“…Cheaper applications can be designed by using low-cost, off-the-shelf solutions (Adlam and Orpwood 2008;Alesii et al 2013;Chaaraoui et al 2012;Chang and Wang 2010;Doctor et al 2014;Drajsajtl, Struk, and Bednárová 2013;Droes et al 2007;Fernandez-Luque et al 2013;Floeck, Litz, and Rodner 2011;Fuxreiter et al 2010;Grech et al 2010;Helal et al 2012;Hristova, Bernardos, and Casar 2008;James et al 2009;Koch 2006;Magjarevic 2007;Mokhtari et al 2012;Moon et al 2011;Olivier et al 2009;Rocha et al 2013;Rodrigues et al 2011;Sanchez-Pi and Molina 2009;Zhang et al 2014;Zheng et al 2012;Zhou et al 2011), such as motion sensors (Alwan 2009;Bamis et al 2010;Fuxreiter et al 2010;Kropf et al 2012) or web cameras (Elbouz, Alfalou, and Brosseau 2011;Mihailidis, Carmichael, and Boger 2004). A typical example is the one provided by Lopes, Jose, and Aguiar (2011) who described an approach for enabling digital photo frames (which are off-the-shelf by nature) to become generic key devices in the AAL ecosystem.…”