Abstract:In the recent years, as a new emerging network architecture, Delay/Disruption Tolerant Networks (DTNs) have received extensive attention and are widely investigated. Since the major application scenarios of DTN are extremely particular routing protocols designed for the traditional networks are not suitable for DTN. Therefore, numerous routing protocols have been proposed for DTN. In this paper, the formulation issues of DTN routing protocols are firstly studied, and the classification concerns are then proposed for those protocols. Thereafter, this paper focuses on analyzing and comparing existing representative DTN routing protocols. Finally, current research status and the existing problems about DTN routing protocols are summarized, the key issues and future trends in DTN routing are pointed out.

Abstract:This paper suggests an ant-like agent service discovery mechanism. There are two types of agents cooperating to search target services: Search Agent and Guide Agent. Search Agent simulates the behavior of an ant that searches for services on the network. Guide Agent is responsible to manage a service route table that consists of pheromone and hop count, instructing Search Agent’s routing. Volatile pheromones make Search Agent sense the change of topology and service resource, and hop count makes them know the distance. Semantic similarity is also introduced in routing selection as a heuristic factor, which improves the recall. The life-span control policy makes query traffic controllable. With system size increasing, the query traffic would increase slightly and has an upper bound. The result of simulation shows that the suggested mechanism is scalable and adaptable enough to be suitable for large-scale dynamic computing environments.

Abstract:Wireless sensor networks are different from traditional networks and highly dependent on applications, so traditional routing protocols cannot be applied efficiently to them. Therefore many routing protocols for wireless sensor networks are studied. After describing the characteristics of wireless sensor networks, the classification standards for routing protocols are presented. Then the key mechanisms of the existing representative routing protocols are analyzed and their classifications, characteristics and application areas are compared. Finally, the important features that good routing protocols possess are summarized, and the future research strategies and trends.