Introduction: Pervasive and Mobile Computing

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IntroductionPervasive and Mobile Computing
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Defining Pervasive Computing

• Make computing available beyond desktop
• Make it mobile and connected
• Instrument the person
• Instrument the physical surroundings

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Scenario 1 (at home)

• At Sue and Mikes home, 10 minutes before their
  alarm clock goes off (at 400 AM), the coffee
  machine is automatically started.
• In making breakfast, Mike realizes that the egg
  supply is low. He adds eggs to the electronic
  shopping list.
• The refrigerator, scanning the barcode on the
  milk, realizes that it will soon expire. Milk
  gets added to the shopping list.
• Before leaving for work, Sue sees that she has a
  message reminding her that her drivers license
  is soon to expire. Sue uses her computer with the
  video camera to get her picture taken and sent to
  the nearest office.

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Scenario 1 (at home)

• Mike is diabetic.
• Mike uses a device that measures the glucose
  level and transmits this information to his
  doctors office.
• The doctors office keeps track of the measures
  and if the doctor is concerned about a trend
  observed in the measurements, the doctors office
  will send a message for Mikes home asking for an
  appointment.
• If the problem is serious, then Mikes dental
  appointment may be cancelled since treating the
  diabetes has high priority. If this happens,
  Mikes personal electronic agent negotiates with
  the dental office-computing environment for an
  alternative time which gets put into Mikes
  schedule.

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Scenario 1 (Mike at work)

• Mike works in an office tower for a company
  called Big Internet Company (Bi Co) which
  occupies floors 11-21.
• There is a separate elevator that accesses these
  floors.
• Mike places his hand on the scanner near the
  elevator. The elevator has sensed Mikes badge,
  passed that information to a computer that took a
  measurement of Mikes hand, validated Mike and
  ordered the elevator to the ground floor.

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Scenario 1 (Mike at work)

• When Mikes office senses that he is within 5
  feet of his office door, it unlocks.
• The computer is already turned on, the printer
  turned on and a list of the days meetings and
  relevant background material is already printing.
• Lets say Mike finds that he has a conference
  call with two colleagues in California and
  Toronto.
• Mike verbally orders the conference call
  Connect me with John Robinson and Tom Smith at
  9.
• The room picks up this information and passes it
  to the communication system to arrange for the
  call.

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Scenario 1 (Mike at work)

• Mikes badge beeps at 855 indicating that his
  conference call is imminent. Mike returns to his
  office.
• Mike has his conference call at 901.
• Just before 10 AM Mike heads to the Conference
  Room A to meet with his lead developers. On the
  way, Mikes badge beeps and he sees that he has a
  message from a developer, Tom who is away at a
  conference.
• Mike opens his PDA and selects PRINTERS. He
  enters Conference Room A and three rooms near
  Room A appear with brief descriptions of
  printers. He selects one of the printers. The
  message from Tom is printed.

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Scenario 1 (Mike at work)

• During Mikes conference call, he writes on a
  whiteboard.
• The contents of the whiteboard are transmitted to
  the other conference call participants and sent
  to Mikes PC in his office.
• The entire verbal dialog is recorded and stored.
  It can be retrieved if one of the conference call
  participants wishes to review the meeting in
  further detail.

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Scenario 1 (Mike at work)

• After Mikes meeting he spends the rest of the
  day quietly in his office doing work and reading
  news.
• Mike has the news delivered to him personalized.
  He is especially interested in sports and local
  politics.
• He started reading at home, but didnt have time.
  During the day (at work) he finishes reading the
  news.
• Mike is working on sensitive documents. When he
  does leave the office (e.g., lunch) his terminal
  automatically invokes a screen saver.
• Sues personalized news consist of national
  politics and technical stories.

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Scenario 1 (Sue at work)

• Sue is a doctor who starts rounds at 6AM.
• When Sue gets to the hospital, she has the charts
  of patients downloaded to her PDA for immediate
  perusal.
• During rounds she orders that a patient be given
  a new medication.
• This gets sent to a computer in the hospital
  which may find that the supply of this medication
  is not enough. An order is automatically made to
  a pharmacy.

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Scenario 1 (Sue at work)

• After rounds, Sue has a series of appointments
  and lectures to attend. She is not able to get
  to her PC for hours.
• She has been tracking several favorite stocks
  especially XYZ.
• Since she is busy she initializes her
  personalized financial advisor agent, Fred.
• Sue tells Fred that she wants to know if the
  price of XYZ reaches a certain point so that she
  may buy it.
• At 1117, Fred notifies her about XYZ.

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Scenario 1 (Sue at work)

• Sue asks Fred to check to see if she has enough
  funds to cover for this.
• If the answer is yes, Fred buys the stock and
  updates all of Sues accounts.
• Sue leaves at 5. Before she leaves, she finds
  out that there has been a change in her schedule
  and she doesnt start rounds until 700AM.

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Scenario 1 (Back at Home)

• Sue cooks for relaxation.
• She feels like making a special dish for which
  she knows that she doesnt have ingredients.
• She goes to a grocery store. She doesnt
  remember all the ingredients so she asks her PDA
  to get the recipe from home and the current
  shopping list.
• Mike and Sue both arrive at home at 600PM. The
  home-computing environment greets them on arrival
  with a message for Mike telling him it is
  imperative for him to check his messages.
• Mike has the next day off and Sue gets to start a
  little later. They instruct the home-computing
  environment to set the alarm an hour later.

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Scenario 2

• Middlesex Building Pervasive Computing
  Environment
• The application scenarios focus on users
  requesting building-related that can be accessed
  by their PDA, laptop or PC.
• We will refer to this as Building Information
  Management (BIM).

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Scenario 2

• BIM Services for Resource Location
• A user in a building is able to query for the
  location of rooms or nearest available resource
  (e.g., nearest available workstation, printer).
  Maps and directions are provided to the user upon
  request.
• For example, Bob can request the location of the
  nearest printer (in Middlesex) that he is allowed
  access to. If needed, Bob could request a map or
  specific directions. Different maps and
  directions are returned based on Bob's location.
  
• Different users will have different requests

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Scenario 2

• BIM Services for Activity Information
• A user can request information about activities
  in the building (e.g., class , exam, meeting).
  Such a query should return a list of activities
  with room numbers.
• For example, upon entering Middlesex, Bob
  requests information on activities. Seeing the
  category for final exam schedule', Bob asks for
  final exams taking place in the building at that
  time.

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Scenario 2

• BIM Services for Status Information
• A user is able to request information about the
  status of a person within a building.
• For example, Bob can request information about
  Sue. The BIM should be able to tell Bob if Sue
  is busy or not. Sue is inferred to be busy if
  her location is in a meeting room or if she is
  working at a computer

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Scenario 2

• Other BIM Services
• A meeting causes the the room to become warm.
• Temperature should be adjusted.

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What do we need to support this?

• Lots of things.
• We need a very complex and distributed
  infrastructure that has the following properties
• Invisible from the users point of view.
• Adaptive
• Very dependable
• All devices are network enabled, although not all
  devices are connected all the time.
• Everywhere

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Issues in Network Communications

• Mix of wireless and wired
• A heterogeneous set of technologies will most
  likely be needed
• Mobility brings its own sets of problems.

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Issues in Network Communications (Mobility)

• Link Effects
• Bandwidth is lower than the bandwidth provided by
  the wired network.
• The link between the base station and mobile host
  is not a reliable as links in a wired network
  (limits bandwidth)
• Need to be able to adapt content based on device
  and available bandwidth.

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Issues in Network Communications (Mobility)

• Link Effects (Continued)
• Remember Mikes and Sues personalized news. The
  presentation of that news may vary depending not
  only on the type of device they are using to read
  the news, but also on the available bandwidth
  between the PDA and a base station.
• Lets say Mike is driving while Sue is reading
  the news off her PDA. As Mike moves, the
  available bandwidth will change. How should the
  presentation change?

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Issues in Network Communications (Mobility)

• Constraints imposed by portable devices
• User interface little real estate
• Power management has an impact on the available
  computing resources available for the mobile
  device.
• Currently, it is not always desirable to have
  mobile devices always connected. This saves
  power, but results in problems related in
  intermittent connections (discussed in more
  detail later).

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Issues in Network Communications (Mobility)

• Dynamic information
• The request for information sometimes depends on
  the location
• Example Where is the nearest gas station?
• Example Where is the nearest Italian restaurant
  where the average meal is less than 30 dollars
  Canadian.
• The presentation of the information relies on the
  available computing resources.
• Example Text is used if available bandwidth is
  below some specified threshold else images may be
  used.

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Issues in Network Communications (Mobility)

• How will a user be found so that important
  information can be delivered to them?
• For example, lets say that Mikes glucose levels
  are very high, the doctor needs to see him right
  away and Mike is traveling between sites that
  day.
• How is Mike to be found?
• Do tagging technologies work?
• What about the PDA? What if Mike doesnt check
  it?

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Issues in Network Communication (Connectivity)

• Intermittent Connectivity
• Ideally, there are invisible, trouble-free
  connections and disconnections.
• However, we need intermittent connectivity so
  that we can disconnect to consume less power.
• Lots of new mobile protocols are appearing (e.g.,
  Bluetooth and HomeRF) are standards that allow
  devices to connect and disconnect as needed.
• Does not address complex issues such as handoffs.

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Issues in Identification and Location

• There is a need to identify physical
  non-computing entities e.g. people, an item in an
  exhibit display
• There are several possible technologies including
  tags, computer vision and positioning.

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Issues in Identification and Location

• Tag technology includes
• Infrared
• Can attach to a person (as a badge) or to a thing
  (e.g. a printer).
• Emit an identifier using IR technology.
• Relatively short distance
• Optically sensed
• Includes standard barcodes
• Readers are needed such that the tag is placed
  right next to the reader.

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Issues in Identification and Location

• Tag technology includes
• RFID
• Use radio frequency (RF)
• Can be read from a distance
• Do not require their own power source
• Contact tags
• Do not require their own power source.

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Issues in Identification and Location

• Tagging technology
• There is not one correct tagging technology to
  use.
• The best choice depends on cost and suitability
  of the physical environment
• Exact location may be difficult to determine.
• Example IR receivers are really only detecting
  that an IR transmitter has sent an identifier.
  You may need several IR receivers reporting that
  they have seen an IR identifier to pinpoint
  location.

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Issues in Identification and Location

• Computer Vision
• Computer vision techniques can be used for object
  recognition
• Example Room uses footsteps to identify a
  person
• Requires a good deal of computing resources
• A lot of work is needed to make this a viable
  technology
• Positioning
• Can be used where objects move rarely
• Example GPS

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Data Transfer

• Need to be able to transfer data in a seamless
  fashion.
• Data initiation and termination takes place using
  a variety of devices.
• Sue sending a picture of herself to get her
  license renewed.
• Mike downloading a document (through his PDA)
  sent by Tom. Tom could have sent the document
  using his PDA or a PC and Mike could have
  downloaded the document through his PC.
• Making sure that the personalized newspaper
  getting to the device that the user is reading
  from. User should not have to worry about things
  like different formats or ftp. The presentation
  of the content should adapt to the device that
  the user is using.

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Data Transfer

• Data is heterogeneous in nature
• Video, Image, Text, WORD Document, Audio,etc
• Services are needed to take content and transform
  to appropriate presentation.
• Network topologies of devices (eg., PDAs,
  sensors, printers, coffee makers) are becoming
  increasingly more dynamic and thus increasingly
  are networks are becoming more ad-hoc.

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Data Transfer

• The progression of data through the network needs
  to be seamless i.e., the users should not have to
  know which devices the data is being transferred
  over or the formats needed to the end user to
  read it.
• The computing system must also manage a
  ubiquitous persistent storage.
• Replicated data should be consistent.

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Resource Discovery

• In the scenario, Mike asked for a list of
  printers that were available to him.
• The set of printers in a building constantly
  change i.e., it is not static.
• When a printer is plugged in how does the
  printer tell the building that it is available.
• There are issues with lookup services and
  connectivity.
• A PDA may store the list of printers so that if
  the lookup service is down, the user still has a
  list of printers.
• When the list of printers changes, when should
  the PDA be informed?

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Resource Discovery

• The home environment will have appliances that
  are part of the home computing environment. This
  includes alarm clock, coffee make, refrigerator,
  etc When an appliance is bought and plugged in,
  it must be made known to the computing
  environment.

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Agent Technology

• The scenario described the use of agents -- one
  for scheduling and one that bought stocks.
• An agent can be defined as a component of
  software and/or hardware which is capable of
  acting exactingly in order to accomplish tasks on
  behalf of its user.
• Agent technology and protocols for mobile
  computing is not well understood. This will draw
  upon knowledge from AI, networking and
  distributed systems, and databases.

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Trigger Management

• An event could cause a number of actions.
• Examples
• Alarm clock and coffee maker
• Entering an office and having the temperature set
  and the PC turned on.
• A high glucose level causing an appointment to be
  made.
• Issues
• What if there are conflicts?
• Seamless integration
• Dynamically changing

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Trigger Management

• Example Sue and Mikes scheduled changed so that
  there is a new time to ring the alarm, start the
  coffee maker.
• Example What if Sue and Mike decided to only
  drink coffee on the weekend or eliminate it
  alltogether.
• Example How does Mikes home computing system
  know that it is ok to have the doctors office
  override all appointments. What if Mike wants to
  hide something from Sue?

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Sensors

• If we are to adjust temperature based on the
  number of people and the current temperature
  then
• Sensors measuring temperature are needed
• Determining the number of people in a room is
  needed
• Sensors are lightweight devices
• Current network protocols e.g., TCP may not work
  well.
• What about power?

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User Interface Devices

• Currently, the primary devices we use to interact
  with the computing system are a keyboard and a
  mouse.
• Voice recognition systems are becoming more
  sophisticated, but I cant tell the room make me
  coffee or set up a conference call. At least
  not yet.
• What about pen input?
• In a conference, a person may write something on
  a whiteboard.
• If the participants are in remote locations, it
  would be nice if that information on the
  whiteboard appeared at each participants
  preferred device.
• This would certainly be easier than having
  someone record everything, type it up and then
  send it.

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Ease of Use

• People cant program their VCR and yet they are
  to program event management in their homes or
  offices.
• We dont want to know about data formats, battery
  power.
• We care about a seamless and inexpensive
  environment.

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Privacy and Security

• Take the temperature adjustment
• An enemy organization could seize control and
  adjust the temperature so that it is difficult
  for people work and thus making it less secure.

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Software Development

• How can software development be faciliated?
• Testing
• Maintenance