11,029 research outputs found
Resilient networking in wireless sensor networks
This report deals with security in wireless sensor networks (WSNs),
especially in network layer. Multiple secure routing protocols have been
proposed in the literature. However, they often use the cryptography to secure
routing functionalities. The cryptography alone is not enough to defend against
multiple attacks due to the node compromise. Therefore, we need more
algorithmic solutions. In this report, we focus on the behavior of routing
protocols to determine which properties make them more resilient to attacks.
Our aim is to find some answers to the following questions. Are there any
existing protocols, not designed initially for security, but which already
contain some inherently resilient properties against attacks under which some
portion of the network nodes is compromised? If yes, which specific behaviors
are making these protocols more resilient? We propose in this report an
overview of security strategies for WSNs in general, including existing attacks
and defensive measures. In this report we focus at the network layer in
particular, and an analysis of the behavior of four particular routing
protocols is provided to determine their inherent resiliency to insider
attacks. The protocols considered are: Dynamic Source Routing (DSR),
Gradient-Based Routing (GBR), Greedy Forwarding (GF) and Random Walk Routing
(RWR)
Impact of network structure on the capacity of wireless multihop ad hoc communication
As a representative of a complex technological system, so-called wireless
multihop ad hoc communication networks are discussed. They represent an
infrastructure-less generalization of todays wireless cellular phone networks.
Lacking a central control authority, the ad hoc nodes have to coordinate
themselves such that the overall network performs in an optimal way. A
performance indicator is the end-to-end throughput capacity.
Various models, generating differing ad hoc network structure via differing
transmission power assignments, are constructed and characterized. They serve
as input for a generic data traffic simulation as well as some semi-analytic
estimations. The latter reveal that due to the most-critical-node effect the
end-to-end throughput capacity sensitively depends on the underlying network
structure, resulting in differing scaling laws with respect to network size.Comment: 30 pages, to be published in Physica
Scaling of critical connectivity of mobile ad hoc communication networks
In this paper, critical global connectivity of mobile ad hoc communication
networks (MAHCN) is investigated. We model the two-dimensional plane on which
nodes move randomly with a triangular lattice. Demanding the best communication
of the network, we account the global connectivity as a function of
occupancy of sites in the lattice by mobile nodes. Critical phenomena
of the connectivity for different transmission ranges are revealed by
numerical simulations, and these results fit well to the analysis based on the
assumption of homogeneous mixing . Scaling behavior of the connectivity is
found as , where , is
the length unit of the triangular lattice and is the scaling index in
the universal function . The model serves as a sort of site percolation
on dynamic complex networks relative to geometric distance. Moreover, near each
critical corresponding to certain transmission range , there
exists a cut-off degree below which the clustering coefficient of such
self-organized networks keeps a constant while the averaged nearest neighbor
degree exhibits a unique linear variation with the degree k, which may be
useful to the designation of real MAHCN.Comment: 6 pages, 6 figure
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