A Framework for enabling Service migration in Ubiquitous Computing

Ubiquitous Computing is a computing paradigm in which applications move with the user. This requires applications to migrate automatically to the environment the user is present and adapt to different contexts and resource availabilities. An important requirement of a ubiquitous computing system is this automatic adaptation of applications to the new environment. At the time of migration, there could be incomplete services that are still in a running state. Such services may have to be suspended and transferred to destination before they are completed. In this paper, we propose a service migration framework for migrating partially executed services. When multiple destinations are available for the migration, an Ontology Server selects one after evaluating a variety of attributes such as energy level, computational ability, availability etc. Migrations are handled at thread level for accuracy. In particular, migration of response-awaiting-services is handled based on the communication behavior of the service. These services are divided into two categories viz. Continuous-Interaction-Demanding Services and Limited Interaction Services based on the nature of their interaction with the user. Two distinct protocols are then proposed for handling the migration of these services.