Smart Public Health: BLE-Based Contact Tracing

As modern healthcare systems evolved to face the challenges of COVID-19, Bluetooth Low Energy (BLE) emerged as a powerful tool for non-invasive, privacy-preserving contact tracing. This project introduces a Bracelet Beacon system designed to automate the recording of proximity events, helping to break transmission chains without compromising personal data.

Bluetooth Low Energy (BLE) and RSSI Logic

The solution relies on the unique properties of BLE to monitor proximity between users:

• Simultaneous Scanning & Broadcasting: Each bracelet acts as both a transmitter (broadcaster) and a receiver (scanner). It constantly transmits a unique encrypted ID while listening for the IDs of other bracelets nearby.
• RSSI Proximity Estimation: The Received Signal Strength Indicator (RSSI) is used to estimate the distance between two bracelets. If the signals are consistently strong (high RSSI), the system logs a "close contact" event.
• Encrypted Identity: To protect privacy, the IDs are rotating cryptographic tokens. Only health authorities with the master decryption key can link a specific ID to a person, ensuring that no location or identity data is exposed to the public.

Efficiency and Battery Management

For a wearable device to be effective, it must last for weeks on a single charge. The MOKO W2 Beacon used in this project features advanced power management:

• Movement Judgment: Built-in accelerometers detect when the user is stationary. If the bracelet is not being worn, it automatically enters a deep-sleep mode, disabling scanning and broadcasting to preserve battery.
• Rechargeable Architecture: Integrated USB charging eliminates the environmental waste of disposable coin cells while ensuring high-current delivery for Bluetooth bursts.

Ecosystem Integration: Gateways and Apps

The tracking data is synchronized through a multi-tier IoT architecture:

1. Local Storage: Encounters are stored locally on the bracelet's on-board flash memory.
2. IoT Gateway: When the user enters a "Sync Zone" (like a hospital entrance or home), the bracelet connects to a gateway that securely uploads the encrypted contact log.
3. Authority Dashboard: Health officials use software (like that from Microshare) to analyze transmission clusters and trigger targeted quarantine alerts via the mobile app, providing a data-driven approach to epidemic management.

Bracelet beacon can record and track via Bluetooth if the user has been in contact with the infected person in recent weeks, then isolate them in time and prevent the virus spread.

The ID in this solution just for an encrypted code, will not expose personal information, only the authorities can access it.

This Bluetooth tracking solution is the method that helps to control the COVID-19 spread.

This is wristband beacon works by Bluetooth technology, it has scanning and broadcasting function at the same time, then it will detect and record another beacon wristband like it. Through the related algorithm of RSSI and device id to track the user information, it will record people who have been in contact in recent days and transmit to the system. Users can check it via app anytime. When someone has the symptoms of COVID-19, the APP and system will alarm and notify authorities immediately. Then the government or related medical institutions will quarantine all contacts for these days.

MOKO Bluetooth bracelet beacon has to move judgment function, when the user didn’t wear it, under the static situation, it will stop scanning and broadcasting. With the battery USB rechargeable function, it will solve the issue that battery consumption quickly.

MOKO wristband W2 beacon can be connected to the Gateway, Recorded data can be emptied by the gateway, then it can be used in the hospital too. When a patient is rehabilitation discharge, then it can be used for the next patient after the alcohol clean. Our partner Microshareproposes a complete solution for contact tracing using the Moko technology.