Hi, what antennas do you use? to reach 10 km of distance or more between the nodes and the gateway, any brand that you recommend? Thanks.
What about first searching the forum for information?
The BIG and SMALL ANTENNA topic part 1
The BIG and SMALL ANTENNA topic part 2
Itās not just a matter of simply selecting some certain antenna to get a reach of 10+ km.
Other factors play an important role as well.
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Do not assume that a ābetterā antenna will give you longer distances for TTN.
In theory you can achieve longer distances with higher gain antennas and these are available.
However to use higher gain antennas and stay legal you need to reduce the power output of the Gateway and nodes. This required reduction in power offsets any increase in antenna gain, so there is no overall benefit.
Hello,
All depends on your setup and locations.
To stay legal you can use at the gateway an omnidirectional transmit antenna and one or more high gain directional receive only antennas. They receive antennas have to be combinded.
Best regards
Microwave Specialist
And which TTN Gateways can be configured to do this, please give examples ?
The significant issue with attempting directional antennas on Gateways, is that to keep them legal the nodes can become one way only, in that they can only send data into TTN did you realise this ?
A gateway I administer uses an Aurel GP868: %product-title% kopen This is a small basic ground plane antenna.
Altitude helps a lot. Being higher up extends the radio horizon, and increases the possiblity for the node and gateway to āseeā each other (line-of-sight propagation) helps. Coverage of this gateway: TTN Mapper
These kinds of maps can be a bit deceiving IMO, since youāre not seeing the places where coverage failed. Iād rather have good coverage in a 2 km radius, than very spotty coverage up to 30 km.
Letās make a short estimation:
f=868 MHz, 14 dBm ERP, distance= 10km
This results in a Receive Power of -93dBm.
This is abt 30 dB more than you need for a PER of 10% at SF7/125kHz.
Conclusion: Line of Sight is much more important than antenna-gain.
If the propagation is disturbed (Fresnel Zone!) it is sometimes not easy to predict the additional attenuation.
Ok OK Ok
Imagine that the Gateway and node use omni directional antennas and the distance covered is 10km.
You add a directional antenna to the Gateway that has gain of 6dB more than the omni. The Gateway will now be able to receive signals from 20km away. But downlinks will still only reach 10km since the ERP restrictions mean the Gateway TX power has to be reduced by 6dBm.
The only way to make the link symetrical is to also use a directional antenna on the node.
Ok OK Ok
Correct if systems symmetric however you are scaling the capability of the gw but not the nodeā¦ā¦ think from nodes p.o.v. Gw has increased Tx capability by 6dbi but then offset that by reducing its Tx power. The gw Rx however gets the full boostā¦ā¦it is now more sensitive and is able to hear the distant node, but the node hasnāt increased its sensitivityā¦. Any benefit to the link from its p.o.v. Has been offset by the reduction in Tx power. The ant gain will also increase level of noise seen by the gw but here we have to assume signal is still strong enough to be recovered from any noise even in neg snr in case of a LoRa signalā¦.
I know the maths.
The other issue with directional antennas, in addition to creating the situation where downlinks to nodes may not be received, is that node coverage outside of the beam of the directional antenna is significantly restricted.
Ok OK Ok
Same in both directionsā¦.that is physics, sensitivity threshold is a device characteristic and is asymmetric in our caseā¦ā¦if the result of the maths puts signal below sensitivity floor result is no signal and that is what we are flagging here. Increase the sensitivity of the gw by adding the ant and you get useable signal further outā¦. Do the maths in reverse and if result at the node is below its reception level no message, of course you could always add a 6db ant at the node 
but then you are making symmetric system changesā¦. 
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Ok OK Ok
Yep agree as like Stuart I too know the maths (esp for such a symmetric system)ā¦now change your first one to GW TX = 8dbm (actually 10 as EU legal limits assume 14dbm TX delivers 16dbm EIRP to keep it legal or alternatively change the last to 0db at both ends, better yet add in the 6db RX gain for the GW antā¦then look at the point where levels get to where they fall below receive sensitivity for either end (try a nominal value of say -120dbm and vary the distance - the GW will hear far nodes no problem (theoretically at ~2x the distance, hence Stuart using 10km & 20km, in reality other environmental and implementation factors may deminish that), the node will not hear a far gw under the same circumstances as it doesnt benefit for the āenhancedā rx gain of the GW ant. (Like you have a few years deploying RF systems, and also (following similar link budget principles) fibre optic networks (where simple passive antennas may be substituted by much more complex active gain systems like EDFAās or Ramon Amplifiers (shine a high powered narrow band ālightā up the fibre in opposite direction to targeted down stream traffic at very close DWDM frequency in order to extend reach - ouch my brain hurts!). BTW agree Directional ants have their place - esp e.g. if there is an intermediate source of interfering noise that serves to raise the impacting noise floor and hinders rx sensitivity - as you will know noise is addative and an iso ant will gather from all directions - a directional ant can help filter/deminish noise gathered from off beam hence helping suppress the intermediate noise source 
Good for private deployments or where you āmustā hear a specific node (set) in the face of such interferrers, not good for community networks where ideally signal conditions are uniform around the GW.
Ok OK Ok
Nope, the UK limit is 14dBm ERP, for both.
So a Gateway or node that has an antenna that has 6dB gain over a standard omni has to reduce its TX power level to 8dBm.
Ok OK Ok
There are no regulatory limits on RX sensitivity that I am aware of.