On the impact of propagation models on TV white spaces measurements in Africa

Author(s):  
Hope Mauwa ◽  
Antoine B. Bagula ◽  
Marco Zennaro ◽  
Guy-Alain Lusilao-Zodi
2015 ◽  
Vol 4 (4) ◽  
pp. 401-404
Author(s):  
Edward C. Y. Peh ◽  
Ser Wah Oh ◽  
Yugang Ma ◽  
Ming-Hung Tao ◽  
Yiyang Pei

2021 ◽  
Author(s):  
Altaf Hussain ◽  
Muhammad Rafiq Khan

Abstract Mobile Ad-hoc Network (MANET) is the most emerging and fast expanding technology since the last two decades. One of the major issue and challenging area in MANET is the process of routing due to dynamic topologies and high mobility of mobile nodes. The exchange of information from source to a destination is known as the process of routing. Spectacular amount of attention has been paid by researchers to reliable routing in ad-hoc networks. Efficiency and accuracy of a protocol depends on many parameters in these networks. In addition to other parameters node velocity and propagation models are among them. Calculating signal strength at receiver is the responsibility of a propagation model while mobility of nodes is responsible for topology of the network. A huge amount of loss in performance is occurred due to variation of signal strength at receiver and obstacles between transmissions. Simulation tools are developed to analyze the weakness and strength of protocols along with different parameters that may impact the performance. The choice of a propagation models have an abundant effect on performance on routing protocols in MANET. In this research, it has been analyzed to check the impact of different propagation models on the performance of Optimized Link State Routing (OLSR) in Sparse and Dense scenarios in MANET. The simulation has been carried out in NS-2 by using performance metrics as average Throughput, average packet drop and average latency. The results predicted that propagation models and mobility has a strong impact on the performance of OLSR in considered scenarios.


2011 ◽  
pp. 113-132 ◽  
Author(s):  
Heikki Kokkinen ◽  
Jukka Henriksson ◽  
Risto Wichman
Keyword(s):  

2011 ◽  
pp. 209-238 ◽  
Author(s):  
Przemysław Pawełczak ◽  
Jihoon Park ◽  
Danijela Čabrić ◽  
Pål Grønsund

2007 ◽  
Vol 5 ◽  
pp. 367-372 ◽  
Author(s):  
M. Neuland ◽  
T. Kürner

Abstract. Propagation models are very important for the development and deployment of wireless communication networks. They are able to predict the path loss for different propagation conditions, but cannot include all propagation phenomena in detail. This fact leads to variations between predicted and measured field strengths. These variations can be reduced by calibrating some parameters of the propagation models with the help of exact measurement data. However, two problems occur when applying measurement data. On the one hand, the maps used for the prediction have only a limited resolution. On the other hand, the GPS data are erroneous due to the limited GPS accuracy and due to sampling errors. These errors can lead to variations up to 200 m between the measured positions and the possible positions on the road network. Therefore, a map-matching algorithm has to be applied which projects the wrong GPS positions automatically onto the street vectors used for the predictions. Thus, a good basis of data for calibration can be created.


Author(s):  
Albert A. Lysko ◽  
Moshe T. Masonta ◽  
Mofolo R.O Mofolo ◽  
Luzango Mfupe ◽  
Litsietsi Montsi ◽  
...  

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