Correct typos

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Loic Guegan 2019-05-25 15:34:00 +02:00
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In a first place, we start by studying the impact of the sensors position on their energy
consumption. To this end, we run several simulations in ns-3 with different sensors position. The
results provided by Figure \ref{fig:sensorsPos} show that sensors position have a very low impact
on the energy consumption and on the application delay. It has an impact of course but it is very
on the energy consumption and on the application delay. It has an impact of course, but it is very
limited. This due to the fact that in such a scenario with very small number of communications
spread over the time, sensors don't have to contend for accessing to the Wifi channel.
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Previous work \cite{li_end--end_2018} on similar scenario shows that increasing application
accuracy impact strongly the energy consumption in the context of data stream analysis. However,
in how case, application accuracy is driven by the sensing frequency and thus the transmit
frequency of the sensors. In this way, we vary the transmission frequency of the sensors from 1s
to 60s. Figure \ref{fig:frequency} present the effects of the sensors transmission frequency on
in our case, application accuracy is driven by the sensing interval and thus, the transmit
frequency of the sensors. Therefore, we varied the transmission interval of the sensors from 1s
to 60s. Figure \ref{fig:frequency} present the effects of the sensors transmission interval on
the IoT/Network part energy consumption. In case of small and sporadic network traffic, these
results show that with a reasonable transmission frequency the energy consumption of the
IoT/Network if almost not affected by the variation of this frequency.
results show that with a reasonable transmission interval the energy consumption of the
IoT/Network if almost not affected by the variation of this transmission interval. In fact,
transmitted data are not large enough to leverage the energy consumed by the network.
#+BEGIN_EXPORT latex
\begin{figure}
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#+END_EXPORT
The number of sensors is the dominant factor that leverage the energy consumption of the
The number of sensors is a dominant factor that leverage the energy consumption of the
IoT/Network part. Therefore, we varied the number of sensors in the Wifi cell to analyze its
impact. The figure \ref{fig:sensorsNumber} represents the energy consumption of each simulated
part. It is clear that the energy consume by the network is the dominant part. However, since the
number of sensors is increasing the energy consume by the network will become negligible face to
the energy consume by the sensors. In fact, deploying new sensors in the cell do not introduce
much network load. To this end, sensors energy consumption is dominant.
impact. The Figure \ref{fig:sensorsNumber} represents the energy consumed by each simulated part
according the the number of sensors. It is clear that the energy consumed by the network is the
dominant part. However, since the number of sensors is increasing the energy consumed by the
network will become negligible face to the energy consume by the sensors. In fact, deploying new
sensors in the cell do not introduce much network load. To this end, sensors energy consumption
is dominant.
#+BEGIN_EXPORT latex
\begin{figure}
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In a first place, we analyze the impact of the VM allocated memory on the server energy
consumption. Figure \ref{fig:vmSize} depict the server energy consumption according to the VM
allocated memory for 20 sensors sending data every 10s. Note that red horizontal line represent
the average energy consumption for sample of energy value. We can see that at each sensing
interval, server face to peaks of energy consumption. However, VM allocated memory do not
influence energy consumption. In fact, simple database requests do not need any particular huge
memory access. Thus, remaining experiments are based on VM allocated memory of 1024MB.
allocated memory for 20 sensors sending data every 10s. Note that horizontal red line represent
the average energy consumption for the considered sample of energy values. We can see that at
each sensing interval, server face to peaks of energy consumption. However, VM allocated memory
do not influence energy consumption. In fact, simple database requests do not need any particular
huge memory access and processing time. Thus, remaining experiments are based on VM with 1024MB
of allocated memory.
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\begin{figure}
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\end{figure}
#+END_EXPORT
Next, we study the effects of increasing the number of sensors on the server energy consumption.
Figure \ref{fig:sensorsNumber-server} present the results of the average server energy
consumption when varying the number of sensors from 20 to 500 while Figure
\ref{fig:sensorsNumber-WPS} present the average server energy cost per sensors according to the
number of sensors. These shows a clear linear relation between the number of sensors and the
server energy consumption. Moreover, we can see that the more sensors we have per server, the
number of sensors. These results show a clear linear relation between the number of sensors and
the server energy consumption. Moreover, we can see that the more sensors we have per server, the
more energy we can save. In fact, since the idle server energy consumption is high, it is more
energy efficient to maximize the number of sensors per server. As showed on Figure
\ref{fig:sensorsNumber-WPS}, a significant amount of energy can be save when passing from 20
sensors to 300 per server.
energy efficient to maximize the number of sensors per server. As shown on Figure
\ref{fig:sensorsNumber-WPS}, a significant amount of energy can be save when passing from 20 to
300 sensors per server.
#+BEGIN_EXPORT latex
\begin{figure}
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\end{figure}
#+END_EXPORT
A last parameter can leverage server energy consumption namely sensors send frequency. In
addition to increasing the application accuracy, sensors send frequency increase network traffic
and database accesses. Figure \ref{fig:sensorsFrequency} present the impact on the server energy
A last parameter can leverage server energy consumption namely sensors send interval. In addition
to increasing the application accuracy, sensors send interval increase network traffic and
database accesses. Figure \ref{fig:sensorsFrequency} present the impact on the server energy
consumption of changing the send interval of 50 sensors to 1s, 10s and 30s. We can see that, the
more sensors send interval is low, the more server energy consumption peaks occurs. Therefore, it
leads to an increasing in the server energy consumption.
lower sensors send interval is, the more server energy consumption peaks occurs. Therefore, it
leads to an increase of the server energy consumption.
#+BEGIN_EXPORT latex
\begin{figure}
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** End-To-End Consumption
To have an overview of the energy consume by the system, it is important to consider the
end-to-end energy consumption. The Figure \ref{fig:end-to-end} represent the end-to-end system
end-to-end energy consumption. The Figure \ref{fig:end-to-end} represents the end-to-end system
energy consumption while varying the number of sensors. It is important to see that, for
small-scale systems, the server energy consumption is dominant face to the energy consumed by the
sensors. However, since we are using a single server, large-scale sensors deployment lead to an
increasing consumption of energy in the sensors side. On the other side, network energy
consumption is stable regarding to the number of sensors that are deployed since network the
system use case do not required large data transfer. Thus, it is important to remember that, to
save energy, we should maximize the number of sensors handle by each cloud server while keeping a
reasonable sensors requests intervals.
increasing consumption of energy in the IoT part. On the other side, network energy consumption
is stable regarding to the number of sensors since the system use case do not required large data
transfert. Thus, it is important to remember that, to save energy, we should maximize the number
of sensors handle by each cloud server while keeping reasonable sensors request intervals.
#+BEGIN_EXPORT latex
\begin{figure}

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