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

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.

Author(s):  
Shahin Vakilinia ◽  
Mohammadhossein Alvandi ◽  
Mohammadreza Khalili Shoja ◽  
Iman Vakilinia

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.


Telecom ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 32-47
Author(s):  
Kento Takabayashi ◽  
Shuhei Harada ◽  
Takumi Kobayashi ◽  
Katsumi Sakakibara ◽  
Ryuji Kohno

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.


In our paper, we evaluate the impact of some QoS parameters on multimedia data in IEEE 802.11 wireless networks by deploying an experimental testbed systems. The evaluation results show that Contention Window (CW) value has a great influence on the throughput ratio between multimedia data types.


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

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.


2021 ◽  
Author(s):  
Vinoth kumar P ◽  
Venkatesh K

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.


IEEE Access ◽  
2018 ◽  
Vol 6 ◽  
pp. 36469-36478 ◽  
Author(s):  
Xingwu Song ◽  
Li Zhou ◽  
Haitao Zhao ◽  
Xiping Hu ◽  
Jibo Wei

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.


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