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These LoRaWAN devices will be deployed in Dubai, flat landscape except for buildings. They already have gateways all over the city. I seem to recall that they want a 3km range out of the 868MHz radios.

The previous project used the NRF24L01+ with Yagi antennas. That gave them about a 1-1/2 mile reach.

Interesting, but I meant how long were your coaxes going to be?

3 km is pretty easy. That's less than 2 miles. So long as you have line of sight, it won't be a problem.

Let me back up a bit. I looked at the specs for the NRF24L01, and it's only 1 miliwatt output power. The RFM69HCW i'm using is 100 miliwatts. I know 100 miliwatts will easily make several miles, but I don't know about 1 miliwatt unless you use some really high gain antennas.

More power is always better. You can't do anything on the receive side other than using a good antenna, but more power on the transmit side will make up for other issues.

OOOOOOH! The coax is about 1 meter in length. The client has an installation with a 50ft coax; and, much to my surprise it actually works. I think the stations are only 1000 feet apart. The NRF24L01+ was not my choice in radios. The customer already had the hardware assembled, but couldn't get the software working. (Student labor is a big mistake)

The Dubai project will use little bat antennas with about 2 meters of coax. They are supposed to last 5-10 years on a C sized lithium primary.

Next radio project I get strong-armed into will definitely make use of something like a RFM69HCW. I'm not fond of radio projects.

I had a nice setup going with DIGI HP900 S3B radios; but, the customer canceled the project: