Biblio

In Named Data Networking (NDN) architectures, a content object is located according to the content's identifier and can be retrieved from all nodes that hold a replica of the content. The default forwarding strategy of NDN is to forward an Interest packet along the default path from the requester to the server to find a content object according to its name prefix. However, the best path may not be the default path, since content might also be located nearby. Hence, the default strategy could result in a sub-optimal delivery efficiency. To address this issue we introduce a vicinity-based replica finding scheme. This is based on the observation that content objects might be requested several times. Therefore, replicas can be often cached within a particular neighbourhood and thus it might be efficient to specifically look for them in order to improve the content delivery performance. Within this paper, we evaluate the optimal size of the vicinity within which content should be located (i.e. the distance between the requester and its neighbours that are considered within the content search). We also compare the proposed scheme with the default NDN forwarding strategy with respect to replica finding efficiency and network overhead. Using the proposed scheme, we demonstrate that the replica finding mechanism reduces the delivery time effectively with acceptable overhead costs.

The network coding optimization based on niche genetic algorithm can observably reduce the network overhead of encoding technology, however, security issues haven't been considered in the coding operation. In order to solve this problem, we propose a network coding optimization scheme for niche algorithm based on security performance (SNGA). It is on the basis of multi-target niche genetic algorithm(NGA)to construct a fitness function which with k-secure network coding mechanism, and to ensure the realization of information security and achieve the maximum transmission of the network. The simulation results show that SNGA can effectively improve the security of network coding, and ensure the running time and convergence speed of the optimal solution.

MANETs have been focusing the interest of researchers for several years. The new scenarios where MANETs are being deployed make that several challenging issues remain open: node scalability, energy efficiency, network lifetime, Quality of Service (QoS), network overhead, data privacy and security, and effective routing. This latter is often seen as key since it frequently constrains the performance of the overall network. Location-based routing protocols provide a good solution for scalable MANETs. Although several location-based routing protocols have been proposed, most of them rely on error-free positions. Only few studies have focused so far on how positioning error affects the routing performance; also, most of them consider outdated solutions. This paper is aimed at filling this gap, by studying the impact of the error in the position of the nodes of two location-based routing protocols: DYMOselfwd and AODV-Line. These protocols were selected as they both aim at reducing the routing overhead. Simulations considering different mobility patterns in a dense network were conducted, so that the performance of these protocols can be assessed under ideal (i.e. error-less) and realistic (i.e. with error) conditions. The results show that AODV-Line builds less reliable routes than DYMOselfwd in case of error in the position information, thus increasing the routing overhead.