Sensing the World Around You

Android Phone Activities

Since the existence of Wi-Fi people have been able to move from room to room within their homes all while connected to the internet. It is also possible to go to a coffee shop and enjoy a latte or cappuccino while using the shop’s Wi-Fi to scroll through the news. Yes, Wi-Fi has become an important part of our society. While it allows us to keep up with the news and our friends it also uses a lot of valuable spectrum. This activity will help you understand just how many Wi-Fi users there are in an area.

Wi-Fi Information

You probably use Wi-Fi every day but do you know how it works? Whenever you have wi-fi you have a router and a modem although they may be combined in one device. A modem is a device that connects your home or business to your internet service provider (ISP). The modem serves as a translator of sorts changing the information from your computer into a form that can be transmitted with the equipment your ISP uses. The router is connected to the modem. A router is a device that sends information to your laptop and other devices and receives information from those devices. This sharing of information is done with radio waves. You can learn more about the electromagnetic spectrum and radio waves by clicking the button below. Wi-Fi routers are able to transmit and receive information at two frequencies, 2.4 GHz and 5 GHz. Each of those frequencies is broken down into several channels. By having several channels, it is possible to have a lot of Wi-Fi accounts in an area without a lot of interference.

Background Information

Image courtesy of Peggy_Marco on Pixabay

Figure 1: Wireless Systems

Activity Instructions

1. Go to the Play Store or another app provider and download the free app, WiFi Analyzer. Look for this icon to be sure you are downloading the correct app.

app icon

Figure 2: App Logo

2. When you open the app. it will ask for permission to access your location. Please choose the option that makes you the most comfortable.

3. At this point a brief tour of the app seems appropriate. Please reference Figure 3 while reading this description.

  • Along the bottom (or x-axis) is a listing of the channels. The vertical (or y-axis) denotes the strength of the signal.
  • Along the top, there are two menu bars. The descriptions below pertain to the top bar starting on the left and moving to the right.
  • The words "Channel Graph" denotes the setting that is selected. Please note that the setting cannot be changed from this menu bar.
  • 2.4, 5, and 6 are the frequency choices all of which have units of GHz. Your selection will be colored blue. Many devices are unable to pick up signals at 6 GHz.
  • The pause button just to the right of the number 6 will cause your device to stop collecting data. Just press the play button (which will appear in the same spot) to restart.
  • The last useful feature on this row is found by clicking on the three dots at the end. The menu that opens contains a link for the user guide.
  • The descriptions below pertain to the bottom menu bar moving from right to left.
  • The first two items in this menu are selection indicators. Click on the bar graph to select the channel graph feature or on the line graph to select the time feature. Your selection will be underlined.
  • The set of three stars is the icon for the Best Channels Feature. This can help you select the channel for a new device.
  • The remaining items on that menu are of no interest for this project.
A graph that shows the signal from routers in the area. Each signal is represented by a colored bar with a rounded end.

Figure 3: Channel Graph Screen

4. Now that you are familiar with the app, let’s explore the spectrum usage around you. As mentioned on the main page the spectrum is getting crowded. That fact can be seen with this app as you realize how many sources of Wi-Fi there are in your area. When you are in your home turn on the app and go to the Channel graph. How many of the Wi-Fi sources are using each channel? Now repeat this investigation in other places such as a friend or family member’s home or a business district. Have fun, explore your surroundings, and be sure to share your findings with us. However, be careful while using this app. DO NOT DRIVE OR WALK while looking at the app.

5. Be sure to upload your data when you are finished using the app. No identifying information, beyond a zip code, is required. We just want to get an idea of how many people are using the spectrum. You are welcome to upload your data as frequently as once per hour. This information will be used to populate the Leader Board on the first day of each month.

Upload Data
Leader Board
Going Further

This is a citizen science project. Citizens are responsible for collecting the data, but they are also responsible for determining how the project expands. This project uses an app for Android cell phones to receive radio frequencies. The activity guide contains a couple of ways to use this app, but there are many more. If you enjoy using the app, explore what else you can do with it. If you find an activity that you enjoy and fits the parameters of this project, please fill out the form below. Your activity may be in the next edition of the activity guide.

Suggest an activity by clicking on the button below:

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