Hi, I’m trying to setup a demo to work with TTN gateways in Europe. I would like to know what frequencies are normally used in EU for ETSI certification. It looks like the ETSI SRD sub-band from 868.0 to 868.6 MHz is used. The three required default channels 868.1 868.3 and 868.5 are defined in this sub-band. What other frequencies are normally used? How wide are the channels? Does TTN use the higher sub-bands with various Duty Cycle and power limits. Would this be in the spec for the TTN Gateway?
Why don’t you download the EU channel plan from github?
Because I didn’t know it was there. I’ll take a look. Thanks for the clue.
In Europe, LoRaWAN operates in the 863-870 MHz frequency band. This is the Regional ISM band (Industrial, Scientific & Medical) assigned for Europe only. In Europe the band(s) you can use is/are:
868 Mhz --> As specified in LoRa specification, you must use at least the 3 main channels you already mentioned (868.1, 868.3 & 868.5) with a duty cycle of <1%
If you are ham radio operator with valid CEP T/R licence you can also run your test or PoC in 433 Mhz but you cannot run in that band a production system except if that is only for ham radio operators.
Application developers are encouraged to keep their payloads small, do not transmit too often and avoid downlink messages if possible.
Hope this helps.
I looked at the Github stuff. I saw EU-global_conf.json, is there all there is? I have limited understanding of JSON, but it looks like there are only five channels defined; 868.1, 868.3, 868.5, 868.7 and 868.9 MHz. Is this correct? Are these used for both uplink and downlink?
Thanks for the info on 433 MHz. We’re just working the 868 band for now.
Yes, what you can see in the JSON file is correct. The LoRa specification estates there should be at least 8 main frequencies (channels) and that ones are those you can see in the JSON clauses named "chan_multiSF*"_.
TX/RX centered on that frequencies, BUT, only the three first ones are compulsory for a successful communication. In EU863-870 ISM Band these 3 channels of 125 kHz
that must be supported by all end-devices are 868.1, 868.3 & 868.5. The additional channels will also be of 125 kHz of bandwidth. The LoRa specification implements pseudo-random channel hopping for TX/RX.
There are 8 channels defined. JSON is just text so that can’t be a problem. Interpreting the information could be more difficult if it wasn’t for the plain english “desc” with a value that tells you the frequencies.
All frequencies can be used for both up- and downlink. An additional downlink only channel not mentioned in the config is 869.525MHz.
Hi, I saw the descriptions. Take a look at line 43 from the EU-global_conf.json file below? is this a typo? It looks like “867.1 MHz”. I’m assuming this is a typo and it’s really 868.1 MHz…
Line 43: “desc”: “Lora MAC, 125kHz, all SF, 867.1 MHz”,
Why would you assume that? It really is 867.1MHz.
I’m looking at EN_300220 Table 5 Maximum Radiated Power Limit etc…
It says there is a sub-band from 868,000 to 868,600 MHz (25 mW 1% Duty Cycle). I’m assuming this is the rule to use. This would exclude 867 MHz. And the CONSTANTS are the same as the 868.1 Mhz structure (except the Radio #)
However, Now that you mention it, there another sub-band from 863,000 to 870,000 for “narrow/wideband” that allows modulation BW of up to 300 kHz (25 mW 0,1% Duty Cycle). LoRa transmissions would fit this description. Is this how 867.1 MHz would be allowed?
or would spread spectrum not classify as wideband?
Also check note 9…
BTW the radios use different base frequencies, combined with offsets equals different operating frequencies.
OK. I thought LoRa was FHSS. But you’re on to it. LoRa is “Chirp” spreading.
Note 9 is good news too.
I get the base frequency thing, now that I know 867 MHz is legit.
BTW is there a GW project in Eu that would let me monitor the traffic. It would be interesting to see how these channels are actually used.
If you have a RPi based gateway with iC880a or RAK831 card (and may-be others as well) you can set it to display some packet information in the logging. However you will only be able to see LoRaWAN packets. SDR should work to check on all spectrum usage.
Hi everyone, I have a question;
Is there a reason TTN does not use:
868.700 MHz (G2 band)
868.900 MHz (G2 Band)
I am wondering if it is because these frequencies are used by alarms in EU.