B. Tina Sherin

A Mobile Ad-hoc Network (MANET) consists of mobile nodes that are arranged autonomously in the network environment. Due to frequent changes in the topology of the network, the nodes in MANET dynamically change its position. It is very difficult to provide the reliable routing in MANET. In this context, if mobile nodes are replaced with the vehicles, then it is called Vehicular Ad-hoc Networks (VANETs) where vehicles are able to communicate with each other and with existent Road Side Units (RSU). VANETs have several different aspects compared to MANETs, in that the nodes move with high velocity because of which the topology changes rapidly. VANETs pose many issues on technology, protocols, and security, which increase the need for
research in this field. In VANETs, vehicle acts as an intelligent sensing unit with the communication and computation capabilities using the On-Board Unit (OBU) installed in them. Traffic data benefits to a group of users rather than a specific individual. In order to Disseminate Data, broadcasting is needed in VANETs. But, dissemination under dense networks results in high redundancy. This results in the wastage of limited radio channel bandwidth. When large number of vehicles rebroadcast in the same vicinity, Broadcast storm problem occurs. Due to rapid changes in the network topology, Broadcast storm problem is a challenging task to predict and manage. Most of the existing solutions for data dissemination in VANETs are unable to provide comprehensive result to meet the Quality of Service (QoS) and do not scale well which leads to extra communication overhead. Techniques were learnt and suggested for the betterment of QoS in Ad hoc Networks.