The increasing pervasive and ubiquitous presence of devices at the edge of the Internet is creating new scenarios for the emergence of novel services and applications. This is particularly true for location and context-aware services. These services call for new decentralized, self-organizing communication schemes that are able to face issues related to demanding resource consumption constraints, while ensuring efficient locality-based information dissemination and querying. Voronoi-based communication techniques are among the most widely used solutions in this field. However, when used for forwarding messages inside closed areas of the network (called Areas of Interest, AoIs), these solutions generally require a significant overhead in terms of redundant and/or unnecessary communications. This fact negatively impacts both the devices' resource consumption levels, as well as the network bandwidth usage. In order to eliminate all unnecessary communications, in this paper we present the MABRAVO (Multicast Algorithm for Broadcast and Routing over AoIs in Voronoi Overlays) protocol suite. MABRAVO allows to forward information within an AoI in a Voronoi network using only local information, reaching all the devices in the area, and using the lowest possible number of messages, i.e., just one message for each node included in the AoI. The paper presents the mathematical and algorithmic descriptions of MABRAVO, as well as experimental findings of its performance, showing its ability to reduce communication costs to the strictly minimum required. INDEX TERMS Area of Interest, multicast, Voronoi networks 1 I. INTRODUCTION We are witnessing a fast and vast expansion of the Internet at its edges [1]. This is mainly due to the pervasive diffusion in the environment of smart objects, such as sensors, Internet of Things (IoT) devices, user personal devices, etc. This scenario allows the emergence of novel services and applications [2]-[8], supported by potentially large networks of highly distributed and autonomous devices. Traditional centralized control and communication techniques do not suit the needs and requirements of such an environment. In particular, these devices are usually equipped with computing and communication capabilities, that allow them to create and exchange information both among themselves and with other remote services. One of the most challenging problems is related to the fact that this kind of systems typically requires frequent exchanges of information among a large number of geographically dispersed devices. The communication complexity is further increased by the fact that devices cannot always count on the support of central communication infrastructures, posing the need to apply autonomous, self-organizing forms of communication and interaction among devices [9]-[13]. Location and context-aware services [14] in this scenario are faced with additional issues. In fact, these services are characterized by the fact that most of the messages are directed (and of interest) only to limited/specific are...
