EU compatibility

[stylesuxx]

Hey, interesting project - thanks for sharing.
In order to use it over here in the EU we would need this to run on 868MHz, which I assume would not be a big deal. How about LBT - did you consider implementing that at all?

[AlessandroAU]

Do you have a reference for the EU lbt requirements? It doesn't take long to take an RSSI measurement of an active channel and in theory it could be done after each tx while the RX is busy

[stylesuxx]

More information about LBT can be found here -> https://www.etsi.org/deliver/etsi_en/300300_300399/300328/01.08.01_30/en_300328v010801v.pdf see section 4.3 for more details. AlessandroAU <notifications@github.com> schrieb am Mi., 23. Okt. 2019, 01:35:

…

Do you have a reference for the EU lbt requirements? It doesn't take long to take an RSSI measurement of an active channel and in theory it could be done after each tx while the RX is busy — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#5>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAHO2EGRBXRJRZQKZJXCRALQP6E3HANCNFSM4JDXDWHA> .

[AlessandroAU]

Just had another look at this, freq band seems really really narrow. Not sure how XF and R9 handle it.

[AlessandroAU]

868 bands have now been added, but LBT is not yet in use.

[stylesuxx]

Awesome, thank you. Will order parts and start testing!

[0crap]

Would love to see a 2.4GHz LBT version as well.
Parts are on order to make my first ExpressLRS 2.4G TX module.
Thx!

[greenbigfrog]

Gonna document my research into this here.
(these results are based on a perspective from Germany. Different regions might still have different regulations, since most EU stuff still needs to be copied into local law.)

2.4:

• 10mW per channel
• LBT etc as defined in ETSI 300 328-v1.8.1

868:

• try minimizing noise, disturbance of self and others, etc 2014/53/EU (implemented in FuAG)
• different power/bandwidth/duty cycle limits across multiple channels as outlined Allgemeinzuteilungen SRD 2018/05

From what I've been able to find, there's no actual on paper requirement for LBT on 868. ERC-REC-70-03E exists, but only is a recommendation, and was only implemented in france law as such from what I've been able to find.

EDIT: Part about ERC-REC-70-03E is probably wrong on a legal level, but as such, it's not applicable (to us)

[greenbigfrog]

Ok, so I've spent a few more hours reading the EU directives regarding 868. (These also (partially) apply to 2.4)

2014/53/EU is about radio equipment. The only truly relevant part of it is Article 3.
[removed quote]
I think we fulfill all of these already to a sufficient degree (for 868).

Actually had to delete most of my comment again, since I just discovered ETSI EN 300 220
This is a jungle... I guess I've got more reading to do

[0crap]

Actually had to delete most of my comment again, since I just discovered ETSI EN 300 220
This is a jungle... I guess I've got more reading to do

The header of that document says "Short Range Devices (SRD) operating
in the frequency range 25 MHz to 1 000 MHz;" so I guess that only applies to 868 MHz and not 2.4 GHz.

[greenbigfrog]

Actually had to delete most of my comment again, since I just discovered ETSI EN 300 220
This is a jungle... I guess I've got more reading to do

The header of that document says "Short Range Devices (SRD) operating
in the frequency range 25 MHz to 1 000 MHz;" so I guess that only applies to 868 MHz and not 2.4 GHz.

Yes, sorry I didn't mention that more explicitly.
ETSI 300 328-v1.8.1 is the relevant document for 2.4, and ETSI EN 300 220 for 868 (SRD frequencies (would also include 433)). (be aware, ETSI EN 300 220 has multiple parts, and I'm not sure how much of it is actually finalized or how they exactly are split up.)

[ManoDaSilva]

Perhaps we could also consider 433MHz?

[greenbigfrog]

Perhaps we could also consider 433MHz?

433 has even less "channels" from my understanding. It's not very interesting like at all, especially if you want to fly with multiple people on 433.

That being said, the requirements should be rather similar to those of 868. But feel free to share whatever you find out or know

[0crap]

Gonna document my research into this here.
(these results are based on a perspective from Germany. Different regions might still have different regulations, since most EU stuff still needs to be copied into local law.)

2.4:

• 10mW per channel
• LBT etc as defined in ETSI 300 328-v1.8.1

I've found a bit more recent ETSI document ETSI 300 328-v2.2.2

Also this document from TI which is a bit more readable, regarding CE regulations, might help with the 2.4GHz LBT stuff.
CE Regulations for SRDs Operating in License-Free 2.4 GHz/5 GHz Bands

[diego0815]

Here the regulations for Switzerland which are pretty much tracking EU requirements:
https://www.ofcomnet.ch/api/RIR/1008/09

More frequencies: https://www.ofcomnet.ch/api/RIR/1008

2.4GHz data transmission: https://www.ofcomnet.ch/api/RIR/1010/01

Or the more restrictive version:
https://www.ofcomnet.ch/api/RIR/1008/11

Seems like on 869MHz you have the choice of either doing LBT or staying below 10% duty cycle.

For 2.4GHz FHSS with minimum 100kHz bandwidth allows for 100mW, else you have to do extreme wideband to reach 100mW. LBT is one possible means to achieve coexistence.

[Dropsleutel]

I have some feeling adding more hopping channels so they overlap each other may possibly be better reject, some small band other signals, also we are sure to use the maximum available space in the band. the chance that two systems hop onto each other partially should stay the same, full hit will become smaller. It seems crossfire use approx 3 times more channels than would fit the band ?

[diego0815]

Cept regulations are here:
For generic short range devices: https://efis.cept.org/adhoc_grabber.jsp?annex=4

And for wideband data transmission: https://efis.cept.org/adhoc_grabber.jsp?annex=6

Actually pretty identical to the swiss documents above, as those are a national implementation of the cept rules.

And for ref the main page: https://efis.cept.org/sitecontent.jsp?sitecontent=srd_regulations

[d-hartmann]

Any update ob the EU compatibility? Is there any possibility to support here in any way?

[Creat]

I'm also very much interested in the state of LBT for 2.4 GHz. Now that 1.0 is released, does it include support for those regulatory requirements? Or is it on the roadmap?

[DocTrucker]

Will the LBT requirement restrict the performance of ELRS at all, hense the difficulty in implementation?

As radio manufacturers have had to comply with EU requirements such as LBT since 2015 may this mean the current youtube tests be a little misleading?

[FlydayOne]

Hello!
I would really like to use 2.4 GHz ELRS in the EU. LEGALLY!
My understanding is, that this is not possible at the moment! Is this correct?
If I'm correct, will there be somewhen a "legal" version that fulfill EU regulation requirements?
And if this is planed, is there a rough idea when this could be?
As this issue was open a long time ago, I have the fear this is not in the focus. But I believe this would be a real benefit for the link as it open it up to a big amount of users that now don't use it for exactly this reason.
Thank you and best regards

[avsaase]

As I understand it, only implementing LBT doesn't make it legal. The hardware/software combination would also need to be certified and there is no way the manufacturers of the hardware we have now are going to bother with that. Hell, they should just slap on a fake CE/FCC sticker like they do with all their other rf hardware. We don't need LBT for that.

[FlydayOne]

Actually I do agree but only partly.
Whether or not LBT is needed is out of my knowledge!
But for the rest, I believe the odds that a manufacturer is going through a validation process is by far higher if you offer them a solution that would pass the process than if you don't.
I am currently using ImmersionRC Ghost JR Module with Ghost! And I am quite sure this link complies. Or I am wrong?!?
Why shouldn't another supplier offer an EU version of such a module if he can get the software for free and the hardware already exists?
I believe that this would be in the interest of the manufacturer (potential better market access), all the manufactures of ELRS components and ready RC-MODLES (more potential customers) and the community (obviously).

[stylesuxx]

@FlydayOne CE certification would be necessary for each and every receiver and transmitter. In order to pass the CE certification LBT would need to be implemented (among other things) and the manufacturers would need to go through certification with every device. Since you have to pay for the certification (or at least for all necessary test), I can not imagine that manufacturers would follow through with this.

This is also the reason why for example TBS or IRC don't release a new product every other day, they release something go through the certification and then run for the product as long as they can. If you take a look at - for example - the BetaFPV product line, they have around 8 items that they would need to get certified, and I don't see this happening anytime soon.

Just slapping the CE/FCC label on it as @avsaase suggests is not the best idea either since it might lead to BIG problems on the vendor site. If for example I import something to the EU with the purpose of reselling I am responsible to make sure it meets the standards, so if it is a fake CE certification, and I just assume that the manufacturer actually did the certification and he did not, I - as the importer am liable for that.

So yeah, unfortunately I don't see any way that ERLS is going to be legally usable in the EU anytime soon.

[avsaase]

Just slapping the CE/FCC label on it as @avsaase suggests is not the best idea either since it might lead to BIG problems on the vendor site. If for example I import something to the EU with the purpose of reselling I am responsible to make sure it meets the standards, so if it is a fake CE certification, and I just assume that the manufacturer actually did the certification and he did not, I - as the importer am liable for that.

I wasn't really serious about this as any sort of solution but I've heard that this happens with some RF hardware in our hobby. Surely, the same risks for importers exist when there is no CE label at all, but I can still find ExpressLRS hardware in local rc shops. I'm not saying I'm opposed to doing things the right way - these regulations exist for good reason - but looking at the way things work right now the lack of LBT/certification doesn't seem to be a problem for manufacturers or users. Maybe there is an untapped market of law-abiding citizens that also never use R9 flex firmware and would like to switch to ELRS, but I don't see manufacturers taking the steps to cater to these users.

[FlydayOne]

Thank you! This is not the answer I was hoping for but it is a clear answer.
I still hope there will be somewhen a legal way to use ELRS in the EU.
So sorry... but for now I will stick with 👻.

[avsaase]

You can flash ELRS to your ghost firmware, that way you still have your sticker and no one will ever know 😜.

[stylesuxx]

@FlydayOne please take my answer with a grain of salt. I opened this issue two years back soon after I found this project. At this time I was toying with the idea to get a small series produced and sell it over here. I am not affiliated with the project itself, so it might be, that the team has something worked out with a manufacturer who is willing to go through the whole certification process. So don't misinterpret my answer as an official statement.

@avsaase I don't think that too many people in the hobby here in the EU care too much about flying legally all the time. Don't get me wrong, most people - if not all - that I know here are very responsible pilots, but expecting them to - for example - only fly on 25mW video output in a Bando is a bit naive. But sometimes you need to be legal, for example when attending races. Often times only certain video transmitter models are permitted. If you don't follow those rules, you will be excluded from the race. Which makes sense: As an organizer I don't want to risk it doing something that is against the law and might cause trouble for myself, and the bigger the event, the bigger the chance of something happening and being exposed.

So yeah, as long as you are flying for yourself and are doing so responsibly, the chances of anyone catching you with "illegal" hardware are basically non existent...

This is just my point of view and not an encouragement to do anything illegal.

[FlydayOne]

I can understand all the mentioned opinion.
Still, I believe it is making a different wether or not the product would pass a potential validation process.

@stylesuxx
You said you were toying with the idea to producing a series... maybe someone else, maybe even an established manufacturer, as well? As long as the software doesn't comply, noone will find out!
That was the reason for my question!

Additionally I believe everybody can judge on his own what is the risk of using a not authorized link and if it is meaningful not to comply with the standards.
Personally I wouldn't in the actual situation.

But I would feel more comfortable with a link that generally complies but has no certificate rather than with one that doesn't.
And I would feel even more comfortable with a certified tx but a non certified rx e.g in a BNF.

[sherghan]

Please correct me if I'm wrong. I'm expert in neither law nor radio equipment. Just an RC hobbyist.

My understanding of our EU law is as follows:

• It's Me as a user of the radio equipment, who is responsible for it's compliance with the regulations.
• If manufacturer puts a certificate sign on the equipment it means: I say it's compliant, trust me - this can be some form of excuse for me
• If I know for sure that equipment is compliant, I don't need a certificate on it. Though it's welcomed and would be helpful for all those who just want to buy without digging into details.

Still to be safe and calm we would need to know that ELRS drives the hardware in a compliant manner at first.

I know it's tempting to hide "below the radar", but it is in fact a ticking bomb. And probability that someone will try to shot us down is growing along side with popularity of ELRS.

[Betriebsrat]

Yea basically what sherghan said. While having a CE sign makes you able to have the manufacturer in charge, it is not the case that a missing CE makes it illigal per se aa far as my research went.
So if lrs speaks the right frequency with lbt we would be able to legally fly that in eu. The downside is that if shit hits the fan you have to prove somrhow that your rc link was eu compliant.
Correct me if i am wrong. Theres alot of false information and greyzoning going on on that topic.
Would be nice to have a lawyer statement maybe.
+1 for having LBT still.

[andlier]

If I remember correctly for lora a smaller bandwidth of e.g. 62.5 kHz instead of 500 kHz should also translate into more range, right?

Yes, the settings I ended up with for 25Hz link, with 62.5kHz bandwidth are just 2dB lower link budget compared with the existing 25Hz mode that uses 500Hz bw, so not really loosing any range on this. And the big benefit of narrower bandwidth is much better co-existence with other radios running the same mode, since there can be almost 100 hopping channels.

[diego0815]

If I remember correctly for lora a smaller bandwidth of e.g. 62.5 kHz instead of 500 kHz should also translate into more range, right?

Yes, the settings I ended up with for 25Hz link, with 62.5kHz bandwidth are just 2dB lower link budget compared with the existing 25Hz mode that uses 500Hz bw, so not really loosing any range on this. And the big benefit of narrower bandwidth is much better co-existence with other radios running the same mode, since there can be almost 100 hopping channels.

Only down side is the duty cycle skyrockets if you lower the bandwidth while the signal remains the same...

[diego0815]

@diego0815 all the requirements and details, both for FHSS channels/bandwidth and duty cycle are described in:
...SNIP...

(this does not apply for the 2.4G band, no need to worry about this duty cycle limitations there.)

Thanks @andlier very much appreciated

Didn't dig into the standard itself yet, might do so when I'm getting some time to spare... Usually digging into railway related standards nowadays for a living, so no more that close with the various radio regulations like i.e. etsi 3gpp and aviation related, as I used to be about 8 years ago... But it's good to see ELRS is in good hands 👍

Edit: just had one thought: as anyone can write standards... Is this aspect of the standard mentioned in some decree / regulation / law / publication in EU official journal? Or is there anywhere written the complete standard has to be taken into account? We are often having such debates at work if a standard is already notified or just any random standard.

In the Swiss RIR-1008-30 I posted above for ex. I see no ref to EN 300 220-1 in the normative section, bit only to EN 300 220-2, and references to LBT and AFA.
However I'm not sure if that makes things any better or if -2 pulls -1 in in some specific parts.

But currently from the swiss regulations I don't think it would require it. But as I didn't look into the topic in depth I don't want to raise hopes too high atm.

Edit2: actually the The radio equipment directive 2014/53/EU (RED) might spoil our dreams.

[drtrigon]

Edit2: actually the The radio equipment directive 2014/53/EU (RED) might spoil our dreams.

I what aspect?

[diego0815]

I what aspect?

In pulling the polite spectrum access in from EN 300 220-1

[andlier]

@diego0815 You are correct that the Radio equipment directive (RED) 2014/53/EU is the important piece of EU legislation here.

This might also be useful reading, Guide to Radio Equipment Directive 2014/53/EU: https://ec.europa.eu/docsroom/documents/33162/attachments/1/translations/en/renditions/native

Actually, it states that the harmonized standard (ETSI EN 300 220-document) doesn't necessarily need to be applied, but if it is not applied, a Notified Body (NB) is required to perform the conformity assessment, which is much more expensive process than just following the harmonized standard... so I don't think not following a harmonized standard is a realistic option here.

[diego0815]

so I don't think not following a harmonized standard is a realistic option here.

Im sure bangood will volunteer to sponser a NoBo ;-)

[GregorPotrebujes]

One thing I wanted to mention regarding these online range calculators...
This calculator (https://www.maxmyrange.com/) said that you will get the range of 3.11km when using 2.4Ghz at 100mW with moxon TX antenna and 1/2 dipole as the RX antenna, which both are pretty much standard.
Well... this guy (https://www.youtube.com/watch?v=GkOCT17a-DE&ab_channel=WezleyVarty) went 33km out with ELRS at 100mW TX and still no failsafe. And that was at 250Hz! I guess the distance would be much longer at say 50Hz, which works very well for drones in my experience.
So I guess this online calculator doesn't really take into account the ELRS advantage :)

[diego0815]

One thing I wanted to mention regarding these online range calculators... This calculator (https://www.maxmyrange.com/) said that you will get the range of 3.11km when using 2.4Ghz at 100mW with moxon TX antenna and 1/2 dipole as the RX antenna, which both are pretty much standard. Well... this guy (https://www.youtube.com/watch?v=GkOCT17a-DE&ab_channel=WezleyVarty) went 33km out with ELRS at 100mW TX and still no failsafe. And that was at 250Hz! I guess the distance would be much longer at say 50Hz, which works very well for drones in my experience. So I guess this online calculator doesn't really take into account the ELRS advantage :)

You can't get reasonable values without knowing the sensitivity of you receiver at the chosen datarate (--> chipset datasheet).

Actually every frequency gives you a so called free space path loss that is same for all 2.4GHz systems. Then you have the max. power, usually 100mW or 20dBm. Further you have the receiver sensitivity depending on modulation and bandwidth and of course also depending on the "quality" of your chipset. If you use additional error correction or implement DSSS it will give you some coding or processing gain. Antennas as usually used are all between 0 and 2 dBi of gain and the coax wires have some losses, so I usually neglect the antennas (IMHO they either work or not). All in all you get a dB value of your link, thelink budget. This has to be > than the path loss, then it should work, at least in interference free free space.

[drtrigon]

If I remember correctly for lora a smaller bandwidth of e.g. 62.5 kHz instead of 500 kHz should also translate into more range, right?

Yes, the settings I ended up with for 25Hz link, with 62.5kHz bandwidth are just 2dB lower link budget compared with the existing 25Hz mode that uses 500Hz bw, so not really loosing any range on this. And the big benefit of narrower bandwidth is much better co-existence with other radios running the same mode, since there can be almost 100 hopping channels.

Is this new mode ready for a PR?

[andlier]

Is this new mode ready for a PR?

I noticed one more drawback with the much narrower bandwidth, the oscillator tolerance decreases from 150ppm to just 18ppm. I think hardware with a TCXO is needed for that, unfortunately.

My proposal was just an attempt at finding out if it is at all possible to meet requirements in the harmonized standard, but I have a feeling the drawbacks with this approach are too big to make it worth it. Should take that discussion to discord with some of the main developers maybe. Also, I don't fly or have any 868MHz gear myself, so probably not any PR from me on this.

[drtrigon]

Oh no ... it was that close ... I wouldn't care if the center frequency drifts by a bit. Or is it that it cannot stay within the small bandwidth?

In the sense of becoming as compliant as possible and not "blow out" using unnecessary high powers I still would love to see this implemented. May be there still is some room for improvement later.

I guess you live in about the same region as I do - I have a BetaFPV 868 Mhz that I could give you for testing - as currently I cannot use it legally anyhow. Only drawback is it currently support 100mW output only, but I can give you a 6dB attenuator as well - and I have contacted BetaFPV with the question on how to modify the PCB to get 25mW output only.

Should take that discussion to discord with some of the main developers maybe.

I would really appreciate it - again - tell me if I can be on any help.

[drtrigon]

Actually I think - even if it turns out that only some or none of the current commerically sold modules can support that mode - it should still be implemented. That would allow the manifacturers to adopt their hardware to be compatible and it would allow to build DIY modules that implement this mode.

This should be a viable way to finally come to a point where EU compliant modules become available.

@andlier: What do you think, is it realistic to try to e.g. add a TCXO to current commercial designs, like e.g. the BetaFPV 868 MHz module?

[diego0815]

What do you think, is it realistic to try to e.g. add a TCXO to current commercial designs, like e.g. the BetaFPV 868 MHz module?

Sounds not very realistic, also as any kind of (third party) HW mod will pull the EMC testing into questions to say the least

[drtrigon]

Does the FrSky R9 have a TCXO? As it has an EU mode it should also be able to stay on those small bands, correct?

[drtrigon]

@andlier: I talked to the betafpv guys - as this is the transmitter module I do own - and as they told me Crystal frequency is 32MHz, tolerance is 10PPM. so it does meet the requirements (of 18ppm).

Also they explained to me on how to reduce output power to 25mW:

If you wanted to change the minimum power output to 25mW, R1,R2, and R3 would be 16.9, 16.9, and 66.5 ohms, respectively;

If you wanted to change the minimum power output to 10mW, R1,R2, and R3 would have values of 24, 24, and 40.2, respectively;

If you don‘t have the above resistance, can choose ±1 ohms

If you have modified the element above, the other levels of power would go down. If changed to 25mW, other levels of power value -6dB; If changed to 10mW, other levels of power value -9dB

@andlier: What was the outcome of the discussion on discord?

[andlier]

@drtrigon

What was the outcome of the discussion on discord?

I'm sorry to say the interest was quite close to non-existing, mainly because of all the caveats (speed, XO ppm requirement etc.)
I also don't think a PR that requires manual modifications to specific hardware would get anywhere tbh.

Get some CE-marked 2.4G hardware, the range surpasses most video-links anyway. Maybe the wait for LBT-enabled, 100mW TX power CE-marked equipment is not too long.

[drtrigon]

There is already hardware existing - like R9M - that does not need to be modified.

Speed; 25 Hz is fast enough for PAL television and more than enough for me. But may be this is just me.

XO ppm requirements; are met on my hardware, I guess there is a quite high probability that this holds for other also.

For me it is kind of surprising that a long range system does not even consider to run on 868 MHz hardware (for EU) because of several reasons:

1. penetration
2. losses (9 dB of free path loss means 25mW @ 868MHz actually gives more range than 100mW @ 2.4G)
3. battery lifetime (see 2.)
4. "polution" (see 2.)

As I want to use it for cars and thus due to the fresnel zone etc. I do always have peneteation to some degree have 1. as major requirement. That cannot be meet in the same way by using 2.4G - this is a fundamental physical restriction.

(I was considering to buy a 2.4G ELRS TX several times - close to click the "buy" button - but it is just not consistent to me; 2.4G is a superb low latency system but long range is 868MHz. There are at least 2 commercial systems out there that manage to be EU LBT / CE - actually even with more analog channels ... I really like all the bells and whistles in ELRS and that it is open source etc. I do really appreciate the effort done by every single developer but to me going for 2.4G - except for the also brilliant MPM - just hurts somehow.)

[MartinHugh]

For me it is kind of surprising that a long range system does not even consider to run on 868 MHz hardware (for EU) because of several reasons:

But there are long range systems which run 868 Mhz.
Crossfire and R9 for example.

How they deal with LBT I am not sure, but the real issue with 868, is that many prefer to run at above 25mW. This is problematic if you wish to be EU compliant. If you run in the 500mW band the number of simultaneous pilots is limited.

[franz4949]

Regarding 2.4 GHz EU compliance:
The LBT matter is not new stuff for me and would like to put a short comment as follows. ETSI allows to switch between adaptive and non-adaptive mode operation (see Sect. 4.2.2). Thus in case of channel being detected to be occupied it is allowed to switch to non-adaptive operation and send with corresponding power calculated for MU10 operation which is about 30mW. And btw exactly this was implemented by FrSky for the big v2 ACCST EU-LBT and v2 ACCESS EU-LBT firmware firmware.

If this is already known and is going to be the basis for also ELRS 2.4 GHz implementation, I am sorry for my lack of knowledge of actual status. Don't want to bother anyone here with my first post in this ELRS thread here.

[andlier]

Thus in case of channel being detected to be occupied it is allowed to switch to non-adaptive operation and send with corresponding power calculated for MU10 operation which is about 30mW.

@franz4949 it would be a nice potential for improvement if the standard can be interpreted this way. I'm interested in discussing this further, created a thread on discord on the matter.

[diego0815]

Today I stunbled over WiFi halow (802.11ah) they claim data rates of up to 15 Mbit/s, and in EU frequency range is 868MHz, I doubt much of the speed will be left over in the end, but interesting to see how this equipment can be operated in EU to maybe draw conclusions for ELRS.

[drtrigon]

If somebody is interessted in working on the 868 implementation I have hardware to donate (BetaFPV Micro TX, R9M 2019, BetaFPV RX and and R9 SX).

By the way would it make sense to put a reward on this? Or could it be added to GSoC e.g.?

[diego0815]

@drtrigon did you check out the new MILO protocol? https://www.rcgroups.com/forums/showthread.php?4144003-New-2-4G-LORA-protocol
It's currently 2.4GHz and AFAICT non LBT, but I guess it would be a good starting point for surface and LOS development.

[franz4949]

@andlier I got a confirmation from German TUV Sud, section Test Lab for Wireless Products, that ETSI EN 300 328 self-evidently allows equipment to be operated in adaptive and also in non-adaptive mode. And ofcourse can equipment switch between those modes. It just has to be taken care for the transmit power to be in compliance with the calculation method (MU10) described in the code. Here's the web page of that TUV SUD section => https://www.tuvsud.com/de-de/dienstleistungen/produktpruefung-und-produktzertifizierung/funkpruefung

[drtrigon]

@diego0815 thanks for the hint.... somehow I do not get the basic concept/idea behind this? Why again another additional protocol? What is the reasoning behind this?

[diego0815]

@drtrigon It's for the fun of it, and because it's possible.

Actually the idea behind MiLo is to have a pretty conventional RC protocol with sport telemetry etc. but leveraging the good RF performance of the SX1280.

So the audience is different, thus it wouldn't have been convenient to try pushing elrs into a direction it never wanted to go. But of course we still profit from readily available HW, enjoying the freedom to experiment in any direction we feel is interesting.

[diego0815]

Actually I don't want to advertise a competing solution in any way, and also think we should soon end this OT bit here, before polluting this bug too much ;-)

[drtrigon]

@diego0815 : it is intressting - tks for sharing - however for this new protocol I would ask for EU compatibility / LBT as well ... what's the current state of implementation? (may be we should put this into a new thread)

[diego0815]

It's implemented but, as the rest of the protocol, not yet properly tested.

Project is on Midelic's github: https://github.com/midelic/MILO-RX, TX is currently still a fork of multi module and not yet merged upstream.

Can talk there or on my MiLo fork, whatever you prefer