WiPush: Opportunistic Notifications over WiFi without Associations

Push notifications have become a prevalent way of communication for user devices to receive updates about their online profiles. State-of-the-art mechanisms for push notification delivery do not take users' spatio-temporal context into account as it would require a user device to retrieve the location and deliver it to the app servers, both of which are costly in terms of energy and traffic. In this paper, we provide an opportunistic, local, network-centric mechanism, emph{nam}, to deliver contextual notifications, leveraging the high density of WiFi access points (AP). nam~ does require association with APs and uses WiFi public action frames to deliver notifications without abusing the underlying standards. Our evaluation shows that while nam can deliver short notifications to the users with high reliability without affecting the networking functionalities of the AP adversely, it can not be used to transfer large volumes of data.