Multipath Research Papers - Academia.edu (original) (raw)

Deterministic channel models have been widely used in simulation and modeling of ad hoc network for a long time. But, deterministic channel models are too simple to represent a real-world ad hoc network scenario. Recently, random channel... more

Deterministic channel models have been widely used in simulation and modeling of ad hoc network for a long time. But, deterministic channel models are too simple to represent a real-world ad hoc network scenario. Recently, random channel models have drawn considerable attention of the researchers in this field. The results presented in the literature show that random channel models have a grave impact on the performance of an ad hoc network. A comprehensive investigation on this issue is yet to be available in the literature. In this investigation, we consider both deterministic and random channel models to investigate their effects on ad hoc networks. We consider two different types of routing protocols namely single path and multipath routing protocols. We choose Destination Sequence Distance Vector (DSDV), Dynamic Source Routing Protocol (DSR), and Ad-hoc On-Demand Distance Vector (AODV) as the single path routing protocols. On the other hand, we choose Ad-hoc On-Demand Multiple Path Distance Vector (AOMDV) as the multipath routing protocol. The results show that some single path routing protocol can outperform multipath routing protocol under both deterministic and random channel conditions. These results surprisingly contradict the popular claim that multipath routing protocol always outperforms single path routing protocol. A guideline for choosing an appropriate routing protocol for adhoc network has also been provided in this work.

AbstrAct: This article introduces a numeric model, developed in a MaTlab environment, in order to monitor NaVSTaR GPS performances concerning accuracy effects and interference phenomenon. The model will be presented as a starting point... more

AbstrAct: This article introduces a numeric model, developed in a MaTlab environment, in order to monitor NaVSTaR GPS performances concerning accuracy effects and interference phenomenon. The model will be presented as a starting point for a future production of an open-source software, shareable and enlargeable, which will be able to provide real-time information about navigation satellite system performance. a sequence of analysis and comparisons with existing owners of the software will be possible using real data acquired with a high-performance monitoring station, in order to validate numeric models compiled.

The 1999 AUVFest was held near Gulfport, Mississippi in a shallow-water area with depths between 3 and 8 meters. The acoustic channel was characterized by multipath spanning up to 20 msec and high noise levels from snapping shrimp.... more

The 1999 AUVFest was held near Gulfport, Mississippi in a shallow-water area with depths between 3 and 8 meters. The acoustic channel was characterized by multipath spanning up to 20 msec and high noise levels from snapping shrimp. Acoustic communication testing was performed with the REMUS AUV transmitting both known test data and realtime status information. In addition, a series of ship-to-ship tests were performed in order to characterize stationary performance at ranges of one to five kilometers. Data rates of 60-5000 bits per second were transmitted and, despite the very shallow water conditions, the communication link was reliable at ranges up to 5 km at all data rates

Orthogonal Wavelet Division Multiplexing (OWDM) has been considered as an alternative of Orthogonal Frequency Division Multiplexing (OFDM) in the recent years. OWDM has lower computational complexity and higher flexibility compared to its... more

Orthogonal Wavelet Division Multiplexing (OWDM) has been considered as an alternative of Orthogonal Frequency Division Multiplexing (OFDM) in the recent years. OWDM has lower computational complexity and higher flexibility compared to its OFDM counterpart. The core component of OWDM is wavelet. Wavelet has been a much investigated and applied topic in digital image processing for a long time. Recently, it has drawn considerable attention of the researchers working in communication field. In this work we investigate the performances of OWDM under different channel conditions. We consider three channel conditions namely Additive White Gaussian Noise (AWGN), Rayleigh, Ricean, and frequency selective. We consider a number of wavelets namely Haar, Daubechies, Biorthogonal, Reverse Biorthogonal, Coiflets, and Symlets in OWDM design. For system model we choose Digital Video Broadcasting-Terrestrial (DVB-T). Originally DVB-T system was designed based on OFDM. In this work we use OWDM instead. The simulation results show OWDM outperforms OFDM in terms of bit error rate (BER), noise resiliency, and peak-to-average ration. The results also show that the Haar wavelet based OWDM outperforms other wavelets based OWDM system under all three considered three channel conditions.

We propose in this paper a connectivity - aware routing algorithm and a set of related theorems. This algorithm allows nodes in Mobile Adhoc and Sensor Networks (MASNets) to provide the highest connectivity life time to a specific... more

We propose in this paper a connectivity
-
aware routing algorithm and a set of related theorems. This
algorithm allows nodes in Mobile Adhoc and Sensor Networks (MASNets) to provide the highest
connectivity life time to a specific destination since the issuance of data becomes a necessity for MAS
Nets.
In the proposed Solution, nodes in MASNets are able to specify the disjointness degree of the available
paths allowing the discovery of the optimal set of backup routes and consequently enhance the survivability
of the connectivity. These nodes perfo
rm an on
-
demand discovery and a generation of a set of routes, by
specifying a disjointness threshold, representing the maximal number of nodes shared between any two
paths in the set of k established paths. The proposed multipath routing algorithm, is ada
ptive, secure, and
uses labels to carry the disjointness
-
threshold between nodes during the route discovery. A set of security
mechanisms, based on the Watchdog and the digital signature concepts, is used to protect t
he route
discovery process
.

Wireless Sensor Networks (WSNs)have sensor nodes that sense and extract information from surrounding environment, processing information locally then transmit it to sink wirelessly. Multimedia data is larger in volume than scalar data,... more

Wireless Sensor Networks (WSNs)have sensor nodes that sense and extract information from surrounding environment, processing information locally then transmit it to sink wirelessly. Multimedia data is larger in volume than scalar data, thus transmitting multimedia data via Wireless Multimedia Sensor Networks (WMSNs) requires stick constraints on quality of services in terms of energy, throughput and end to end delay.Multipath routing is to discover multipath during route discovery from source to sink. Discover multipath and sending data via these different paths improve the bandwidth and decrease the end to end delay. This paper introduces an Energy Location Aware Routing Protocol (ELARP) which is reactive multipath routing protocol establishing three paths with awareness of node’s residual energy and distance. ELARP has experimented with NS2 simulator. The simulation results show that ELARP enhances QoS for multimedia data in terms of end to end delay and packet delivery ratio.

In this paper the study has been carried out for finding the position of a mobile subscriber from a network independent brokers' point of view. As each mobile device monitors signal strength, this helps in assisting the network to... more

In this paper the study has been carried out for finding the position of a mobile subscriber from a network independent brokers' point of view. As each mobile device monitors signal strength, this helps in assisting the network to take timely handoff decisions. These signal ...

A flooding attack in wireless sensor networks is a type of threat that shortens the lifetimes of the sensor networks. Although flooding attack prevention techniques have been proposed, if a continuous flooding attack occurs, the sensor... more

A flooding attack in wireless sensor networks is a type of threat that shortens the lifetimes of the sensor networks. Although flooding attack prevention techniques have been proposed, if a continuous flooding attack occurs, the sensor node energy is depleted during detection. In this paper, we use multi-path routing to solve this problem. In order to balance the load of the sensor node, energy balancing of the sensor node is controlled by determining the number of pathways using fuzzy logic. By adjusting the energy balancing of the sensor nodes, the number of energy-exhausting sensor nodes can be reduced. As a result, when a flooding attack occurs, the energy efficiency of the sensor node is increased by determining the number of pathways.

Oblique incidence performance of a novel two-layer absorb/transmit frequency selective surface (FSS) is investigated. The FSS has good frequency stability for both horizontally and vertically polarized waves incident normally or at... more

Oblique incidence performance of a novel two-layer absorb/transmit frequency selective surface (FSS) is investigated. The FSS has good frequency stability for both horizontally and vertically polarized waves incident normally or at oblique angles. Due to its transmission for 900/1800/1900 MHz mobile bands and good absorption for 5 GHz waves, it has the potential as a security wall or isolator for