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Issues and Limitations on Mobile Computing. Contents Wireless Issues Mobile Computing Wireless Architecture Wireless Access Technologies Wireless Applications Wireless Limitations Middleware for Mobile Computing Summary & Further Issues. Mobile Computing. What is the computing?
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Issues and Limitations on Mobile Computing Contents • Wireless Issues • Mobile Computing • Wireless Architecture • Wireless Access Technologies • Wireless Applications • Wireless Limitations • Middleware for Mobile Computing • Summary & Further Issues Theodoros Chrysafis - Computer Science Department - CITY Liberal Studies - (24-25/05/2002)
Mobile Computing • What is the computing? • Operation of computers as Oxford Advanced Learner’s Dictionary states. • What is the mobile? • That someone/something can move or be moved easily and quickly from place to place as Oxford Advanced Learner’s Dictionary states. • What is the mobile computing? • Users with portable computers still have network connections while they move. Theodoros Chrysafis - Computer Science Department - CITY Liberal Studies - (24-25/05/2002)
Wireless Architecture • Personal Communication Network (PCN) • Extension of nowadays Infranstructure • ITU Spesifications • Hierarchical Cell Structure • Global Roaming • Expansion of Radio Spectrume Theodoros Chrysafis - Computer Science Department - CITY Liberal Studies - (24-25/05/2002)
Wireless Access Technologies • Past and Current State • AMPS, TDMA, CDMA in USA, GSM in Europe, Public Packet Radio and CDPD • Private Mobile Radio • Wireless LAN • Satelite Systems Theodoros Chrysafis - Computer Science Department - CITY Liberal Studies - (24-25/05/2002)
Wireless Applications • Horizontal Applications • Yellow Pages • Movies Info • Vertical Applications • Access to large amount of data (databases) • Requirements • support to any mobile appliance • support to any network • capability to sustain long - short time disconections • access replicated data or databese file systems Theodoros Chrysafis - Computer Science Department - CITY Liberal Studies - (24-25/05/2002)
Wireless Limitations • Mobility • Auto configuration of the system • Location management • Lookups (Track user’s call) • Updates (Update user’s position and/or data) • Heterogeneity • Security Authentication • Spectrum range Theodoros Chrysafis - Computer Science Department - CITY Liberal Studies - (24-25/05/2002)
Wireless Limitations • Wireless Medium • Cost of Networks • Quantity and reliability of bandwidth • Environment obstacles • Portability = Mobile Restrictions • Low Resources • Battery Constraints • Lack of Security Theodoros Chrysafis - Computer Science Department - CITY Liberal Studies - (24-25/05/2002)
Middleware for Mobile Computing • Middleware • What is the middleware? • Considerations • Application Integration • Device Independence • Mobile Agents • Wireless Application Protocol (WAP) • bring Internet content to digital cellular phones • creation of global wireless protocol specification • enable creation of contents with wide range of usage • to extend existing standards Theodoros Chrysafis - Computer Science Department - CITY Liberal Studies - (24-25/05/2002)
WAP Research Interests • Over the air provision • Persistent Storage • SIM Tool Kit • Location Services • Network Management • Broadband Services • Corporate Data Access • IMT - 2000 (3G) Multimedia Capabilities Theodoros Chrysafis - Computer Science Department - CITY Liberal Studies - (24-25/05/2002)
Summary & Further Issues • Wireless Issues • Wireless Limitations • Wireless Middleware • Research on: • Broadcast • Location Management • Spectrum Utilisation • Extension on existent ptotocols Theodoros Chrysafis - Computer Science Department - CITY Liberal Studies - (24-25/05/2002)