Hi there, looking for a simple and straightforward radio-link between a base-station and a few netmf devices with a range of at least 5 km.
The base station will be powered in a house, but the remote radios are powered with a battery and needs to be very economic with their power usage.
There is so many radio-link offerings out there, but it seems to be hard to find 5 km ones…
Any hints?
Looks interesting, any easy to go modules using that?
@ njbuch - I have a couple of those lying around, but never got the time to try them out:
We’ve been using Freewave modems for decades on some of our Oceanographic platforms.
Don’t forget to look carefully at the antenna configuration.
A very high gain antenna on your base station will help enormously. When you pick a radio try to consider the availiability of cheap antennas. Anything around mobile phone frequencies or WiFi will be cheap and commonplace.
Also any additional height will make a massive difference.
If you need a propagation model to make some predictions then try Okumura Hats. That’s designed for exactly this kind of link. There are some online and phone app based tools, but it’s pretty easy to put the formula into a spreadsheet and roll your own.
Beware the range specs in the datasheets. Generally these are quoted in the absolute best line of sight cases. Look at sensitivity figures if they are availiable. Other factors such as other in band signals can cause degradation or blocking.
I’ll add that this LoRa modules look ideal. As they say the 900MHz signal is good for penatrating buildings and has much less interference than 2.4ghz.
Also there are plenty of good high gain antennas availiable.
Thanks everybody, I will do some research on these suggestions. Thank you so much!