Radio equipment manufacturers follow ETSI recommendations cause the product declaration process is easier


#1

I'm new here in the forum and I've been using OpenWRT a long time ago - in those good old times, when you were still able to increase transmission power.

So here my critical voice on Open WRT regarding the implementation of TX power increase.

In the US I doubt that there is any road where you are allowed to go with more than 85 miles per hour - I think this is about 137 km/h - so really slow :slight_smile: . But it is still alowed to produce cars (hardware), that can go faster than that. And even worse, they are not only produced, but even sold in a state, were they can go up to more than 350 km/h. Some car producers (BMW, Mercedes, Audi ...) restrict the max speed of their cars to 250 km/h (via software) - which is still slightly above the US speed limit. And guess what - these cars are still allowed to be sold and bought in the US.

Of course this is forbidden for the user of a car and everyone is aware of the regulation. The same applies to many other countries (except Germany, where on some highways there is no speed limit (although insurance does not cover accident cost in case you go faster than a "recommended" speed).

So OpenWRT

  • why do you restrict the capabilities of the hardware (many routers are able to provide 1000 mW TX power) to 1/10 - potentially slightly more? Is there a regulatory need for open source software or is it anticipatory obedience?
  • Why is it not respected, that a router might be "driven" in a country, where no speed limit applies? Is this the reason, why the Brazil/Lithuania and other countries limits of 1W do not work?
  • Why do you assume, that users are basically irresponsible people - that do not apply to regulatory requirements? Do you want to protect these dummies from themselfes?

I'm aware, that US regulations try to rule this world, but please get back to the roots, where it is the people who make decisions, what is right and what is wrong for them. And of this does not meet regulatory restrictions it is a topic up for discussion and improvement.

Just imagine, that hundreds or thousends of year ago there would have been a regulation, that any construction similar to a wheel is forbidden. Imagine everyone would have accepted this regulation :slight_smile: - good by current world.

PLEASE!!!!
Kick out the regulatory anticipatory obedience that rules OpenWRT regarding TX power. Leave it to the responsibility of the users - as car manufactureres also leave it to the drivers respnsibility how fast they drive their car. Consult car accident statistics to find out how many accidents are coused by speeding and how many by driving drunk ...

Please share you opinion on this topic - I'm mor ethan open for any discussion on this topic!


#2

I get that your a bit frustrated about all this. But your approach isnt likely to get you to where you want.

I just found this link.
https://w.wol.ph/2015/08/28/maximum-wifi-transmission-power-country/

Following your line of reasoning i guess someone could change their router’s country code to get to settings that are more lenient than what they were using. However, (also as per your reasoning) that would be illegal (unless you lived in that country) and the fines could pretty high if it was found they did this intentionally. Even if they set their router transmit higher, their client devices will almost certainly be resticted to the lower transmit levels - and devices cant communicate unless they can both hear eachother.

If i may , shall we discuss your particular problems you are having with wifi reception in your setup?

  • Any chance your router has detachable antennas? Are they screwed on as tightly as they’ll go?

  • Are you living in an area where the wifi channels are all saturated? (High densitity apartments). Try using a scanner software eg Netstumbler, or iStumbler .

  • are all your wifi devices affected or only some?

  • are you in a position to run ethernet cabling around your house? (I did mine with cat 6a for about $300 USD.). One thing people seem to forget is that wifi is halfduplex . Cabled ethernet is full (meaning sender and reciever can talk at the same time)


#3

Hi @Sparks,

thanks for your reply, you're right - my frustration might not get me closer to any solution.

I know the link you posted, but OpenWRT does not accept any country setting.
If I look to the OPENWRT:

root@OpenWrt:~# iw reg get
global
country 98: DFS-UNSET
(2402 - 2472 @ 40), (N/A, 20), (N/A)
(5170 - 5250 @ 80), (N/A, 20), (N/A), AUTO-BW
(5250 - 5330 @ 80), (N/A, 20), (0 ms), DFS, AUTO-BW
(5490 - 5710 @ 160), (N/A, 23), (0 ms), DFS
(57240 - 63720 @ 2160), (N/A, 40), (N/A)

phy#2
country US: DFS-FCC
(2402 - 2472 @ 40), (N/A, 30), (N/A)
(5170 - 5250 @ 80), (N/A, 23), (N/A), AUTO-BW
(5250 - 5330 @ 80), (N/A, 23), (0 ms), DFS, AUTO-BW
(5490 - 5730 @ 160), (N/A, 23), (0 ms), DFS
(5735 - 5835 @ 80), (N/A, 30), (N/A)
(57240 - 63720 @ 2160), (N/A, 40), (N/A)

phy#1
country FR: DFS-ETSI
(2402 - 2482 @ 40), (N/A, 20), (N/A)
(5170 - 5250 @ 80), (N/A, 20), (N/A), AUTO-BW
(5250 - 5330 @ 80), (N/A, 20), (0 ms), DFS, AUTO-BW
(5490 - 5710 @ 160), (N/A, 27), (0 ms), DFS
(57000 - 66000 @ 2160), (N/A, 40), (N/A)

phy#0
country FR: DFS-ETSI
(2402 - 2482 @ 40), (N/A, 20), (N/A)
(5170 - 5250 @ 80), (N/A, 20), (N/A), AUTO-BW
(5250 - 5330 @ 80), (N/A, 20), (0 ms), DFS, AUTO-BW
(5490 - 5710 @ 160), (N/A, 27), (0 ms), DFS
(57000 - 66000 @ 2160), (N/A, 40), (N/A)

No way to set anything higher than country US - but this does not work. I found some statement, that says, that WRT3200 has some internal information with a pre build country setting (I bought the router in Europe).

Whatever I do - setting country code to BR (Brasil), US or any other the TX power remains at 100mW (20db).
So either there is a bug in the software or some other strange things happen. I'm not a techy, so I I need good instructions to get that stupid limitations out of a useful use.

I'm also frustrated about comments like "Don't do it. Increasing transmit power over the the limits for your country is against the law. (OpenWrt automatically set the levels properly if you select the right nation in the wifi settings.)" on the page "https://openwrt.org/docs/guide-user/network/wifi/transmit.power.limits". I do care about laws, if useful and applicable.
I'm having my router out nowwhere in the vineyards in my old house. There is nowone around within 500 meters - and I'm unable to receive wifi goind above 2mbs in my workshop just 20m away from my router.

Your questions

  • My router (linksys WRT3200ACM) has 4 detachable antennas, tightly screwed.
  • Noone around me - at least no wifi I could find around me (Netstumbler).
  • All devices -so any computer or smartphone or tablet have almost no connection in my workshop.
  • Yes, I could run cables everywhere with lot's of effort to make them whether save - but why than use Wifi or any capable router or OpenWRT :slight_smile:

I also considered mesh networks, but read, that it might not really help in difficult wifi situations.


#4

This is a limitation of the SW as provided by mwlwifi, your grief originates with the provider of that driver/firmware. Many discussion on that github regarding same.


#5

@Sparks: what makes me think is you comment, that clients may also be restricted - any reading recommendations on that - couse you're right - I can send with 200mW, but no resonse will arive .....
hmmmm - will search for that issue as well - thanks!


#6

found the following intersting discussion:


#7

A waveguide / reflector can do amazing things.... as a simple test go grab the biggest frypan from your kitchen and position it around 20 cm away from and on the opposing side of your router....

Retest :slight_smile:


#8

@wulfy23 :wink: id love to see a photo of what that looks like - is there any trick to it? Perpendicular / or inline with the antenna, etc? Would it be possible to use two of them to bounce a signal around a corner of a house?

@regulatory_freek , if you happen to have a laptop, put netstumbler on that , and start with verifying you router is actually putting out the power levels it says it is. (From memory, netstumbler shows signal db levels, and going from info in that link i posted above that would be 100 mW for ~20 dBm or 200mW for ~23dB if you were in the ideal position near the router. Once youve confirmed the baseline is good, maybe try the frypan tricky that wulfy23 mentioned .


#9

Good to see such good advice on how to identify and potentially resolve range issues.

As pointed out, there may be driver limitations beyond the regulatory limits. As far as I know, these driver limits are from the "upstream" driver projects. They are not imposed by OpenWrt. Similarly, the "regdb" is an upstream project. I would guess that there are enough people with the desire to run their radios as hard as legally possible that it does not impose restrictions past those called out in the jurisdictions' regulations.

There may also be hardware limitations. Just because you are permitted by regulation to run 30 dBm (or whatever it might be), doesn't mean that your hardware has an RF chain that can support 30 dBm. I've run into devices that only support 20 dBm or less in the hardware. For example, a device I'm working with right now only supports 17 dBm on 2.4 GHz and 18 dBm on 5 GHz. This is typical of SoC-only devices that don't have a power amp in the RF chain. These types of hardware limitations can be discovered prior to purchase by searching for the FCC registration number (the OpenWrt wiki and Wikidevi are good places to look) and then looking at either the official FCC sites, or a site like https://fccid.io/


#10

Actually most consumer devices range between 16- and 20 dBm, with some even down to 14 dBm (yes, antenna gains between 2-3 dBm also need to be accounted for). You basically won't find 'normal' devices that will actually do 30 dBm - and that does make sense, considering that most routers will have much better antennas than just about any client you can throw at it anyways. Considering that communications is always two-ways, there's no need for massively asymmetric rf conditions, as it won't help range at all.


#11

As far as I understand your complaint is with Linksys, they have set the output power to one single value at the factory, you can not increase or decrease the power output. I myself would like to decrease power on my WRT1900ACS but no luck.


#12

just imagine those spinning radar things you see on ships / airports etc.

i believe you could do a web search on homemade parabolic wifi / antennae and pull up some really useful stuff.

these work both ways... in that for private premises, and i'd expect in more than 50% of these installs.... they provide the added gain ( :wink: ) of limiting signal behind the reflector area.... so as to reduce wave propagation toward i.e. the street and direct it toward the client area.....

also extremely useful in multistorey setups where an old cd placed over a consumer aerial on the diagonal will approximate to a 7-15% improvement.

as you mentioned, client side is often a bottleneck, so external antennae ( often directional ) are preferred for tricky signal paths.

tweaking non-dBm parameters is often required too.... in that the latest and greatest standards often waste more bandwidth attempting to satisfy all parties or negotiate parameters that are simply not going to happen.

physical obstacles raise a question of alternative frequency or physical layer options.... try yelling at someone who is three or four rooms away and you get an idea of just how much energy is wasted trying to pass energy through objects.


#13

@dlakelan reducing the power works - if I go down to 20mW I cannot even receive internet in the next room :wink:
At full power I have at least about 1/2 throughput in the next room ...


#14

When I look at all the obstacles (antennas, regulatory restrictions, driver limitations, strange country tables ...) in the way to set up good working internet connection via wireless transmission I have to admit - let's go back to @Sparks recommendation #4 - establish wired connections ...
Considering all the time we all put in such topics this is most likely the "best" solution

  • a cheap switch
  • 200m of CATwhatever cable
  • 70m of electro hose
  • 5 sockets
    and potentially 5 of the cheapest WLAN routers all running the same SSID and the same PW :slight_smile:

#15

You can get much better antennas for the wrt3200acm.


That price is not good tho!


#16

This is at least nice for you. I think the 1900ACSv2 came out right about the time that the FCC started threatening router mfgs, and it really is fixed power. Might be a US only issue.

Wiring up areas that get bad reception and sticking an extra AP there is by far a better method of extending networks than trying to crank the power. It brings the radio closer and hence helps in both directions send and receive.


#17

According to the author the TX power can be neither increased nor decreased on the rango. My understanding is that this is true on all the wrtpac devices with fixed eeprom power table.


#18

thanks @anomeome for the link - to be honest - what is FCC - it's an american regulation body and I generally do not care about american regulations as I'm lucky to live in - what I thought - overregulated Europe :frowning:
What is strange - and this is the topic here - is that internationally operating companies seem to be obedient to a US regulatory bureau although they sell their stuff in many other countries ....
If OpenWRT has no chance to provide working software I should change the title to "American FCC forces wifi device manufacturers to be worldwide obedient" :wink:

Would love to see car manufacturers only delivering cars with max speed of 85mph worldwide, but not letting customers know upfront :+1: Imagine Justin Bieber bying his €250k+ Audi R8 finding out, that it can only go 85 mpH - hohoho. And this is exactly what happens to routers .... :disappointed_relieved: - and this happened to me, when I bought my Linksys WRT3200ACM-EU - by the way in Lithuania - also EU you are allowed to use 1000mW TX power.


#19

The truth is 1000mw is really only useful for directional symmetric point to point links. If it were possible to get good wifi connections by boosting the output of one end only on general omnidirectional links the router mfg would figure out how to sell regionally specialized devices. But try it. Have your friend stand across the street and whisper while you talk with a megaphone see how well you can have a conversation describing some intricate details that must be 100% correct.


#20

Title 47, United States Code of Federal Regulations, Part 15:

users manual or instruction manual for an intentional or unintentional radiator shall caution the user that changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment

  • It's actually a crime to do what you want
  • You are no longer authorized under Part 15 to operate the equipment if you run your radio outside of the manufacturer's parameters or modify the [radio portion of the] device
  • Your understanding of the US law on Part 15 intentional radiators is flawed
  • Increasing any harmonic or other spurious emissions beyond the manufacturers parameters can be considered illegal interference
  • @dlakelan covered that the power needs to be symmetric
  • Your post is close to encouraging OpenWrt into breaking of the law, which is against the Community Guidelines
  • Notwithstanding the US, similar rules are also covered under the International Radio Regulations

EDIT See: Reghack works in the latest stables versions of LEDE?