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Challenges in Location-Aware Computing

Challenges in Location-Aware Computing. Cynthia A. Patterson, Richard R. Muntz, and Cherri M. Pancake IEEE Pervasive Computing 2003. Outline. Location-Aware Computing Location-sensing infrastructure Adaptive resource management Other research challenges Conclusion.

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Challenges in Location-Aware Computing

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  1. Challenges in Location-Aware Computing Cynthia A. Patterson, Richard R. Muntz, and Cherri M. Pancake IEEE Pervasive Computing 2003

  2. Outline • Location-Aware Computing • Location-sensing infrastructure • Adaptive resource management • Other research challenges • Conclusion

  3. Independent Technologic

  4. Location-aware computing • Context-aware computing-反應到real-world context • User identity • Physical location • Current Condition • Time of day,date,season • User asleep or awake • Location information and identity是主要關鍵 • Location-aware computing • Mobile computing • Location sensing • Wireless networking

  5. Hardware for mobile computing • Integrating mobile hardware system and seamlessly bridge user’s desktop • Design issue: • battery,size,weight • Security • Performance and reliability • Energy source

  6. seamlessly bridge user’s desktop

  7. Location sensing • Global Positioning System (GPS)是個方法,目前大概$100,越來越廣泛

  8. GPS • 一些問題考量: • 不能使用於室內,特別是金屬建築 • 對於一些應用準確度還是不夠好 • 使用coordinate system • Weight ,cost,energy consumption • Other location-sensing mechanism • 一按即發出訊號的信號器,行動徽章…

  9. LAR(location aided routing)

  10. MESH: multi-eye spiral-hopping routing

  11. How to serach location ? PDA Tablet PC PDA PDA Tablet PC PDA Notebook Notebook PDA Tablet PC PDA

  12. 802.11 Ad Hoc mode PDA PDA PDA PDA Tablet PC Notebook Notebook PDA Tablet PC PDA Tablet PC

  13. Location-Aware Multicast Protocol for Bluetooth

  14. Location-Aware Multicast Protocol for Bluetooth 利用flooding達成收集location information

  15. Location sensing ? • A mechanism for discovering spatial relationships between objects

  16. ? Variety of Mechanisms Definitely no “one size fits all” solution

  17. Target Synchronization channel Ranging channel ACTIVE • System emits signal, deduces target location from distortions in signal returns

  18. Target Synchronization channel Ranging channel CO-OPERATIVE • Target cooperates with the system

  19. Target Synchronization channel Ranging channel PASSIVE • System deduces location from observation of signals that are “already present”

  20. Target Synchronization channel Ranging channel ? BLIND • System deduces location of target without a priori knowledge of its characteristics

  21. Wireless communications • Voice commnication(cell phones) • IEEE802.11 WLAN • Bluetooth • IrDA • Power is important factor for mobile device • Other: frequency,bandwidth,range,density of wired infrastructure • Trade-offs 就要看需求來決定了

  22. Bluetooth

  23. Using Bluetooth Technology

  24. 無線區域網路技術比較表

  25. 無線區域網路技術比較表

  26. 無線區域網路技術比較表

  27. Location-sensing Infrastructure • Location-based services • GPS and other localization technologies • Wireless communication • Mobile computing • Location-sensing infrastructure can become commercially viable

  28. Technology-independent location sensing • 因素太多,於是討論發展a technology-independent , high-level software application programming interface for location-sensing. • 發展middleware level API將有助於long-lived applications,而且遇到的障礙將刺激發展new location-sensing technologic. • API最好是open, specification, dynamically combining location information from multiple source

  29. Opportunistic data acquisition • Cars,Road maintenance personnel using data-mining and visualization software, GPS,Real-time system,可以防止事故,節省能量,預防結冰 • Challenge • Address scalability • Mobile sensor source • Appropriate information-sharing policy • Privacy • Not sacrificing functionality(功能)

  30. End-to-end control of location information • Cell-based location sensing,loss of privacy • Historical location information可以幫助預測user’s typical movement • 需要發展end-to-end control of location information, 也就是需要好的 access control mechanism,得到正確的資料,不正確的丟棄,而且利用location information加強Security機制

  31. Test bed for experimental research • Lack adequate large-scale experimental infrastructure,可以促進發展commercialization • Standard protocols • APIs • Platform-independent capability • Scalability • Different network nodes information conflicting • Resource management • Static-mobile load balancing

  32. NS2

  33. Adaptive Resource Management • Cyber foraging • Guide a mobile user from a bandwidth-impoverished to a bandwidth-rich enviroment. This technique is cyber foraging. • Temporarily extends a mobile computer’s resources by pointing to remote resources. • Infostation • Provide low-cost,low-power access information services • 處理這些事情可以使用surrogates(代理人)的方法,對使用者無察覺無狹縫,要有選擇代理人的方法

  34. Tracking and predicting location • 例如:eletronic map結合tracking and predicting location 選擇最好的路 • 物體的移動和速度對於location資料的正確性將是挑戰, trade-offs 頻寬浪費和location資料正確性 • 所以開始研究預測路徑,典型的home-office-home,但是如果不正常的移動,就會無法完美預測,而且必須發展認證或確認身分的機制 • 前提還要有其他技術支援,如public transportation, good software回應user的要求

  35. Bluetooth Location Networks

  36. Location Tracking Protocol in Sensor Network

  37. Other Research challenges • Geospatial database and data mining • Database integrate geospatial data • Query language and algorithmic分解data space and time • Data mining and Data analysis and evaluation benefit • Human interaction with geospatial information • 缺乏綜合framework來理解human interaction with geospatial information • New location information research • Smart dust sensors-農業,…

  38. Sensing Networking Computation Wireless Sensor Networks • New technologies have reduced the cost, size and power of micro-sensors and wireless interfaces Circulatory Net Environmental Monitoring • Systems can • Embedded into environment • Sense phenomena at close range • Systems will revolutionize • Environmental monitoring • Disaster scenarios • Structure Response

  39. Some Networked Sensor Node Developments LWIM III UCLA, 1996 Geophone, RFM radio, PIC, star network AWAIRS I UCLA/RSC 1998 Geophone, DS/SS Radio, strongARM, Multi-hop networks WINS NG 2.0 Sensoria, 2001 Node development platform; multi- sensor, dual radio, Linux on SH4, Preprocessor, GPS Sensor Mote UCB, 2000 RFM radio, PIC Processor

  40. Real-World Experiences Ad Hoc Sensor Network Gateway node Each audience member is given a voting device, users respond to questions by pressing the buttons. 100 node voting devices in the San Francisco Moscone Convention Center. Routing topology using DSDV protocol.

  41. Conclusion • IT Roadmap report (http://www.cstb/project_geospatial.html)

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