*3.4. Server*

Mobile computing platforms have limited processing power and storage capacity compared to desktops and workstations. In particular, the processing power of wearable devices, such as smart watches and smart bands, is only adequate for their typical tasks, which include visual notifications, data collection and wireless communications. Smart phones offer improved processing power and memory capacity, but they still lag behind server-class computing solutions. To overcome these limitations, we have adopted a cloud-based solution for our system, which involves a server being responsible for the computationally-intensive tasks. More specifically, the role of the server is to process the data sent from mobile devices and then recognise the activity being performed. Initially, the classifiers that run on the server need to be trained using the data gathered during the data gathering phase. In normal operation mode, the server uses the trained classifiers to recognise the activities being performed by the users.
