Vehicular Communications 19 (2019) 100180 Contents lists available at ScienceDirect Vehicular Communications www.elsevier.com/locate/vehcom Adaptive alert content dissemination protocol inspired from volunteer’s dilemma game for Vehicular Ad-hoc Networks Assia Naja a,b,∗ , Mohammed Boulmalf b , Mohamed Essaaidi a , Omar Ait Oualhaj a a ENSIAS, Mohammed V University of Rabat, Morocco b International University of Rabat, FIL, TICLab, Morocco a r t i c l e i n f o a b s t r a c t Article history: Received 2 May 2019 Received in revised form 29 June 2019 Accepted 22 August 2019 Available online 2 September 2019 Keywords: VANET Data dissemination Game theory Volunteer’s dilemma Probabilistic-broadcasting protocol Nash equilibrium Vehicular Ad hoc Networks (VANETs) can serve to guarantee road safety and comfort for drivers. This is done using broadcasting which is the most used technique to disseminate data. If done blindly, it leads to the famous broadcast storm problem. The broadcast storm problem occurs when a huge amount of messages is sent, which increases resource consumption. Therefore, to solve this problem, it is important to find the compromise between minimizing the number of rebroadcast messages while maintaining good latency, throughput, and reachability. In this work, we opt for a non-cooperative forwarding, which is a valuable technique enabling vehicle nodes to cover the network with a minimum amount of rebroadcasts. We modeled this behavior using game theory through a volunteer dilemma approach. This paper presents a novel broadcasting protocol called the Nash Equilibrium Scheme (NES), which investigates how a volunteer dilemma approach can be implemented in the context of VANETs. This is aiming to mitigate the storm problem. Using this approach, we successfully solved the content and alert incident messages dissemination problem. Simulations were performed using NS2 while considering two scenarios (a highway and a grid). The performance simulation shows that our implementation outperforms prior work in terms of several metrics.  2019 Elsevier Inc. All rights reserved. 1. Introduction Vehicular ad hoc networks (VANETs) are used to implement all kinds of applications related to vehicles, road traffic, drivers, passengers, and pedestrians [1]. They also serve to guarantee road safety and comfort for drivers. Thus, VANETs aim to reduce the high number of accidents. However, to improve road safety, vehicles may broadcast packets containing relevant information about their speed and position and potentially dangerous incidents. While to improve comfort, vehicles can disseminate information about road state to inform farther away vehicles about a traffic congestion situation. In the context of safety-related applications in VANETs, data are mostly spread among vehicles in a broad- cast fashion. However, the available wireless bandwidth is strictly limited and must, therefore, be used carefully. The simplest broad- cast mechanism is flooding (pure diffusion), where each vehicle retransmits each received message once, with probability 1. Then, this process continues until all vehicles in the network receive * Corresponding author. E-mail addresses: assia.naja@uir.ac.ma (A. Naja), mohammed.boulmalf@uir.ac.ma (M. Boulmalf), essaaidi@ieee.org (M. Essaaidi), aitoualhaj@gmail.com (O. Ait Oualhaj). the message. This results in redundancy, contention, collisions, and wastage of bandwidth in the network. Thus, it leads to the afore- mentioned broadcast storm problem [2,3]. This problem inspires researchers and motivates them to design more effective rebroad- casting schemes. VANET has many critical characteristics such as dynamic topol- ogy, frequently disconnected network, difficulty of predicting ve- hicle movement, and communication environment (urban, semi- urban, or rural scenario, and also highway scenario). Those con- straints must be considered in the design of a broadcasting pro- tocol in a VANET context. It must suit several situations and sce- narios, which is the challenging task. It also has to ensure that all vehicles in the area receive the message while maximizing the number of vehicles that have received the message and not re- sent it. Several algorithms were proposed to inhibit some nodes from rebroadcasting in order to reduce redundancy. But they have different methods which make the decision of rebroadcasting or discarding the message not efficient. It is to note that the conven- tional single forwarder performance is insufficient in a vehicular scenario, especially for a sparse network where shadowing, fad- ing, and several disconnections occur. This results in bad reach- ability performance (informed vehicles). However, non-cooperative forwarding is a valuable technique, enabling vehicle nodes to cover https://doi.org/10.1016/j.vehcom.2019.100180 2214-2096/ 2019 Elsevier Inc. All rights reserved.