1. 1 Mobile Computing and Wireless Networking CS 851 Seminar 2002 Fall University of Virginia

2. 2 First Thing to Do !  Everything is in the Web  Syllabus, materials, http://www.cs.virginia.edu/~cs851-2/course.html

3. 3 What Are We Going to Learn?  What are the challenges facing Mobile Computing?  What are fundamental principles in Mobile Computing  What is the state-of-the-art research for Mobile Computing?  What are the open problems?

4. 4 Selected Topics  Vision and Challenges  Wireless Medium Access Control  IEEE 802.11  Mobile Ad Hoc Routing  Mobile IP  TCP over Wireless Link  Energy Efficient and Power Aware Protocols  Capacity of Wireless Network  Mobile Data Access/Dissemination  Address auto configuration  Location Discovery/Tracking  Multicast in Mobile Ad Hoc Network (option)  Security (option)

5. 5 What is Mobile Computing?  Building distributed systems with portable computers and wireless communications to allow mobile users to access services and resources at anytime from anywhere

6. 6 Buzzwords  Nomadic computing (by L. Kleinrock): focus on In-door mobile with pedestrian speed  Mobile computing: focus on Out-door mobility with pedestrian or vehicular speed  Ubiquitous computing (1990 by Mark Weiser):  Pervasive computing (1997 by M. Satyanarayanan ?)== Ubiquitous computing  creation of environments saturated with computing and communication capacity yet gracefully integrated with human users” (M. Satyanarayanan)  the goal is to enhance computer use by making many computers available throughout the physical environment, but making them effectively invisible to the users

7. 7 Many Applications  Military environments  soldiers, tanks, planes  Civilian environments  taxi cab network  meeting rooms  sports stadiums  boats, small aircraft  Emergency operations  search-and-rescue  policing and fire fighting  Killer application  Anywhere and anytime access to the Internet

8. 8 Evolution of Computing Freedom from Collocation (space & time) Flexible Resource Usage Single User OS Batch Time Sharing Networked Computing Mobile Computing Pervasive Computing

9. 9 Challenges (1)  Wireless Communication  Limited transmission range  Limited bandwidth  Frequent disconnections or network partitions  Uncertainty of performance Variance of data error Variance of latency Variance of bandwidth  Easier for intruders to insert themselves into networks

10. 10 Challenges (2)  Mobility  Address migration (network access point varies) route changes  High performance variability (error rate, latency, cost, connectivity …)  Time-location dependent correctness of information

11. 11 Challenges (3)  Poor local resources due to portability  CPU, Memory  limited battery life time All these challenges are instinct and need innovative and system-wide solutions

12. 12 Several Areas for Achieved Results of Mobile Computing  Mobile networking  Mobile information access/disseminate  Adaptive techniques  Power management and energy saving  Location tracking and context-aware applications

13. 13 Mobile Networking  Mobile Ad-Hoc networks  Multiple Access Control  Distributed scheduling algorithms  Mobile ad-hoc routing  Security  Mobile IP  Offering seamless roaming to mobile computing in the Internet  Wireless TCP  I-TCP  Snoop TCP

14. 14 Selected Topics for This Area  Wireless Medium Access Control  IEEE 802.11  Mobile Ad Hoc Routing  Mobile IP  TCP over Wireless Link

15. 15 Mobile Information Access  Shield the mobile and make frequent disconnected state transparent from mobile users such that they can continuously operate even while intermittent connected and low bandwidth connection  Information delivery modes  Server push  Client pull  Hybrid  Data organization  Data consistency requirement

16. 16 Selected Topics for This Area  Mobile Information Access/Dissemination

17. 17 Adaptive Techniques  Exploiting dynamical (networking, physical, users) information to perform effective mobile computing  Adaptive resource management  Adaptive networking  Application-aware adaptations

18. 18 Selected Topics for This Area  Energy Efficient and Power Aware Protocols

19. 19 Power Management and Energy Saving  Topology control of ad-hoc networks using transmit power adjustment  Power aware routing protocols  Power aware MAC protocols

20. 20 Selected Topics  Location Discovery/Tracking

21. 21 Location Sensitivity  Location-aware applications  Location information systems  Indoor location tracking system  Outdoor location determination system without GPS

22. 22 Selected Topics  Location Discovery/Tracking

23. 23 Summary  Mobile computing  Very active and evolving research field  Plenty of interesting research problems  We will learn a lot in this course  Understand the state of the art  New ideas and new contributions  New ways of using mobile computing  It will be Very Rewarding Dedicate your time and make contributions

24. 24 Several Areas for Achieved Results of Mobile Computing  Wireless networking  Ad-Hoc Networks, Mobile IP, Wireless TCP …  Mobile information access/disseminate  Disconnected operation, …  Adaptive techniques  Adaptive modulation, power control, routing, MAC … to take advantage of dynamical information of location and situation to perform computing in a distributed fashion  Power management and energy saving  Location tracking and context-aware applications  Security