9,695 research outputs found
Parameterized Verification of Safety Properties in Ad Hoc Network Protocols
We summarize the main results proved in recent work on the parameterized
verification of safety properties for ad hoc network protocols. We consider a
model in which the communication topology of a network is represented as a
graph. Nodes represent states of individual processes. Adjacent nodes represent
single-hop neighbors. Processes are finite state automata that communicate via
selective broadcast messages. Reception of a broadcast is restricted to
single-hop neighbors. For this model we consider a decision problem that can be
expressed as the verification of the existence of an initial topology in which
the execution of the protocol can lead to a configuration with at least one
node in a certain state. The decision problem is parametric both on the size
and on the form of the communication topology of the initial configurations. We
draw a complete picture of the decidability and complexity boundaries of this
problem according to various assumptions on the possible topologies.Comment: In Proceedings PACO 2011, arXiv:1108.145
Routing efficiency in wireless sensor-actor networks considering semi-automated architecture
Wireless networks have become increasingly popular and advances in wireless communications and electronics have enabled the development of different kind of networks such as Mobile Ad-hoc Networks (MANETs), Wireless Sensor Networks (WSNs) and Wireless Sensor-Actor Networks (WSANs). These networks have different kind of characteristics, therefore new protocols that fit their features should be developed. We have developed a simulation system to test MANETs, WSNs and WSANs. In this paper, we consider the performance behavior of two protocols: AODV and DSR using TwoRayGround model and Shadowing model for lattice and random topologies. We study the routing efficiency and compare the performance of two protocols for different scenarios. By computer simulations, we found that for large number of nodes when we used TwoRayGround model and random topology, the DSR protocol has a better performance. However, when the transmission rate is higher, the routing efficiency parameter is unstable.Peer ReviewedPostprint (published version
Topology Control for Maintaining Network Connectivity and Maximizing Network Capacity Under the Physical Model
In this paper we study the issue of topology control under the physical Signal-to-Interference-Noise-Ratio (SINR) model, with the objective of maximizing network capacity. We show that existing graph-model-based topology control captures interference inadequately under the physical SINR model, and as a result, the interference in the topology thus induced is high and the network capacity attained is low. Towards bridging this gap, we propose a centralized approach, called Spatial Reuse Maximizer (MaxSR), that combines a power control algorithm T4P with a topology control algorithm P4T. T4P optimizes the assignment of transmit power given a fixed topology, where by optimality we mean that the transmit power is so assigned that it minimizes the average interference degree (defined as the number of interferencing nodes that may interfere with the on-going transmission on a link) in the topology. P4T, on the other hand, constructs, based on the power assignment made in T4P, a new topology by deriving a spanning tree that gives the minimal interference degree. By alternately invoking the two algorithms, the power assignment quickly converges to an operational point that maximizes the network capacity. We formally prove the convergence of MaxSR. We also show via simulation that the topology induced by MaxSR outperforms that derived from existing topology control algorithms by 50%-110% in terms of maximizing the network capacity
Optimized network structure and routing metric in wireless multihop ad hoc communication
Inspired by the Statistical Physics of complex networks, wireless multihop ad
hoc communication networks are considered in abstracted form. Since such
engineered networks are able to modify their structure via topology control, we
search for optimized network structures, which maximize the end-to-end
throughput performance. A modified version of betweenness centrality is
introduced and shown to be very relevant for the respective modeling. The
calculated optimized network structures lead to a significant increase of the
end-to-end throughput. The discussion of the resulting structural properties
reveals that it will be almost impossible to construct these optimized
topologies in a technologically efficient distributive manner. However, the
modified betweenness centrality also allows to propose a new routing metric for
the end-to-end communication traffic. This approach leads to an even larger
increase of throughput capacity and is easily implementable in a
technologically relevant manner.Comment: 25 pages, v2: fixed one small typo in the 'authors' fiel
Localized Support for Injection Point Election in Hybrid Networks
Ad-hoc networks, a promising trend in wireless technology, fail to work
properly in a global setting. In most cases, self-organization and cost-free
local communication cannot compensate the need for being connected, gathering
urgent information just-in-time. Equipping mobile devices additionally with GSM
or UMTS adapters in order to communicate with arbitrary remote devices or even
a fixed network infrastructure provides an opportunity. Devices that operate as
intermediate nodes between the ad-hoc network and a reliable backbone network
are potential injection points. They allow disseminating received information
within the local neighborhood. The effectiveness of different devices to serve
as injection point differs substantially. For practical reasons the
determination of injection points should be done locally, within the ad-hoc
network partitions. We analyze different localized algorithms using at most
2-hop neighboring information. Results show that devices selected this way
spread information more efficiently through the ad-hoc network. Our results can
also be applied in order to support the election process for clusterheads in
the field of clustering mechanisms.Comment: The Sixth International Conference on Networking (ICN 2007
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