Identifying Node Falls In Mobile Wireless Networks: A Probabilistic Method

We adopt a probabilistic strategy and propose two node failure discovery plots that deliberately join restricted monitoring, area estimation and node  joint effort. Broad reproduction brings about both associated and detached network s exhibit that our plans accomplish high failure identification rates (near an upper bound) and low false positive rates, and bring about low correspondence overhead. Contrasted with approaches that utilization incorporated checking, our approach has up to 80% lower correspondence overhead, and just marginally bring down location rates and somewhat higher false positive rates. Moreover, our approach has the favorable position that it is relevant to both associated and disengaged network s while brought together checking is just material to associated networks

Node Failure Detection And Fault Management In Mobile Wireless Networks With Persistent Connectivity

We adopt a probabilistic strategy and propose two hub disappointment recognition plots that deliberately consolidate limited observing, area estimation and hub cooperation. Broad reproduction brings about both associated and disengaged systems show that our plans accomplish high disappointment identification rates (near an upper bound) and low false positive rates, and cause low correspondence overhead. Contrasted with methodologies that utilization concentrated checking, our approach has up to 80% lower correspondence overhead, and just somewhat bring down recognition rates and marginally higher false positive rates. Also, our approach has the favorable position that it is relevant to both associated and detached systems while brought together observing is just material to associated systems

Temporal Modeling of Link Characteristic in Mobile Ad hoc Network

Ad hoc network consists of a set of identical nodes that move freely and independently and communicate among themselves via wireless links. The most interesting feature of this network is that they do not require any existing infrastructure of central administration and hence is very suitable for temporary communication links in an emergency situation. This flexibility, however, is achieved at a price of communication uncertainty induced due to frequent topology changes. In this article, we have tried to identify the system dynamics using the proven concepts of time series modeling. Here, we have analyzed variation of link utilization between any two particular nodes over a fixed area for differentmobility patterns under different routing algorithm. We have considered four different mobility models – (i) Gauss-Markov mobility model, (ii) Manhattan Grid Mobility model and (iii) Random Way Point mobility model and (iv) Reference Point Group mobility model. The routing protocols under which, we carried out our experiments are (i) Ad hoc On demand Distance Vector routing (AODV), (ii) Destination Sequenced Distance Vector routing (DSDV) and (iii) Dynamic Source Routing (DSR). The value of link load between two particular nodes behaves as a random variable for any mobility pattern under a routing algorithm. The pattern of link load for every combination of mobility model and for every routing protocol can be well modeled as an autoregressive model of order p i.e. AR(p). The order of p is estimated and it is found that most of them are of order 1 only

Temporal Modeling of Node Mobility in Mobile Ad hoc Network

Ad-hoc network consists of a set of identical nodes that move freely and independently and communicate via wireless links. The most interesting feature of this network is that it does not require any predefined infrastructure or central administration and hence it is very suitable for establishing temporary communication links in emergency situations. This flexibility however is achieved at the price of communication link uncertainties due to frequent topology changes. In this article we describe the system dynamics using the proven concept of time series modeling. Specifically, we analyze variations of the number of neighbor nodes of a particular node over a geographical area and for given total number of nodes assuming different values of (i) the speeds of nodes, (ii) the transmission powers, (iii) sampling periods and (iv) different mobility patterns. We consider three different mobility models: (i) Gaussian mobility model, (ii) random walk mobility model and (iii) random way point mobility model. The number of neighbor nodes of a particular node behaves as a random variable for any mobility pattern. Through our analysis we find that the variation of the number of neibhbor nodes can be well modeled by an autoregressive AR$(p)$ model. The values of $p$ evaluated for different scenarios are found to be in the range between $1$ and $5$. Moreover, we also investigate the relationship between the speed and the time of measurements, and the transmission range of a specific node under various mobility patterns

The Node Distribution of the Random Waypoint Mobility Model for Wireless Ad Hoc Networks

The random waypoint model is a commonly used mobility model in the simulation of ad hoc networks. It is known that the spatial distribution of nodes moving according to this model is in general non-uniform. However, an in-depth investigation and a closed-form expression of this distribution is still missing. This fact impairs the accuracy of the current simulation methodology of ad hoc networks and makes it impossible to relate simulation results to analytical results on the properties of adhoc networks. To overcome these problems, we present a detailed analytical study of the node distribution resulting from random waypoint mobility. More specifically, we consider a generalization of the model, in which the pause time of the mobile nodes is chosen arbitrarily in each waypoint and a fraction of nodes may remain static for the entire simulation time. We show that the structure of the resulting distribution is the weighted sum of three independent components: the static, pause, and mobility component. This division enables us to understand how the model\u27s parameters influence the distribution. By describing mobility as a stochastic process, we derive an exact equation of the asymptotically stationary distribution for movement on a line segment, and an accurate approximation for a square area. The good quality of this approximation is validated through simulations with various settings of the mobility parameters

How Human Mobility Models Can Help to Deal with COVID-19

[EN] One of the key factors for the spreading of human infections, such as the COVID-19, is human mobility. There is a huge background of human mobility models developed with the aim of evaluating the performance of mobile computer networks, such as cellular networks, opportunistic networks, etc. In this paper, we propose the use of these models for evaluating the temporal and spatial risk of transmission of the COVID-19 disease. First, we study both pure synthetic model and simulated models based on pedestrian simulators, generated for real urban scenarios such as a square and a subway station. In order to evaluate the risk, two different risks of exposure are defined. The results show that we can obtain not only the temporal risk but also a heat map with the exposure risk in the evaluated scenario. This is particularly interesting for public spaces, where health authorities could make effective risk management plans to reduce the risk of transmission.Hernández-Orallo, E.; Armero-Martínez, A. (2021). How Human Mobility Models Can Help to Deal with COVID-19. Electronics. 10(1):1-24. https://doi.org/10.3390/electronics1001003312410

Two-Hop Monitoring Mechanism Based on Relaxed Flow Conservation Constraints against Selective Routing Attacks in Wireless Sensor Networks

In this paper, we investigate the problem of selective routing attack in wireless sensor networks by considering a novel threat, named the upstream-node effect, which limits the accuracy of the monitoring functions in deciding whether a monitored node is legitimate or malicious. To address this limitation, we propose a one-dimensional one-class classifier, named relaxed flow conservation constraint, as an intrusion detection scheme to counter the upstream node attack. Each node uses four types of relaxed flow conservation constraints to monitor all of its neighbors. Three constraints are applied by using one-hop knowledge, and the fourth one is calculated by monitoring two-hop information. The latter is obtained by proposing two-hop energy-efficient and secure reporting scheme. We theoretically analyze the security and performance of the proposed intrusion detection method. We also show the superiority of relaxed flow conservation constraint in defending against upstream node attack compared to other schemes. The simulation results show that the proposed intrusion detection system achieves good results in terms of detection effectiveness

Estudio de parámetros de conectividad y topología en redes ad-hoc con distintos patrones de movilidad

La popularitat de les tecnologies sense fils i la progressiva reducció dels dispositius amb capacitat computacional han suscitat l'interès de la comunitat científica per les anomenades xarxes mòbils ad-hoc. Les xarxes ad-hoc són una col•lecció de nodes que es comuniquen sense fils i sense infrastructura. En aquests tipus de xarxes, qualsevol node pot ser origen, destí o encaminador de tràfic. La mobilitat dels nodes provoca que la topologia de la xarxa variï freqüentment. Un dels aspectes fonamentals de les xarxes ad-hoc és la seva connectivitat, és a dir, la probabilitat que un node sigui capaç de comunicar-se amb un altre; en altres paraules, és la probabilitat de que existeixi una ruta entre un origen i un destí. En aquest TFC es planteja el desenvolupament d'un software que permeti obtenir la connectivitat d'una xarxa ad-hoc, donats uns paràmetres d'entrada (com el model de mobilitat, el radi de transmissió dels nodes, les dimensions del recinte on es mouen, etc.), així com altres dades relacionades. El software permetrà avaluar la connectivitat d'una xarxa ad-hoc segons els paràmetres esmentats

Estudio de parámetros de conectividad y topología en redes ad-hoc con distintos patrones de movilidad

La popularitat de les tecnologies sense fils i la progressiva reducció dels dispositius amb capacitat computacional han suscitat l'interès de la comunitat científica per les anomenades xarxes mòbils ad-hoc. Les xarxes ad-hoc són una col•lecció de nodes que es comuniquen sense fils i sense infrastructura. En aquests tipus de xarxes, qualsevol node pot ser origen, destí o encaminador de tràfic. La mobilitat dels nodes provoca que la topologia de la xarxa variï freqüentment. Un dels aspectes fonamentals de les xarxes ad-hoc és la seva connectivitat, és a dir, la probabilitat que un node sigui capaç de comunicar-se amb un altre; en altres paraules, és la probabilitat de que existeixi una ruta entre un origen i un destí. En aquest TFC es planteja el desenvolupament d'un software que permeti obtenir la connectivitat d'una xarxa ad-hoc, donats uns paràmetres d'entrada (com el model de mobilitat, el radi de transmissió dels nodes, les dimensions del recinte on es mouen, etc.), així com altres dades relacionades. El software permetrà avaluar la connectivitat d'una xarxa ad-hoc segons els paràmetres esmentats