A testbed for evaluating human interaction with ubiquitous computing environments

Core to ubiquitous computing environments are adaptive software systems that adapt their behavior to the context in which the user is attempting the task the system aims to support. This context is strongly linked with the physical environment in which the task is being performed. The efficacy of such adaptive systems is thus highly dependent on the human perception of the provided system behavior within the context represented by that particular physical environment and social situation. However, effective evaluation of human interaction with adaptive ubiquitous computing technologies has been hindered by the cost and logistics of accurately controlling such environmental context. This paper describes TATUS, a ubiquitous computing simulator aimed at overcoming these cost and logistical issues. Based on a 3D games engine, the simulator has been designed to maximize usability and flexibility in the experimentation of adaptive ubiquitous computing systems. We also describe how this simulator is interfaced with a testbed for wireless communication domain simulation.

1. Introduction

Weiser's vision of pervasive or ubiquitous computing [1] involves devices, sensors and actuators that are inter-networked and embedded in the fabric of everyday life. These collaborate to sense and attend to the tasks users in a space are currently aiming to perform, adapting the behavior of available software services to meet that task while reflecting the context of the situation. More so than other distributed systems, ubiquitous computing systems must dynamically adapt to the needs of the user and to the current operational context. This requires ubiquitous computing systems to exhibit a high level of adaptive behavior in order to respond to a wide range of contexts and stimuli that may be difficult to define a priori in a comprehensive manner. In addition, the context and input stimuli experienced by adaptive software applications and the effectiveness of the adaptive behavior they exhibit are highly dependent on the user's involved and the environmental and social context in which they are attempting the tasks which the adaptive systems aim to support. Experimentation and testing of such adaptive software is therefore problematic due to the number of independent variables associated with such context. Accurate assessment of the perceived human benefits achieved by using such adaptive systems therefore requires that this context is accurately controllable, recordable and replicable. In developing such adaptive systems, human interactions must be recorded and later replicated in synchronization with their interactions with the physical ubiquitous computing environment. This experimental requirement is further complicated by the need to test scenarios that involve multiple users collaborating in a ubiquitous computing environment.