Plan B: Using Files instead of Middleware Abstractions

Abstract

resources We provide abstract interfaces, amenable to both users and applications, through (virtual) file trees. Unlike other systems that use files for interfaces (Plan 9, for example), we don't provide pixmaps or other low-level artifacts to support GUIs. We support user interfaces by providing a file tree in which a different file represents each UI element (that is, widget). The same applies to other resources.These files aren't on disk but are provided by resource servers, such as in Plan 9 or Unix's /proc. 3 In addition, we don't propose to intercept file system calls. Rather, we take the Plan 9 approach to the limit and provide all services by implement- Plan B maps abstract interfaces to files and adapts to file tree availability. It is easy to program, offers a general-purpose computing environment, and supports smart spaces without using middleware.The system ensures that the namespace reflects which resources are available and which ones aren't, cleanly removing unavailable resources from the file trees. JULY-SEPTEMBER 2007 PERVASIVE computing 63 Figure 2. A typical Plan B screen, serviced by the Omero UI volume.

Easing the Smart Home: A rule-based language and multi-agent structure for end user development in Intelligent Environments

“…That is, by creating an Intelligent Environment Operating System (OS). This is the case of Gaia [108] and PlanB [7], each of which present a different approach. Thus, while Gaia provides an ad-hoc operating system, with numerous modules specially designed to deal with ubiquitous computing problems (such as a presence service or a context service), PlanB focuses on adapting a Unix-based operating system to the Ubiquitous Computing domain, being able to use all the already existing potential of said OS to create context-aware applications.…”

Opening pervasive computing to the masses using the SEAP middleware

“…For example, Weis et al [6] use visual programming techniques to reduce the learning curve typically required. Other approaches [7], [8] provide additional layers of abstraction to manage complexities that can be hidden from the developer. We anticipate that these techniques will be complementary to the SEAP middleware architecture and might be combined to further ease software development for pervasive computing.…”

A demonstration of pervasive device integration with SEAP-based middleware

“…For example, Weis et al [13] use visual programming techniques to reduce the learning curve typically required. Other approaches such as [7] and [1] provide additional layers of abstraction to manage complexities that can be hidden from the developer. We anticipate that these techniques to be complementary to the SEAP middleware architecture, and might be combined to further ease software development for pervasive computing.…”

“…Using only two numerical outputs, speed and turning angle, a SEAP application will be able to steer the robot remotely. 1 The Sun SPOT devices mentioned in the previous subsection will be providing sensor data to the SEAP server. However, the devices also provide eight tri-color LEDs.…”