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Context-Aware Communication for People
Telephone amazing technology has helped communication from the 1870s
• could ring at most inappropriate and inconvenient times and be a source of annoyance
• the callee does not have a choice and is forced to hear the ringing by the caller, even if the callee does not answer the phone.
Making the phone not ring, 2005, H. Schulzrinne, Columbia Univ.
• presentation at the Internet2 Spring Meeting
Context-aware communication
• Make the phone not ring except in an appropriate manner
• The Phone rings at the callee situations
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Evolution of VoIP
PRID : Rich Presence IDautomatically derived from
sensors: physical presence, movementelectronic activity: calendars
Provide watchers with better information aboutthe what, where, how of presentities
1. Routing
Routing : Messages or voice calls can be routed to the appropriate destination
• The phone in the right room can ring by call forwarding :
who they are with, where they are, what they are doing, what the time it is
• Augmenting device-mediated communication with context information enrich user interaction.
Architectural Considerations for Scalable, Secure, Mobile Computing with Location Information, 1994, Mike Spreitzerm Xerox Palo Alto
Ubiquitous Message Delivery at Xerox PARC (UMD, 1994)
• An autonomous system for both sensing and communication acts
• User location - active badges, keyboard input activity, and explicit commands
• Text delivered “at the soonest acceptable time via the most appropriate terminal near the recipient”, waited for a suitable situation or terminal to be available
• User agent process : User location and the user’s policy regarding message
delivery were maintained
• Terminal agents : manage the policy of outputting messages on terminals
• No user-oriented heuristics for deciding acceptable times and appropriate terminals
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2. Addressing
Addressing : contextually appropriate people (mailing lists and shared spaces)
• Entities can be addressed based on their context instead of their unique identifier or names
A Conceptual Framework and a Toolkit for Supporting the Rapid Prototyping of Context-Aware Applications, 2001, Dey, Georgia Tec
The Context-Aware Mailing List
• Dynamic distribution list is used to deliver email messages to members of a research group who are currently in the building
• Addressing email-style communication to a group of people who are selected by their location.
• Context-aware mailing list built with the
Context Toolkit
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Architecture diagrams for the In/Out Board and
Context-Aware Mailing listApplications
3. MessagingMessaging : contextual reminder/messaging
• By knowing the situation of the receiver or addressee,
the right message can be delivered at the right time and in the right form,
be it a reminder message or an incoming e-mail
Hanging Messages – using Context-Enhanced messages for just-In-Time communication, 2001, Chang and Maes, MIT
What is a hanging message?
• Context-enhances message for just-in-time communication
• A message which is delivered to a recipient at a specific place and time
• Envision the message as “hanging” in a certain location, waiting for the recipient
• Messages are context enhanced for better filtering
Mobile wireless device agent : Located an on each user's device
• make use of existing context to filter incoming communications.
• A user should never receive any unsolicited or irrelevant message
Filtering mechanisms :
hierarchical categorization for messages
user profiling by rules
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4. Providing Awareness of callee
Providing awareness of callee or receiver
• One can determine if the individual is available to talk by presence awareness
• Presence awareness is similar to the idea of status in Instant Messenger systems
Context-aware communication with Live Contacts, 2004, G. Henriter Hofte
Live Contacts system (running on pocket PC phones, PC)
Presence information of listed contacts,
• current Messenger status (e.g., busy, online, away, on-the-phone, etc.)
• current calendar information (e.g., work and non-work times, appointments,…)
• last-known location information (e.g., at work, at home, on move, or unknown)
One can initiate contact (via telephone call, SMS, IM, or e-mail)
or ask to be reminded to make contact at a nominated future time.
Live Contact servers : A client–server architecture - querying for updates on contacts
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5. ScreeningScreening : establishing communication under appropriate conditions
• Filtering or redirecting calls based on the situation of the receiver combined with the previous application types
• Inform the caller of the callee’s situation , and takes action automatically on perceiving that the callee is unavailable
Ex) In a meeting, then the phone can be put in a certain mode, virtually filtering the call
Calls.calm : callee specifies the extent of a caller’s access to situation information and communication channels in a database of relationships
Uses Web phones to mediate communication with subscribers.
A person selects who to call, and he is greeted by the callees, contact page contextualized and customized for the caller; if the caller is unknown, (c) a generic page.
For trusted callers, Calls.Calm reveals status, messages, and a list of preferred communication channels.
The system supports negotiating a time to make a voice call by an exchange of short text messages
The aforementioned application types may be combined in a specific application
Ex) Route messages using context as well as filter appropriate messages
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Call Services Applying a Disciplined Approach to the Development of a Context-Aware
Communication Application, 2005, Ted McFadden, Australia
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Context Information : location , the status of the user, available communication mode (e.g., voice, text, or video), device battery power
Context Modeling Language (CML) :represent the context representation for context-communication application
ECA (Event, Condition, Action) modelthe precondition in this case is always true, and the action is to re-evaluate preferences for the call of concernProcess the ‗Locate‘ messages1. Context Manager is queried to discover
devices near the user2. devices are rated against the FinalEval
preference3. If any device gets an oblige score,
it is selected for use.4. The SIP address for the device selected at
step 3 is determined from the “has address”
Call Services
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Context fact model for the communication application
Application Types
Application types: addressing & context-aware commands
Ex) “when the 8 p.m. news is finished and if no one is watching, turn off the television next to the chair John is sitting in.”
addressing : to TV by the context
command : “turn off” performed in the right context
Context ensures that commands are delivered in the right way and at the right time to appliances.
Sensing/thinking/acting subsystems are studied previously.
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Command Interpreter Determine the attribute
Sensing Reasoning Action
Smart Space
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Smart space : it can intercept and understand user commands
Context-aware command processor : execute commands issued by a speaker
- interprets the user’s commands, translates it into an operation on a device,
- and invokes the operation on the device
Query sensors & devices whether a command has been successfully completed
Server : continuously listens for user commands and has access to devices
Devices have an API or a Web service-like interface for invoking the operations
UPnP Design by Example, 2003, Jeronimo, Intel
UPnP(Universal Plug & Play) for future devices.
Interface to devices to communicate with or make use of the device
Action invoking to a UPnP control point
Ex) 3 services for Super Toaster device
• Lifetime Statistics, Toaster Status, Toaster Control
http://www.jini.org/wiki/Category:Introduction_to_Jini
Jini : SUN
• Provides a Java-based object model of devices
• Discovery, Join, look-up, and client uses service.
Smart Space
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TV
door
Lamp
Smart Space
Utterance WOperation
Infra Structure : Determine the situation such as which device ?
Sensing/Thinking/Action
Sensors
Query
Command to target devices
Query
Context-Aware Sensor networks
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Context-Aware SensorsA survey on sensor network, 2002, Akyldiz, Georgia
Life Patterns: structure from wearable sensors, 2002, Brian Patrick Clarkson MIT
Sensor Networks
• Numerous applications : from kinder garden to traffic management
• Understanding regularity in everyday life behavior (wearable sensors MIT)
• Life patterns are the reoccurring events in daily behavior, such as those induced by the regular cycle of night and day, weekdays and weekends,
work and play, eating and sleeping
Researches : networking protocols, Hardware, Operating systems, Programming model
2 related topics for Sensors and Context-aware Computing
• Sensors are used to acquire context information
• Sensors themselves can be made to be aware of their own context
Context-Aware Sensors:
Sensor networks + Context-aware computing
• whose behavior can be changed in response to their current context,
• power-conserving actions depending on the situation the sensors are in.상황인식 2010 가을 12 주차 53
Context Information
Sensor
Aware
Acquire
Context-Aware Sensors: The Concept
WSN : wireless sensor network
a combination of low cost, low-power, multifunctional miniature sensor devices consisting of sensing, data processing, and communicating components, networked through wireless links between neighboring nodes
Large number of sensor nodes are deployed over an area
Mesh network : relay sensed information to base station
Energy constraints of sensors
for Sensing/Computing/Networking
Idea of Context-aware sensors
• If sensors know more about their own context, then they could adapt their behavior and function only when needed in the current circumstances
they becomes more prudent for spending energy
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Architecture
Framework
• Setting of groups of sensors – provide context & send/receive commands
• Several support services – provide communication between sensors and the system
• Components to provide the core functionalities for context discovery & use
the sensor nodes –
• Programming : nesC under TinyOS
• To interface with the sensors : Java 1.1 API is used for modules that provide data collection, analysis, and communication between the motes and the base station
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Architectural diagram
Architectural diagram showing the main components of the framework
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Frameworks
Sensor groups :
• Send sensor readings to communication server
• Receive sensor control commands from the “Context Trigger Engine” via communication server.
Communication server:
Acts as a mediator between the base station and the sensors
and provides a unified protocol of communication for applications
• Parse raw data packets from the sensors into a format recognizable by App.
• Parse control messages from the application to the sensors
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Frameworks
Context locator service: Interpret the current context from the raw sensor readings
• If-else condition rules – decide whether certain context has been acquired
• Form secondary context by conjunctions of different primary context information
Context mining service: context discovered autonomously in the system
• User programmed rules - Static context discovery and dependent on designed scenarios
• With this service,
• Context locator service would be sampling sensor data
• Context mining service would be discovering context
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TempSensor Context locator
serverTempSensor
IF temp sensor < threshold,Primary context is cold
IF groups of temp sensors < threshold,Secondary context is coldweatherContext
Lookup
Context name
Frameworks
Context trigger engine: determines the sensor operations triggered,
• using a combination of given context and sensor profiles
• Action macros : a command or a combination of actual commands sent to sensors
Context action data store: Relationship between context & its respective actions
• 1-to-1 mapping, mapping with interdefined relationship
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Context scheduler
Macro Decoder
Action Interpreter
Context Actions
Data store
Request
Action macroTime-to-trigger
Context, Sensor group
Sensor control message
Sensor command
Action operation
DB
Sensor profile
operationsSensor ID
Other context information (Ex: current time,) about the system can be used.
Put found action macro on the queue to be scheduled for triggering.The queue operates based on a time-to-trigger parameter
Decompose the macro into simpler instructions to be sent to the listeningapplication running at a base station
Context-Aware Security
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