On the resilience of personal networks

A personal network (PN) is a network of devices belonging to a person. It may consist of a number of ad hoc sub-networks, referred to as clusters. Clusters of a PN could be linked together through the Internet. In this paper, we study the resilience of clusters in a PN, when nodes fail due to battery depletion. A cluster is resilient until a given pair of source-destination nodes can communicate in a multi-hop fashion in the presence of failed nodes. The communication between two nodes stops, if either there is no route between them, or one of the two nodes fails. We derive a closed-form expression for the expected duration that a PN cluster remains resilient. The derived expression determines how and to what extend different parameters such as node density, transmission range, network deployment area, packet length and rate, and energy consumption characteristics of the wireless interface can affect this duration. We verify the accuracy of our analysis using simulation.