scholarly journals Design of Adaptive Array Antenna for Wireless Communications

Author(s):  
Pramod Kumar ◽  
Shiwani Y. P. ◽  
H. K. Kanchana Kumari

Abstract In the ad hoc networks, it consists of many sensor nodes, and each sensor node is equipped with five units. The transmission unit cares for the transmission and receiving of data through the antenna. In this paper, the microstrip patch and 1x2 array antennas are designed and fabricated. The results of simulated and measured results are compared at operating frequency 5.4GHz. The results show the enhancement in the bandwidth and low VSWR which shows the maximum radiation of power. The array antenna can be operated for the wideband with better reflection coefficient, gain, bandwidth, and VSWR and radiation pattern. This smart antenna is self-efficient to configure with multiple high directivity beam to save the power, range and use reuse of channels. Such smart antennas are used for the ad-hoc network, Wi-Fi, UWB, and high-speed LTE applications.

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.


Author(s):  
Sudesh Kumar ◽  
Abhishek Bansal ◽  
Ram Shringar Raw

Recently, the flying ad-hoc network (FANETs) is a popular networking technology used to create a wireless network through unmanned aerial vehicles (UAVs). In this network, the UAV nodes work as intermediate nodes that communicate with each other to transmit data packets over the network, in the absence of fixed an infrastructure. Due to high mobility degree of UAV nodes, network formation and deformation among the UAVs are very frequent. Therefore, effective routing is a more challenging issue in FANETs. This paper presents performance evaluations and comparisons of the popular topology-based routing protocol namely AODV and position-based routing protocol, namely LAR for high speed mobility as well as a verity of the density of UAV nodes in the FANETs environment through NS-2 simulator. The extensive simulation results have shown that LAR gives better performance than AODV significantly in terms of the packet delivery ratio, normalized routing overhead, end-to-end delay, and average throughput, which make it a more effective routing protocol for the highly dynamic nature of FANETs.


2020 ◽  
Vol 17 (6) ◽  
pp. 2575-2581
Author(s):  
Manjit Kaur ◽  
Sahil Verma ◽  
Kavita

Flying Ad-hoc Networks (FANET) play a vital part in military (defence), environment and civilian areas, for examples surveillance, traffic monitoring, search, rescue, weather monitoring, fire fighting, agriculture, videography, photography and delivery goods or product from one place to another place etc. Flying Ad-hoc Network is mainly ad-hoc network between unmanned air vehicles. There are several difficulties in flying ad-hoc network. The primary problem is in the communication between unmanned air vehicles. UAV are also known as Unmanned Aircraft Systems (UAS). The problem of Flying Ad-hoc Network is routing of multiple unmanned air vehicles. The reason behind is high speed which required highly dynamic routing protocols. The designing of routing protocol is a complicated for various parameters such as traffic monitoring, load balancing etc. Here, flying ad-hoc networks are described along with mobility models, features and routing protocols. This paper presented various routing protocols used to resolve these types of problems in Flying Ad-hoc Networks. Finally, some open research challenges in developing efficient routing protocols in the Flying Ad-hoc Networks are highlighted.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Marco Di Filippo ◽  
Leonardo Lucci ◽  
Dania Marabissi ◽  
Stefano Selleri

Among the mobile ad hoc networks appealing characteristics there are network reconfigurability and flexibility. In this context a smart antenna capable of self-configuring multiple high-directivity beams provides a major advantage in terms of power saving, increased range, and spatial reuse of channels. In this paper a smart antenna made of a cylindrical array of patches suitable for MANETs is presented.


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.


Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 225 ◽  
Author(s):  
Jiaqi Liu ◽  
Shiyue Huang ◽  
Hucheng Xu ◽  
Deng Li ◽  
Nan Zhong ◽  
...  

As a special mobile ad-hoc network, Vehicular Ad-hoc Networks (VANETs) have the characteristics of high-speed movement, frequent topology changes, multi-hop routing, a lack of energy, storage space limitations, and the possible selfishness of the nodes. These characteristics bring challenges to the design of the incentive mechanism in VANETs. In the current research on the incentive mechanism of VANETs, the mainstream is the reward-based incentive mechanism. Most of these mechanisms are designed based on the expected utility theory of traditional economics and assume that the positive and negative effects produced by an equal amount of gain and loss are equal in absolute value. However, the theory of loss aversion points out that the above effects are not equal. Moreover, this will lead to a deviation between the final decision-making behavior of nodes and the actual optimal situation. Therefore, this paper proposed a Loss-Aversion-based Incentive Mechanism (LAIM) to promote the comprehensive perception and sharing of information in the VANETs. This paper designs the incentive threshold and the threshold factor to motivate vehicle nodes to cooperate. Furthermore, based on the number of messages that the nodes face, the utility function of nodes is redesigned to correct the assumption that a gain and a loss of an equal amount could offset each other in traditional economics. The simulation results show that compared with the traditional incentive mechanism, the LAIM can increase the average utility of nodes by more than 34.35%, which promotes the cooperation of nodes.


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.


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.


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].


Sign in / Sign up

Export Citation Format

Share Document