Gregory D. Abowd The Future Computing Environments (FCE) Group, Georgia Institute of Technology

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Gregory D. AbowdThe Future Computing
Environments (FCE) Group,Georgia Institute of
Technology

• Ubiquitous Computing Research Themes and Open
  Issues from an Applications Perspective GVU
  Technical Report GIT-GVU-96-24. December 1996.
• Software Design Issues forUbiquitous
  ComputingInvited paper to the IEEE CS Annual
  Workshop on VLSI System Level Design (IWV '98),
  Orlando, FL, April, 1998

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Three Emergent Research Themes

1. Automated capture, integration and access
2. Context awareness
3. Ubiquitous software services

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Ubiquitous Computing Technology

• any computing technology that permits human
  interaction away from a single workstation.

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1. Automated Capture, Integration and Access

• PROBLEM A lot of time is spent on listening to
  and recording the events that surround us
• SOLUTION CIA automatically records, we relate,
  summarize and interpret
• EXAMPLE (Classroom 2000) Smartboards, personal
  pen-based interfaces, digital AV, WWW

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Automated CIA (cont.)Open Research Issues

• Granularity of integratione.g. sound links, any
  slide vs. any gesture
• Supporting revision during access i.e. upon
  reflection
• Supporting networked interactione.g. copy
  teachers notes, anonymous feedback

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Automated CIA (cont.)Software Challenges

• Interaction transparencye.g. the rooms
  presentation software knows the rooms schedule.
• Integratione.g. linking and synchronize
  different streams
• Accesse.g. visualise multiple streams

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2. Context-aware Computing

• PROBLEM Applications on, for example PDAs, are
  deigned for desktops, or very simple none take
  eg. position into account
• SOLUTION Use e.g. GPS receivers to provide
  position info
• EXAMPLE (CYBERGUIDE) Automatically update a
  tourist guide according to users position

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Context-aware Computing (cont.)Open research
issues

• Providing ubiquitous positioning and
  communicatione.g. GPS only available outdoor and
  to communicate feedback to the teacher
• There is more to context than position e.g who
  is around, historical info, time
• Use of personalized vision and voice
  technologyHCI issues

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Context-aware Computing (cont.)Software
Challenges

• Collect information
• Analyse information
• Perform some action
• Repeat with some adaptation
• Challenge To create a general and scalable
  context inferencing engine

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3. Ubiquitous Software Services

• PROBLEM The service should find the user
• SOLUTION Services should be available on any
  device (service integration, transformation,
  scalability etc.)
• EXAMPLE A messaging service that choose
  communication technology (phone, email, fax etc.)
  depending on e.g. urgency

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Ubiquitous SW Services (cont.)Open Research
Issues

• Scaleable interfaces(E.G. WWW, Java vm, phone to
  access the calendar)
• Ubiquity should not be annoying(the user may,
  for example, never be able to hide from the
  interface)

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Mark WeiserXerox Palo Alto Research Center

• Some Computer Science Issues in Ubiquitous
  Computing
• Communications of the ACM, July 1993. (reprinted
  as "Ubiquitous Computing". Nikkei Electronics
  December 6, 1993 pp. 137-143.)

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Three Size of Computers

• Tabe.g. a display and/or a touchpad (hundreds
  of)
• Padnotebook-sized computers (tens of)
• Boarde.g. wall-sized interactive surface (one
  or two)

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Issues of Hardware Components

• Low power
• Wireless
• Pens

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Network Protocols

• Wireless media access
• Wide-bandwidth range
• Real-time capabilities
• Packet routing

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Interaction Substrates

• Touch-printing
• Location independent interaction
• Moving applications (e.g. window migration)
• Bandwidth

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Applications of course the whole point of
ubiquitous computing.

• Locating people(e.g. Automatic phone forwarding,
  locating an individual for a meeting, watching
  general activity in a building)
• Shared tools(e.g. shared drawing)

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Privacy of Location

• Store/access from where?
• For how long time?
• Social issues must be considerated!

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Computational Methods

• Cache sharingThe Cache Sharing Problem. A
  problem instance is given by a sequence of page
  requests. Pages are of two types, U and C (for
  uncompressed and compressed), and each page is
  either IN or OUT. A request is served by changing
  the requested page to IN if it is currently OUT.
  Initially all pages are OUT. The cost to change a
  type-U (type-C) page from OUT to IN is CU
  (respectively, CC). When a requested page is OUT,
  we say that the algorithm missed. Removing a page
  from memory is free. Lower Bound Theorem No
  deterministic, on-line algorithm for cache
  sharing can be c-competitive for c lt MAX
  (1CU/(CUCC), 1CC/(CUCC)) This lower bound
  for c ranges from 1.5 to 2, and no on-line
  algorithm can approach closer to the optimum than
  this factor.