling in order to establish a connection between the radio towers. • first digital cellular phone call was made in the United States in 1990 and still in use. • Second Generation Mobile Phones were digital circuit and the use of advanced and fast phone to network signaling. • Frequency was much higher.
GSM – GLOBAL SYSTEM FOR MOBILE COMMUNICATION • GSM technology which stands for GLOBAL SYSTEM FOR MOBILE COMMUNICATION, The GSM belonging to TDMA is the most widely used technology across the world and was first started in Finland • Phase I of GSM specifications was published in 1990 • International demand was so great that the system name was changed from Groupe Special Mobile to Global Systems for Mobile Communications (still GSM).
Commercial service started in mid-1991 • 1992 first paying customers were signed up for service. • By 1993 there were 36 GSM networks in 22 countries • Early 1994 there were 1.3 million subscribers worldwide • By 1996 there were more than 25 million subscribers worldwide • By October 1997 it had grown to more than 55 million subscribers worldwide
Mobile Equipment • Produced by many different manufacturers • Must obtain approval from the standardization body • Uniquely identified by an IMEI (International Mobile Equipment Identity
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
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)
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
Base Station Controller (BSC) • Manages Resources for BTS • Handles call set up • Location update • Handover for each MS
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
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
Authentication Center (AUC) • Mainly used for security • Mata 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
Present scenario • 2.5G is a stepping stone between 2G and 3G cellular wireless technologies. • 2.5G provides some of the benefits of 3G (e.g. it is packet-switched) and can use some of the existing 2G infrastructure such as GSM networks. • GPRS and EDGM services got introduced due to the increase in the demand of internet. Currently we are in 2.5G which comprises of GSM, EDGM and GPRS.
GPRS • Stand for General Packet Radio Service • packet oriented Mobile Data Service available to users of Global System for Mobile Communications (GSM). • Provide Internet communication services such as email and World Wide Web access. • Always connected and send data immediately • higher speeds: typically 32-48 kbps.
GPRS data is handled as a series of "packets" that can be routed over several paths through the network, rather than as a continuous bit-stream. • the information is split into separate but related "packets" before being transmitted and reassembled at the receiving end.
EDGE • Stands for Enhanced Data rates for GSM Evolution. • maximum data transfer rate of 384 kbps • EDGE offers the best that can be achieved with a 2.5G network
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
3rd Generation • 3G was introduced in the United States early in 2002. • send data up to 40 times the rates of earlier digital networks. • Applicable to mobile as well as fixed wireless systems. • Should be operational on, above and below the earth. • Example: UMTS
Possibilities with 3G • Mobile internet connectivity. • Mobile e-mail. • Multimedia services such as digital photos. • Wireless application downloading. • Video on demand.
Real-time multiplayer gaming. • Enhanced emergency and location based service. • Push to talk & push to video message. • Voice/high quality audio. • E-Commerce
Evolution of 3G I.T.U.
I.T.U. • Leading UN agency for Information & Communication. • Organizes Telecom events. • Includes 191 member states and more than 700 sector members and associates. • Made a 3G standard called IMT-2000
IMT 2000 • Single global wireless standard. • linking of diverse systems of terrestrial and/or satellite based networks.
Various 3G services used across the world • Mobile T.V. based on video streaming, T-Mobile (Germany). • Mobile Earth for navigation, Vodafone (Germany). • Mobile Radio based on audio streaming, TELUS Mobility (Canada). • Banking & Finance services, Telstra (Australia).
W-CDMA • Technology behind UMTS • Closely linked to GSM standard • It was evolved by 3GPP • Was finalized in 1999
Technical Specifications • Chip Rate 3.84 Mcps. • UMTS uses 15 slots per frame. • Adaptive power control based on SIR. • Smart antennas can be used to increase capacity and coverage. • QPSK Modulation
Frequency band 1920-1980 MHz and 2110-2170 MHz. • Channel Bit Rate 5.76 Mbps. • Frame length is 10 ms(38400 chips). • Number of Chips per slot is 2560
TDD • Time-division duplexing (TDD) is the application of time-division multiplexing to separate outward and return signals. It emulates full-duplex communication over a half-duplex communication link • In this method uplink and downlink transmission are carried over the same frequency band using synchronized time intervals.
