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Management for Ubiquitous Computing

Management for Ubiquitous Computing. Choong Seon HONG <cshong@khu.ac.kr> School of Electronics and Information Kyung Hee University. Outline. Introduction System Issues Networking issues Middleware & Operating System support Fault Tolerance & Disaster Recovery

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Management for Ubiquitous Computing

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  1. Management for Ubiquitous Computing Choong Seon HONG <cshong@khu.ac.kr> School of Electronics and Information Kyung Hee University.

  2. Outline • Introduction • System Issues • Networking issues • Middleware & Operating System support • Fault Tolerance & Disaster Recovery • Security and Privacy • Management • Requirements • Technologies • Sample Architecture

  3. Introduction

  4. Ubiquitous Computing • The process of removing the computer out of user awareness and seamlessly integrating it into everyday life.

  5. Mark Weiser’s Vision of Ubiquitous Computing • “The age of calm technology, when technology recedes into the background of our lives” • Pervasive devices (“computers so imbedded, so fitting, so natural, that we use them without even thinking about it” – Mark Weiser) • Devices at varying scales, ranging in size from hand-held “inch-scale” personal devices to “yard-scale” shared devices. • New applications would emerge that leverage off these devices and infrastructure. • Everyday computing: characterized by continuously present, integrative, and unobtrusive interaction.

  6. Evolution of Ubiquitous Computing • Mainframe: One computer, many people • PC: One computer, one person • Ubiquitous computing: one person, many computers

  7. Evolution of Computing Intelligent Environment Desktop Computing Mobile Computing • Disaggregated Computing (dynamic-intelligent device environment) • Invisible Computing (devices embedded in the environment) • Augmented Reality The Ubiquitous Computing Equation: Ubiquitous Computing = Mobile Computing + Intelligent Environment

  8. Differences from Existing Technologies • Virtual Reality: • attempts to create a virtual world by fooling the user – as opposed to better integrating the computer into the human environment (virtual vs. augmented reality). • Personal Digital Assistants: • They are still assistants of which the user is fully aware • Internet: • Represents a transitional era of computing showing the first way of bringing information and services to our fingertips. Networking is a fundamental component of pervasive computing.

  9. Challenges • Information Processing moves to the background: • A good tool is an invisible tool. An invisible tool does not intrude into our consciousness, allowing us to focus on the task, and not the tool • Computing is perceived as an invisible, ubiquitous background assistance • invisible, specialized computers will become an integral part of the natural human environment • The computer disappears – it merges with physical objects. enhancing their functionality and interaction with the physical environment (ubiquitous background assistance). • Hardware: Low power, wireless everything • Network Protocols: wireless media access, broadband, multimedia over standard networks, routing • Interaction Substrates: Pads, Live-boards • Applications: the most important part

  10. Major Driving Forces 1. Microelectronic technology providing smaller devices and displays with lower energy consumption. 2. Communication technology providing higher bandwidth and higher data transfer rates at lower cost. 3. Ongoing standardization of all components in the system by international standardization committees and industry associations

  11. Driving Forces: Embedded Computers

  12. Driving Forces: Ubiquitous Connectivity • Powerline connectivity • Bluetooth • HAVi • 802.11(a,b) up to 54 Mbps • ZigBee : 802.15 • Cellular: GSM, UMTS up to 2 Mb/s

  13. Wireless LAN WirelessWAN Ad HocLAN Wireless WAN: is cell-phone-based ISP Wireless LAN: gives access to network resources Ad Hoc (Proximity) LAN: gives access to nearby resources (e.g. Bluetooth) Wireless Networks

  14. Driving Forces: Plug and Play • Network protocols for • Dynamic discovery • Cooperation • Auto-configuration • Communication with intermittent connectivity • Current Technologies • Java Jini • Microsoft Universal Plug and Play

  15. Driving Forces: Context Awareness Sensors: • Cameras • Microphones • Biometrics (face, fingerprints, etc.) • Speech Recognition • Location (GPS, GSM) • Environment (inertia sensors for acceleration, temperature, atmospheric density, physical souroundings, etc.)

  16. Example: Tabs, Pads, and Boards • The Tab is a tiny information doorway. For user interaction it has a pressure sensitive screen on top of the display, three buttons underneath the natural finger positions, and the ability to sense its position within a building. The display and touchpad it uses are standard commercial units. The Pad is a prototype pen computer. It can communicate through infrared, nearfield radio, and through a 1Mbps tether. Yard-size displays (boards) serve a number of purposes: in the home, video screens and bulletin boards; in the office, bulletin boards, whiteboards or flip charts.

  17. Active Badges • The Active Badge system provides a means of locating individuals within a building by determining the location of their Active Badge

  18. Others • Expert Chef • Remote Eyes • Interactive Books

  19. Notable Pervasive Computing Projects • GATech Classroom 2000 http://www.cc.gatech.edu/fce/eclass/overview/ • Microsoft Easy Livinghttp://research.microsoft.com/easyliving • IBM Worldboardhttp://www.worldboard.org/about.html

  20. Natural Interfaces - Introduction • Physical interaction between humans and computation will be less like the current desktop keyboard/mouse/display paradigm and more like the way humans interact with the physical world. • Pen-based interaction (handwriting, drawing) • Speech • Gestures • Graspables (manipulation of sensor-equipped physical objects)

  21. Common User Input Devices

  22. Other Interfaces • Pen computing • Handwriting recognition • Wearable Computers • MicroOptical Integrated Eyeglass Display

  23. Context-awareness • Types of context: • Location • GPS-based navigation • Handheld tour guide systems • Recognizing Individual Objects • barcodes or identifying tags • visual object recognition • Presence • identity of people • objects • Time • History • Other information in the environment

  24. The five W’s • Who: identity of the user and the presence of others around him/her • What: Perceiving and interpreting human activity. • Where: Location. Of particular interest is coupling notions of “where” with other contextual information, such as “when.” • When: awareness of the passage of time. Of particular interest is understanding relative changes in time as an aid for interpreting human activity. • Why: Even more challenging than perceiving “what” a person is doing is understanding “why” that person is doing it.

  25. The Need for Context Ubiquity • The main difficulty in context sensing is that it does not always work. • For example, GPS-based devices do not work indoors. • Context fusion techniques handle the seamless handing off of sensing responsibility between boundaries of different context services. • Negotiation and resolution strategies need to integrate information from competing context services when the same piece of context is concurrently provided by more than one service.

  26. System Issues- Networking- Middleware & Operating System support- Fault Tolerance & Disaster Recovery- Security and Privacy

  27. Tasks in a typical pervasive computing environment • Collecting sensor data • Scalability, heterogeneity • Raw format • Measurement error, noisy environment • Processing sensor data into “context” • Adjust format, correct for error • Aggregate for higher-level context • Disseminating to interested applications • Scalability, heterogeneity • Securing access to secret and private data

  28. Sensor networks • Tiny sensor for some physical property • Ad-hoc wireless network UC Berkeley “mote”

  29. Sensor network applications • Many applications • Battlefield reconnaissance • Smart floors • Smart “skin” for robots, vehicles, etc • Heating and ventilation systems • Space exploration • Traffic monitoring • …

  30. Wireless Networks of Pervasive Devices • Purpose: sense the environment and inform users through self organization and configuration • Self-organization between the communicating nodes • Bring the initial system on-line via discovery mechanisms • Establish needed end-to-end connections, • Allow new nodes to be added and reconfigured when existing nodes fail, • Low power operation.

  31. Medium Access Control (MAC) • Important Issues: • Energy efficiency • Scalability (node density) • Latency • Fairness • Throughput • Bandwidth utilization

  32. Identifying the Energy Consumers • Need to shutdown the radioFrom Tsiatis et al. 2002 TX RX IDLE CPU SLEEP SENSORS RADIO

  33. Common to all wireless networks Energy Efficiency in MAC • Major sources of energy waste • Idle listening • Long idle time when no sensing event happens • Collisions • Control overhead • Overhearing • Try to reduce energy consumption from all above sources • TDMA requires slot allocation and time synchronization • Combine benefits of TDMA + contention protocols

  34. Latency Fairness Energy Sensor-MAC (S-MAC) Design(Wei et al. 2002) • Tradeoffs • Major components of S-MAC • Periodic listen and sleep • Collision avoidance • Overhearing avoidance • Message passing

  35. sleep listen listen sleep Periodic Listen and Sleep • Problem: Idle listening consumes significant energy • Nodes do not sleep in IEEE 802.11 ad hoc mode • Solution: Periodic listen and sleep • Turn off radio when sleeping • Reduce duty cycle to ~10% (200 ms on/2s off) • Increased latency for reduced energy

  36. Node 1 sleep sleep listen listen Node 2 sleep sleep listen listen Schedule 1 Schedule 2 Periodic Listen and Sleep • Schedules can differ • Preferable if neighboring nodes have same schedule • — easy broadcast & low control overhead Border nodes: two schedules broadcast twice

  37. Adaptive Topology • Can we do more than shut down radio in between transmissions/receptions? • Can we put nodes to sleep for longer periods of time? • Goal: • Exploit high density (over) deployment to extend system lifetime • Provide topology that adapts to the application needs • Self-configuring system that adapts to environment without manual configuration

  38. Adaptive Topology: Problem Description Simple Formulation (Geometric Disk Covering) • Given a distribution of Nnodes in a plane. • Place a minimum number of disks of radius r (centered on the nodes) to cover them. • Disk represents the radio connectivity (simple circle model). • The problem is NP-hard.

  39. Middleware • Benefits of Using Middleware • Hiding the complexity of heterogeneous network transport protocols. • Ease of application development. • Extensible architecture to allow addition of new services. • Interoperability among applications across various heterogeneous platforms.

  40. Reconfigurable Context - Sensitive Middleware • University of Arizona • RCSM is a middleware to enable context-sensitive ad hoc interactions among devices in MANET. • Combines the power of abstraction of mainstream middleware specifications with the performance and economy of hardware. Resources: http://www.eas.asu.edu/~rcsm/ http://www.eas.asu.edu/~rcsm/Papers/pervasivecomp2002.pdf

  41. Principal Functionality of RCSM •Facilities for situation-aware interface definition and application-specific situation-analysis. • Mechanism for autonomous communication channel establishment and object activation based on application-specific situation. • Context-sensitive service information discovery/distribution. • Services for ephemeral group communication and information dissemination.

  42. Context • Definition of context • Any detectable and relevant attribute of a device, its interaction with other devices, and/or its surrounding environment at an instant of time. • Categories of context • Device-Specific Context • Numbers of objects activated, remaining battery power, time, speed, mobility, network connection, communication bandwidth,… • Environment-Specific Context • Numbers of devices in the vicinity, light intensity, noise level, temperature, location, … • User-Specific Context • User name, user address, user categories, such as student, faculty, etc.

  43. Situation • Definition of situation • Any action taken by the device over a period of time that is of interest to the device, and/or • Variation of a set of contexts over a period of time. • Example of situation • During the last two hours, the battery power has reduced by 10% and no recharge action has taken place.

  44. Context vs. Situation Context is the basic element that builds situation up. • Context includes an instant of time, while situation is for a period of time. • Context does not involve device behavior, while situation does. • Situation often contains more than one context. • Context is direct reflection of device and environment, while situation needs analysis and computation on contexts of the device and environment.

  45. Architecture

  46. Fault Tolerance and Disaster Recovery Usually built in the control mechanisms (middleware, network topology, etc.) Autonomic computing is a new area of research addressing these issues in pervasive computing environments (and not only). Self-configuringAdapt to dynamically changing environments Self-healingDiscover, diagnose, and act to prevent disruptions Self-optimizingTune resources and balance workloads to maximize use of resources Self-protectingAnticipate, detect, identify, and protect against attacks

  47. Security and Privacy • Position tracking and audio-visual recording generates significant privacy issues: • one immediately becomes part of the public record(POTUS does not send email to his family) • Who has control of the information? • The knowledge of a session being recorded may deter people from contributing to it.

  48. Simplified Principles 1. Notice and Disclosure • Purpose • Specification 2. Choice and Consent • Individual Participation 3. Anonymity and Pseudonymity • Collection limitation 4. Data Security • Security Safeguards • Use Limitation 5. Access and Recourse • Data Quality • Accountability 6. Meeting Expectations • Openness

  49. Solutions • Privacy Enhancing Technologies (PETs) • Notice and Disclosure: Transparency Tools • Choice and Consent: Anonymity and Pseudonymity Tools • Anonymizing proxies • Privacy policies (long and hard to understand) • P3P project (exchange of XML-encoded policies and preferences) • Identity managers and Info-mediaries • Security: Encryption and Authentication Tools • Plenty of Encryption options (IPSec, SSH, SSL, …) • Who are you talking to? • Access and Control: PETs in the Enterprise • Processing data should comply with collection policies • Allow individual policies, closed user groups • Accountability • Recourse: Laws and Regulations • US: sector-specific laws with minimal protections • EU: strong privacy laws

  50. Management of Pervasive Computing Environments

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