A proximity-based indoor navigation system tackling the COVID-19 social distancing measures Maria Fazio *† , Alina Buzachis * , Student Member, IEEE, Antonino Galletta * , Student Member, IEEE, Antonio Celesti * , Member, IEEE, and Massimo Villari * ,Member, IEEE * MIFT Department, University of Messina, Viale F. Stagno D’Alcontres 31, 98166 Messina, Italy {mfazio, abuzachis, angalletta, acelesti, mvillari}@unime.it † IRCCS Centro Neurolesi “Bonino Pulejo”, Messina, Italy maria.fazio@irccsme.it an efficient and cost-effective web-based indoor navigation system the provides hints on how to arrive at destination to mobile users equipped with a smartphone. For example, let consider a patient at the hospital that has to arrive at a specific ward. He/she can use a web-app through his/her smartphone to ask for indications towards the destination. In our vision, the web-app should have the following features: 1) it should be able to detect the position of the user inside the buildings and track it during the time, 2) it should have knowledge of the environment, 3) it should be able to calculate the best path between the user and destination optimizing the metric of interest (e.g., the shortest path, the largest way and/or passage, the lowest people density level, and so on) and 4) it should drive the user till the destination visualizing a map and providing vocal or iconographic instructions. From a technical point of view, our solution implements a multi-layer communication infrastructure integrating IoT, Edge and Cloud solutions (see Figure 1). At different layers, specific data are collected and processed to match user requirements (e.g., the destination that he/she has to reach), environment requirements (people density, size of passages,...) and dis- tancing measure regulations for COVID-19 [2]. In this paper, since we have to limit the treatment of the proposed solution, we present the reference architecture and provide design and development details on user tracking and the indoor navigation service; algorithms running at the cloud to optimize paths will be investigated in our future works. We will discuss some experimental results on the commu- nication system according to two types of criteria: objective criteria (i.e., Received Signal Strength Indicator (RSSI) values) to provide quantitative evaluations of the proposed solution, and subjective criteria (i.e., Mean Opinion Score (MOS)) to analyze the experience in the adoption of the application. All these criteria suitably combined validates and verify the applicability of the presented Indoor Navigation Application. The main scientific contributions of this paper can be summarized as follows: • we identified innovative technologies, such as Bluetooth Low Energy (BLE) short-range wireless communication Abstract—The emergency we are experiencing due to the coronavirus infection is changing the role of technologies in our daily life. In particular, movements of persons need to be monitored or driven for avoiding gathering of people, especially in small environments. In this paper, we present an efficient and cost-effective indoor navigation system for driving people inside large smart buildings. Our solution takes advantage of an emerging short-range wireless communication technology - IoT- based Bluetooth Low Energy (BLE), and exploits BLE Beacons across the environment to provide mobile users equipped with a smartphone hints on how to arrive at the destination. The main scientific c ontribution of o ur w ork is a n ew proximity- based navigation system that identifies the user position according to information sent by Beacons, processes the best path for indoor navigation at the edge computing infrastructure, and provides it to the user through the smartphone. We provide some experimental results to test the communication system considering both the Received Signal Strength Indicator (RSSI) and the Mean Opinion Score (MOS). Index Terms—Indoor navigation, Smart cities, Smart buildings, Beacon, Proximity-based positioning, Bluetooth Low Energy, COVID-19. I. I NTRODUCTION The emergency we are experiencing due to the coronavirus infection is changing the role of technologies in our daily life. Governments around the world are funding initiatives to identify new digital solutions to tackle the coronavirus crisis. For example, the European Commission has called for a common EU approach for using mobile apps and mobile data to assess social distancing measures, support tracking efforts, and contribute to limiting the spread of the virus [1]. In this context, IoT (Internet of Things) technologies and Indoor Navigation Systems (INSs) can really help us to reduce contagious risks and support the provisioning of services in smart cities after the lockdown. Following this vision, we identified as s trategic t he oppor- tunity to support the movement of people in a smart city and, in particular, in smart buildings, giving access to public and private services and facilities, but avoiding gathering of people, especially in small environments. In this paper we present © IEEE 2020. This article is free to access and download, along with rights for full text and data mining, re-use and analysis