| Abstract: Need for it? A fundamental goal of researches in WSNs is to reduce the communication operations and prolong the total lifetime of sensor networks. Making effective use of the vast amounts of data gathered by large scale sensor networks will require scalable, self-organizing, and energy-efficient data dissemination algorithms Distributed Hash Tables (DHTs) over WSNs is a new routing paradigm promises several advantages over conventional routing protocols ROUTING TECHNIQUES USING DHTS OVER WSNS 1) GHT (Geographic Hash Table) Assumption: ->large scale sensor network spread out over an area which geographical boundary is known ->nodes know their geographical position this can be achived through GPS. ->sensor network is connected to the outside word by some access point. ->the data dissemination algorithms should seek to minimize communication in order to extend overall system lifetime. ->GHT uses a novel perimeter refresh protocol to provide both persistence and consistency when nodes fail or move |