Please login first
Power Efficiency analysis in Internet of Things Sensor nodes
, , *
1  Faculty of Electrical Engineering, University of East Sarajevo, East Sarajevo, Bosnia and Herzegovina


Development of new technologies, particularly the Internet and Sensor Networks, creates a completely new paradigm of the Internet utilization, commonly known as “The Internet of Things (IoT)”. Interconnected sensor-based systems are a key enabler in the realization of an IoT vision. Therefore, the IoT can be defined as a worldwide network of “smart things” enabled to interact and communicate to each other, as well as with the environment, empowering better understanding of the “real/physical world” and discovering and extracting information about objects and actions that drive that world. By populating the environment with real-world sensor-based devices, the IoT is opening the door to exciting possibilities for a variety of novel applications. Considering that sensor nodes today can be looked as smart objects, they can produce significant computational power which can be used for manipulating and processing collected information. Therefore, computational power increases cost per unit, and what is more important raises energy consumption which is still a primary limiting factor. Additionally, energy consumption is increased by execution of complex algorithms, and in the process of design and building a smart information system it is crucial to choose the optimal location (sensor nodes or remote processing unit) for implementation and execution of the computational logic. Considering that energy and power efficiency are essential factors in the design and operation of sensor nodes and that there are a number of initiatives and tendencies to improve the power efficiency in variety of areas, analysis of this concept in the sensor nodes is shown as very interesting.

Relying on the fact that the choice of control algorithm and location of the computational logic may strongly influence power efficiency, a prototype sensor node, empowered by using fuzzy logic in decision making process, is built and tested in real case environment scenario. Used fuzzy logic processing algorithm is based on predefined rules and can detect a temperature changes in order to ensure accurate and timely response in the case of fire presence. Comparative analysis of power efficiency has been done, and was carried out for best, worst and average case of timely depended temperature changes. The aim of the experiment is to show which solution is the optimal in the sense of energy consumption – implementation of computational logic on sensor node or on a remote host. Regard to this, transmitted and received power, voltage supply and minimum of required voltage level are essential factors for correct operation. In addition, the valuable factor, primarily for the network supply nodes, is power quality improvement in the energy network of nodes due to the relocation of control logic.

Keywords: Power Efficiency, Internet of Things, sensor node
Comments on this paper
Guillermo Robles
About consumption
Interesting paper, congratulations.

I am very interested in power consumption especially when the power supply comes from energy harvesting. How do you measure the voltage and current of the temperature sensor?

The rasp can be accessed remotely, does Figure 3 include remote access to the node? Is the power consumption so stable under any circumstances?

Is the horizontal axis in the Figures in seconds?
Mirjana Maksimovic
The horizontal axis in the Figures is in seconds. The sampling time on the graph is the value of one second. Each of the three cases has the same length of 15 minutes, or 900 seconds.

The measurements of voltage and current of the temperature sensor are performed with Raspberry Pi and controlled with a digital USB multimeter. The precision of the measurements depends of chosen AD converter (± 0.5% in our case).

In the performed experiment, RPi is accessed remotely via LAN, and therefore Fig. 3. includes also a consumption of LAN modules. It has been shown that consumption is stable what can be viewed in three considered cases presented in Fig. 3. But, in the case of communication module change (e.g. WiFi) consumption should be changed. It must be noted that the graph represents the average value of the three signals, and that the maximum and minumum values in discrete increments are excluded from the preview. Overall, the total consumption is stable in time.

Guillermo Robles
Thank you for your kind answer.

I understand that you can measure the voltage of temperature sensor with the Rasp. However, how do you measure the current? Do you use a current sensor or a shunt resistance?

Could you please post the type and model of the digital USB multimeter?

Mirjana Maksimovic
Thank you for your interest!
We used a shant resistance of 10 kOhm. The multimeter type is PeakTech 3315 USB. Feel free to ask additional questions.
Guillermo Robles
Thank you for the information, I didn't know that USB multimeter.