Evaluating a Dynamic Keep-Alive Messaging Strategy for Mobile Pervasive Systems

:Timely loss-of-contact detection between devices in pervasive systems using mobile networks is an important aspect for both functionality and user experience. Traditional schemes where time-to-live is defined by the service provider are not adequate in mobile networks where communication failures are frequent. On the other hand, schemes using keep-alive messaging tend to increase the communication overhead, in particular if the time to detect a loss of contact needs to be short. We introduce a strategy where the time between keep-alive messages is adjusted dynamically according to the need in a particular application. Our solution was evaluated with usage data from a professional application built on the PalCom framework. The measurements show a 96 % decrease of the communication overhead while still maintaining the same system responsiveness.