# An Effective and Efficient Adaptive Probability Data Dissemination Protocol in VANET
## 2 Related Works
The disadvantage of this protocol is how to maintain its clusters since each node needs to update its table from time to time when receiving updates. Although the CGSR transmission delay is reduced to 32,238, to run this scheme incurs significant overheads. [PERSON] et al. [28], introduce a different degree of synchronization, where the cluster-heads control data packet routing and forwarding in order to handle channel scheduling e.g., The Code Division Multiple Access/Time Division Multiple Access (CDMA/TDMA) techniques. The problem with these techniques comes when assigning a code to a different cluster and cluster-head focus on the traffic of a cluster. [PERSON] et al. [29], propose an approach in which a software agent is used to gather data from the specified area called \"target region (TRs)\" and to disseminate data in MANET and VANET. Software agents use context geographical information about the node (position information e.g., current location and future location, direction information, and route to reach destination) to make a decision on migration among the mobile nodes in the network. In this work, the authors address an important feature on how these software agents may use a different technique and decision parameter to conduct their movement in the network. The work proposed three categories of approaches depending on the different levels of intelligence on the conduct of the agents' movement decision. First, the destination-based approach, whereby a software agent determines whether the hosted node is inside or outside the target region and whether the future destination of a node is inside or outside the target region. Second, for this level of intelligence, the software agent has both information from the course, hosting node position and the destination node using a global positioning system (GPS). Lastly, the direct path approach, in which the agent is considered to have the complete route of the hosted node and destination node that keeps the agent inside the target region. However, in this mechanism, the protocol does not indicate the reality of data dissemination in terms of message delivery and the end-to-end delay of software agent migrating from one node to another. However, in [30] authors propose a simple and efficient adaptive dissemination (SEAD) protocol in the vehicular environment. SEAD considers message direction and vehicles' density to decide the probability of broadcasting. This protocol also considers no beacon exchange in neighbors' information such as speed, location, angle etc. Upon receiving a packet, the nodes allocated to the farthest road segment are assigned minimum \(W_{t}\), then rebroadcast after the expiration of \(W_{t}\) (\(0\delta\)). As the time number of nodes allocated to the same slot increases, the probability of re-broadcast is calculated on advanced terms, but this protocol does not explain in detail the impact of road segments on rebroadcasting probability in term of high vehicle density and low vehicle density. Particularly,there is a fixed parameter (\(\alpha\)) which helps to manipulate the packet delivery ratio depending on the application's requirements. In delay-based [31] systems, authors examine two techniques of this protocol, namely slotted and continuous techniques in a vehicular environment. This strategy every receiving node depend on a certain waiting timer denoted \(W_{t}\) before decide to rebroadcast the message. Authors examine these techniques to evaluate the performance of a \"redundancy-based protocol\" (RBP) [32], which is the combination of probability-based and delay-based. For every calculation of waiting timer, rely on deployed technique. The authors consider a slotted technique in a dense network when the nodes in the single segment increased and try to rebroadcast the message simultaneously, which may result in message collision. This technique has the following features; first, when two nodes are close to each other but belonging to different slots they have enough time to exchange the received message.