The problem Safesignal solves

During disasters, communication systems such as mobile networks and the internet often fail due to damaged infrastructure, power outages, or network congestion.
As a result,

• Victims are unable to send SOS alerts or share their location
• Rescue teams lack real-time situational awareness
• Coordination between survivors and responders becomes extremely difficult
• Delays in response increase the risk to human life

StillAlive addresses this critical gap by enabling communication even when traditional networks are unavailable.

What Can People Use It For?

StillAlive can be used in multiple real-world scenarios:

Emergency Communication:

• Send SOS alerts instantly to nearby devices
• Notify rescuers and volunteers without relying on the internet

Real-Time Location Sharing:

• Share live location with nearby users
• Helps rescuers locate victims faster and more accurately

Community Coordination:

• Join local disaster chat rooms
• Coordinate evacuation, relief distribution, and rescue efforts

Offline Connectivity:

• Communicate even when mobile data and Wi-Fi are down
• Useful in remote areas, disaster zones, or network outages

Cross-Device Accessibility:

• Works on phones, laptops, and tablets
• No installation required (web-based)

How It Makes Tasks Easier and Safer?

• Faster rescue operations through immediate SOS alerts
• Improved safety by ensuring victims are not isolated without communication
• Decentralized reliability with no single point of failure
• Better coordination through two-way communication
• Accessible to everyone with a simple browser-based interface

Challenges we ran into

1. Establishing Peer-to-Peer Communication

Setting up reliable WebRTC connections between devices was difficult due to NAT traversal and unstable connectivity in disaster-like conditions.

How it was solved:
We implemented a lightweight signaling mechanism and added retry logic to handle failed or dropped connections, improving overall stability.

2. Maintaining Communication Without Internet

Ensuring communication without relying on traditional networks was a major challenge.

How it was solved:
We designed a mesh-based system where devices relay messages to nearby nodes, allowing information to propagate even with limited connectivity.

3. Handling Message Duplication in Mesh Network

Messages being forwarded across multiple devices led to duplication and potential congestion.

How it was solved:
We introduced unique message IDs and deduplication logic so each message is processed only once per device.

4. Cross-Device Compatibility

Ensuring smooth performance across different devices, browsers, and operating systems was challenging.

How it was solved:
We built the application as a Progressive Web App (PWA) and optimized it for responsiveness and compatibility across platforms.