160 likes | 296 Views
Policy-Based Context-Aware Applications for Mobile Computing. José Viterbo Filho viterbo@lac.inf.puc-rio.br. Laboratory for Advanced Collaboration. Norms and policies.
E N D
Policy-Based Context-Aware Applications for Mobile Computing José Viterbo Filho viterbo@lac.inf.puc-rio.br Laboratory for Advanced Collaboration
Norms and policies • Multi-agent systems usually assume some form of structure, or set of norms or conventions that articulate or restrain interactions in order to make them more effective… • Mobile computing represents a typical scenario where these norms or policies are constantly changing • Inside this scenario, agents must be able to adapt to each new set of rules and policies accordingly Gustavo R. Carvalho. Governance in Open Multi-Agent Systems. Seminar’s Opening Session, 2005.
Mobile computing • Using agent technology to support mobile computing: • Is motivated by agent’s intrinsic properties such as autonomy, mobility, proactivity • In order to exploit these properties, policies may be attached to agents’ behaviors • These policies define • the actions that agents can perform • resources that they can use • information that they can access… H. Harroud., M. Khedr and A. Karmouch - University of Ottawa. Building Policy-Based Context-Aware Applications for Mobile Environments. Mobility Aware Technologies and Applications, MATA 2004.
Context-aware • In addition these policies are tightly bound to the context in which they are evaluated and used • A policy may be triggered based on the agent’s state, tasks and/or operating environment conditions • Applications must be able to efficiently manage, exchange and interpret context information H. Harroud., M. Khedr and A. Karmouch - University of Ottawa. Building Policy-Based Context-Aware Applications for Mobile Environments. Mobility Aware Technologies and Applications, MATA 2004.
Example 1: Smart Environments • Mobile and wearable computational devices that interact with the environment are becoming widespread… • NOT ONLY: laptops and PDAs • BUT ALSO: watches, active badges, smartphones, mp3 players, digital cameras • Devices should be able to automatically reconfigure themselves based on current context and user preferences • Behavior rules may be imposed to devices that enter a given space K. Connelly and A. Khalil - Indiana University. On Negotiating Automatic Device Configuration in Smart Environments. 2nd IEEE Annual Conf. on Pervasive Computing and Communications Workshops, 2004.
Example 1: Smart Environments PREVENT ABUSE PREVENT ABUSE • A user may want his cell phone to vibrate, instead of ringing, whenever he enters in a theater or concert room IMPROVE USABILITY • Following legislation that outlaws the use of video phones in locker rooms, a gym may want the ability to temporarily turn off the camera capabilities of a video phone • A university may wish to disable all cell phone calls (except for an outgoing 911) in a lecture hall when an exam is taking place K. Connelly and A. Khalil - Indiana University. On Negotiating Automatic Device Configuration in Smart Environments. 2nd IEEE Annual Conf. on Pervasive Computing and Communications Workshops, 2004.
Example 1: Smart Environments • Aside from the user preferences (policies), the smart environment may have its own policies when it comes to devices brought into that space • Conflict may arise when the device policy differs from the space policy • Policy resolution techniques may be implemented automatically adopting an agent-based negotiation approach K. Connelly and A. Khalil - Indiana University. On Negotiating Automatic Device Configuration in Smart Environments. 2nd IEEE Annual Conf. on Pervasive Computing and Communications Workshops, 2004.
Example 2: Travel aide • A university professor flies to a new city and stays the night for two project meetings, one in the morning, one in the afternoon • With a MAS, the professor’s PDA has a connection with the local weather and traffic network, his agent matches this information with his calendar and wakes him up 15 minutes earlier, preventing him to be delayed by a traffic jam • In the first meeting, his agent receives the information that the second meeting was postponed, and arranges for another night’s stay M. Khedr and A. Karmouch - University of Ottawa. ACAI: Agent-Based Context-Aware Infrastructure for Spontaneous Applications. Journal of Network and Computer Applications, 2005.
Example 2: Travel aide • To evolve from a passive state to an active pervasive state, the infrastructure must be able to support uniform context representation, to reason about context, to offer context-based service discovery, and to support a context management and communication protocol M. Khedr and A. Karmouch - University of Ottawa. ACAI: Agent-Based Context-Aware Infrastructure for Spontaneous Applications. Journal of Network and Computer Applications, 2005.
Example 2: Travel aide Common context representation Must be able to reason about context Context provider Context consumer M. Khedr and A. Karmouch - University of Ottawa. ACAI: Agent-Based Context-Aware Infrastructure for Spontaneous Applications. Journal of Network and Computer Applications, 2005.
Policies and context again • The effective contextual information that is used by mobile applications is translated into a set of policies • Generated context policies are represented semantically to help achieve the common understanding across different domains H. Harroud., M. Khedr and A. Karmouch - University of Ottawa. Building Policy-Based Context-Aware Applications for Mobile Environments. Mobility Aware Technologies and Applications, MATA 2004.
Policy-based approach • Agents are provided with a set of policies that govern their overall behavior in the environment and specify their privileges and constraints • Each policy includes conditions that permit or prohibit an agent to perform actions on target components • Conditions may concern the subject, the target or a particular state or event of the operating environment H. Harroud., M. Khedr and A. Karmouch - University of Ottawa. Building Policy-Based Context-Aware Applications for Mobile Environments. Mobility Aware Technologies and Applications, MATA 2004.
Policy-based approach UA UA User moves CPM CPM SA SA PSA SAT PSA SAT Network Network H. Harroud., M. Khedr and A. Karmouch - University of Ottawa. Building Policy-Based Context-Aware Applications for Mobile Environments. Mobility Aware Technologies and Applications, MATA 2004.
Policy-based approach • POLICY SERVICE AGENTManages policies of the domain under its administration to control the behavior and decision-making of the system agents PSA • SITE ASSISTANTIs in charge of preparing and setting up a temporary working environment to a user at a visited site SAT • CONTEXT POLICY MANAGERResponsible for monitoring the context information and managing the environment resources based on this context CPM H. Harroud., M. Khedr and A. Karmouch - University of Ottawa. Building Policy-Based Context-Aware Applications for Mobile Environments. Mobility Aware Technologies and Applications, MATA 2004.
Modeling Context and Policies • Policies have to be defined and understood by both machines and humans and to be domain interoperable • Modeled using ontology (OWL) • The CLNP is a multi-attribute negotiation protocol that allows automated context identification and agreement H. Harroud., M. Khedr and A. Karmouch - University of Ottawa. Building Policy-Based Context-Aware Applications for Mobile Environments. Mobility Aware Technologies and Applications, MATA 2004.
Next step • Extending the context policy manager with a fuzzy inference engine in generating policies • This will provide a necessary robustness against uncertain situations in the environment and maintain the performance of the system even in vague corrupted context information H. Harroud., M. Khedr and A. Karmouch - University of Ottawa. Building Policy-Based Context-Aware Applications for Mobile Environments. Mobility Aware Technologies and Applications, MATA 2004.