scholarly journals Low-Computational Extended Orthogonal Matched Filter Structure for Multiuser Detection

Telecom ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 32-47
Author(s):  
Kento Takabayashi ◽  
Shuhei Harada ◽  
Takumi Kobayashi ◽  
Katsumi Sakakibara ◽  
Ryuji Kohno
Keyword(s):  
Computational Complexity ◽  
Multiuser Detection ◽  
Wireless Ad Hoc Networks ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Matched Filter ◽  
Wireless Ad Hoc Network ◽  
Bit Error Ratio ◽  
Hoc Networks ◽  
Code Division Multiple

This research provides a novel extended orthogonal matched filter (EOMF) structure that supports multiuser detection. In addition, this structure is designed to suppress increases in computational complexity and circuit scale. In coming years, the number of Internet of Things (IoT) applications that use wireless ad hoc networks is expected to increase. To realize a highly reliable wireless ad hoc network, it is essential to introduce a method for cancelling the interference from other users. This research adopts a method based on code division multiple access (CDMA). However, a CDMA-based method has difficulty with deteriorating performance due to the near-far problem and the increase in the amount of interference as the number of users increases. Another problem is that the spreading sequence of each user is unknown in a wireless ad hoc network. The EOMF effectively removes interference while solving the above problems by combining an OMF and an adaptive array antenna. In this research, an EOMF structure with multiuser detection and lower computational complexity than the conventional EOMF is proposed. By the derived formulas and numerical examples, the proposed structure reduces the computational complexity by approximately 75% compared to the conventional EOMF and obtains sufficient bit error ratio (BER) performance.

Cross-Layered Secure and QoS Aware Design of VOIP over Wireless Ad-Hoc Networks

2013 ◽  
Vol 9 (4) ◽  
pp. 23-45 ◽  
Author(s):  
Shahin Vakilinia ◽  
Mohammadhossein Alvandi ◽  
Mohammadreza Khalili Shoja ◽  
Iman Vakilinia
Keyword(s):  
Ad Hoc Networks ◽  
Wireless Ad Hoc Networks ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Denial Of Service ◽  
Cross Layer ◽  
Wireless Ad Hoc Network ◽  
Cross Layer Design ◽  
Hoc Networks

In this paper, Cross-layer design has been used to provide quality of service (QoS) and security at the same time for VOIP over the wireless ad-hoc network. In this paper the authors extend their previous work (i.e. Multi-path Multi-Channel Protocol Design for Secure QoS-Aware VOIP in Wireless Ad-Hoc Networks) by adding transport and application layers considerations. The goal of this paper is to support QoS and security of VOIP simultaneously. Simulation results shows that the proposed cross-layered protocol stack design significantly improve QoS parameters of the VOIP calls under the jamming or Denial-of-service attacks.

ASYMPTOTIC DISTRIBUTION OF THE NUMBER OF ISOLATED NODES IN WIRELESS AD HOC NETWORKS WITH UNRELIABLE NODES AND LINKS

2010 ◽  
Vol 02 (01) ◽  
pp. 107-124 ◽  
Author(s):  
CHIH-WEI YI ◽  
PENG-JUN WAN ◽  
CHAO-MIN SU ◽  
KUO-WEI LIN ◽  
SCOTT C.-H. HUANG
Keyword(s):  
Ad Hoc Networks ◽  
Wireless Ad Hoc Networks ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Unit Area ◽  
Wireless Ad Hoc Network ◽  
Key Predistribution ◽  
Key Predistribution Schemes ◽  
Hoc Networks ◽  
Maximum Transmission

In this paper, we study the connectivity of wireless ad hoc networks that are composed of unreliable nodes and links by investigating the distribution of the number of isolated nodes. We assume that a wireless ad hoc network consists of n nodes distributed independently and uniformly in a unit-area disk or square. All nodes have the same maximum transmission radius rn, and two nodes have a link if their distance is at most rn. Nodes are active independently with probability 0 < p1 ≤ 1, and links are up independently with probability 0 < p2 ≤ 1. Nodes are said isolated if they do not have any links to active nodes. We show that if [Formula: see text] for some constant ξ, then the total number of isolated nodes (or isolated active nodes, respectively) is asymptotically Poisson with mean e-ξ (or p1e-ξ, respectively). In addition, in the secure wireless networks that adopt m-composite key predistribution schemes, a node is said isolated if it does not have a secure link. Let p denote the probability of the event that two neighbor nodes have a secure link. If all nodes have the same maximum transmission radius [Formula: see text], the total number of isolated nodes is asymptotically Poisson with mean e-ξ.

scholarly journals Detection and Prevention of Drop Attack in WANET Using Robust Scheme Method

2021 ◽  
Author(s):  
Vinoth kumar P ◽  
Venkatesh K
Keyword(s):  
Wireless Ad Hoc Networks ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Network Routing ◽  
Wireless Ad Hoc Network ◽  
Drop Attack ◽  
Network Protection ◽  
High Speeds ◽  
Digital Signature Algorithm ◽  
Hoc Networks

Abstract Performance and protection are the main important factors of Wireless Ad-hoc Network. Network protection includes the protection, stability and parameters of WANET. This helps to avoid significant service disruptions and increases network productivity by making the network more efficient. Since wireless ad hoc networks lack concentrate network management, these methods are vulnerable to data attack. In selected intruder finding tests, the neighboring locations are not trusted to send messages below. It is important to expose the invalid node, which pulls the capture mode and separates it from the network by pushing its routing mechanism. In this paper, we introduce the Resistant Drop Attack (RDA) method to provide effective protection against data loss. An RDA network protocol is recommended to detect weak nodes in the network during a fixed-speed attack. The RDA protocol can be embedded with present Wireless Ad-hoc Network routing systems such as AODV and DSR. Using the Digital Signature Algorithm (DSA) improves the reliability of the route by blocking links at high speeds and verifying the nodes.

Study of Ad hoc Networks with Reference to MANET, VANET, FANET

2017 ◽  
Vol 7 (7) ◽  
pp. 390 ◽  
Author(s):  
Bodhy Krishna .S
Keyword(s):  
Ad Hoc Networks ◽  
Ad Hoc Network ◽  
Vehicular Ad Hoc Networks ◽  
Ad Hoc ◽  
Mobile Network ◽  
Wireless Ad Hoc Network ◽  
Mobile Ad Hoc ◽  
Autonomous Nodes ◽  
Hoc Networks ◽  
Network Administration

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.

scholarly journals Enhancing Reactive Ad Hoc Routing Protocols with Trust

2022 ◽  
Vol 14 (1) ◽  
pp. 28
Author(s):  
Yelena Trofimova ◽  
Pavel Tvrdík
Keyword(s):  
Wireless Ad Hoc Networks ◽  
Routing Protocols ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Sensor Nodes ◽  
Delivery Ratio ◽  
Ad Hoc Routing ◽  
Trust Mechanism ◽  
Packet Delivery ◽  
Hoc Networks

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.

scholarly journals Fault Tolerant Mechanism for Multimedia Flows in Wireless Ad Hoc Networks Based on Fast Switching Paths

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Juan R. Diaz ◽  
Jaime Lloret ◽  
Jose M. Jimenez ◽  
Sandra Sendra ◽  
Joel J. P. C. Rodrigues
Keyword(s):  
Fault Tolerance ◽  
Wireless Ad Hoc Networks ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Fault Tolerant ◽  
Research Work ◽  
Convergence Time ◽  
Wireless Ad Hoc Network ◽  
Qos Parameters ◽  
Multimedia Transmissions

Multimedia traffic can be forwarded through a wireless ad hoc network using the available resources of the nodes. Several models and protocols have been designed in order to organize and arrange the nodes to improve transmissions along the network. We use a cluster-based framework, called MWAHCA architecture, which optimizes multimedia transmissions over a wireless ad hoc network. It was proposed by us in a previous research work. This architecture is focused on decreasing quality of service (QoS) parameters like latency, jitter, and packet loss, but other network features were not developed, like load balance or fault tolerance. In this paper, we propose a new fault tolerance mechanism, using as a base the MWAHCA architecture, in order to recover any multimedia flow crossing the wireless ad hoc network when there is a node failure. The algorithm can run independently for each multimedia flow. The main objective is to keep the QoS parameters as low as possible. To achieve this goal, the convergence time must be controlled and reduced. This paper provides the designed protocol, the analytical model of the algorithm, and a software application developed to test its performance in a real laboratory.

scholarly journals A Study of Attack on Wireless Ad-Hoc Network

2019 ◽  
pp. 168-174 ◽  
Author(s):  
Pawitar Dulari
Keyword(s):  
Ad Hoc Networks ◽  
Mobile Ad Hoc Networks ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Mobile Ad Hoc Network ◽  
Wireless Ad Hoc Network ◽  
Essential Requirement ◽  
Mobile Ad Hoc ◽  
Hoc Networks ◽  
Random Nature

Security is an essential requirement in wireless ad hoc network. The type of ad hoc networks makes them vulnerable to distinct forms of attack. The random nature of these networks makes invoke of security a challenging issue. The paper shows the main vulnerabilities in the mobile ad hoc networks, which have made it much easier to suffer from attacks. Then it presents the main attack categories that exist in it. Finally presents the current security solutions for the mobile ad hoc network.

Game Theory for Wireless Ad Hoc Networks

2014 ◽  
pp. 130-145
Keyword(s):  
Wireless Networks ◽  
Ad Hoc Networks ◽  
Wireless Ad Hoc Networks ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Wired Networks ◽  
Mode Of Operation ◽  
Ieee 802.11 Wireless Networks ◽  
Hoc Networks ◽  
Network Device

An ad hoc network typically refers to any set of networks where all devices have equal status on a network and are free to associate with any other ad hoc network device in link range. In particular, ad hoc network often refers to a mode of operation of IEEE 802.11 wireless networks. A wireless ad hoc network is a decentralized type of wireless network. The network is ad hoc because it does not rely on a pre-existing infrastructure, such as routers in wired networks or access points in managed (infrastructure) wireless networks. The decentralized nature of wireless ad hoc networks makes them suitable for a variety of applications where central nodes cannot be relied on and may improve the scalability of networks compared to wireless managed networks, though theoretical and practical limits to the overall capacity of such networks have been identified. This chapter explores this.

Performance Analysis of Prevention of AODV-based Mobile AdHoc Networks under Cooperative Wormhole Attacks

2018 ◽  
pp. 114-120
Author(s):  
A. S. Bhandare ◽  
B. S. Patil ◽  
M. A. Khade ◽  
S. D. Patil
Keyword(s):  
Wireless Ad Hoc Networks ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Mobile Ad Hoc Network ◽  
Network Simulator ◽  
Central Administration ◽  
Wormhole Attack ◽  
Hoc Networks ◽  
Set Up ◽  
Mobile Computers

A Wireless ad-hoc network is a temporary network set up by wireless mobile computers (or nodes) moving arbitrary in the places that have no network infrastructure called as Mobile Ad-hoc Network (MANET). As MANET does not have fixed infrastructure and central administration, due to security vulnerabilities of the routing protocols, wireless ad-hoc networks are unprotected to attacks of nodes. Wormhole attack is one of the severe attacks which absorb all data packet instead of sending it to destination. An Enhanced HSAM technique is used in order to compare the different performance parameters with HSAM and the results are monitored with the use of network simulator.

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