Telecommunication between ground and uav

[Tom1234]

I would like to create a  project in which i would like to transfer data from uav to station and also to control the UAV. I would need your advice what module to use. The requierement is to be able to control UAV to the most away distance.

I am thinking either the NRF24L01 module or zigbee/xbee .

How to calculate the max distance which can be use these modules? (I can't find anything from the datasheet)

[ChristosSDR]

You need some sort of LNA for large distances.

Have a look at these type of modules
https://www.aliexpress.com/item/2-Pcs-Long-Range-E01-ML01DP5-Ebyte-20dBm-2100m-SPI-NRF24L01-PA-LNA-2-4GHz-RF/32759715802.html

[xeontory]

Check with Digi Int. website for more Zigbee modules types. If you are located in US or Canada and your budget is not limited you can try some of these Xbee modules : https://www.sparkfun.com/products/9411
 
NRF24L01 modules are usually restricted in range but they offer more bandwidth, choose according to your application. For UAV, there are some 433MHz commercial grade complete radio/remote control you can buy for out of the box communication.

How much distance is suitable for your application? How much data bandwidth you need? Range depends on too many factors, so manufacturers usually state output power and receiver sensitivity in ideal line of site operation.

[pablo2048]

I've never get reasonable result with Zigbee/Xbee modules - probably because overcomplicated protocol for my needs, but I suggest to try RFRM69H modules, or new Ra-02 433MHz LoRa module...

[rtm]

I have made device with Zigbee communication on mrf24j40ma modem. It has these features:

ISM Band 2.405-2.48 GHz Operation
Data Rate: 250 kbps
-94 dBm Typical Sensitivity with +5 dBm Maximum Input Level;
+0 dBm Typical Output Power with 36 dB TX Power Control Range

The distance was not so big. I have reached maximum distance as 200 meters on open place. 10 meters in building.

You can use more powerful modem mrf24j40mb. It has additional output power amplifier & input amplifier:

ISM Band 2.405-2.475 GHz Operation
Data Rate: 250 kbps
-102 dBm Typical Sensitivity with -23 dBm Maximum Input Level
+20 dBm Typical Output Power with 56 dB TX Power Control Range

I think that it's distance will be 1-2 km in open place.

[pablo2048]

Yes, but did You test REAL data throughput speed? This was very dissapointing to me...

[xeontory]

For UHF, as long as the antenna is matched, and still further range is needed, you need to use range extenders or power amplifiers with the TX and LNA for the RX. I have got over 1km LOS range with 2.4GHz Xbee Modules without any packet loss. Simple 250Kbps UART protocol was implemented in those modules with RPSMA antenna. The 900MHz series was supposed to have greater range but in my case, I could not get beyond 250 meter. I think it was due to the lack of a matched antenna for that frequency.

 

[pablo2048]

I don't believe that You can reach 250kbps UART over 250kbps data rate channel @ full speed - in my measurements it was 10 times smaller actually and it gets even worse when switching between transmit and receive (bidirectional transfer).

[xeontory]

Dear Pablo, I have used the modules in 1 km sniper training firing range, it was LOS. 250kbps was the default baud rate of the modules and was tested packed loss by Xbee's XCTU software. The modules were Series-2, 63mW modules configured Point to Multi point operation and the antenna was from D-Link.
The actual data transfer rate was not tested up to the peak as we needed very small data packets after short intervals. If you have tested the actual data transfer rate is much lower in a specified baud rate, that is normal.

[pablo2048]

Yep - Zigbee is good for transfer small packets from time to time so IMHO for data-link for UAV not suited very well compared to sub GHz transceivers I've suggest. That was my point...