2,915 research outputs found
Virtual Communication Stack: Towards Building Integrated Simulator of Mobile Ad Hoc Network-based Infrastructure for Disaster Response Scenarios
Responses to disastrous events are a challenging problem, because of possible
damages on communication infrastructures. For instance, after a natural
disaster, infrastructures might be entirely destroyed. Different network
paradigms were proposed in the literature in order to deploy adhoc network, and
allow dealing with the lack of communications. However, all these solutions
focus only on the performance of the network itself, without taking into
account the specificities and heterogeneity of the components which use it.
This comes from the difficulty to integrate models with different levels of
abstraction. Consequently, verification and validation of adhoc protocols
cannot guarantee that the different systems will work as expected in
operational conditions. However, the DEVS theory provides some mechanisms to
allow integration of models with different natures. This paper proposes an
integrated simulation architecture based on DEVS which improves the accuracy of
ad hoc infrastructure simulators in the case of disaster response scenarios.Comment: Preprint. Unpublishe
Metaheuristic approaches for optimal broadcasting design in metropolitan MANETs
11th International Conference on Computer Aided Systems Theory. Las Palmas de Gran Canaria, Spain, February 12-16, 2007Mobile Ad-hoc Networks (MANETs) are composed of a set of communicating devices which are able to spontaneously interconnect without any pre-existing infrastructure. In such scenario, broadcasting becomes an operation of tremendous importance for the own existence and operation of the network. Optimizing a broadcasting strategy in MANETs is a multiobjective problem accounting for three goals: reaching as many stations as possible, minimizing the network utilization, and reducing the duration of the operation itself. This research, which has been developed within the OPLINK project (http://oplink.lcc.uma.es), faces a wide study about this problem in metropolitan MANETs with up to seven different advanced multiobjective metaheuristics. They all compute Pareto fronts of solutions which empower a human designer with the ability of choosing the preferred configuration for the network. The quality of these fronts is evaluated by using the hypervolume metric. The obtained results show that the SPEA2 algorithm is the most accurate metaheuristic for solving the broadcasting problem.Publicad
A New Approach to Coding in Content Based MANETs
In content-based mobile ad hoc networks (CB-MANETs), random linear network
coding (NC) can be used to reliably disseminate large files under intermittent
connectivity. Conventional NC involves random unrestricted coding at
intermediate nodes. This however is vulnerable to pollution attacks. To avoid
attacks, a brute force approach is to restrict the mixing at the source.
However, source restricted NC generally reduces the robustness of the code in
the face of errors, losses and mobility induced intermittence. CB-MANETs
introduce a new option. Caching is common in CB MANETs and a fully reassembled
cached file can be viewed as a new source. Thus, NC packets can be mixed at all
sources (including the originator and the intermediate caches) yet still
providing protection from pollution. The hypothesis we wish to test in this
paper is whether in CB-MANETs with sufficient caches of a file, the performance
(in terms of robustness) of the restricted coding equals that of unrestricted
coding.
In this paper, we examine and compare unrestricted coding to full cache
coding, source only coding, and no coding. As expected, we find that full cache
coding remains competitive with unrestricted coding while maintaining full
protection against pollution attacks
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