scholarly journals Localized Fault Tolerant Algorithm Based on Node Movement Freedom Degree in Flying Ad Hoc Networks

Symmetry ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 106 ◽  
Author(s):  
Qiang Guo ◽  
Jichen Yan ◽  
Wei Xu

Flying ad hoc network (FANET) is a communication network for data transmission among Unmanned Aerial Vehicles (UAVs). In ad hoc network, the UAVs movement is usually applied to improve network fault-tolerance, but it easily causes the disconnection of communication links, and the success rate is low. In this paper, we propose a local fault-tolerant control algorithm based on node movement freedom degree (LFTMF). Under the constraint of node movement freedom degree, the algorithm transforms the single-connected network into bi-connected network through the autonomous movement of UAVs to improve the fault-tolerant ability of the FANET network. Firstly, the consistency between k-hop cut-points and global cut-points in FANET network is analyzed. Then, based on the k-hop local topology of FANET network, the UAV node movement freedom degree model is established. Finally, according to the location distribution of k-hop cut-points in the FANET network, the bi-connected fault-tolerant network is realized by UAVs cascade movement. Compared with the existing algorithms, simulation results show that the proposed algorithm achieves better performance in success rate, deviation distance, cascade movement ratio and adjustment period.

Author(s):  
Shu-Ching Wang ◽  
Ya-Jung Lin ◽  
Yao-Te Tsai ◽  
Kuo-Qin Yan

The era of Internet of Things (IoT) has begun to evolve and with this the devices around us are getting more and more connected. Vehicular Ad-hoc NETworks (VANETs) is one of the applications of IoT. VANET allow vehicles within these networks to communicate effectively with each another. VANETs can provide an extensive range of applications that support and enhance passenger safety and comfort. It is important that VANETs are applied within a safe and reliable network topology; however, the challenging nature of reaching reliable and trustworthy agreement in such distributed systems is one of the most important issues in designing a fault-tolerant system. Therefore, protocols are required so that systems can still be correctly executed, reaching agreement on the same values in a distributed system, even if certain components in the system fail. In this study, the agreement problem is revisited in a VANET with multiple damages. The proposed protocol allows all fault-free nodes (vehicles) to reach agreement with minimal rounds of message exchanges, and tolerates the maximal number of allowable faulty components in the VANET.


Author(s):  
Bodhy Krishna .S

A wireless ad hoc network is a decentralized type of wireless network. It is a type of temporary computer-to-computer connection. It is a spontaneous network which includes mobile ad-hoc networks (MANET), vehicular ad-hoc networks (VANET) and Flying ad-hoc networks (FANET). A MANET is a network that has many free or autonomous nodes often composed of mobile devices that can operate without strict top-down network administration [1]. A VANET is a sub form of MANET. It is a technology that uses vehicles as nodes in a network to create a mobile network. FANET is an ad-hoc network of flying nodes. They can fly independently or can be operated distantly. This paper discusses the characteristics of these three ad-hoc networks.


Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3571 ◽  
Author(s):  
Antonio Guillen-Perez ◽  
Maria-Dolores Cano

The advent of flying ad hoc networks (FANETs) has opened an opportunity to create new added-value services. Even though it is clear that these networks share common features with its predecessors, e.g., with mobile ad hoc networks and with vehicular ad hoc networks, there are several unique characteristics that make FANETs different. These distinctive features impose a series of guidelines to be considered for its successful deployment. Particularly, the use of FANETs for telecommunication services presents demanding challenges in terms of quality of service, energy efficiency, scalability, and adaptability. The proper use of models in research activities will undoubtedly assist to solve those challenges. Therefore, in this paper, we review mobility, positioning, and propagation models proposed for FANETs in the related scientific literature. A common limitation that affects these three topics is the lack of studies evaluating the influence that the unmanned aerial vehicles (UAV) may have in the on-board/embedded communication devices, usually just assuming isotropic or omnidirectional radiation patterns. For this reason, we also investigate in this work the radiation pattern of an 802.11 n/ac (WiFi) device embedded in a UAV working on both the 2.4 and 5 GHz bands. Our findings show that the impact of the UAV is not negligible, representing up to a 10 dB drop for some angles of the communication links.


2013 ◽  
Vol 660 ◽  
pp. 184-189 ◽  
Author(s):  
Yan Zhai ◽  
Xing Wei ◽  
Lei Liu ◽  
Liao Yuan Wu

In order to tackle the data transmission bottlenecks of the gateway node in clustering Ad hoc Networks, the paper proposes a communication method. Firstly, DMAC (Distributed and Mobility-Adaptive Clustering) algorithm and Omni-directional antenna is well introduced and discussed. Then the ICMMDA (The Inter-cluster Communication Method based on Directional Antennas) policy building virtual channels between two hops away cluster-head and using directional antenna is brought about. Lastly, the simulation shows that the method can reduce the end-to-end delay between two clusters and improve the network throughput.


Transport ◽  
2008 ◽  
Vol 23 (4) ◽  
pp. 291-298 ◽  
Author(s):  
Saleh Yousefi ◽  
Mahmood Fathy

In the recent years, direct message exchange between vehicles in order to improve the safety of road traffic has been attracting lots of interest in both networking and road safety communities. While travelling on a road, vehicles form an ad hoc network called Vehicular Ad hoc NETwork (VANET) and deploy life safety applications. Evaluating the performance of these applications is primordial for realizing VANETs in real life. Current literature lacks efficient ways to evaluate the performance of safety applications and mostly leverages on classical networking metrics like delay, delivery rate etc. In this paper, we consider both networking and safety concerns simultaneously to come up with more efficient methods. In particular, we first point out the significance of fairness and coverage from safety viewpoint. Then, we introduce two new metrics called beaconing rate and effective range aiming at providing more facilities for safety performance evaluation in VANET s research. Furthermore, realizing special characteristics of safety applications while disseminating beacon messages, we study the way that beacon dissemination protocols affect the performance of safety applications. We then conduct extensive simulation study to show the usefulness of the introduced metrics and derive some insights on the feasibility of driver‐assistant safety applications. Our evaluation also shows that sending the aggregated status of neighbouring vehicles in addition to vehicle's own status, and instead, increasing beacon transmission interval may be invoked in order to assist safety applications in providing satisfactory services to drivers.


2010 ◽  
Vol 42 (02) ◽  
pp. 559-576
Author(s):  
Emilio De Santis ◽  
Fabrizio Grandoni ◽  
Alessandro Panconesi

Consider the following classical problem in ad-hoc networks. Suppose that n devices are distributed uniformly at random in a given region. Each device is allowed to choose its own transmission radius, and two devices can communicate if and only if they are within the transmission radius of each other. The aim is to (quickly) establish a connected network of low average and maximum degree. In this paper we present the first efficient distributed protocols that, in poly-logarithmically many rounds and with high probability, set up a connected network with O(1) average degree and O(log n) maximum degree. Our algorithms are based on the following result, which is a nontrivial consequence of classical percolation theory. Suppose that each device sets up its transmission radius in order to reach the K closest devices. There exists a universal constant K (independent of n) such that, with high probability, there will be a unique giant component (i.e. a connected component of size Θ(n)). Furthermore, all remaining components will be of size O(log2 n). This leads to an efficient distributed probabilistic test for membership in the giant component, which can be used in a second phase to achieve full connectivity.


2012 ◽  
Vol 224 ◽  
pp. 520-523
Author(s):  
Hyun Jong Cha ◽  
Jin Mook Kim ◽  
Hwang Bin Ryou

A mobile ad-hoc network is a method of communication between different nodes (mobile devices) without the use of base stations, which are used in wired networks. In a Mobile ad-hoc network, nodes can play the role of a receiver, sender, or a relay. As movement is flexible in Mobile ad-hoc networks and nodes have limited resources, nodes may join the communication or exit it at any time. Therefore, for Mobile ad-hoc networks, routing techniques - selecting communication routes and maintaining them – is considered important in an environment of constantly changing network topology. To overcome this problem, this paper proposes a reliable routing protocol based on MP-AOMDV, which monitors changes in signal strength not only for GPS signals but reception signals as well. Although MP-AOMDV was researched under the assumption of fixed movement direction and speed, this paper proposes a routing technique that works with changing movement direction or speed of nodes.


2022 ◽  
Vol 14 (1) ◽  
pp. 28
Author(s):  
Yelena Trofimova ◽  
Pavel Tvrdík

In wireless ad hoc networks, security and communication challenges are frequently addressed by deploying a trust mechanism. A number of approaches for evaluating trust of ad hoc network nodes have been proposed, including the one that uses neural networks. We proposed to use packet delivery ratios as input to the neural network. In this article, we present a new method, called TARA (Trust-Aware Reactive Ad Hoc routing), to incorporate node trusts into reactive ad hoc routing protocols. The novelty of the TARA method is that it does not require changes to the routing protocol itself. Instead, it influences the routing choice from outside by delaying the route request messages of untrusted nodes. The performance of the method was evaluated on the use case of sensor nodes sending data to a sink node. The experiments showed that the method improves the packet delivery ratio in the network by about 70%. Performance analysis of the TARA method provided recommendations for its application in a particular ad hoc network.


2018 ◽  
Vol 45 (1) ◽  
pp. 67-82
Author(s):  
Zbigniew Kasprzyk ◽  
Mariusz Rychlicki

Abstract Bluetooth is a type of wireless communication used to transmit voice and data at high speeds using radio waves. It is a standard protocol for short-range radio communications between many different types of devices, including mobile phones, computers and other electronics [1]. The use of this type of data transmission standard for voice communications at close range in the vehicle is commonly known. The trend of integrating new services in vehicles increases rapidly and Bluetooth is one of the emerging communication technologies for realizing ad-hoc networks. The paper presents the possibility of using Bluetooth to build ad-hoc network suitable for the transmission of sound, in particular voice data using the modulation GSFK. We analyzed the features or problems that Bluetooth offers for transmitting audio data in an ad-hoc network. Some initial results of simulations and real-life tests give an impression of the performance and efficiency this standard for the transmission of voice data in an ad-hoc networks [2].


2020 ◽  
Vol 1 (1) ◽  
pp. 7-14
Author(s):  
Chen Chao ◽  
Liang Jun ◽  
Sun Xin

Mobile ad hoc networks use the wireless network and have wider applications especially in emergency situation, military combat zones, and the mobility vehicles. The mobile ad hoc network especially poses the problem of security and efficiency as the network is often subject to internal and external attacks. To overcome such problems, different protocols are proposed. In this study, an improved protocol is proposed which makes use of hexacol cluster method and thus provide greater efficiency and security to the network. For validating the proposed method, a stimulation was performed and results were compared with other protocols. The results indicate that the proposed method showed improved performance compare to the other protocol.


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