So my son is involved in a University of Alabama college class project. The project goal is to design a tracking device that will track hobby level RC and Quad "drones" while in the air. Their group is handling all the details of the tracking side of the project and has a stable way of tracking them and thank god for that because it's way way over my knowledge level. My son stated that they are having issues with finding an RC pilot to be the target aircraft. I am a very accomplished RC fixed wing pilot with a strong love of mechanical engendering and absolutely love designing, building and flying RC aircraft. I, of course, jumped on that opportunity to help them.
The project tracking aircraft has to have a 2g, 5g and a 900mhz signal transmitting from the aircraft to make it "trackable". The signal does not have to be a single unit transmitting all 3 at once. Switching the payload between tracking sessions is fine and I figured we would have to just for simplicity sake. Any frequency within those three ranges will work, as long as it's a fixed frequency. The transmitter(s) will only need to have to have enough TX power to be readable at about 100 feet or less from their projects receiving antennas. From what I'm gathering from their antenna setup and project sensitivity, I'll get away with transmitters in the low low milliwatt range. If the wattage is higher, within reason. This project is a "Proof of Concept" level project so we are not talking coming in from miles inbound, only flying the perimeter or even a portion of it for them to get a video demonstrating the concept and showing the project can track these three frequency ranges reliably.
This is where I need your help. I need three separate transmitters that involve the Arduino platform. I power them up as a payload separately, fly them around and complete my promised mission. If you all think there is a more crazy fun way to set it up, I'm all ears. As long as I can TX those 3, I'm good.
Total project flight time, maybe 30 minutes.... Me being a intricate part of my son's team project for his final year... priceless!
I'm not seeing anything in that link that has to do with transmitting frequencies, only an autopilot system. I have dug through there blogs earlier in depth and have found nothing that will solve my project goal. Thanks for pointing me there, it looks like a fun project but not what I'm looking for.
Those frequency bands are ALL assigned to business use, such as cell phone and internet access companies. There is a portion of the 900 mHz that is ISM for experimental use and is also used by amature radio. Even is you tried to receive in those ranges, your signal is likely to be covered up by commercial users. MY internet access uses the 5gHz band, but requires a dish antenna and low noise receiver.
Use Google to look for ISM frequencies. Industrial, Scientific, Medical.
Please post the complete details of this tracking requirement. The above is far too vague. If "2G" refers to the cell phone service band, most of those services are long obsolete and have been disconnected in the U.S. 5G cell phones and WiFi are short range.
I apologize, I thought I did explain what I was looking for. I need a module, preferrable Arduino platform based, that will transmit in those three frequency ranges. Anything, small enough, hence why I am leaning in the Arduino direction. What data it transmits is not of concern, just as long as the RF is emanating from the transmitting antenna, we're good.
So its entirely reasonable that you are having suggestions as to the legal limits on transmissions etc. You would assume that for the project to be accepted by the college it has to be legal.
Yes sir, there is nothing illegal about this project. They are only needing an RC aircraft to fly that is capable of transmitting any radio frequency in that range for them to track using their completed class project. I can fly this payload; 1Mii 2.4Ghz Wireless Audio Transmitter Receiver for TV, 320ft Long Range 20ms Low Delay 192kHz/24bit HiFi Audio, Wireless Adapter Kit curtesy Amazon. I can easily fly other type transmitters in both the other ranges that do different things, ie, wifi extenders, ect that tx those frequency ranges. The reason I was looking towards the Arduino is for it's size, and making all 3 payloads the same would add to the "trick" look of having them match when completed as well as coming close to matching weight. I hope that helps.
2G is obsolete in many parts of the world. I would be surprised if a 2G equiped device could be made to transmit anything unless there was already an active 2G base station within range. Most likely it'll just report 'no service' and sit there forever waiting.
Do you know for certain that you have 2G support in your area?
Also 2G doesn't define a specific frequency or modulation. For example, using a spectrum analyzer, even if you know the center frequency, you would struggle to spot a 2G signal that uses CDMA due to the way energy is spread across the spectrum.
Some RC drones use 5.8 GHz for first person view video transmission back to the drone pilot. 2.4 GHz and 900 MHz are used for RC control and telemetry.
If your drone does not already transmit those frequencies, you could buy RC radios from Amazon. I do not know of a Arduino with built-in RC radios.
Packet radios running 433MHz (sometimes referred as 400MHz) like the ones mentioned in your link are allowed internationally and within the US for “industrial, scientific, and medical” use. The other frequencies allocated for this purpose include the 900MHz band (915 MHz specifically) you mentioned, 2.4 GHz (original WiFi and Bluetooth devices plus current RC control systems), and 5.8GHz (second WiFi band). No license for 433MHz
As for an RC aircraft transmitter, a cheap “915 MHz Arduino compatible transmitter” (available on Amazon and Ali) would work. For “2G” and “5G”, assuming these refer to WiFi 2.4GHz and 5.8GHz WiFi bands, any Arduino board with integrated dual-band WiFi could transmit just fine. Of course, equipment designed specifically for cell phone tracking will be looking for other frequencies and will not see the transmitters I mentioned.
Raspberry Pi 4 and 5 boards have built-in WiFi 2.4 and 5 GHz. Configure the Pi WiFi as an access point and it will broadcast its SSID on both frequencies. But if your drone is using these frequencies for RC control/telemetry and FPV video, this might not be needed. And WiFi might interfere with the operation of the drone. But perhaps channel selection might allow them to work together.
The Wikipedia article you referenced covers voice communication radios and not the ISM data packet radios. I knew that I could use transmitters at 433MHz in the US because Adafruit and Amazon both sell 433MHz transmitters for use in the USA. Before I posted last night, I looked at the FCC Frequency Allocation Table and confirmed my information. The 70cm Amateur Radio Band consists of 410-450 MHz for communication radios. Within that spectrum, PDF pages 68 and 69 have several footnotes allowing other radio transmitters to operate within the same frequencies primarily assigned to Amateur Radio Operators.
