In earthquakes, floods, or large-scale infrastructure failures, base stations become inoperable or overloaded can disrupt communication at critical moments. Developed by 17-year-old high school student Emirhan Duman, Crisis Connect stands out as an offline-first disaster communication application that activates in scenarios where mobile networks collapse. Establishing a direct connection between devices via Bluetooth without requiring internet, cellular data, or a SIM card, the application is available for free on Android and iOS platforms.

Device-to-Device Communication Without Internet and SIM Card

Crisis Connect eliminates dependence on telecommunication operators and central servers as its basic operating principle. Thanks to its proximity mode, the application detects compatible smartphones in the vicinity via Bluetooth signals and directly creates a peer-to-peer network. Through this infrastructure, users can transmit vital text messages, voice notes, real-time location information, and emergency assistance (SOS) signals to their immediate surroundings in emergency situations.

Although the system adopts an “offline-first” architecture, it offers a hybrid structure. During normal times when network or internet access is available, it operates internet-based standard messaging protocols; When contact is completely lost, it automatically switches to the local Bluetooth network, creating a seamless connection layer.

Crisis Connect Basic Capabilities and Operating Parameters

• Connection Type: Bluetooth Low Energy (BLE) and direct device pairing.
• Infrastructure Requirement: Zero; The base station does not require a Wi-Fi network or SIM card.
• Shared Data: SOS invitation, GPS coordinates, short text messages, and voice recordings.
• Source Model: Open source on GitHub with the goal of transparency and auditability.

Open Source Solution Born from the February 6th Earthquakes

The significant communication disruptions experienced during the February 6, 2023 Kahramanmaraş earthquakes played a decisive role in the emergence of the project. Focusing on the adaptation problems experienced in the first hours of the disaster, the developer aimed to design a complementary digital tool that would intervene in the critical window where central infrastructures could not respond. After approximately one year of development, the application, published, quickly surpassed the 10,000 mark on Google Play, successfully reaching a wide user base.

Developer Emirhan Duman describes the scope and purpose of the project with these words:

“My aim is not to replace portable operators or professional radio systems. Crisis Connect is designed as a complementary layer that allows people nearby to maintain basic communication with their phones when the main infrastructure fails.”

Boundaries, Transparency and Global Recognition

Highlighting the importance of reliable information during disasters, the project also clearly reveals the technical limitations of Bluetooth-based technologies. Communication range varies depending on the physical structure of buildings, wall thicknesses, electromagnetic interference, and device hardware. Therefore, the system is positioned not as an alternative to satellite communication, professional radio networks, or official search and rescue channels, but as a local support channel that facilitates individuals reaching each other.

Crisis Connect’s disaster-focused offline communication model is attracting attention internationally. The project’s architecture was evaluated in a technical article published on PreventionWeb, the United Nations Office for Disaster Risk Reduction (UNDRR) information sharing platform. The study emphasizes that organizing these networks in community-based areas such as schools, apartment buildings, and neighborhoods before a disaster will significantly increase their effectiveness during a crisis.