1,865,742 research outputs found
Recipients' anonymity in multihop ad-hoc networks
No full textMultihop ad-hoc networks have a dynamic topology. Retrieving a route towards a remote peer requires the execution of a recipient lookup, which can publicly reveal sensitive information about him. Within this context, we propose an efficient, practical and scalable solution to guarantee the anonymity of recipients' nodes in ad-hoc networks.Los saltos múltiples de redes ad-hoc tienen una topología dinámica. La recuperación de una ruta hacia un par remoto requiere la ejecución de una búsqueda de destinatarios, que puede revelar públicamente información confidencial. Dentro de este contexto, proponemos una solución
eficiente, práctica y escalable para garantizar el anonimato de los nodos destinatarios en redes ad-hoc.Els salts múltiples de xarxes ad hoc tenen una topologia dinàmica. La recuperació d'una ruta cap a un parell remot requereix l'execució d'una recerca de destinataris, que pot revelar públicament informació confidencial. Dins d'aquest context, proposem una solució eficient, pràctica i escalable per garantir l'anonimat dels nodes destinataris en xarxes ad-hoc
Ad hoc Cloud computing
Get PDFThis paper presents the first complete, integrated and end-to-end solution for ad hoc cloud computing en- vironments. Ad hoc clouds harvest resources from existing sporadically available, non-exclusive (i.e. primarily used for some other purpose) and unreliable infrastructures. In this paper we discuss the problems ad hoc cloud computing solves and outline our architecture which is based on BOINC
Link stability estimation based on link connectivity changes in mobile ad-hoc networks
Get PDFDear Wang,
Re: Link Stability Estimation Based on Link Connectivity Changes in Mobile Ad-hoc Networks
I have not been able to assess if this is an author version peer-reviewed or is it an author version non peer reviewed. Could you please clarify this so I can proceed to add your paper to Spiral. Spiral digital repository only accept peer-reviewed papers.
30/11/12 author has confirmed peer reviewe
Quorum based geographically static data storage in ad-hoc networks
Get PDFLarge-scale wireless ad-hoc networks are formed automatically and allow nodes to communicate over greater distances. Every node acts as a router forming a complex network, which is simplified by the use of geodesic routing. However, a method to discover a node.s location is needed for geodesic routing. In this paper we propose two algorithms which could support location servers in ad-hoc networks and examine their performance
Communication issues in Large Scale Wireless Ad hoc Networks
Get PDFAd-hoc networks are networks that are formed automatically without any pre-existing infrastructure. These networks may consist of various types of mobile devices . such as PDAs, laptops, cell phones and other mobile computing devices. Each node in a wireless ad hoc network performs computational tasks as well as communication routing. Without the existence of dedicated routing devices, the nodes relay traffic to each other to extend their communication range. This paper gives an overview on the current technologies . intelligent agent systems . and their implications to solve common problems in ad hoc networks. We will also introduce our current research directions, and provide a promising analysis to achieve efficient transmissions in a large-scale ad hoc network using multiple channels, an option, which is already in the MAC layer of IEEE 802.11. We will show also that in noisy environments latency reduction in multi-hops is significant to single hop networks even for greater number of relay nodes. The approach described in this paper could be use to develop efficient large-scale ad hoc networks
An enhanced broadcasting algorithm in wireless ad-hoc networks
Get PDFIn a multi-hop wireless ad hoc network, broadcasting is an elementar}' operation to support many applications. Broadcasting by flooding may cause serious redundancy, contention, and collision in the network, which is referred to as the broadcast storm problem. Many broadcasting schemes are proposed to give better performance than simple flooding in wireless ad hoc network. How to decide whether rebroadcast or not also poses a dilemma between reachability and efficiency under different host densities. In this paper, we propose enhanced broadcasting schemes, which can reduce rebroadcast packets without loss of reachability. Simulation results show that proposed schemes can offer better reachability as well as efficiency as compared to other previous schemes
A multi-protocol framework for ad-hoc service discovery
Get PDFDiscovering the appropriate services in ad-hoc computing environments where a great number of devices and software components collaborate discreetly and provide numerous services is an important challenge. Service discovery protocols make it possible for participating nodes in a network to locate and advertise services with minimum user intervention. However, because it is not possible to predict at design time which protocols will be used to advertise services in a given context/environment, it is now becoming clear that dynamic discovery mechanisms are required by mobile nodes to cope with the heterogeneity of discovery platforms. Existing adaptive mobile middleware solutions such as ReMMoC and INDISS have investigated this style of dynamic discovery. However, these have yet to consider the emerging suite of protocols for discovery in ad-hoc networks. In this paper we present a component-based service discovery framework for the development of an adaptive multi-personality service discovery middleware, which will operate in diverse environments e.g. fixed and ad-hoc networks. This supports a common architecture for individual discovery protocols to enhance configurability and re-configurability of the framework, and minimize resource usage through component reuse. Finally, to evaluate this framework we investigate the development of four existing ad-hoc service discovery protocols using our approach
Toward an efficient solution for dynamic ad hoc network interoperability
Get PDFAn ad hoc network is formed by an impromptu grouping of network capable nodes. The nodes forming the network have unconstrained mobility, and so provide a dynamic network topology. Current work in this research area has focused on designing routing protocols capable of efficiently forwarding packets in these dynamic network environments. This has led to several designs for ad hoc routing protocols based on various routing algorithms, each suited to specific usage characteristics. This paper will discuss issues relating to routing in ad hoc networks. We will describe an active networking based solution that provides dynamic routing protocol interoperability and enables migration of nodes between ad hoc groups. Our design is motivated by a squad and base scenario which consists of two groups wishing to communicate. These groups have contrasting deployment characteristics and so use different routing protocols
Servidores móveis em redes AD HOC
Get PDFDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência da Computação.A arquitetura web services permite que aplicações desenvolvidas em diferentes plataformas interajam com o intuito de trocar dados e realizar tarefas sobre a rede mesmo em ambientes heterogêneos. A arquitetura utiliza uma pilha de padrões entre os quais destacam-se três: WSDL, linguagem utilizada para descrever o serviço, SOAP, protocolo que encapsula as mensagens XML trocadas pela rede e UDDI, mecanismo que age como um repositório de web services, todos com base na linguagem XML. As redes Ad hoc possuem como principal característica uma formação rápida e temporária. Por não necessitar de infra-estrutura fixa, essas redes são estabelecidas rapidamente em locais onde as redes fixas teriam dificuldade ou até mesmo a impossibilidade de serem instaladas. Nessas redes, os nodos comunicam-se diretamente sem a necessidade de infra-estrutura fixa, sendo eles próprios responsáveis pelo roteamento dos pacotes. Este trabalho de pesquisa apresenta um modelo que visa possibilitar a execução de web services em redes Ad hoc. Tendo em vista a usual carência de serviços que os usuários dessas redes possuem, nossa contribuição permite a tais usuários dispor do acesso a alguns serviços, que geralmente estão disponíveis apenas na rede fixa, restringindo o acesso aos serviços móveis à área de cobertura alcançada por essas redes. Nos últimos anos, os dispositivos móveis a capacidade de processamento e armazenamento aumentaram significantemente, o que torna possível, atualmente, a execução de um conjunto relativamente grande de serviços. Por esta razão, assumimos como objetivo principal deste trabalho possibilitar a qualquer dispositivo móvel, conectado a uma rede Ad hoc, o oferecimento de serviços a quaisquer outros dispositivos na mesma rede, tornando-o um servidor móvel. O funcionamento do modelo tem como principal característica o fato de disponibilizar serviços sem que o usuário dependa do auxílio de qualquer infra-estrutura fixa no momento da execução desses serviços. Uma vez concluída essa etapa, o usuário móvel tem autonomia suficiente para coordenar sua função de fornecer os serviços em momentos e locais apropriados. Nossos resultados experimentais indicam que o modelo possui claras vantagens ao ser utilizado em redes Ad hoc. Dentre elas, destacamos o fato de explorar as características desses ambientes com a execução do serviço de modo Ad hoc, levando de fato, serviços a qualquer lugar
Mobile Ad Hoc Networks: the DHT paradigm
Get PDFIn this thesis, the adoption of the hierarchical routing paradigm to achieve a scalable network layer for ad hoc networks has been proposed. The main concept of hierarchical routing is to keep, at any node, complete routing information about nodes which are close to it and lesser information about nodes located further away.
The Augmented Tree-based Routing protocol, a routing protocol for ad hoc networks exploiting both a location-aware addressing schema and a distribute hash table (DHT) system, has been proposed. The adopted addressing schema allows nodes to adopt hierarchical routing, limiting so the overhead introduced in the network, while the DHT system provides the mapping between transient identifiers and node identities.
Since the Augmented Tree-based Routing protocol adopts a multi-path strategy and since most studies in the area of multi-path routing focus on heuristic methods and the performances of these strategies are commonly evaluated by numerical simulations, an analytical framework to evaluate the performance gain achieved by multi-path routing has been proposed. The framework
is based on on graph theory and on terminal-pair routing reliability (TPRR) as performance measure.
Moreover, some features of the proposed protocol has been exploited design a peer-to-peer (P2P) system over a mobile ad hoc network (MANET) resorting to a cross-layer approach. It has been proved that simply deploying P2P systems over MANETs may cause poor performances. By coupling both the direct and the indirect key-based routing at the network layer and by resorting to the same hierarchical address space structure of ATR, we are able to build a P2P overlay network in which the logical proximity agrees with the physical one, limiting so the message overhead and avoiding the redundancy.
Finally, by extending the proposed location-aware addressing to match with the opportunistic forwarding protocol, a novel routing protocol for disruption tolerant network (DTN) and delay tolerant network (DTN) has been proposed. By exploiting both the temporal diversity and the broadcast nature of the wireless propagation, such a protocol can enable connectivity in ad hoc environments characterized by non stationary wireless propagation as well as sparse topologies
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