Droning On about Signal Strength and Antenna LocationBy Tom Carpenter On 03/24/2020
Researchers at North Carolina State University (NCSU) reported on a project, sponsored in part by NASA, wherein drones were used to improve signal strength in a LoRa link. LoRa is a PHY protocol using spread spectrum for transmissions and is the wireless link on which LoRaWAN is based. The project revealed that, by doubling the height of the antennas using unmanned aerial vehicles (UAVs) or drones, the signal could be significantly improved, which one would expect.
The novel idea here is that drones can be used to put the antenna where you need it when you need it there. Using motion recognition, visual image processing and other controls, one could see how a drone-based implementation could dynamically position the antenna for transmission and reception at required intervals. Of course, the "fear factor" of seeing a drone rise into the air periodically is something to consider, but from an implementation perspective, I can see many scenarios where such a use case could be beneficial. Several monitoring and control factors would have to be in place, such as:
- Monitoring the battery level in the drones and implementing a dynamic park and charge method
- Ensuring the drones do not "crash" into any new obstacles placed permanently or temporarily in their normal air spaces
- Using drones that provide significant hovering stability to maintain a burst short-term link
- Developing the logic (software) to make it all happen
- Possible use of tethered drone deployments ensuring a maximum height and greater stability of location
So, yes, there are indeed hurdles to overcome, but we have all the technology to do it. The question is this: do real cases exist where this research could be applied? I think the answer is a resounding yes, particularly in agriculture, environmental monitoring, pipeline monitoring, power monitoring, etc.
Imagine the scenario where you need a daily report of data to be sent from a remote sensor to a gateway that is 3-4 (or more) kilometers away in an area with varied terrain, forests, and more. The sensor could transfer the data to the drone (or the sensor could simply be attached to the drone in some cases) and then the drone can fly up to the height required to get a link with the gateway, transfer the information, and return to its resting location. Using solar, or some other, power options, the drone/sensor could be recharged as needed and commands could be sent back to the drone during transmission windows when configuration changes are required. You could even have the drone fly itself back to the central monitoring location at some regular interval for inspection, maintenance, etc.
Yes, this is the world we're moving into and drones can have a significant application in the IoT space. As we continue to evolve in the world of IoT, we will see exciting and interesting implementations. In the end, with wireless IoT, it will be about getting the link you need, when you need it (time), where you need it (location), and how you need it (performance).Tagged with: drone, iot, lora, lorawan, signal, iot