Radio Propagation Fundamentals*

Bullington, K.

doi:10.1002/j.1538-7305.1957.tb03855.x

Cited by 101 publications

(28 citation statements)

References 20 publications

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“…Predictions of signal decay in the case of irregular terrain at frequencies less than 500 MHz have been made by a number of authors [6][7][8][9][10] in the end of the fifties to the beginning of the sixties. Usually their estimations are fairly involved and aimed at calculating the loss of point-to-point paths.…”

Section: Introductionmentioning

confidence: 99%

Radio Propagation in Rural Residential Areas with Vegetation

Blaunstein¹,

Censor²,

Katz³

et al. 2003

PIER

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Abstract-In this paper we describe radio wave propagation within mixed residential area consisting of vegetation and houses. We assume no specific knowledge of the houses and vegetation location, but only of their statistical parameters. A three-dimensional (3D) stochastic approach, which is based on the statistical description of the terrain features, houses and vegetation, and deterministic description of signal decay is presented. The scattering and diffraction from trees and buildings, as well as the diffused reflection from the rough structures of the obstructions are modeled using the statistical description of an array of non-transparent phase screens randomly distributed on the rough terrain. The model, which accounts for single scattering and diffraction phenomena and a similar model, which accounts for multiple scattering effects without effects of diffraction are compared with measurements carried out in typical rural mixed residential areas with vegetation. The accuracy of the theoretical prediction is analyzed accounting possible variations of the terrain features. The approach presented here is applicable in many cases, where specific topographical information is not available.

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Section: Introductionmentioning

confidence: 99%

Radio Propagation in Rural Residential Areas with Vegetation

Blaunstein¹,

Censor²,

Katz³

et al. 2003

PIER

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“…For terrestrial propagation, this is usually for a communications link between two points over the earth. Thus, a propagation model may include the effects of the atmosphere, the terrain, foliage, man made structures, or other items which affect the propagation of radio waves [64].…”

Section: Radio Propagation Modelsmentioning

confidence: 99%

“…The tables could provide estimates for a wide variety of specific design cases, and were useful above 30 MHz. The work was updated and revised in 1957, with more data for higher frequencies [64].…”

Section: Empirical Modelsmentioning

confidence: 99%

A Technique for Evaluating the Uncertainties in Path Loss Predictions Caused by Sparsely Sampled Terrain Data

Davis¹

2013

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Radio propagation models provide an estimate of the power loss in a communication link caused by the surface of the ground, atmospheric refraction, foliage, and other environmental factors. Many of the models rely on digital topographic databases to provide information about the terrain, and generally the databases are sparsely sampled relative to the electromagnetic wavelengths used for communication systems. This work primarily develops a technique to evaluate the effects of that sparsity on the uncertainty of propagation models.That is accomplished by accurately solving the electromagnetic fields over many randomly rough surfaces which pass through the sparse topographic data points, many possible communication links, all of which fit the underlying data, are represented. The power variation caused by the different surface realizations is that due to the sparse sampling. Additionally, to verify that this solution technique is a good model, experimental propagation measurements were taken, and compared to the computations. The experimental work presented in Chapter 7 required the help of many individuals from VT, NSWC, and NRAO. In addition to Ben and Dr. Brown, Wes Sizemore at NRAO, and Bruce Naley, Punk Chilton and Natasha Lagoudous from NSWC all put in lots of work during the weeks conducting the experiment. Bruce was invaluable for climbing 100 feet up the water tower, with the antenna and spectrum analyzer, to take measurements. Additionally, equipment was provided by NSWC, and many at NRAO provided help in experiment planning, regulatory approval, and scrounging for parts, and fixing broken equipment.iii

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“…The scheduling packet transmissions technique is the First in First out (FIFO) type. The propagation model used is the two-ray ground model [27].…”

Section: Simulation Environmentmentioning

confidence: 99%

Incidences of the improvement of the interactions between MAC and routing protocols on MANET performance

Hamrioui

Daoui²,

Chamek

et al. 2012

Journal of Advanced Computer Science &Amp; Technology

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In this paper, we present an improvement for the interactions between MAC and routing protocols to better energy consumption in MANET (Mobile Ad hoc Networks) and show its incidences on the performance of the network. We propose a new approach called IMR-EE (Improvement of the Interactions between MAC and Routing protocol for Energy Efficient) which exploits tow communication environment parameters. The first one is the number of nodes; our approach reduces the additional energy used to transmit the lost data by making the size of the backoff interval of MAC protocol adaptable to the nodes number in the network. The second parameter is the mobility of nodes; IMR-EE uses also the mobility of nodes to calculate a fairness threshold in order to guarantee the same level of the residual energy for each node in the network. We evaluate our IMR-EE solution with NS (Networks Simulator) and study its incidences on data lost and energy consumption in the network under varied network conditions such as load and mobility. The results showed that IMR-EE outperform MAC standard and allows significant energy saving and an increase in average lifetime of a mobiles nodes in the network.

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Radio Propagation Fundamentals*

Cited by 101 publications

References 20 publications

Radio Propagation in Rural Residential Areas with Vegetation

Radio Propagation in Rural Residential Areas with Vegetation

A Technique for Evaluating the Uncertainties in Path Loss Predictions Caused by Sparsely Sampled Terrain Data

Incidences of the improvement of the interactions between MAC and routing protocols on MANET performance

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