exploring_lora
Differences
This shows you the differences between two versions of the page.
Both sides previous revisionPrevious revisionNext revision | Previous revisionNext revisionBoth sides next revision | ||
exploring_lora [2017/10/10 20:38] – [6.4. Path Loss] samer | exploring_lora [2018/09/27 13:41] – [4.2. Packet Error Rate] samer | ||
---|---|---|---|
Line 8: | Line 8: | ||
* How LoRa is compatible with LPWAN requirements and constraints? | * How LoRa is compatible with LPWAN requirements and constraints? | ||
</ | </ | ||
- | ===== -. Hardware Platform | + | |
+ | ===== -. Setting the Lab ===== | ||
+ | |||
+ | ==== -. Hardware Platform ==== | ||
In order to design and implement experiments with LoRa, you will use the following devices: | In order to design and implement experiments with LoRa, you will use the following devices: | ||
Line 21: | Line 24: | ||
* Give an estimated cost of your platform. | * Give an estimated cost of your platform. | ||
</ | </ | ||
- | ===== -. Software Tools ===== | + | |
+ | ==== -. Software Tools ==== | ||
Download the following software on your PC: | Download the following software on your PC: | ||
- | * RadioHead: The Packet Radio library for embedded microprocessors can be downloaded from [[http:// | + | * RadioHead: The Packet Radio library for embedded microprocessors can be downloaded from [[http:// |
- | * Arduino IDE: Specific OS versions can be downloaded from [[https:// | + | * Arduino IDE: Specific OS versions can be downloaded from [[https:// |
Unzip the RadioHead library and copy it to your sketchbook library folder as detailed in [[https:// | Unzip the RadioHead library and copy it to your sketchbook library folder as detailed in [[https:// | ||
- | ===== -. Installation | + | |
+ | <WRAP center round tip 75%> | ||
+ | Note well the location of the library folder on your computer. In the following, you will be required to modify source files located in this folder. | ||
+ | </ | ||
+ | |||
+ | ==== -. Installation ==== | ||
Start by plugging the Dragino shields on the Arduino devices and mounting the antennas as shown in Fig. 1. | Start by plugging the Dragino shields on the Arduino devices and mounting the antennas as shown in Fig. 1. | ||
Line 41: | Line 50: | ||
For Arduino Mega 2560, additional drivers for Microsoft Windows can be installed from [[http:// | For Arduino Mega 2560, additional drivers for Microsoft Windows can be installed from [[http:// | ||
</ | </ | ||
- | ===== -. Running | + | |
- | Start by setting the central frequency of the LoRa modules. For this, open the '' | + | ===== -. Theoretical Study ===== |
+ | |||
+ | In this section, you will perform a theoretical assessment of the performance of LoRa modulation. You will later compare this theoretical results to the experimental ones as in a typical scientific study. | ||
+ | |||
+ | <WRAP left round help 100%> | ||
+ | * What is the relation between processing gain and spreading factor in LoRa modulation? Explain. | ||
+ | * How does the spreading factor impact the coverage of a LoRa transmitter? | ||
+ | * For each of the three possible configurations of your LoRa module, what is the transmission bit rate? Explain your computation. | ||
+ | * Compute the receiver sensitivity, | ||
+ | * Compare the computed sensitivity to that provided by the {{ : | ||
+ | </ | ||
+ | |||
+ | ===== -. Configuring and Running | ||
+ | |||
+ | ==== -. Modifying the Radio Parameters ==== | ||
+ | |||
+ | Start by setting the central frequency of the LoRa modules. For this, open the '' | ||
+ | |||
+ | ^ | ||
+ | | 1 | ||
+ | | 2 | ||
+ | | | ||
+ | | | ||
+ | | | ||
+ | | | ||
+ | | | ||
+ | | | ||
+ | | | ||
+ | | | ||
+ | | | ||
+ | | | ||
<file cpp RH_RF95.cpp> | <file cpp RH_RF95.cpp> | ||
setFrequency(868.X); | setFrequency(868.X); | ||
</ | </ | ||
- | |||
- | Download the {{ : | ||
- | |||
- | [{{ : | ||
- | [{{ : | ||
- | ===== -. Modifying the Radio Parameters ===== | ||
The typical configuration for LoRa modules consists of 125 kHz sub-channels, | The typical configuration for LoRa modules consists of 125 kHz sub-channels, | ||
Line 64: | Line 97: | ||
setModemConfig(Bw125Cr45Sf128); | setModemConfig(Bw125Cr45Sf128); | ||
</ | </ | ||
+ | ==== -. Running Basic Sketches ==== | ||
- | <WRAP left round help 100%> | + | Download |
- | * What is the relation between processing gain and spreading factor in LoRa modulation? Explain. | + | |
- | * How does the spreading factor impact the coverage of a LoRa transmitter? | + | [{{ :client-iotlab1.png? |
- | * For each of the three possible configurations of your LoRa module, what is the transmission bit rate? Explain your computation. | + | [{{ :server-iotlab1.png? |
- | * Compute | + | |
- | * Compare the computed sensitivity to that provided by the {{ :an1200.22.pdf | + | |
- | </ | + | |
In the remainder of this lab, you will conduct measurements to validate the obtained theoretical receiver sensitivity. | In the remainder of this lab, you will conduct measurements to validate the obtained theoretical receiver sensitivity. | ||
+ | |||
===== -. Performance Evaluation ===== | ===== -. Performance Evaluation ===== | ||
- | In the following, you will design and implement a set of scenarios that enable to evaluate the performance of the LoRa modulation. As you will deal with scientific assessment, you are required to use scientific tools to show the results. You have the choice between [[http:// | + | In the following, you will design and implement a set of scenarios that enable to evaluate the performance of the LoRa modulation. As you will deal with scientific assessment, you are required to use scientific tools to show the results. You have the choice between [[http:// |
- | ==== -. Round Trip Time ==== | + | |
+ | ==== -. Time on Air ==== | ||
- | In this section, you will measure the Round Trip Time of LoRa communication | + | In this section, you will measure the Time on Air (ToA) under the three different radio configurations |
<WRAP center round help 100%> | <WRAP center round help 100%> | ||
- | * Draw a box plot of the RTT under the three different radio configurations. | + | * Draw a box plot of the ToA under the three different radio configurations |
* Analyze the obtained results and compare with the theoretical computations. | * Analyze the obtained results and compare with the theoretical computations. | ||
</ | </ | ||
- | ==== -. Packet | + | ==== -. Packet |
In this section, you will measure the Packet Error Rate (PER) under the three different radio configurations and for different transmission periods. For this, you can start by implementing a function on the client that measures the ratio of successfully delivered packets. | In this section, you will measure the Packet Error Rate (PER) under the three different radio configurations and for different transmission periods. For this, you can start by implementing a function on the client that measures the ratio of successfully delivered packets. | ||
Line 96: | Line 129: | ||
* What type of mathematical models enables to theoretically compute the PER? | * What type of mathematical models enables to theoretically compute the PER? | ||
</ | </ | ||
+ | |||
==== -. Coverage ==== | ==== -. Coverage ==== | ||
Line 120: | Line 154: | ||
* What is the path loss exponent? | * What is the path loss exponent? | ||
* Using regressions, | * Using regressions, | ||
+ | * Compare the obtained sensitivity with the theoretical results computed in the previous section. | ||
</ | </ | ||
In order to compute distances in your experiment, you can get the GPS coordinates as recorded by your smartphone using an application such as [[https:// | In order to compute distances in your experiment, you can get the GPS coordinates as recorded by your smartphone using an application such as [[https:// | ||
+ | ===== -. Coverage Challenge ===== | ||
+ | |||
- | ===== -. Rubrics | + | ===== -. Grading |
| ^ Exemplary | | ^ Exemplary | ||
- | ^ Answer to questions | + | ^ Answer to questions |
- | ^ Design | + | ^ Design experiments |
- | ^ Results and analysis | + | ^ Analyse results |
exploring_lora.txt · Last modified: 2021/10/20 12:52 by samer