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Mobile Networks

Mobile Networks. Asst. Prof. Dr. Mohammad kaleem Computer Engineering Department, National University of Sciences and Technology, Islamabad. Text Book. Wireless Communications and Networks, by William Stallings, Prentice Hall, 2nd Edition, 2005

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Mobile Networks

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  1. Mobile Networks Asst. Prof. Dr. Mohammad kaleem Computer Engineering Department, National University of Sciences and Technology, Islamabad

  2. Text Book • Wireless Communications and Networks, by William Stallings,Prentice Hall, 2nd Edition, 2005 • This textbook will be followed for most of the course.  • The material on multihop and sensor networks will be taken from research papers, • and other collections.

  3. Prerequisites • Computer Communications And Networks • Digital Communications

  4. Introduction Chapter 1

  5. Wireless Comes of Age • Guglielmo Marconi invented the wireless telegraph in 1896 • Communication by encoding alphanumeric characters in analog signal • Sent telegraphic signals across the Atlantic Ocean • Communications satellites launched in 1960s • Advances in wireless technology • Radio, television, mobile telephone, communication satellites • More recently • Satellite communications, wireless networking, cellular technology, ad hoc networks, Sensor networks

  6. Broadband Wireless Technology • Higher data rates obtainable with broadband wireless technology • Graphics, video, audio • Shares same advantages of all wireless services: convenience and reduced cost • Service can be deployed faster than fixed service • No cost of cable plant • Service is mobile, deployed almost anywhere

  7. Future Generations 4G 3G 2G Other Tradeoffs: Rate vs. Coverage Rate vs. Delay Rate vs. Cost Rate vs. Energy Rate 802.11n 802.11b WLAN Wimax/3G 2G Cellular Mobility Fundamental Design Breakthroughs Needed

  8. Evolution of Current Systems • Wireless systems today • 3G Cellular: ~200-300 Kbps. • WLANs: ~450 Mbps (and growing). • Next Generation is in the works • 4G Cellular: Likely OFDM/MIMO • 4G WLANs: Wide open, 3G just being finalized • Technology Enhancements • Hardware: Better batteries. Better circuits/processors. • Link: Antennas, modulation, coding, adaptivity, DSP, BW. • Network: more efficient resource allocation

  9. Network Network Application Application Transport Transport Network Network Data Link Data Link Data Link Data Link Physical Physical Physical Physical Medium Radio Scope of this course: Anything above and related protocols

  10. Wireless communication systems • Target information systems: “Anytime, Anywhere, Anyform” • Applications: Ubiquitous computing and information access • Market in continuous growth: • 35-60% annual growth of PCS(Personal Communications Services) • Number of subscribers: • by 2001: over 700M mobile phones • by 2003: 1 billion wireless subscribers (source Ericsson) • 300% growth in wireless data from 1995-1997 • Large diversity of standards and products • Confusing terminology

  11. Mobile Subscribers in Pakistan More than15,511,045 subscribers of Cellular Networks *From Telecom Indicators section of PTA Website

  12. Limitations and Difficulties of Wireless Technologies • Wireless is convenient and less expensive • Limitations and political and technical difficulties inhibit wireless technologies • Lack of an industry-wide standard • Device limitations • E.g., small LCD on a mobile telephone can only displaying a few lines of text • E.g., browsers of most mobile wireless devices use wireless markup language (WML) instead of HTML

  13. Wireless around us… WLAN, DAB, GSM, etc… Personal Travel Assistant, PDA, Laptop, GSM, cdmaOne, WLAN, Bluetooth, ...

  14. Radio frequency spectrum • Wireless technologies have gradually migrated to higher frequencies

  15. Wireless & Mobility • Wireless: • Limited bandwidth • Broadcast medium: requires multiple access schemes • Variable link quality (noise, interference) • High latency, higher jitter • Heterogeneous air interfaces • Security: easier snooping • Mobility: • User location may change with time • Speed of mobile impacts wireless bandwidth • Need mechanism for handoff • Security: easier spoofing • Portability • Limited battery, storage, computing, and GUI

  16. Challenges in Mobile Networking • Three major challenges: • Wireless Channel • Mobility • Device Limitation

  17. Part One: Background • Provides preview and context for rest of book • Covers basic topics • Data Communications • TCP/IP

  18. Chapter 2: Transmission Fundamentals • Basic overview of transmission topics • Data communications concepts • Includes techniques of analog and digital data transmission • Channel capacity • Transmission media • Multiplexing

  19. Chapter 3: Communication Networks • Comparison of basic communication network technologies • Circuit switching • Packet switching • Frame relay • ATM

  20. Chapter 4: Protocols and the TCP/IP Protocol Suite • Protocol architecture • Overview of TCP/IP • Open systems interconnection (OSI) reference model • Internetworking

  21. Part Two: Wireless Communication Technology • Underlying technology of wireless transmission • Encoding of analog and digital data for wireless transmission

  22. Chapter 5: Antennas and Propagation • Principles of radio and microwave • Antenna performance • Wireless transmission modes • Fading

  23. Chapter 6: Signal Encoding Techniques • Wireless transmission • Analog and digital data • Analog and digital signals

  24. Chapter 7: Spread Spectrum • Frequency hopping • Direct sequence spread spectrum • Code division multiple access (CDMA)

  25. Chapter 8: Coding and Error Control • Forward error correction (FEC) • Using redundancy for error detection • Automatic repeat request (ARQ) techniques

  26. Part Three: Wireless Networking • Examines major types of networks • Satellite-based networks • Cellular networks • Cordless systems • Fixed wireless access schemes • Use of mobile IP and Wireless Access Protocol (WAP) to provide Internet and Web access

  27. Chapter 9: Satellite Communications • Geostationary satellites (GEOS) • Low-earth orbiting satellites (LEOS) • Medium-earth orbiting satellites (MEOS) • Capacity allocation

  28. Chapter 10: Cellular Wireless Networks • Cellular wireless network design issues • First generation analog (traditional mobile telephony service) • Second generation digital cellular networks • Time-division multiple access (TDMA) • Code-division multiple access (CDMA) • Third generation networks

  29. Chapter 11: Cordless Systems and Wireless Local Loop • Cordless systems • Wireless local loop (WLL) • Sometimes called radio in the loop (RITL) or fixed wireless access (FWA)

  30. Chapter 12: Mobile IP and Wireless Access Protocol • Modifications to IP protocol to accommodate wireless access to Internet • Wireless Application Protocol (WAP) • Provides mobile users access to telephony and information services including Internet and Web • Includes wireless phones, pagers and personal digital assistants (PDAs)

  31. Part Four: Wireless Local Area Networks • Examines underlying wireless LAN technology • Examines standardized approaches to local wireless networking

  32. Chapter 13: Wireless LAN Technology • Overview of LANs and wireless LAN technology and applications • Transmission techniques of wireless LANs • Spread spectrum • Narrowband microwave • Infrared

  33. Chapter 14: IEEE 802.11 Wireless LAN Standard • Wireless LAN standards defined by IEEE 802.11 committee

  34. Chapter 15: Bluetooth • Bluetooth is an open specification for wireless communication and networking • Personal computers • Mobile phones • Other wireless devices

  35. Internet and Web Resources • Web page for this book • WilliamStallings.com/Wireless1e.html • Useful web sites, errata sheet, figures, tables, slides, internet mailing list, wireless courses • Computer Science Student Support Site • WilliamStallings.com/StudentSupport.html • Newsgroups • comp.std.wireless • comp.dcom.*

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