Euphoria: A Scalable, event-driven architecture for designing interactions across heterogeneous devices in smart environments

Abstract

Context: From personal mobile and wearable devices to public ambient displays, our digital ecosystem has been growing with a large variety of smart sensors and devices that can capture and deliver insightful data to connected applications, creating thus the need for new software architectures to enable fluent and flexible interactions in such smart environments. Objective: We introduce Euphoria, a new software architecture design and implementation that enables easy prototyping, deployment, and evaluation of adaptable and flexible interactions across heterogeneous devices in smart environments. Method: We designed Euphoria by following the requirements of the ISO/IEC 25010:2011 standard on Software Quality Requirements and Evaluation applied to the specific context of smart environments. Results: To demonstrate the adaptability and flexibility of Euphoria, we describe three application scenarios for contexts of use involving multiple users, multiple input/output devices, and various types of smart environments, as follows: (1) wearable user interfaces and whole-body gesture input for interacting with public ambient displays, (2) multi-device interactions in physical-digital spaces, and (3) interactions on smartwatches for a connected car application scenario. We also perform a technical evaluation of Euphoria regarding the main factors responsible for the magnitudes of the request-response times for producing, broadcasting, and consuming messages inside the architecture. We deliver the source code of Euphoria free to download and use for research purposes. Conclusion: By introducing Euphoria and discussing its applicability, we hope to foster advances and developments in new software architecture initiatives for our increasingly complex smart environments, but also to readily support implementations of novel interactive systems and applications for smart environments of all kinds.