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A decentralized, offline-first mobile app that allows communication without internet or cellular service. It creates a mesh network using Bluetooth Low Energy (BLE) and Wi-Fi Direct to hop messages between devices during disasters.
Client
NGO & Government (B2G)
Role
Mobile Team Lead
Duration
8 Months
EchoMesh is a decentralized, offline-first mobile app that allows communication without internet or cellular service. It creates a mesh network using Bluetooth Low Energy (BLE) and Wi-Fi Direct to 'hop' encrypted messages between devices during disasters like hurricanes or earthquakes.
Smartphones are designed to connect to towers, not each other. Building a reliable mesh network on consumer Android/iOS phones is fighting against the OS's desire to sleep the radio to save battery. We needed a protocol that could route messages through 10+ devices without a central map.
We implemented a custom 'Flooding with Deduplication' protocol (inspired by AODV) on top of the Bluetooth GATT layer. We also designed an intelligent duty-cycling system that sleeps the radio 90% of the time but wakes up in sync with neighbors.
Zero Infrastructure: Works in the middle of a desert or a blackout
Multi-Hop Routing: Messages hop from phone to phone to reach distant targets
SOS Broadcast: One-tap emergency beacon propagated with high priority
Geotagged Digital Drops: Leave virtual messages at a GPS location for rescuers
Max distance achieved via hopping
During the outage period
On standard emergency mode
"When the towers went down, EchoMesh was the only thing that worked. I found my brother because someone relayed his GPS signal to me. It literally saved lives."
