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In Battery-Free Wireless Sensor Network (BF-WSN), nodes are powered by the energy harvested from ambience instead of batteries. The nodes may frequently suffer from insufficient energy so that they need to alternate normal operation (such as transmitting/receiving, etc.) with harvesting energy. This brings in extra packet delay for the nodes to deliver data to the sink(s). Therefore, delivering data...
Topology control is one of the key technologies in ad hoc network. Recently some topology control algorithms focus on reducing the end-to-end delay have been proposed. However, they do not consider the delay which is caused by contending for the shared channel and collision at MAC layer. In this paper, we put forward a new delay model to character the link delay which is composed by the transmission...
A Mobile Ad-hoc networks (MANETs) is composed of Mobile Nodes without any fixed infrastructure. Multicast routing in mobile Ad-hoc networks (MANETs) have many defiance due to implicit characteristics of the network such as node mobility, reliability, finite network resources etc. So, in this paper we have introduced a new scheme to improve the performance and efficiency of multicast routing protocols...
Usage of wireless networks is rising in popularity. In this setting different kinds of networks for indoor environments, such as Ad-Hoc, IEEE 802.11b (Wi-Fi) and Wireless Distribution System (WDS) has been developed. In this paper, an analysis of Quality of Service (QoS) has been made for each network in order to verify the values of bit rate, delay, jitter and packet loss. For performance comparison...
Industrial application of wireless sensor networks require timelines in exchanging messages among nodes. IEEE 802.15.4 is a standard to address the need for low-rate low-power low-cost wireless networking. In wired connection, the components such as actuators or sensors provides high performance besides wired links consist of many mechanical problems. Hence to achieve low latency, high performance...
Tremendous research effort has been made to reduce the idle time on the wireless medium of mobile adhoc network. Tradeoff among idle channel, collision and throughput was always a challenge. Hidden terminal problem creates collisions. On the other hand exposed terminal problem makes channel unnecessarily idle. Standard virtual carrier mechanism and many other alternative proposals for solving these...
In this paper, an improved AODV - PWAODV (Piggyback and Weighted neighbor stability Ad hoc On-demand Distance Vector routing) protocol with lower route cost and smaller delay is presented. In the algorithm we introduce a piggyback mechanism and weighted neighbor stability algorithm. Essentially, the route cost can be reduced greatly by the use of piggyback mechanism and the link stability algorithm...
Supporting QoS for safety-critical applications for intelligent transportation systems accentuates the analytical modeling of delays in vehicular networks. Such analysis is, however, challenging due to the dynamics of such a network. We make progress by deriving lower- and upper-bounds for information dissemination delays in multi-hop vehicular networks using two different routing schemes. In particular,...
In delay tolerant network, message delivery can be inspired by biological communication models in realizing encountering and delivering. One way of communications can be through "thrown box" where the messages can be left and collected by different nodes in mimicking pheromone-based communications. In thrown box based model, the box is viewed as message relay and the delivery rate is enhanced...
End-to-end delay is critical for the real-time safety message delivery in Vehicular Ad Hoc Networks (VANETs). In this paper, we present an analytical model to evaluate the impact of transmission range on the end-to-end delay in 802.11p-based VANETs. Compared with the previous works, our model derives a concise expression of the transmission delay in saturated networks, and obtains the service rate...
The paper presents the Vehicular Ad hoc Networks and the typical routing protocol: the ad hoc on-demand routing protocol (AODV) in mobile ad hoc networks and the optimized protocol AODV_OBD for protocol AODV; also presents a practical mobility model that enable the simulation experiment more veritable. Then it use network simulation tool(ns2) to simulate the two routing protocols in ad hoc networks...
The classical sequential change detection problem [1] aims at detecting a change in the state of a system from the normal state to the abnormal state at a random time T. The state of the system can not be observed directly and is observed only partially through the noisy observations Xk which are obtained at discrete time instants k = 1, 2, 3, ... . Given the state of the system, Xks are conditionally...
Contention-based forwarding (CBF) has proven to achieve a good performance in routing in mobile and vehicular ad hoc networks. CBF's main advantage is that it does not require the knowledge about the local neighborhood, eliminating, therefore, the periodic beacon exchange that causes degradation in the network performance, especially when the density of the neighborhood is high. On the other hand,...
This paper investigates the performance of Multihop connectivity for inter-vehicle communication (IVC) systems in Vehicular Ad Hoc NETwork (VANET). The hop path between two or more vehicles is dedicated when a broadcast signaling for initiation connectivity is successfully guaranteed. In addition, the performance of vehicular connectivity is not only based on maximum transmission range, but also based...
The performance evaluation of wireless networks for industrial applications represents a relevant issue for the scientific community. One of the most important aspects of these activities is concerned with the validation of the theoretical models derived from accurate analysis of the protocols employed by the networks. In this paper we focus on a typical industrial application of the IEEE 802.11 wireless...
Coding has traditionally been used at the physical layer in communication networks to prevent and correct errors and erasures incurred in transmission of data. In the past decade, other benefits of coding have been demonstrated, in particular in environments with unpredictable dynamics and limited resources. In this paper, we are concerned with using coding to reduce delay in communications environments...
The design of a routing protocol for the provision of quality of service (QoS) in a mobile ad hoc network is a challenging task. In this paper, we propose a QoS routing protocol based on path durability and end-to-end delays. Our protocol tries to identify multiple node-disjoint paths between a given source and a destination. The path selection mechanism employed in our protocol selects paths that...
Delay-Tolerant/Disruption-Tolerant Networks (DTNs) have been proposed to cope with the challenges of communication in some extreme or special environments. Due to the uncertainty of node mobility, application traffic demand and other factors, it is difficult to provide performance guarantee for a DTN where all nodes may move arbitrarily. With controlled mobility, message ferries can be utilized to...
We analyze the multihop delay of ad hoc cognitive radio networks, where the transmission delay of each hop consists of the propagation delay and the waiting time for the availability of the communication channel (i.e., the occurrence of a spectrum opportunity at that hop). Using theories and techniques from continuum percolation and ergodicity, we establish the scaling law of the minimum multihop...
We propose a simple scheme for detecting selfish behavior achieved by manipulating the 802.11 Medium Access Control (MAC) protocol. Specifically, attacks that exploit the Distributed Coordination Function (DCF) parameters and data rate adaption scheme to maximize individual throughput pose a denial of service threat against protocol abiding nodes. We detect this malicious behavior by employing a combination...
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