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.
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.
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.
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 2 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. Looking at the top bar on the left side you see the words “Channel Graph” that is just telling us what setting is selected. Next, you see 2.4 GHz which is blue. That is the frequency the app is currently scanning. Next to it you see the option to select a different frequency, either 5 or 6 GHz. While 5GHz should work for everyone 6 GHz will not be available to a lot of users. Continuing to move to the right you next see a pause symbol. If you touch that the scanning will pause or not update. The only other thing in that menu bar which you will use is the stacked three dots at the end. If you click on that you will find the user guide. Now, on to the second menu bar. On the far left you see a graph symbol which is underlined in yellow. That tells us the channel graph feature is selected. Moving to the right you see a symbol that looks like a couple of lines. This is the icon for the time graph. This display shows you how the signal changes over time. If you sit in one place and watch it you can determine if your signal is stable or not. Alternatively, you can monitor how the signal decreases with distance if you walk away from your router with this option selected. Moving to the right along the menu bar the next thing you see is a set of three stars. That icon represents 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 to this project.
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.
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.