1. CAMP-UP System Interaction
1) Space Manager identifies that a device has entered the space,
Space sends context information, such as a label for the space’s location and a
description of the space’s current activity, to the device.
At the same time, the space also asks the device for the set of functionalities
that it is exposing to the space, given the context information.
A device is said to expose a functionality (e.g., ringer volume, vibration) if it
allows the Space Manager to have control over that particular functionality (e.g.,
allows the space to set the ringer volume to certain level)
2) Phone Manager passes the context information it received from the space to the
Context Aggregator
3) Context Aggregator update the context database, in which all the context
Information is stored
4) Context Interpreter derive higher-level context information using the passed
context information,
5) Context Interpreter store the derived context information in the context database
6) Phone Manager gets the derived context information from the database.
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2. CAMP-UP System Interaction
7) Phone Manager uses the derived context information as parameter in a query to
retrieve the set of exposed functionalities the functionality database
8) the response is obtained to Phone Manager
09) Phone Manager send exposed functionalities back to the Space Manager
10) Space Manager determines the set of functionalities that need to be set for the
current space’s activity, by consulting the space policy
11) Policy Controller tries to match the device’s exposed functionalities with space
required functionalities, based on the space’s current policy DB
12) Policy Controller updates the Space Manager with the required functionalities
13) Space Manager sends a message to the phone asking to set functionalities to
certain modes
14) phone manager sets the phone to certain modes, based on the space
requirements
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3. On the Space Side
Two basic types of context information
• Location - current location of the Space Manager (e.g., home, car, room)
• Activity - represents the current actual activity within the space.
• Derived from an activity schedule
• the space has its own context aggregator and context interpreter, as well as
sensors to determine the current activity occurring within the space.
Space Manager
• discovering new devices that enter the space and leave the space
• When the device enters the space, the Space Manager will initiate a new
connection with the client and send the current context information
• ask for the set of exposed functionalities from any device in the space area and
connected to the Space Manager
• Space control over device functionality
• for compliance reasons to follow the space policy
– In the hospital or air plane  silent mode
• for convenience of the user
– Watching a movie in a cinema  silent mode
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4. On the Space Side
Policy controller
• perform a comparison to match the set of exposed functionalities sent by the
device with the space-required functionality based on the space’s current
policy
Policy database
• stores the space policy for each particular type of space activity.
• space policy identifies the required settings on the device functionalities
based on the space’s current activity.
Ex) Rule such as “when the space’s activity context is lecture, every mobile phone
is required to be silent and set to vibration off mode.”
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5. On the Client Side
Five components for supporting context awareness and user preferences
1. Phone Manager
2. Context Aggregator
3. Context Information
4. Context Interpreter
5. Functionality Database
Phone Manager : main software component to control the mobile phone interaction
with the Space Manager
Four tasks of the Phone Manager
1. Establish and maintain the connection with the Space Manager
2. Update the context aggregator : new context information received from the
space
3. Send the set of functionalities that are exposed from the phone to the space
4. Update the phone mode
when the Space Manager sends a message requiring functionalities to be
set to a certain mode based on the space policy
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6. On the Client Side
Context Aggregator – gather the context information & record it in the Context DB
• Context information from the Space Manager , and other sources as well,
such as the device’s calendar that resides in the phone itself or other sensors
attached to the phone
• For new context information or a context change, asks the context interpreter
to derive new high-level contexts
Information stored in the Context Database
• Low level context information : location, space’s current activity
Ex) “bathroom, hotel, and restaurant”, “lecture, meeting and conference, dinner”
• Higher level, derived using the inference engine.(=Context Interpreter)
Ex) “lecture at Sogang University” and “meeting with supervisor,”
• Updated whenever the context aggregator receives new context information.
Ex) 회의실 입장(location), 이사회 중(activity),…
Functionality database
• Store data of associates’ phone functionalities for each level of exposure
• Store rules that map situations (or derived context in this case) to levels of
exposure.
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7. Discussions for control
The first is the space control of device functionality for compliance reasons;
• the device has an obligation to follow the space’s policy
• There are a number of ways to enforce compliance by the user’s device,
such as asking the user to sign an agreement before utilizing services or
coming into particular spaces. For compliance, there has to be a
mechanism to ensure that the device obeys the space requirements
The second perspective is the space control of device functionality for the
convenience of the user
• the space automatically sets the phone to particular modes to avoid the
users having to do this manually
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8. Context-aware
Mobile Software Agents For
Interaction with WEB Services in
Mobile Environments
윤 용운
2010.11.04
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9. CALMA Agents
CALMA : Context-Aware Lightweight Mobile BDI Agents
• Intelligent S/W agents running on mobile agents , which are context aware
for interacting with WEB services
• Implementation issues & Evaluation of CALMA
Compare to previous weeks (=Context-Aware mobile services),
• We attempt a deeper exploration of the notion of the agents for
functionality and intelligent behavior.
We think the AGENTS, not the Services, as being context aware.
• We consider the context in which software agents find themselves
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10. Agents : Mobile and Intelligent
What is an agent?
• Interact with users, applications, and agents
• collaborate with the user
Situated in their environment and react/respond to stimuli from their environment
 Proactive (상황에 앞서서 주도, 사전 대책)
 Autonomous (자동적)
 Communicative (다른 것들과 연계)
 Adaptive (상황에 따른 유연하게 적응/ 조정)
Software agents help with repetitive tasks
Applications,
 Personal assistant (mail filter, scheduling)
 Information agent (tactical picture agent)
 E-commerce agent (stock trader, bidder)
 Recommendation agent (Firefly, Amazon.com)
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11. What is a mobile agent?
Mobile Agents and the Future of the Internet, 1999, David Kotz
Mobile agent: programs that
• migrates from machine to machine
• in a heterogeneous network
• at times of its own choosing
Definition : In a broad sense, an agent is any program that acts on behalf of a
(human) user. A mobile agent then is a program which represents a user in a
computer network, and is capable of migrating autonomously from node to
node, to performs some computation on behalf of the user.
Search
engine
Machine A Machine B
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12. What is a mobile agent?
Evolution
Mobile Agents are a distributed computing paradigm
End point in the incremental evolution of mobile abstractions such as mobile code,
mobile objects, mobile processes.
 Mobile Code – transfers code
 Mobile Object – transfers code + data
 Mobile Process – transfers
code + data + thread state
 Mobile Agent – transfers
code + data + thread + authority of its owner
Applet – Downloaded from server to client
Servlet – Uploaded from client to server
Mobile Agents – Detached from client, can have multiple hops
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13. Advantages of the Mobile Agent Paradigm
Advantages of the Mobile Agent
 Reduce bandwidth consumption and network loads
 Allow dynamic deployment of application components to arbitrary network
sites
 Encapsulate protocols
 Execute asynchronously and autonomously
 Can adapt by moving
 Run on heterogeneous platforms
 Most distributed applications fit naturally into the mobile agent model
 Intuitively suitable for mobile users and disconnected operations
Mobile agents combine the strengths of techniques such as RPC, java applets etc.
into a single, convenient framework
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14. Context -Awareness : key attribute for mobile agents
Context awareness is a key attribute for mobile agents in ubiquitous
environments
• perform tasks such as migrate when resources are running low
• migrate when a connection is available
• avoid embarking on a task that requires continuous connectivity
• a computational overhead needs to be taken into consideration of using
context awareness
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15. MyCampus
MyCampus : An Agent-based semantic web environment for context-aware mobile
services : CMU
• Revolves around a growing collection of customizable agents capable of (semi-)
automatically discovering and accessing Intranet and Internet services
• planning an evening out, organizing a study group, looking for a place where to
eat, or filtering incoming messages
Shared Ontologies : Describing contextual attributes, user preferences and web services,
Making easily accommodate new task-specific agents and new Web services.
User access personalized, context-aware agents
from PDA over the campus’s wireless LAN
Context information : location on campus by WiFi,
Calendar, preferences, friends& classmates, weather
Message filtering agents, Message routing agents,
Context-sensitive reminder agents,…
Ex) Restaurant Concierge : MyCampus Agent.
It returns recommendations on where to have eat
based on the user’s current context and preferences
Plans : Developing & Executing plans by agents
based on the user’s current context & information
(semi-)automatic discovery & access of Web SVC’s
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16. MyCampus
Personal Resource Ontology:
Automatic identification of
available sources of contextual
information
Each entity has its own set of policies &
policy evaluation agents
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17. CALMA Architecture
BDI agent Model
Wooldridge, 2002, An introduction to multiagent systems, JOhnWiley & Sons
BDI agent model :
• A software model developed for
programming intelligent agents, used
in complex multiagent systems
• draws inspiration from the philosophy
of human mentalistic concepts of
beliefs, desires, and intentions
• From the programming perspective,
two key concepts in the BDI model are
1. goals
2. plans : XML base language
the procedure for accomplishing
goals)
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18. BDI agent Model
Beliefs: Informational state of the agent, in other words its beliefs about the world
(including itself and other agents).
• also include inference rules, allowing forward chaining to lead to new beliefs
• Belief set: Beliefs are stored in database called a belief base or a belief set .
Desires: The motivational state of the agent.
• Situations that the agent would like to accomplish or bring about.
Ex) find the best price, go to the party or become rich.
• Goals: A goal is a desire that has been adopted for active pursuit by the agent.
Ex) one should not have concurrent goals to go to a party and to stay at home -
even though they could both be desirable.
Intentions: Desires to which the agent has to some extent committed.
• In implemented systems, he agent has begun executing a plan.
• Plans: Plans are sequences of actions (recipes or knowledge areas)
Events: Triggers for reactive activity by the agent.
• An event may update beliefs, trigger plans or modify goals.
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19. Context-aware
Addressing and Communication
for People, Things, and Software
Agents
윤 용운
2010.11.11
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20. Context Aware Communication
Use of context for enhancing communication among Entities,
• Including People, Things, Software Agents
• Gather context information about entities, which is used to enhance or
regulate communication-related actions
• Sensing and Thinking subsystems can be decoupled, built separately.
CAMP-UP case (studied before)
• Show how a device can be adapted via context information
• The device is a communication device though the idea is applicable to
other devices, including the coffee maker
Use of context for communication
• People to people
• People to objects (devices, appliances, everyday objects with embedded
computers)
• People to software agents
• Software agent to software agent
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