During disaster situations, there may be no Internet connectivity or cellular networks. We wanted a way to use the short-range communication capabilities of smartphones to create a network that will pass along emergency messages.

What it does

The app uses WiFi Direct on Android phones to send messages from phone to phone in order to reach a phone that is out of range in situations where there is no internet connection or cellular networks. It first sends the message to a phone with WiFi Direct enabled, which will then forward the message to another phone, creating a path that will bring the message to its intended receiver.

How I built it

We used Android Studio, and used the Android Wifi Direct P2P API. We integrated this with a messaging app interface. We based our code off of an example template found on GitHub. We also experimented with the Google Nearby API, which uses Bluetooth instead of WiFi Direct, integrating sample code from the Google Nearby Documentation.

Challenges I ran into

We spent the bulk of our time doing research, since this is a relatively unexplored concept. We also did not have a lot of experience with networking, so we had to rely heavily on example code from Google and Github. We also did not have enough Android devices.

Accomplishments that I'm proud of

We are proud of the fact that we came up with a feasible concept of creating a network without internet capability. We were able to pass a message from phone to phone with a longer range than Bluetooth alone.

What I learned

We learned about mesh networks, connectivity, APIs, WiFi direct, and Android.

What's next for Safety Net

Make it work for many phones.

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