On the limits of DTN monitoring

Compared to wired networks, Delay/Disruption Tolerant Networks (DTN) are challenging to monitor due to their lack of infrastructure and the absence of end-to-end paths. This work studies the feasibility, limits and convergence of monitoring such DTNs. More specifically, we focus on the efficient monitoring of intercontact time distribution (ICT) between DTN participants. Our contribution is two-fold. First we propose two schemes to sample data using monitors deployed within the DTN. In particular, we sample and estimate the ICT distribution. Second, we evaluate this scheme over both simulated DTN networks and real DTN traces. Our initial results show that (i) there is a high correlation between the quality of sampling and the sampled mobility type, and (ii) the number and placement of monitors impact the estimation of the ICT distribution of the whole DTN

On the feasibility of monitoring DTN: Impacts of fine tuning on routing protocols and the user experience

The “machine to machine” communication paradigm will become a central element for mobile networks. This paradigm can be easily constructed by a contact-based network, notably a disruption/delay tolerant networks (DTN). To characterize a DTN, we can use the Inter-contact time among the nodes. The better understanding of inter-contact time (ICT) has practical applications on the tuning of forwarding strategies, and hence in the quality of the User Experience. Nevertheless, the fine tuning of those parameters is tight to a set of assumptions about the regularity of movement or periodicity of patterns in an usually non complete and cumbersome statistical analysis. That is why in a dynamic environment where we cannot assume any previous information the tuning of parameters is usually overestimated. In this work we study how monitoring can help to adapt those parameters to give a better understanding of both natural evolution of the network and non periodical events

Swarm-based Intelligent Routing (SIR) - a new approach for efficient routing in content centric delay tolerant networks

This paper introduces Swarm-based Intelligent Routing (SIR), a swarm intelligence based approach used for routing content in content centric Pocket Switched Networks. We first formalize the notion of optimal path in DTN, then introduce a swarm intelligence based routing protocol adapted to content centric DTN that use a publish/subscribe communication paradigm. The protocol works in a fully decentralized way in which nodes do not have any knowledge about the global topology. Nodes, via opportunistic contacts, update utility functions which synthesizes their spatio-temporal proximity from the content subscribers. This individual behavior applied by each node leads to the collective formation of gradient fields between content subscribers and content providers. Therefore, content routing simply sums up to follow the steepest slope along these gradient fields to reach subscribers who are located at the minima of the field. Via real traces analysis and simulation, we demonstrate the existence and relevance of such gradient field and show routing performance improvements when compared to classical routing protocols previously defined for information routing in DTN

Pervasive intelligent routing in content centric delay tolerant networks

This paper introduces a Swarm-Intelligence based Routing protocol (SIR) that aims to efficiently route information in content centric Delay Tolerant Networks (CCDTN) also dubbed pocket switched networks. First, this paper formalizes the notion of optimal path in CCDTN and introduces an original and efficient algorithm to process these paths in dynamic graphs. The properties and some invariant features of these optimal paths are analyzed and derived from several real traces. Then, this paper shows how optimal path in CCDTN can be found and used from a fully distributed swarm-intelligence based approach of which the global intelligent behavior (i.e. shortest path discovery and use) emerges from simple peer to peer interactions applied during opportunistic contacts. This leads to the definition of the SIR routing protocol of which the consistency, efficiency and performances are demonstrated from intensive representative simulations

How mobility increases mobile cloud computing processing capacity

In this paper, we address a important and still unanswered question in mobile cloud computing ``how mobility impacts the distributed processing power of network and computing clouds formed from mobile ad-hoc networks ?''. Indeed, mobile ad-hoc networks potentially offer an aggregate cloud of resources delivering collectively processing, storage and networking resources. We demonstrate that the mobility can increase significantly the performances of distributed computation in such networks. In particular, we show that this improvement can be achieved more efficiently with mobility patterns that entail a dynamic small-world network structure on the mobile cloud. Moreover, we show that the small-world structure can improve significantly the resilience of mobile cloud computing services

Editorial

At the start of the present century, a scenario was formed in Latin America in answer to neoliberal projects, which were disseminated strongly during the dominationperiod of economic and institutional strategies associated with the Washington Consensus. Since then, on the grounds of what some called The Pink Tide (Marearosa), a group of governments in the region converged on reinstating the idea of promoting projects inspired by greater national autonomy and, to achieve that, inthe strengthening of internal markets and a renewed state intervention, appealing in many cases to renationalization processes and, in practically all of those governments, to redistribution of income policies through public spending. By the year 2010, Argentina, Bolivia, Brazil, Chile, Ecuador, Honduras, Nicaragua, Paraguay, Uruguay, and Venezuela had governments that shared these features, beyond the specificity of their experiences.O início deste século encontrou a formação de um cenário de resposta a projetos neoliberais na América Latina, que foi disseminado fortemente durante o período deprotagonismo das estratégias econômicas e institucionais associadas ao Consenso de Washington. Desde então, sob o que alguns chamam de Onda Rosa (Pink Tide),um grupo de governos da região convergiu para reintegrar a ideia de promover projetos inspirados em uma maior autonomia nacional e, para isso, no fortalecimentodos mercados internos e uma renovada intervenção estatal, recorrendo em muitos casos a processos de renacionalização e, em praticamente todos, a políticas de redistribuição de renda por meio de gastos públicos. No ano de 2010, a Argentina, Bolívia, Brasil, Chile, Equador, Honduras, Nicarágua, Paraguai, Uruguai e Venezuela apresentaram governos que, além da especificidade de suas experiências, compartilhavam essas características.El inicio del reciente siglo encontró en América Latina la formación de un escenario de respuesta a los proyectos neoliberales, difundidos fuertemente durante elperiodo en que dominaron las estrategias económicas e institucionales asociadas al Consenso de Washington. Desde entonces, bajo lo que algunos denominaron la marea rosa (Pink Tide), un conjunto de gobiernos de la región convergió en reinstalar la idea de impulsar proyectos inspirados en una mayor autonomía nacional y,para ello, en el fortalecimiento de los mercados internos y una renovada intervención estatal, apelando en muchos casos a procesos de renacionalización y, en prácticamente todos, a políticas de redistribución del ingreso a través del gasto público. Para el año 2010, Argentina, Bolivia, Brasil, Chile, Ecuador, Honduras, Nicaragua, Paraguay, Uruguay y Venezuela presentaban gobiernos que, más allá de la especificidad de sus experiencias, compartían estas características

Escalaridade e periferia. Uma reconstrução conceitual do ponto de vista histórico-estrutural

The coexistence of social relations that are defined on different territorial scales and the asymmetric structuring of world space, with central and peripheral positions, constitute two central dimensions of the spatial structuring of socioeconomic systems. Although these two moments were extensively studied, their internal connections are a relatively less explored area. In this framework, the aim of this work is to explore the intrinsic relationships between these moments, constructing a historical-structural interpretation. In order to achieve this objective, the main contributions that focused on the specificity of each moment were analyzed, mobilizing different theories about the relationship between society and space. First, the theoretical development of the scalar question is discussed, showing how the relational turn constituted the key theoretical bet of the articulation between the world unity of the capital accumulation process and its spatial structuring on multiple scales. Secondly, the limitations that this option faces are synthesized when the contingency is prioritized as the basis of its conceptual apprehension. Third, a symmetrical criterion is taken to study the theories of dependency and Latin American structuralism, showing how, particularly in the latter case, there are theoretical potentialities to synthesize the scalarity and asymmetric spatial structuring of socioeconomic systems. The work concludes observing that the latter depends on returning to the historical-structural specificity of the peripheral modernization, considering the specific ways in which territoriality and capitalist relations of production are articulated.La coexistencia de relaciones sociales que se definen en escalas territoriales diferentes y la estructuración asimétrica del espacio mundial, con posiciones centrales y periféricas, constituyen dos dimensiones centrales de la estructuración espacial de los sistemas socioeconómicos. Si bien estos dos momentos fueron extensamente estudiados, sus conexiones internas resultan un área relativamente menos explorada. En este marco, el trabajo tiene por objetivo explorar las relaciones intrínsecas entre dichos momentos, construyendo para ello una interpretación de carácter histórico-estructural. A fin de alcanzar dicho objetivo, se evalúan las contribuciones principales que se centraron en la especificidad de cada momento, movilizando diferentes teorías sobre la relación entre sociedad y espacio. En primer lugar, se analiza el desarrollo teórico de la cuestión escalar, mostrando cómo el giro relacional constituyó la apuesta teórica clave de la articulación entre la unidad mundial del proceso de acumulación de capital y su estructuración espacial en múltiples escalas. En segundo lugar, se sintetizan las limitaciones que esta opción enfrenta al jerarquizarse la contingencia como fundamento de su aprehensión conceptual. En tercer lugar, se tomó un criterio simétrico para estudiar las teorías de la dependencia y estructuralismo latinoamericano, mostrando cómo, particularmente en este último caso, anidan potencialidades teóricas para sintetizar la escalaridad y la estructuración espacial asimétrica de los sistemas socioeconómicos. El trabajo concluye, observando que esto último depende de volver sobre la especificidad histórico-estructural de la modernización periférica considerando las formas específicas en las que la territorialidad y las relaciones capitalistas de producción se articulan.A coexistência de relações sociais que se definem em diferentes escalas territoriais e a estruturação assimétrica do espaço mundial, com posições centrais e periféricas, constituem duas dimensões centrais da estruturação espacial dos sistemas socioeconômicos. Embora esses dois momentos tenham sido amplamente estudados, suas conexões internas são uma área relativamente menos explorada. Nesse quadro, o trabalho visa explorar as relações intrínsecas entre esses momentos, construindo uma interpretação de cunho histórico-estrutural. Para atingir este objetivo, são avaliadas as principais contribuições que incidiram na especificidade de cada momento, mobilizando diferentes teorias sobre a relação entre a sociedade e o espaço. Em primeiro lugar, analisa-se o desenvolvimento teórico da questão escalar, mostrando como a virada relacional constituiu a aposta teórica chave da articulação entre a unidade mundial do processo de acumulação de capital e sua estruturação espacial em múltiplas escalas. Em segundo lugar, as limitações que esta opção enfrenta são sintetizadas observando a contingência como base de sua apreensão conceitual. Terceiro, adotou-se um critério simétrico para estudar as teorias da dependência e do estruturalismo latino-americano, mostrando como, particularmente neste último caso, potencialidades teóricas se aninham para sintetizar a escalaridade e a estruturação espacial assimétrica dos sistemas socioeconômicos. O trabalho conclui, observando que este último depende do retorno à especificidade histórico-estrutural da modernização periférica, considerando as formas específicas de articulação da territorialidade e das relações capitalistas de produção