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Bandwidth Constrained Multi-interface Networks

Bandwidth Constrained Multi-interface Networks

Related work. Multi-interface wireless networks have recently been studied in a variety of contexts, usually focusing on the benefits of multiple radio devices of each node. Many basic problems of standard wireless network optimization can be reconsidered in such a setting [3], in particular, focusing on issues related to routing [7] and network connectivity [5, 8]. The study of combinatorial prob- lems on multi-interface wireless networks has originated from [4]. That paper, as well as [13] investigate the so called Coverage problem, where the goal is the activation of the minimum cost set of interfaces in such a way that all the edges of G are covered. Connectivity issues have been addressed in [2, 6, 14]. The goal becomes to activate the minimum cost set of interfaces in G in order to guaran- tee a path of communication between every pair of nodes. In [14], the attention has been devoted to the so called Cheapest path problem. This corresponds to the well-known shortest path problem but in the context of multi-interface net- works. A natural continuation on investigating such kind of networks is certainly to consider also quality of service constraints in the problem. To the best of our knowledge, bandwidth issues have never been treated before in this context.
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Connectivity in Multi-Channel Multi-Interface Wireless Mesh Networks

Connectivity in Multi-Channel Multi-Interface Wireless Mesh Networks

† CNRS, University of Strasbourg, UMR 7005, France Email: {oliveira,duda}@imag.fr, theoleyre@unistra.fr Abstract—We can improve the performance of wireless mesh networks by using multiple interfaces tuned to non-overlapping channels. A Channel and Interface Assignment (CIA) decides when to switch interfaces and which channel to use. Surprisingly, the impact of CIAs on connectivity has received little attention so far. In this paper, we present a comparison and performance evaluation of the existing CIA strategies addressing the connectiv- ity issues: network topology, density of connections, and neighbor discovery. The results presented in this paper provide guidelines for network designers in planning multi-channel multi-interface network deployments.
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Maximum Flow and Minimum-Cost Flow in Multi-Interface Networks

Maximum Flow and Minimum-Cost Flow in Multi-Interface Networks

4. CONCLUSION We have considered two fundamental optimization prob- lems which take into account bandwidth constraints in Multi-Interface Networks: MFMI and MCFMI. In MFMI, we aim to activate a set of interfaces in the network in or- der to guarantee the maximal bandwidth between two given nodes. In MCFMI, we look for activating the cheapest set of interfaces among a network in order to guarantee a minimum bandwidth of communication between two specified nodes. The obtained results have shown that MFMI is polynomially solvable while MCFMI is NP-hard. However, we experimen- tally analyzed algorithm ALG 2 for MCFMI, showing that in practical cases it guarantees a low approximation ratio which allows us to use it in real-world. Further investigation for better performing approximation algorithms or heuristics re- main challenging problems. Another interesting issue is to
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Broadcast Strategies with Probabilistic Delivery Guarantee in Multi-Channel Multi-Interface Wireless Mesh Networks

Broadcast Strategies with Probabilistic Delivery Guarantee in Multi-Channel Multi-Interface Wireless Mesh Networks

Several papers tried to tackle the broadcast problem in multi-channel multi-interface wireless mesh networks. Qadir et al. [4] proposed to optimize the delay for multi-rate mesh networks. However, they focused on the global flooding prob- lem, i.e. how each node in the network receives the flooded packets. [5] proposed to use additionally network coding to reduce the overhead. Xing et al. [6] proposed superimposed codes to tackle both the unicast and broadcast problems in multi-channel multi-interface mesh networks.

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Min-Max Coverage in Multi-interface Networks

Min-Max Coverage in Multi-interface Networks

1.1 Related work Multi-interface wireless networks have been recently studied in a variety of con- texts, usually focusing on the benefits of multiple radio devices of each node [6, 9, 10]. Many basic problems of standard wireless network optimization can be reconsidered in such a setting [2]. However, previous works have been mainly focused on the minimization of the costs among the whole network. In [5, 14], for instance, the same problem of Coverage has been investigated, but with the goal of activating the minimum cost set of interfaces among all the nodes in the network in such a way that all the edges of G are covered. Connectivity issues have been addressed in [1, 8, 14, 15]. The goal becomes to activate the minimum cost set of interfaces in G in order to guarantee a path of communication between every pair of nodes. In particular, [8] considers the connectivity task under the same objective function of this paper, i.e., the minimization of the maximum cost spent by each single node. In [3, 15], the attention has been devoted to the so called Cheapest path problem. This corresponds to the well-known shortest path problem, but in the context of multi-interface networks.
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Flow problems in multi-interface networks

Flow problems in multi-interface networks

Index Terms—Multi-Interface Networks, Flow, Computational complexity, Approximation algorithms, Experimental analysis I. I NTRODUCTION The interest in heterogeneous networks has rapidly grown during the last decades. Their success is certainly due to the wide range of applications for which such networks are designed. One of the most relevant property is the variety of the devices which might interact in order to exchange data. Heterogeneous networks are, in fact, composed of devices with different characteristics like computational power, energy consumption, communication interfaces, communication pro- tocols, and so forth. In this paper, we are mainly interested in devices equipped with multiple interfaces (like Ethernet, ADSL, Bluetooth, WiFi, GPRS, etc.). A connection between two or more devices might be accomplished by means of different communication networks according to connectivity and quality of service requirements. The selection of the most suitable interface for a specific connection might depend on various factors. Such factors include: the availability of an interface in specific devices, the required communication bandwidth, the cost (in terms of energy consumption) of maintaining an active interface, the available neighbors, and so forth. While managing such connections, a lot of effort must be devoted to energy consumption issues. Devices are, in fact, G. D’Angelo is with the MASCOTTE Project, I3S(CNRS/UNSA)/INRIA, France. e-mail: gianlorenzo.d angelo@inria.fr
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Minimize the Maximum Duty in Multi-interface Networks

Minimize the Maximum Duty in Multi-interface Networks

Gabriele Di Stefano · Alfredo Navarra the date of receipt and acceptance should be inserted later Abstract We consider devices equipped with multiple wired or wireless inter- faces. By switching of various interfaces, each device might establish several connections. A connection is established when the devices at its endpoints share at least one active interface. Each interface is assumed to require an activation cost. In this paper, we consider two basic networking problems in the field of multi-interface networks. The first one, known as the Coverage problem, requires to establish the connections defined by a network. The sec- ond one, known as Connectivity problem, requires to guarantee a connecting path between any pair of nodes of a network. Both are subject to the con- straint of keeping as low as possible the maximum cost set of active interfaces at each single node. We study the problems of minimizing the maximum cost set of active interfaces among the nodes of the network in order to cover all the edges in the first case, or to ensure connectivity in the second case. We prove that the Coverage problem is NP-hard for any fixed ∆ ≥ 5 and k ≥ 16, with ∆ being the maximum degree, and k being the number of different in- terfaces among the network. We also show that, unless P = NP, the problem cannot be approximated within a factor of η ln ∆, for a certain constant η. We then provide a general approximation algorithm which guarantees a fac- tor of O((1 + b) ln ∆), with b being a parameter depending on the topology
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Interface selection and flow/interface association decision schemes for multi-interface mobile terminals

Interface selection and flow/interface association decision schemes for multi-interface mobile terminals

En outre, une issue avec le réglage du poids. Comment pouvons-nous définir exactement l'importance relative des attributs? Dans notre contexte, les pondérations sont estimées par le jugement humain. Par exemple, l'échelle de l'importance relative entre les attributs peuvent être jugés que même importance, un peu plus important, plus important, fortement plus important, ou absolument plus important, etc. La question de pondération devrait être étudiée pour augmenter la précision de l'objectif de sélection. Le deuxième modèle d’association flux/interface permet d'associer simultanément les applications aux interfaces en maximisant l'utilité de terminaux. Le modèle pourrait envisager l’optimal sociale et les questions d'équité. En d'autres termes, le modèle associe simultanément les applications aux interfaces qui non seulement optimise l'utilité de terminaux globaux, mais aussi considère également le niveau de satisfaction équitable de chaque application.
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DIVA Graphical User Interface

DIVA Graphical User Interface

direct visualization with interface : PlPlot → incompatibility contour and mesh → Matlab script meshvisu.m. analysed eld and error map → Matlab script NetCDF output → Ncview, Ncbrowse..[r]

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Animist interface : experiments in mapping character animation to computer interface

Animist interface : experiments in mapping character animation to computer interface

"Animist Interface" incorporates intelligence and dynamism into screen and its interface elements; it also increases in-band communication, allowing existing messa[r]

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The Character as subjective interface

The Character as subjective interface

Virtual agents are generally evaluated in terms of their usability—how efficiently they allow users to perform such tasks as finding the right information, redirecting a call to the right person, booking a train ticket at the right time for the right destination. But that’s not how I value Jean. I like him because of all the boring, routine events happening in his office, he will choose the interesting anecdote, and spin it in his own inefficient but charming way. He’s not great as a proxy either. Even when acting upon my recommendations, he will always end up doing things the way he wants. If he had done exactly as I had said, the prank would have been better. But then, much of the fun is in finding out what he actually made of my suggestions as it gives me further insight into his personality. If some designers dream of transparent and immediate interfaces, I have to admit Jean is rather to be classified with the murky and viscous ones. That mindset is different enough to make interface characters like Jean completely different from humanized interfaces like Cortana or Siri. Their nature, and the context in which we use them, belong to the realm of aesthetics, rather than functionality.
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A totally Eulerian Finite Volume solver for multi-material fluid flows: Enhanced Natural Interface Positioning (ENIP)

A totally Eulerian Finite Volume solver for multi-material fluid flows: Enhanced Natural Interface Positioning (ENIP)

struction, Condensate evolution, Reconstruction, and Projection. The present paper points the weakness of the NIP method in pure advection context and, consequently, in a full multi-material hydrodynamics one. An enhanced NIP method is proposed (ENIP). It modifies several of the previous listed steps. More precisely the condensate is assumed to evolved in an almost-Lagrangian fashion. The reconstruction step assumes that the condensate keeps the same form modulo some expansion/compression that the numerical scheme already provides. So the displacement of the condensate is performed either with the true computed velocity or with an interpolation of it. In fine the condensate preserves its topology contrarily to the original NIP method for which the condensate has no recollection of its shape from the beginning of the time step.
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Camera-microcomputer interface

Camera-microcomputer interface

The Camera Director, under software control via a status register, broadcasts the START and CLOCK pulses to all three cameras, but allows onto the interface only th[r]

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Interface Scicos-SynDEx

Interface Scicos-SynDEx

Unité de recherche INRIA Rocquencourt Domaine de Voluceau - Rocquencourt - BP 105 - 78153 Le Chesnay Cedex France Unité de recherche INRIA Lorraine : LORIA, Technopôle de Nancy-Brabois -[r]

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Interface SIGNAL-SynDEx

Interface SIGNAL-SynDEx

HAL Id: inria-00077109 https://hal.inria.fr/inria-00077109 Submitted on 29 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

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Magnetosheath-cusp interface

Magnetosheath-cusp interface

tions in the coordinates invariant latitude and MLT in the Northern Hemisphere. From Fig. 7a one can see that the multi-spacecraft data provide the unprecedented wide cov- erage of the high latitude magnetic field lines in invariant lat- itude, MLT and UT. At lower altitudes the HEO 95-034 and DMSP F12 and F13 registered the cusp, shown by the thick blue lines (their traces have been calculated without usage of the MHD model, see Grande et al., 1997 for details). The crosses show projections of the reconnection locations from the global MHD model. Figure 7a demonstrates a wide cusp, the TBL (red thick lines) and an even mantle (green line) spread in MLT and UT. Figures 7b and 7c show the character- istic ionospheric equipotential patterns from the global MHD model; equipotential contours are plotted for cross-cap po- tential 6 kV and field-aligned current 4 10 − 6 A/m. Note that the ionospheric convection is along the equipotential con- tours; the convection directions are displayed by the green arrows in the center and by the gray ones at the periphery. Traces of Polar (violet asterisks), Interball-1 (red circled tri- angle) and reconnection point footprints (brown arrow) are depicted as well. Figure 7b presents the main features of the MHD model convection up to 03:06 UT (inclusively). The global MHD model predicts Polar connection to the north- ern pole for the entire period, while Interball has no such connection starting from ∼03:20 UT, which is why it does not appear in Fig. 7c. The latter is in good correspondence with the Interball outbound MP at 03:17 UT in Plate A2 (see Sect. 2.1).
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Experimental studies on the detachment of multi-walled carbon nanotubes by a mobile liquid interface

Experimental studies on the detachment of multi-walled carbon nanotubes by a mobile liquid interface

In a previous experiment that dealt with retention and detachment of carboxylated CNTs in bulk electrolytes, a systematic reduction of CVD-grown MWNT detachment was also seen in low-pH environment [14] . The effect was attributed to dissociation of the chemical groups adhered both on the substrate and the nanotubes. In our case, opposing behavior is seen: the detachment due to the interface is enhanced in low-pH environment. However, as we pointed out, our arc-discharge MWNTs are of high quality, with a relatively low level of defects or associated molecular groups. Therefore their surface potential is un- likely to change drastically in environments of different pH. On the other hand, the surface chemistry of the substrate is highly hydrophilic with hydroxylation of the silica, and therefore some effect upon the change of pH is expected.
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Interface Java : interagir avec utilisateur

Interface Java : interagir avec utilisateur

Richard Grin Interface graphique 80 Adaptateurs • Pour éviter au programmeur d’avoir à implanter toutes les méthodes d’une interface « écouteur », AWT fournit des classes (on les appelle des adaptateurs), qui implantent toutes ces méthodes

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Interface science in JMS

Interface science in JMS

HAL Id: hal-03002037 https://hal.archives-ouvertes.fr/hal-03002037 Submitted on 12 Nov 2020 HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

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Computer-video interface system

Computer-video interface system

The video system is a versatile instrument. Though the data paths require some complex control, they are effectively very general. The system will proceed at video rates regar[r]

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