*Article* **Adaptive Probabilistic Flooding for Information Hovering in VANETs**

#### **Andreas Xeros 1,†,‡, Taqwa Saeed 2,\*,‡, Marios Lestas 2,‡, Maria Andreou 3,‡, Cristiano M. Silva 4,5,‡ and Andreas Pitsillides 1,‡**


Received: 7 May 2020; Accepted: 4 June 2020; Published: 11 June 2020

**Abstract:** Information hovering is an information dissemination concept over a mobile set of peers which has not been investigated to the extent that other information dissemination paradigms have. It naturally appears in many vehicular network applications where information must be made available to vehicles within a confined geographical area for during some time period. One elementary strategy is to flood the area with data. Even in this case, some vehicles may never receive the content due to potential partitions created by low traffic density. In order to address this issue, in this work we propose a strategy based on epidemic routing in the hovering area, and probabilistic flooding outside it. Vehicles outside the hovering area serve as bridges towards partitions, leading to high reachability. We highlight the adaptive feature of the protocol, where the rebroadcast probability in partitions is adaptively regulated based on estimates of the density of vehicles in the hovering area. The performance of the proposed scheme is evaluated in VISSIM, using as the reference model in all simulation experiments a section of the road network in cities of Washington. The proposed protocol is shown to achieve the set design goals.

**Keywords:** vehicular networks; probabilistic flooding; vehicular communication
