id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-173774-idj19hd3	Li, Jinfeng	COVID-19 Contact-tracing Apps: a Survey on the Global Deployment and Challenges	2020-05-07		.txt	text/plain	1671	97	53	There is an ongoing debate on the deployment of the Apps regarding their technology framework, i.e. centralised [3, 4] versus decentralised [5, 6] , and their corresponding sensor technologies, i.e. the Global Positioning System (GPS) integrated with Quick Response (QR) codes scanning [7, 8] and big data analysis [9,10], versus the wireless Bluetooth devices [11] enabled by microwave [12, 13] and millimetre-wave [14] [15] [16] [17] communications. These Apps follow the DP-3T (Decentralised Privacy-Preserving Proximity Tracing) [19] data protection solution recently developed by the European Academics. 6. Apple and Google partner on COVID-19 contact tracing technology framework [20] (yet to be released in May) -privacy-preserving contact tracing, Bluetooth based, decentralised, free of GPS. We produce the first geolocation mapping for the global deployment of the COVID-19 contact-tracing apps in Fig. 1 , with the format codes in an order of the country name, App name, the number of users (download times), and the underpinning technologies (GPS, QR codes, Bluetooth).	./cache/cord-173774-idj19hd3.txt	./txt/cord-173774-idj19hd3.txt