: Vehicular Ad hoc Network (VANET), a subclass of mobile ad hoc networks (MANETs), is a promising approach for the intelligent transportation system (ITS). The design of routing protocols in VANETs is important and necessary issue for support the smart ITS. The key difference of VANET and MANET is the special mobility pattern and rapidly changeable topology. It is not effectively applied the existing routing protocols of MANETs into VANETs VANET (Vehicular Ad-hoc Network) is a new technology which has taken enormous attention in the recent years. Due to rapid topology changing and frequent disconnection makes it difficult to design an efficient routing protocol for routing data among vehicles, called V2V or vehicle to vehicle communication and vehicle to road side infrastructure, called V2I. The existing routing protocols for VANET are not efficient to meet every traffic scenarios. Thus design of an efficient routing protocol has taken significant attention. So, it is very necessary to identify the pros and cons of routing protocols which can be used for further improvement or development of any new routing protocol. The easiest way to classify the geographic routing protocolsis by type of routing (Unicast, Broadcast or Geocast). Other way to classify them is by the use that the protocol gives to the position information (Packet forwarding, Route Selection, Cluster formation, Formation of cells, Classify Forwarding Group, or RouteRequest Forwarding). For this survey we will use the type of routing classification and in each protocol we'll talk about how the protocol uses the geographic information.

This Fourth-generation wireless networks may require an integration of mobile ad hoc networks (MANET) into external network to enhance the flexibility of the communication and roaming. This phenomenon is well-suited for commercial and military applications which yield additional benefit of roaming. However, integration of MANET with external network poses a serious security challenge for communication because of open and distributed nature of the ad hoc network. This paper discusses about the 4 G network architecture, its challenges and finally the use of manet in 4G networks.