SubGHz USB-Dongles used in Firmware Over the Air Update Server ( FOTA )
Mobile LPWAN devices operating in the ISM bands often lack the option to do firmware updates over the air (FOTA) due to limited bandwidth of the networks. Potential applications: e.g. non-stationary devices or asset trackers.
To overcome this, a stationary mounted FOTA System can be used.
One of our customers created a system, which is synchronizing the local FOTA server with their cloud server, providing the latest firmware packages to be flashed into the devices.
The FOTA server is mounted with 2 of our SubGHz USB Dongles.
One is acting as a beacon, the other is acting as a broadcasting transmitter. Each dongle is using a different frequency
The beacon is transmitting cyclically the time duration until the next broadcast starts.
The transmitter begins transmitting the FW packets with this timing with a much higher transmission rate than possible within LPWAN.
In this way the system can deal with a large number of devices being within the local subGHz reception range, with a “send” only communication.
The devices listen to the beacon frequency and catch the next time of broadcast, and can prepare meanwhile the reception of the FW packets.
When all packets are received, the device starts its flashing procedure.
Voila, all devices in range are updated simultaneously.