FEATURES AND CHALLENGES OF VANET1.1 Features of VANET [2, 5]: Dynamic Topology - One of the most important features of VANET is dynamic topology. In this case, the nodes or vehicles move at high speed relative to each other. No power constraints and adequate storage - In VANET, we use vehicles as nodes instead of other devices so that vehicles have sufficient amount of energy and power, including both processing and storage ; So power and battery storage are not a problem in VANET. Frequent disconnection from the network - In VANET, vehicles move very frequently on the roads, in the network, hence the connectivity of links in VANET also changes frequently. The risks of network disconnection are high when vehicle density is low. Mobility Modeling and Prediction - Due to the highly dynamic topology, mobility modeling and prediction plays a very important role in designing data delivery in VANET. Different communication environments – VANET has two types of environments, i.e. road environment and urban environment. In a road traffic environment, communication is comparatively simpler and direct. But in an urban traffic environment, it becomes quite complex compared to the road traffic environment. 1.2 Challenges of VANET [6, 7]: Hidden terminal problem - This problem can arise when two or more objects send packets, these packets are not in direct transmission. range from each other. Collision at the common receiver node. Error-Prone Shared Report – In VANET, during propagation, the radio wave experiences several deficiencies such as attenuation, multipath propagation, and interference. Insecure Medium – In VANET, due to the nature of broadcast, communication is not secure. It is difficult for these networks to support different...... middle of paper...... warding. This protocol also adopts periodic broadcast, i.e. used to reduce network fragmentation. In this protocol, a broken down vehicle broadcasts an alert message to all vehicles in the group and the neighbor who received the alert message analyzes its applicability based on its location, informing the risk area. The Robust Vehicle Routing (ROVER) protocol [9] is geographic multicast. protocol. In ROVER, control packets use broadcast and data packets use a unicast mechanism. The main objective of this protocol is to broadcast a message to all vehicles presented within the specified zone of relevance (ZOR). ZOR can be referred to as a rectangle specified by its corner coordinates. In this, a message can be described using three terms called triplet (application, message, ZOR). If the vehicle is in its ZOR and has received a message, it accepts this message..