Recently, swarms or formations of drones have received increased interest both in the literature and in applications. To dynamically adapt to their operating environment, swarm members need to communicate wirelessly for control and coordination tasks. One fundamental communication pattern required for basic safety purposes, such as collision avoidance, is beaconing, where drones frequently transmit information about their position, speed, heading, and other operational data to a local neighbourhood, using a local broadcast service. In this paper, we propose and analyse a protocol stack which allows to use the recurring-beaconing primitive for additional purposes. In particular, we propose the VarDis (Variable Dissemination) protocol, which creates the abstraction of variables to which all members of a drone swarm have (read) access, and which can naturally be used for centralized control of a swarm, amongst other applications. We describe the involved protocols and provide a performance analysis of VarDis.

Recently there has been interest in using drones/unmanned aerial vehicles in search-and-rescue applications. Here we apply a formation of drones equipped with sectorised antennae to navigate to a transmitter using Direction of Arrival (DoA) estimation to navigate. We present results indicating that the error of the DoA estimate is dependent on the DoA and evaluate a mitigation technique, finding that incrementally changing the drone orientation across the formation reduces the DoA estimation error. Further, we investigate a "dumbbell" formation in which the two "weights" generate independent DoA estimates, the difference between which are used to broadly classify the distance to the transmitter. We found that the choice of distance thresholds and relative direction of the transmitter substantially changes the performance of this distance heuristic.

This paper evaluates Cellular-V2X (C-V2X) and IEEE 802.11p (802.11p) in the logistics warehouse environment. Unlike for traditional road networks, the performance of these technologies has never been compared in the warehouse environment, despite the potential benefits to safety, efficiency, and automation they may bring. To perform this evaluation, we use the simulated failure rate of an aisle-end collision avoidance application as a metric. As part of this work a simulation scenario and simulator including a custom aisle-end warehouse channel model was developed based upon path loss measurements taken in a representative warehouse. The performance of each technology was simulated as vehicle density, transmit power, and modulation and coding scheme (MCS) changed. For 802.11p, density, transmit power, and MCS had no significant effect on the technology’s performance within the resolution of the evaluation scenario. C-V2X performed worse than 802.11p for all densities, MCS values, and transmit powers. Based on this evaluation, 802.11p is more appropriate than C-V2X for the warehouse environment.