Ubiquitous Computing Environments feature massively distributed systems containing a large number of devices, services and applications that help end-users perform various kinds of tasks. One way by which administrators and end-users can manage these environments is through the use of policies. In particular, obligation policies are used to specify what actions must or must not be performed by the environment on the occurrence of certain events. Obligation policies are often specified as Event-Condition-Action (ECA) rules. However an important problem in ubiquitous computing systems is that different users and administrators may have conflicting policies for managing the system. Hence, a key challenge in policy-based management is detecting and resolving conflicts between multiple policy rules that get activated by a single event. Existing approaches are limited in power and scope mainly because they do not have semantic information about the effects of policy actions; hence, they can...
Chetan Shiva Shankar, Anand Ranganathan, Roy H. Ca