The SENSE-ME platform: Infrastructure-less smartphone connectivity and decentralized sensing for emergency management

In emergency scenarios, network coverage constitutes a fundamental requirement for both crisis management and rescue operations. However, coverage might not be sufficient to avoid chaotic crowd behaviours that could possibly occur when there is lack of accurate sensing data, and of distributed coordination among the main actors. In this paper, we investigate the role that Commercial Off-The-Shelf (COTS) smartphones can play in emergency scenarios. Modern smartphones hide a great potential for emergency monitoring and management: (i) they are truly pervasive, (ii) they can establish peer-to-peer wireless links using short-range communication technologies, thus guaranteeing coverage even when fixed infrastructures are unavailable, and finally (iii) they can sense the environment through several embedded sensors. In order to maximally exploit such capabilities, we propose the SENSE-ME framework, which enables the creation of a spontaneous phone-sensing platform, by providing integrated functionalities of opportunistic networking, mobile sensing, and distributed information processing. Moreover, we introduce a realistic usage scenario (building evacuation), characterized by the presence of Android devices deployed over a two-dimensional space. Through SENSE-ME, each smartphone is able to quantify its level of danger by analysing its sensor data, to share such metrics with the surrounding devices via Wi-Fi Direct links, and finally to detect an emergency event, and compute a safe path, by applying a consensus-based algorithm to the received observations. In this scenario, we present a modular evaluation of the SENSE-ME networking/sensing/information processing components, clearly highlighting the strengths of a multi-layer approach for emergency monitoring and management.