Brad Johanson

The Interactive Workspaces project: experiences with ubiquitous computing rooms

The Interactive Workspaces project explores new possibilities for people working together in technology-rich spaces. The project focuses on augmenting a dedicated meeting space with large displays, wireless or multimodal devices, and seamless mobile appliance integration.

Integrating information appliances into an interactive workspace

The authors present a robust, infrastructure-centric, and platform-independent approach to integrating information appliances into the iRoom, an interactive workspace. The Interactive Workspaces Project at Stanford explores new possibilities for people to work together in technology-rich spaces with computing and interaction devices on many different scales. It includes faculty and students from the areas of graphics, human-computer interaction (HCI), networking, ubiquitous computing, and databases, and draws on previous work in all those areas. We design and experiment with multidevice, multiuser environments based on a new architecture that makes it easy to create and add new display and input devices, to move work of all kinds from one computing device to another, and to support and facilitate group interactions. In the same way that todays standard operating systems make it feasible to write single-workstation software that uses multiple devices and networked resources, we are constructing a higher level operating system for the world of ubiquitous computing. We combine research on infrastructure (ways of flexibly configuring and connecting devices, processes, and communication links) with research on HCI (ways of interacting with heterogeneous changing collections of devices with multiple modalities).

The Event Heap: a coordination infrastructure for interactive workspaces

Coordinating the interactions of applications running on the diversity of both mobile and embedded devices that will be common in ubiquitous computing environments is still a difficult and not completely solved problem. We look at one such environment, an interactive workspace, where groups come together to collaborate on solving problems. Such a space will contain a heterogeneous collection of both new and legacy applications and devices. We propose the Event Heap, a coordination model most similar to tuplespaces, as being appropriate for such environments. We also present a prototype implementation of the Event Heap, and show that the system has performed well in actual use over the last two years in our prototype interactive workspace, the iRoom.

PointRight: experience with flexible input redirection in interactive workspaces

We describe the design of and experience with PointRight, a peer-to-peer pointer and keyboard redirection system that operates in multi-machine, multi-user environments. PointRight employs a geometric model for redirecting input across screens driven by multiple independent machines and operating systems. It was created for interactive workspaces that include large, shared displays and individual laptops, but is a general tool that supports many different configurations and modes of use. Although previous systems have provided for re-routing pointer and keyboard control, in this paper we present a more general and flexible system, along with an analysis of the types of re-binding that must be handled by any pointer redirection system This paper describes the system, the ways in which it has been used, and the lessons that have been learned from its use over the last two years.

Portability, extensibility and robustness in iROS

The dynamism and heterogeneity in ubicomp environments on both short and long time scales implies that middleware platforms for these environments need to be designed ground up for portability, extensibility and robustness. In this paper, we describe how we met these requirements in iROS, a middleware platform for a class of ubicomp environments, through the use of three guiding principles - economy of mechanism, client simplicity and levels of indirection. Apart from theoretical arguments and experimental results, experience through several deployments with a variety of apps, in most cases not done by the original designers of the system, provides some validation in practice that the design decisions have in fact resulted in the intended portability, extensibility and robustness. A retrospective examination of the system leads the authors to the following lesson: A logically-centralized design and physically-centralized implementation enables the best behavior in terms of extensibility and portability along with ease of administration, and sufficient behavior in terms of scalability and robustness.

Extending tuplespaces for coordination in interactive workspaces

The current interest in programming models and software infrastructures to support ubiquitous and environmental computing is heightened by the falling cost of hardware and the ubiquity of local-area wireless networking technologies. Interactive workspaces are technologically augmented team-project rooms that represent a specific sub-domain of ubiquitous computing. We argue both from related work and from our own experience with a prototype that the tuplespace model of communication forms the best basis for a coordination infrastructure for such workspaces. This paper presents the usage and characteristics expected of interactive workspaces, from which we derive a set of key system properties for any coordination infrastructure in an interactive workspace. We show that the design aspects of tuplespaces, augmented with some new extensions, yield a system model, which we call the Event Heap, that satisfies all of the desired properties. We also briefly discuss why other coordination models fall short of the desired properties, and describe our experience using our implementation of the Event Heap model. The paper focuses on a justification of the use of tuplespaces in interactive workspaces, and does not provide a detailed discussion of the Event Heap implementation or our more general experience with interactive workspaces, each of which is treated in detail elsewhere.

Interactive Workspaces

We are rapidly entering a world in which people equip themselves with a small constellation of mobile devices and pass through environments rich in embedded technology. However, we are still a long way from harnessing the power of this technology in a way that seamlessly and invisibly assists users in their day-to-day activities. Bringing pervasive computing to maturity requires innovations in systems integration and human-computer interaction (HCI). To investigate these challenges, Stanford Universitys Interactive Workspaces project (http://iwork.stanford.edu/) is exploring team-based collaboration in technology-augmented environments. These workspaces are designed to allow groups of five to ten people to work together using computing and interaction devices on many scales.

The Stanford Interactive Workspaces Project

The Stanford Interactive Workspaces project developed a set of technologies for integrating multiple devices in a co-located workspace, based on a few basic principles: 1. The interactions should maximize the potential for “fluency” of the users, reducing as much as possible the need to shift attention from the content of the work to the mechanism. 2. The integration should focus on commodity devices running existing operating systems and applications, so the workspace is not an isolated island. It should provide an “overface” that brings them together, rather than replacing the existing widely used interfaces. 3. The system should be loosely coupled and robust, so that failures and changes of individual elements are gracefully handled and do not disrupt the functioning of the overall workspace.