or, Infrastructure Support for ContextAware Applications

1
Context Fabric
Jason I. Hong James A. Landay
or, Infrastructure Support for Context-Aware
Applications
http//guir.berkeley.edu/projects/cfabric
What is Context-Aware Computing?
Context Specification Language
The goal of context-aware computing is to provide
tighter ties between the physical and social
worlds we live in and the virtual world in which
computers operate. Context-aware computing does
this by expanding the richness and diversity of
inputs that computers can sense.
Provide a flexible and high-level interface for
declaratively stating context needs.
"What are the five nearest movie theaters?"
Location
"Turn off my cell phone when I'm in a meeting or
in a restaurant."
Activity
Who is ltthis person / that persongt?
"Remind me to talk to Chris about Iron Chef
next time I see him."
Identity Proximity
Is ltpersongt near ltpersongt?
Is ltpersongt currently ltbusy / availablegt?
Multiple
"Where on earth was that picture taken?" "Is this
a photo from Phoebe's wedding?" "Who is that
sitting next to Ralph?"
Is ltplacegt currently ltbusy / availablegt?
Where ltis / was / willgt ltpersongt?
What are the ltNgt nearest ltpeoplegt right now?
Problem - Still Very Hard to Build Context-Aware
Systems
However, there are still high barriers to entry.
App developers must deal with distributed systems
issues, sensors, recognition algorithms, and so
on. An infrastructure provides an always-on
context dialtone that all apps can rely on
being there.
Automatic Path Creation
Network Services
Privacy?
Agents
Coordinate available sensor input and services
together to address queries made with the context
specification language.
What are the nearby movie theaters?
Diverse Platforms
Diverse Context
Sensor and Context Fusion
Sensor Input
Data Ambiguity
GPS
Sensor Input
Cell Location
Automatic Path Creation
Recognition Algorithms
Probabilistic Framework
Sensor Input
Problem Areas
Cell Location
Is there a meeting in this room right now?
Precision Granularity Accuracy Metadata
wav
single speaker?
Sensor Input
Unreliable Sensors
Diverse Sensors
wav
au
Proposed Solution
Sound
wav
audible?
meeting?
fusion
mpeg
motion?
Video