# Compacted Area with Effective Links (CAEL) for Data Dissemination in VANETs
## 2 Related Work  
In VANET, the connection stability is a critical component to consider when creating a routing system. When developing routing algorithms, there are a variety of approaches that may be used to incorporate GPS coordinates and the route expiration time (RET) [11; 12] to obtain the enhanced performance. An overview of the routing protocols is given where different techniques are applied to enhance the routing protocol's efficiency. For the purpose of improving the quality of service (QoS), researchers devised a unique clustering-based technique [13] in which, instead of broadcasting the route request (RREQ) message to all cars, the algorithm is fitted with a clustering mechanism and the RREQ message is only communicated to the cluster head (CH). As a result, the CHs will be responsible for spreading routing information among the cluster participants. The route replay (RREP) message is transmitted to vehicles if a route is available; otherwise, the CH will send the RREQ message. It was projected that there would be less congestion and network overload as well as fewer connection failures because of this reduction in RREQ messages. In order to establish the link with the most stable path, the authors of [14] proposed a routing protocol that integrates the direction and prediction of the path duration into the ad hoc on-demand distance vector (AODV) [15] protocol. The position of all vehicles is used to group them, and the route is chosen depending on the duration of the link. The authors did not account for the possibility of not having a sufficient number of nodes participating in a particular direction during the route finding process. The authors [16] presented an improved QoS-based routing system that was dependent on the length of time a link has been in operation as well as the error rate experienced over the link. By synthesizing the network's temporal, geographical, and environmental interactions, the article models and quantifies the robustness of links and routes, as well as their resilience to failure. In addition, a route selection method was provided on the basis of this information. The experiments conducted in this study showed that the ideal setting of the maximum routing hop count has not been taken into account throughout the routing process to date. In [17], the authors proposed a QoS-based routing protocol that depends on the hop count, link duration, and connectivity, in order to deal with the dynamic topology and maintain the algorithm's balance between stability and efficiency. However, the use of only global distance to represent the cumulative QoS of a routing path is insufficient. The authors [18] proposed a routing protocol that makes use of software-defined network (SDN) and reinforcement learning to sense environmental data such as vehicle density and speed, and built the Q-learning-based cognitive routing algorithm to adopt alternative routing strategies depending on the environment. The lifespan of a link was predicted using mobility and location data by the authors [19]. All node clocks are presumed to be synchronized using GPS. For instance, if two mobile nodes know their speed, direction, and position, then it is possible to predict the link's lifespan. LET is calculated at each hop so that the time of the entire journey may be easily computed. The authors in [20] proposed a new clustering technique to obtain a reliable low-latency multi-path routing scheme by incorporating the ant colony optimization (ACO) technique. However, even though the latency and RREQ messages are decreased, the technique does not determine the most stable path and does not take into account velocity fluctuations during direct engagement between the vehicles. The authors of [10] devised a mechanism to focus on limiting the area of communication between the node. They created a trilateral zone which was is beneficial because it minimizes the participation of unnecessary nodes in the communication process.