A Survey of Routing Techniques for Mobile Collaborative Virtual Environment Applications <s> Structured Overlay Network <s> A fundamental problem that confronts peer-to-peer applications is to efficiently locate the node that stores a particular data item. This paper presents Chord, a distributed lookup protocol that addresses this problem. Chord provides support for just one operation: given a key, it maps the key onto a node. Data location can be easily implemented on top of Chord by associating a key with each data item, and storing the key/data item pair at the node to which the key maps. Chord adapts efficiently as nodes join and leave the system, and can answer queries even if the system is continuously changing. Results from theoretical analysis, simulations, and experiments show that Chord is scalable, with communication cost and the state maintained by each node scaling logarithmically with the number of Chord nodes. <s> BIB001 </s> A Survey of Routing Techniques for Mobile Collaborative Virtual Environment Applications <s> Structured Overlay Network <s> Content-based publish-subscribe middleware is emerging as a promising answer to the demands of modern highly dynamic distributed computing by providing the necessary decoupling and flexibility. The majority of currently available systems implement event dispatching on top of an overlay network with a tree topology. However, they fail to provide any mechanism to maintain it in the presence of failures, thus hampering their applicability in dynamic scenarios. In this paper, we present a novel approach to reconfiguring the overlay topology by exploiting a distributed hash table. Our algorithm supports arbitrary tree topologies and deals very well with the dynamicity of network scenarios by limiting the impact of reconfigurations induced by topology changes. These results are confirmed by simulations, which validate the applicability of our approach in reconfigurable publish-subscribe middleware. Beyond publish-subscribe, the algorithm is applicable in a wide range of contexts and provides a general way to maintain an overlay network with a controlled topology in dynamic environments. <s> BIB002
In structured overlay network, specific nodes strictly control the topology. The lookup service is based on a distributed hash-table (DHT) BIB002 to efficiently locate the data in the network. There are many structured overlay proposed in the literature, however in this survey we limit our discussion to the most well known ones used in MANETs: Pastry  and Chord BIB001 . Adapting structured overlay for MANETs has attracted more researches in the recent years; however the major application area of such approaches is about studying the performance behavior of protocol itself [64, and 66] , applicability to a real scenario such as disaster, battlefield etc is not practical. The fundamental concept is to improve the routing performance by exploring DHT in MANETs. What follows is the discussion of some relevant applications and their classification based on the routing techniques.