NACRP: A Connectivity Protocol for Star Topology Wireless Sensor Networks

Wireless sensor networks (WSNs) are an ever growing field of applications and one constituent of the future Internet-of-Things (IoT). In this work, we investigate star topology sensor networks compliant with the recent IEEE 802.15.4k standard in which sensors could fail to report sensing information to the access point (AP) due to temporary obstructions that clutter the link with the AP. The contribution of this work is twofold. First, we study general connectivity requirements in relay networks. Second, to restore connectivity and to recover from information loss, we propose the neighbor-assisted connectivity recovery protocol (NACRP), which automatically selects a subset of sensor nodes to act as relays for those which lack connectivity with the AP. In our study, we rely on the tool of stochastic geometry and in particular, on Poisson point processes to seek the tradeoff, which arises from the selection of a subset of relay nodes and the necessary transmitted power that relays need to use to restore network connectivity.