In ad-hoc WSN is a collection of mobile nodes that are dynamically and randomly located in such a manner that the interconnections between nodes are changing on a continual basis. The dynamic nature of these networks demands new set of network routing strategy protocols to be implemented in order to provide efficient end-to end communication. Moreover, such issues are very critical due to severe resource constraints like efficient energy utilization, lifetime of network, and drastic environmental conditions in WSNs. Neither hop-by-hop nor neither direct reach ability is possible in case of WSNs. In order to facilitate communication within the network, a routing protocol is used. In this paper we have carried out an extensive survey on WSN protocols based on structure of network, routing protocol of network & clustering techniques of routing protocols