A loss-aware adapter chaining and evaluation scheme for service continuity in ubiquitous environments

Abstract

One of the key features in ubiquitous computing is service continuity which allows a user to transparently continue a task regardless of movement across multiple heterogeneous places. As different places have different services, the user cannot use the same service during his movement across the multiple places. In this situation, alternative services can help the user continue doing the task. The possible alternative services are not limited to the services with exactly the same interfaces and semantically compatible services also can provide the functionality what the user wants, although they don``t have same interfaces to the original service. For utilizing semantically compatible services, the user should adapt to new user interface of the alternative service. For resolving this adaptation burden on the user, the developer can provide predefined adaptation component called adapter. It hides the adaptation procedure from the user by automatically converting the exchanging messages between the user and service. Adapter is specialized to one pair of interfaces, so the overhead of adapter generation becomes one of serious problems in the adapter-based approach. There have been many research efforts regarding adapter generation load reduction like semi-automatic adapter generation and adapter chain construction scheme. Semi-automatic adapter generation scheme has limitations on load reduction, because it requires developer``s input to resolve interface differences between the original service and alternative one. As an alternative approach, the system can compose multiple adapters into one adapter for unspecified adaptation procedure. Maybe, there exist multiple adapter chains and one of them is selected and used for adaptation provisioning. However, there is no quality optimization effort to select or construct optimal adapter chain, so, previous work may not provide optimal adapter chain to user. This thesis focuses on the quality evaluation problem, which sh...